/* VGTAI professional UI: fixed sidebar on desktop, slide menu + bottom nav on phones. */
:root{
  --bg:#07111f; --panel:#0d192b; --card:#111f33; --card-hover:#162942;
  --ink:#f8fafc; --muted:#91a1b8; --line:rgba(255,255,255,.09);
  --accent:#3b82f6; --accent2:#2563eb; --cyan:#22d3ee; --purple:#8b5cf6;
  --green:#22c55e; --danger:#ef4444;
  --side:rgba(8,18,33,.92); --top:rgba(7,17,31,.72);
  --bubble:var(--card); --composer:var(--panel); --btn:#162942; --sheet:var(--panel);
  --chip:var(--card); --code:#0b1627; --hero1:#0e1b31; --hero2:#091321;
  --shadow:0 20px 70px rgba(0,0,0,.35);
  --font:Inter,system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans Devanagari",sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --grad:linear-gradient(135deg,#2563eb,#06b6d4,#8b5cf6);
}
[data-theme="light"]{
  --bg:#f5f8fc; --panel:#ffffff; --card:#ffffff; --card-hover:#edf5ff;
  --ink:#0f172a; --muted:#64748b; --line:rgba(15,23,42,.10);
  --side:rgba(255,255,255,.95); --top:rgba(255,255,255,.82);
  --btn:#e8eef7; --code:#f1f5f9; --hero1:#ffffff; --hero2:#eef5ff;
  --shadow:0 20px 60px rgba(15,23,42,.10);
}
*{box-sizing:border-box;margin:0;padding:0;-webkit-tap-highlight-color:transparent}
html,body{width:100%;height:100%;overflow:hidden}
body{font:15px/1.5 var(--font);color:var(--ink);
  background:radial-gradient(circle at 5% 0%,rgba(37,99,235,.20),transparent 30%),
             radial-gradient(circle at 95% 0%,rgba(139,92,246,.18),transparent 28%),var(--bg);
  padding-left:env(safe-area-inset-left,0px);padding-right:env(safe-area-inset-right,0px)}
button{background:none;border:0;cursor:pointer;font:inherit;color:inherit}
input,textarea,select{font:inherit;color:var(--ink)}
a{color:var(--accent)}
.hidden{display:none!important}
.muted{color:var(--muted);font-size:13px}
.empty{color:var(--muted);text-align:center;padding:24px 12px;font-size:14px}

.app{display:flex;height:100%;overflow:hidden}

/* ---------- sidebar ---------- */
.sidebar{width:280px;flex:none;display:flex;flex-direction:column;padding:18px;background:var(--side);
  border-right:1px solid var(--line);backdrop-filter:blur(25px);z-index:200;overflow-y:auto}
.brand-row{display:flex;align-items:center;gap:11px;margin:3px 4px 20px}
.logo{width:42px;height:42px;border-radius:13px;display:grid;place-items:center;color:#fff;font-weight:900;font-size:18px;
  background:var(--grad);box-shadow:0 8px 30px rgba(37,99,235,.35);flex:none}
.brand-title{font-weight:900;font-size:18px;line-height:1.1}
.brand-sub{color:var(--muted);font-size:9px;letter-spacing:1.2px}
.new-chat{width:100%;padding:12px;border-radius:14px;color:#fff;font-weight:800;
  background:linear-gradient(135deg,var(--accent2),var(--accent));box-shadow:0 10px 30px rgba(0,0,0,.25);transition:.2s}
.new-chat:hover{transform:translateY(-1px)}
.sidebar-label{color:var(--muted);font-size:10px;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;margin:20px 8px 7px}
.nav{display:flex;flex-direction:column;gap:3px}
.nav button{width:100%;display:flex;align-items:center;gap:12px;padding:11px 12px;border-radius:12px;text-align:left;color:var(--muted);transition:.2s}
.nav button:hover,.nav button.active{color:var(--ink);background:rgba(59,130,246,.12)}
.nav-icon{width:21px;text-align:center}
.sidebar-bottom{margin-top:auto;border-top:1px solid var(--line);padding-top:13px}
.user-mini{display:flex;align-items:center;gap:9px;padding:5px}
.user-info{flex:1;min-width:0}
.user-info strong{display:block;font-size:12px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.user-info small{color:var(--muted);font-size:10px}
.avatar{width:36px;height:36px;border-radius:50%;display:grid;place-items:center;color:#fff;font-weight:900;flex:none;
  background:linear-gradient(135deg,#2563eb,#8b5cf6);overflow:hidden}
.avatar img{width:100%;height:100%;object-fit:cover}
.circle{width:40px;height:40px;border-radius:50%;display:grid;place-items:center;background:var(--btn);transition:transform .2s;flex:none;overflow:hidden}
.circle:active{transform:scale(.9)}

/* ---------- main + topbar ---------- */
.main{min-width:0;flex:1;height:100%;display:flex;flex-direction:column}
.topbar{height:66px;flex:none;display:flex;align-items:center;justify-content:space-between;padding:0 18px;
  border-bottom:1px solid var(--line);background:var(--top);backdrop-filter:blur(20px);z-index:100}
.top-left,.top-right{display:flex;align-items:center;gap:8px}
.mobile-brand{display:none;align-items:center;gap:8px;font-weight:900}
.mobile-brand .logo{width:32px;height:32px;border-radius:10px;font-size:15px}
.icon-button.menu-button{display:none}
.icon-button{width:39px;height:39px;display:grid;place-items:center;border:1px solid var(--line);border-radius:11px;background:var(--card);transition:.2s;flex:none}
.icon-button:hover{border-color:rgba(59,130,246,.45);transform:translateY(-1px)}
.model-selector{display:flex;align-items:center;gap:8px;padding:8px 12px;border:1px solid var(--line);border-radius:11px;background:var(--card);font-size:12px}
.status-dot{width:7px;height:7px;border-radius:50%;background:var(--green);box-shadow:0 0 10px var(--green);flex:none}
.status-dot.off{background:var(--danger);box-shadow:0 0 10px var(--danger)}
.pill-btn{display:flex;align-items:center;gap:6px;background:var(--card);border:1px solid var(--line);padding:6px 12px;border-radius:999px;font-size:13px;font-weight:600;transition:transform .2s}
.pill-btn:active{transform:scale(.95)}
.pill-btn.on{background:var(--accent);border-color:var(--accent);color:#fff}

/* ---------- screens ---------- */
.content{flex:1;min-height:0;position:relative;display:flex;flex-direction:column}
.view-screen{flex:1;overflow-y:auto;padding:28px;display:none;min-height:0}
.view-screen.active{display:block;animation:screenIn .3s cubic-bezier(.1,.9,.2,1)}
.view-screen.chat-screen{padding:0}
.view-screen.chat-screen.active{display:flex;flex-direction:column}
.container{max-width:1150px;margin:auto}
@keyframes screenIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
.page-title{font-size:27px;margin-bottom:5px}
.page-subtitle{margin-bottom:22px;color:var(--muted);font-size:13px}

/* hero */
.hero{position:relative;overflow:hidden;border:1px solid rgba(96,165,250,.22);border-radius:28px;padding:34px;box-shadow:var(--shadow);
  background:radial-gradient(circle at 90% 10%,rgba(34,211,238,.14),transparent 28%),
             radial-gradient(circle at 10% 100%,rgba(139,92,246,.14),transparent 34%),
             linear-gradient(135deg,var(--hero1),var(--hero2))}
.hero-badge{display:inline-flex;align-items:center;gap:7px;padding:7px 11px;border-radius:99px;color:#60a5fa;
  background:rgba(59,130,246,.08);border:1px solid rgba(59,130,246,.22);font-size:10px;font-weight:800}
.hero h1{font-size:clamp(30px,5vw,52px);line-height:1.08;letter-spacing:-1.5px;margin-top:17px}
.gradient-text{background:linear-gradient(90deg,#60a5fa,#22d3ee,#a78bfa);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-description{max-width:680px;color:var(--muted);margin-top:13px;font-size:14px}
.hero-search{margin-top:24px;display:flex;align-items:center;gap:8px;padding:7px 8px 7px 14px;border:1px solid var(--line);border-radius:17px;background:rgba(127,127,127,.08)}
.hero-search input{flex:1;min-width:0;border:0;outline:0;background:transparent;font-size:16px}
.hero-search input::placeholder{color:var(--muted)}
.primary-button,.btn{padding:10px 16px;border-radius:11px;color:#fff;background:linear-gradient(135deg,var(--accent),var(--accent2));
  font-weight:800;box-shadow:0 8px 20px rgba(37,99,235,.25);display:inline-flex;align-items:center;gap:8px;transition:transform .2s,opacity .2s}
.btn:active,.primary-button:active{transform:scale(.96)}
.btn[disabled]{opacity:.5;pointer-events:none}
.btn.ghost{background:var(--btn);color:var(--ink);box-shadow:none;font-weight:600}
.btn.danger{background:var(--danger);box-shadow:none}
.btn-row{display:flex;gap:8px;flex-wrap:wrap;margin-top:8px}
.quick-actions{display:flex;gap:8px;overflow:auto;padding:16px 1px 5px;scrollbar-width:none}
.quick-actions button{flex:none;padding:9px 14px;border-radius:99px;border:1px solid var(--line);background:var(--card);color:var(--muted);font-size:12px;transition:.2s}
.quick-actions button:hover{color:var(--ink);border-color:rgba(59,130,246,.4)}
.section-header{display:flex;align-items:center;justify-content:space-between;margin:25px 0 12px}
.section-header h2{font-size:15px}
.link-btn{color:var(--accent);font-size:12px}
.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:11px}
.feature-card{display:flex;flex-direction:column;align-items:flex-start;text-align:left;padding:17px;border:1px solid var(--line);border-radius:18px;
  background:var(--card);cursor:pointer;transition:transform .2s,border-color .2s,background .2s}
.feature-card:hover{transform:translateY(-3px);background:var(--card-hover);border-color:rgba(59,130,246,.45)}
.feature-card:active{transform:scale(.97)}
.feature-icon{width:39px;height:39px;display:grid;place-items:center;border-radius:12px;background:rgba(59,130,246,.12);margin-bottom:12px;font-size:18px}
.feature-card h3{font-size:13px}
.feature-card p{margin-top:4px;color:var(--muted);font-size:11px}

/* lists / panels / forms */
.list-card,.recent{background:var(--card);border:1px solid var(--line);border-radius:16px;overflow:hidden}
.list-item{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:13px 15px;border-bottom:1px solid var(--line);font-size:14px;width:100%;text-align:left}
.list-item:last-child{border-bottom:0}
.list-item[data-conv]:hover{background:rgba(59,130,246,.05)}
.list-item .grow{flex:1;min-width:0}
.list-item strong{display:block;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:13px}
.list-item small{color:var(--muted);font-size:11px;display:block}
.icon-btn{width:32px;height:32px;border-radius:10px;display:grid;place-items:center;color:var(--muted);flex:none}
.icon-btn:hover{background:rgba(127,127,127,.15);color:var(--ink)}
.panel{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:18px;margin-top:14px}
.panel:first-child{margin-top:0}
.field{display:block;margin-bottom:12px}
.field>span{display:block;font-size:12px;color:var(--muted);margin-bottom:4px}
.input,.select,.textarea{width:100%;background:var(--composer);border:1px solid var(--line);border-radius:14px;padding:10px 14px;outline:0;font-size:16px}
.input:focus,.select:focus,.textarea:focus{border-color:var(--accent)}
.textarea{resize:vertical;min-height:84px}
.row{display:flex;align-items:center;gap:10px}
.screen-title{font-size:18px;font-weight:700;margin-bottom:14px;display:flex;align-items:center;gap:10px}
.spinner{display:inline-block;width:18px;height:18px;border:2px solid var(--line);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.img-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:10px;margin-top:14px}
.img-grid figure{background:var(--card);border:1px solid var(--line);border-radius:14px;overflow:hidden}
.img-grid img{width:100%;display:block}
.img-grid figcaption{padding:6px 10px}
.stat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:14px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:12px;text-align:center}
.stat b{display:block;font-size:20px}
.profile-head{display:flex;align-items:center;gap:15px;margin-bottom:20px}
.big-avatar{width:70px;height:70px;border-radius:20px;font-size:26px}

/* ---------- chat ---------- */
.chat-head{height:57px;display:flex;align-items:center;gap:10px;padding:0 18px;border-bottom:1px solid var(--line);flex:none}
.chat-head h3{font-size:14px;font-weight:700;flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ai-avatar{width:31px;height:31px;display:grid;place-items:center;border-radius:9px;color:#fff;font-weight:900;font-size:14px;background:linear-gradient(135deg,#2563eb,#8b5cf6);flex:none}
.chat-scroll{flex:1;min-height:0;overflow-y:auto;padding:24px max(14px,calc((100% - 850px)/2))}
.welcome{max-width:570px;margin:40px auto;text-align:center}
.welcome .logo{width:62px;height:62px;border-radius:19px;margin:auto;font-size:26px}
.welcome h2{margin-top:17px;font-size:24px}
.chips{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-top:18px}
.chip{background:var(--card);border:1px solid var(--line);padding:8px 14px;border-radius:999px;font-size:13px;max-width:100%}
.chip:hover{border-color:rgba(59,130,246,.45)}
.msg{display:flex;flex-direction:column;margin-bottom:20px;animation:fadeInUp .25s ease}
.msg.user{align-items:flex-end}
.msg.assistant{align-items:flex-start}
.bubble{padding:10px 14px;border-radius:17px;max-width:min(780px,92%);font-size:15px;line-height:1.65;overflow-wrap:anywhere}
.msg.user .bubble{color:#fff;white-space:pre-wrap;background:linear-gradient(135deg,#2563eb,#3b82f6);border-radius:17px 17px 5px 17px}
.msg.assistant .bubble{background:var(--card);border:1px solid var(--line);border-radius:17px 17px 17px 5px}
.msg.error .bubble{border-color:var(--danger)}
.msg-actions{display:flex;gap:2px;margin-top:2px}
.msg-actions button{font-size:12px;color:var(--muted);padding:4px 8px;border-radius:8px}
.msg-actions button:hover{background:rgba(127,127,127,.15);color:var(--ink)}
.typing{display:inline-flex;gap:4px;padding:4px 0}
.typing i{width:6px;height:6px;border-radius:50%;background:#60a5fa;animation:blink 1.2s infinite}
.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}
@keyframes blink{0%,80%,100%{opacity:.25;transform:translateY(0)}40%{opacity:1;transform:translateY(-3px)}}
@keyframes fadeInUp{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.md>*:first-child{margin-top:0}.md>*:last-child{margin-bottom:0}
.md p{margin:.5em 0}
.md h3,.md h4,.md h5,.md h6{margin:.9em 0 .3em;line-height:1.3}
.md ul,.md ol{margin:.5em 0 .5em 1.3em}
.md li{margin:.15em 0}
.md blockquote{border-left:3px solid var(--accent);padding-left:10px;color:var(--muted);margin:.5em 0}
.md hr{border:0;border-top:1px solid var(--line);margin:.8em 0}
.md code{font-family:var(--mono);font-size:.9em;background:var(--code);padding:1px 5px;border-radius:6px}
.md .code{background:var(--code);border:1px solid var(--line);border-radius:12px;margin:.6em 0;overflow:hidden}
.md .code-head{display:flex;justify-content:space-between;align-items:center;padding:4px 10px;font-size:11px;color:var(--muted);border-bottom:1px solid var(--line)}
.md .code pre{padding:10px 12px;overflow-x:auto;font-size:13px;line-height:1.5}
.md .code code{background:none;padding:0}
.md .tbl{overflow-x:auto;margin:.6em 0}
.md table{border-collapse:collapse;font-size:13px}
.md th,.md td{border:1px solid var(--line);padding:6px 10px;text-align:left}
.md th{background:var(--code)}

.composer-area{flex:none;padding:10px 15px calc(12px + env(safe-area-inset-bottom,0px));background:linear-gradient(transparent,var(--bg) 35%)}
.attach-row{display:flex;gap:8px;flex-wrap:wrap;margin:0 auto 8px;max-width:860px}
.attach-chip{display:flex;align-items:center;gap:6px;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:4px 8px;font-size:12px;max-width:100%}
.attach-chip img{width:28px;height:28px;border-radius:6px;object-fit:cover}
.attach-chip button{color:var(--muted);padding:0 4px}
.composer-inner{max-width:860px;margin:auto;background:var(--panel);border:1px solid var(--line);border-radius:23px;padding:7px 8px;display:flex;align-items:flex-end;gap:6px;box-shadow:0 15px 50px rgba(0,0,0,.20)}
.composer-inner textarea{flex:1;min-width:0;background:transparent;border:0;outline:0;resize:none;max-height:150px;min-height:24px;color:var(--ink);font-size:16px;line-height:1.45;padding:8px 2px;overflow-y:auto}
.composer-inner textarea::placeholder{color:var(--muted)}
.composer-note{text-align:center;margin-top:6px;color:var(--muted);font-size:10px}
.round{width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:18px;flex:none;transition:transform .2s,color .2s}
.round:active{transform:scale(.92)}
.round.plain{color:var(--muted);font-size:22px;font-weight:700}
.round.plain:hover{color:var(--ink);background:rgba(127,127,127,.12)}
.round.blue{background:linear-gradient(135deg,#2563eb,#3b82f6);color:#fff;box-shadow:0 2px 8px rgba(59,130,246,.4)}
.round.listening{background:var(--danger);color:#fff;animation:pulse 1.2s infinite}
@keyframes pulse{50%{box-shadow:0 0 0 8px rgba(239,68,68,.2)}}
.waves{display:flex;align-items:center;gap:3px}
.waves span{width:3px;height:12px;background:#fff;border-radius:99px;animation:pulseBar 1.2s infinite ease-in-out}
.waves span:nth-child(2){height:18px;animation-delay:.2s}.waves span:nth-child(3){height:8px;animation-delay:.4s}
@keyframes pulseBar{0%,100%{transform:scaleY(.5)}50%{transform:scaleY(1.2)}}

/* ---------- bottom nav (phones) ---------- */
.bottom-nav{display:none}

/* ---------- overlays, sheets ---------- */
.backdrop,.sheet-backdrop{position:fixed;inset:0;background:rgba(0,0,0,.62);opacity:0;visibility:hidden;transition:opacity .25s,visibility .25s;backdrop-filter:blur(4px)}
.backdrop{z-index:150}
.sheet-backdrop{z-index:250}
.backdrop.show,.sheet-backdrop.show{opacity:1;visibility:visible}
.sheet{position:fixed;bottom:0;left:0;right:0;background:var(--panel);border:1px solid var(--line);border-radius:27px 27px 0 0;
  padding:20px 20px calc(20px + env(safe-area-inset-bottom,0px));z-index:300;transform:translateY(100%);transition:transform .35s cubic-bezier(.1,.9,.2,1);
  box-shadow:0 -25px 80px rgba(0,0,0,.6);max-height:88%;overflow-y:auto;max-width:700px;margin:0 auto}
.sheet.show{transform:none}
.sheet-handle{width:42px;height:4px;background:var(--line);border-radius:99px;margin:0 auto 18px}
.sheet-top{display:flex;gap:12px;overflow-x:auto;padding-bottom:15px;border-bottom:1px solid var(--line);scrollbar-width:none}
.sheet-circle{display:flex;flex-direction:column;align-items:center;gap:6px;flex:none;min-width:64px}
.sheet-circle .ic{width:53px;height:53px;border-radius:50%;background:var(--card);display:grid;place-items:center;font-size:21px;border:1px solid var(--line)}
.sheet-circle span.l{font-size:11px;color:var(--muted)}
.sheet-list{display:grid;grid-template-columns:repeat(2,1fr);gap:7px;margin-top:14px}
.sheet-item{display:flex;align-items:center;gap:10px;padding:12px;border-radius:13px;text-align:left;width:100%}
.sheet-item:hover,.sheet-item:active{background:rgba(127,127,127,.12)}
.sheet-item .ic{width:39px;height:39px;border-radius:11px;background:var(--card);border:1px solid var(--line);display:grid;place-items:center;font-size:18px;flex:none}
.sheet-item h4{font-size:12px;font-weight:700}
.sheet-item p{font-size:10px;color:var(--muted)}
.toggle-row{display:flex;align-items:center;justify-content:space-between;padding:14px 10px;margin-top:10px;border-top:1px solid var(--line);gap:10px}
.badge{font-size:10px;background:rgba(59,130,246,.2);color:var(--accent);padding:2px 6px;border-radius:6px;margin-left:4px}
.switch{position:relative;display:inline-block;width:48px;height:26px;flex:none}
.switch input{opacity:0;width:0;height:0}
.slider{position:absolute;cursor:pointer;inset:0;background:#334155;transition:.3s;border-radius:34px}
.slider:before{position:absolute;content:"";height:20px;width:20px;left:3px;bottom:3px;background:#fff;transition:.3s;border-radius:50%}
input:checked+.slider{background:var(--accent)}
input:checked+.slider:before{transform:translateX(22px)}

/* live voice */
.live-modal{position:fixed;inset:0;background:rgba(3,8,18,.96);z-index:400;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:20px;text-align:center;backdrop-filter:blur(20px);opacity:0;visibility:hidden;transition:opacity .3s,visibility .3s;color:#f8fafc}
.live-modal.show{opacity:1;visibility:visible}
.live-title{font-size:22px;font-weight:800;margin:16px 0 6px}
.live-waves{display:flex;gap:7px;align-items:center;height:80px;margin:24px 0}
.live-waves i{width:6px;height:22px;background:#22d3ee;border-radius:99px}
.live-modal.active .live-waves i{animation:waveAnim 1s infinite ease-in-out}
.live-waves i:nth-child(2){animation-delay:.1s}.live-waves i:nth-child(3){animation-delay:.2s}.live-waves i:nth-child(4){animation-delay:.3s}.live-waves i:nth-child(5){animation-delay:.4s}
@keyframes waveAnim{0%,100%{height:20px}50%{height:72px}}
.live-text{max-width:460px;font-size:14px;color:#cbd5e1;min-height:42px}

.toast{position:fixed;left:50%;bottom:90px;transform:translateX(-50%);background:#0b1220;color:#f8fafc;border:1px solid var(--line);padding:10px 16px;border-radius:999px;font-size:13px;z-index:500;max-width:90%;box-shadow:var(--shadow);animation:fadeInUp .25s}
.auth-modal{max-width:420px}

/* ---------- responsive ---------- */
@media(max-width:1000px){
  .sidebar{position:fixed;left:-300px;top:0;bottom:0;transition:left .35s cubic-bezier(.1,.9,.2,1);box-shadow:5px 0 25px rgba(0,0,0,.5);padding-top:calc(18px + env(safe-area-inset-top,0px))}
  .sidebar.show{left:0}
  .icon-button.menu-button{display:grid}
  .mobile-brand{display:flex}
  .model-selector{display:none}
  .feature-grid{grid-template-columns:repeat(3,1fr)}
  .topbar{padding-top:env(safe-area-inset-top,0px);height:calc(61px + env(safe-area-inset-top,0px))}
  .bottom-nav{display:flex;flex:none;padding:6px 6px calc(6px + env(safe-area-inset-bottom,0px));background:var(--panel);border-top:1px solid var(--line);z-index:100}
  .nav-item{display:flex;flex-direction:column;align-items:center;flex:1;font-size:10px;color:var(--muted);gap:2px;transition:color .2s,transform .2s}
  .nav-item.active{color:#60a5fa}
  .nav-item:active{transform:scale(.9)}
  .nav-item span:first-child{font-size:18px}
}
@media(max-width:700px){
  .view-screen{padding:18px 14px}
  .view-screen.chat-screen{padding:0}
  .hero{padding:24px 18px;border-radius:23px}
  .feature-grid{grid-template-columns:repeat(2,1fr)}
  .sheet-list{grid-template-columns:1fr}
  .composer-area{padding:8px 8px calc(8px + env(safe-area-inset-bottom,0px))}
  .chat-scroll{padding:18px 12px}
  .bubble{max-width:94%}
  .topbar{padding-left:10px;padding-right:10px}
  .toast{bottom:150px}
}
@media(max-width:430px){
  .feature-card{padding:14px}
  .feature-card h3{font-size:12px}
  .feature-card p{font-size:10px}
  .pill-btn{padding:6px 10px}
}

/* typing effect caret */
.caret{display:inline-block;width:2px;height:1.05em;margin-left:2px;vertical-align:-2px;background:var(--accent);animation:caretblink 1s steps(2,start) infinite}
@keyframes caretblink{to{visibility:hidden}}

/* Student Suite hub */
.stu-profile{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-bottom:16px}
.stu-profile .field{margin-bottom:0}
.stu-grid{margin-top:4px}
@media (max-width:720px){.stu-profile{grid-template-columns:1fr}}

/* Student widgets: quiz, flashcards, plan, progress */
.stu-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:10px}
.stu-wait{margin:8px 0;padding:10px 14px;border:1px dashed var(--line);border-radius:14px;color:var(--muted);font-size:13px}
.stu-btn{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:9px 14px;font-size:13px;cursor:pointer;margin-top:10px}
.stu-btn:hover{border-color:rgba(59,130,246,.55)}
.qz,.fc,.plan{border:1px solid var(--line);background:var(--card);border-radius:16px;padding:14px;margin:10px 0}
.qz-q{margin-bottom:14px}
.qz-text{font-weight:600;margin-bottom:8px}
.qz-opts{display:flex;flex-direction:column;gap:7px}
.qz-opt{display:flex;gap:10px;align-items:flex-start;text-align:left;width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:12px;background:var(--composer);font-size:14px;cursor:pointer}
.qz-opt b{min-width:20px;color:var(--muted)}
.qz-opt:not(:disabled):hover{border-color:rgba(59,130,246,.55)}
.qz-opt.right{border-color:#22c55e;background:rgba(34,197,94,.14)}
.qz-opt.wrong{border-color:#ef4444;background:rgba(239,68,68,.14)}
.qz-opt:disabled{cursor:default}
.qz-exp{margin-top:8px;font-size:13px;color:var(--muted)}
.qz-result{margin-top:6px;padding:10px 12px;border-radius:12px;background:rgba(59,130,246,.12);font-weight:600}
.qz-score{font-weight:700;color:var(--accent)}
.fc-card{display:flex;flex-direction:column;gap:10px;align-items:center;justify-content:center;width:100%;min-height:150px;padding:18px;border:1px solid var(--line);border-radius:16px;background:var(--composer);font-size:16px;text-align:center;cursor:pointer}
.fc-a{color:var(--accent);font-weight:600}
.fc-hint{color:var(--muted);font-size:11px}
.fc-bar{display:flex;gap:10px;justify-content:center}
.fc-bar .stu-btn{flex:1}
.plan-days{max-height:280px;overflow:auto}
.plan-day{padding:8px 0;border-top:1px solid var(--line)}
.plan-day ul{margin:4px 0 0 18px;font-size:13px}
.stu-bar{height:8px;border-radius:99px;background:var(--line);overflow:hidden;margin:8px 0 4px}
.stu-bar span{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2))}
.stu-task{display:flex;gap:10px;align-items:flex-start;padding:7px 0;font-size:14px}
.stu-task input{margin-top:3px}
.stu-recent{margin:4px 0 0 18px;font-size:13px}
.pick-row{margin-top:12px}
.chip.pick{border-color:rgba(59,130,246,.45)}

/* ---------- library / reader / revision / planner ---------- */
.lib-st{display:block;font-size:12px}.lib-st.ok{color:var(--green)}.lib-st.warn{color:#eab308}.lib-st.bad{color:var(--danger)}.lib-st.work{color:var(--cyan)}
.lib-item{align-items:flex-start;flex-wrap:wrap}.lib-hit{width:100%;text-align:left;cursor:pointer}
.pl-clock{font-size:54px;font-weight:700;font-variant-numeric:tabular-nums;margin:6px 0}
#srs-card .fc-card{width:100%;margin:8px 0}

/* ---------- exam master + analytics ---------- */
.ex-form{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px;margin-bottom:8px}
.ex-types{display:flex;gap:14px;flex-wrap:wrap;margin:6px 0 12px}.ex-types label,.ex-check{display:flex;align-items:center;gap:6px;font-size:14px}
.ex-top{display:flex;align-items:center;gap:10px;justify-content:space-between;margin-bottom:10px;flex-wrap:wrap}
#ex-clock.warn{background:var(--danger);color:#fff;border-color:var(--danger)}
.ex-grid{display:flex;flex-wrap:wrap;gap:6px;margin:12px 0}
.ex-n{width:36px;height:36px;border-radius:10px;border:1px solid var(--line);background:var(--card);font-weight:600}
.ex-n.done{background:rgba(34,197,94,.25)}.ex-n.flag{outline:2px solid #eab308}.ex-n.cur{border-color:var(--accent);box-shadow:0 0 0 2px var(--accent)}
.qz-opt.picked{border-color:var(--accent);background:rgba(59,130,246,.18)}
.ex-rev p{margin:6px 0}.ex-sum{text-align:center}.ex-sum .stat-grid{margin:10px 0}
.an-row{display:flex;align-items:center;gap:10px;margin:8px 0}.an-row>span{flex:0 0 38%;overflow:hidden;text-overflow:ellipsis}.an-row .stu-bar{flex:1;margin:0}.an-row b{flex:0 0 44px;text-align:right}
.stu-bar.bad span{background:var(--danger)}
.an-chart{width:100%;max-width:420px;display:block;margin:8px auto 0}.an-bar{fill:var(--accent)}.an-bar.empty{fill:var(--line)}.an-lbl{fill:var(--muted);font-size:11px}
.an-scores{display:flex;align-items:flex-end;gap:8px;height:110px;margin-top:8px}.an-scores div{flex:1;height:100%;display:flex;flex-direction:column;justify-content:flex-end;align-items:center}
.an-scores i{width:100%;max-width:30px;background:var(--grad);border-radius:6px 6px 0 0;display:block}.an-scores small{font-size:11px;color:var(--muted)}
.an-badges{display:flex;flex-wrap:wrap;gap:8px;margin-top:8px}.an-badge{padding:6px 12px;border-radius:999px;background:rgba(234,179,8,.18);border:1px solid rgba(234,179,8,.45);font-size:13px}.an-badge.lock{opacity:.35;filter:grayscale(1)}
.an-tiles{margin-bottom:14px}

/* navigation bar, per-screen search, global search, offline badge */
.navbar{display:flex;gap:8px;align-items:center;margin:0 0 12px;position:sticky;top:0;z-index:5;padding:6px 0;background:var(--bg,#0f172a)}
.nav-btn{flex:0 0 auto;width:40px;height:40px;border-radius:12px;border:1px solid var(--line,#334155);background:var(--panel,#1e293b);color:inherit;font-size:20px;cursor:pointer}
.nav-find{flex:1;min-width:0;margin:0}
.nav-hide{display:none!important}
.gs-box{margin-top:10px}.gs-box input{flex:1}
#gs-out{margin-top:10px;max-height:60vh;overflow:auto}
.gs-h{padding:8px 12px;font-weight:600;opacity:.8;font-size:13px}
.offline-badge{position:fixed;left:50%;transform:translateX(-50%);bottom:12px;z-index:60;background:#b45309;color:#fff;padding:6px 14px;border-radius:999px;font-size:13px;box-shadow:0 4px 14px rgba(0,0,0,.35)}

/* notebook / calendar / utilities / pdf tools */
.cal-head{display:flex;align-items:center;gap:10px;justify-content:space-between;margin:8px 0}
.cal-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:4px}
.cal-h{text-align:center;font-size:12px;color:var(--muted);padding:4px 0}
.cal-d{position:relative;aspect-ratio:1;border-radius:10px;background:var(--card);border:1px solid var(--line);font-weight:600}
.cal-d.today{border-color:var(--accent)}.cal-d.sel{background:var(--accent);color:#fff}
.cal-d i{position:absolute;bottom:5px;left:50%;width:6px;height:6px;margin-left:-3px;border-radius:50%;background:var(--cyan)}.cal-d i.ex{background:var(--danger)}
.fm-f{font-family:var(--mono);font-size:13.5px;margin:3px 0;word-break:break-word}
.cv-out{margin-top:12px;font-size:22px;font-weight:700;text-align:center;word-break:break-all}
.dash{margin:14px 0}.dash-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.dash-tile{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:12px 8px;text-align:center;display:flex;flex-direction:column;gap:2px}
.dash-tile b{font-size:18px}.dash-tile span{font-size:11.5px;color:var(--muted)}.dash-tile.hot{border-color:var(--accent);box-shadow:0 0 0 1px var(--accent) inset}
.dash-resume{display:block;width:100%;margin-top:10px;padding:12px;border-radius:14px;background:var(--grad);color:#fff;font-weight:600;text-align:left}
/* ALFA neon theme */
[data-theme="neon"]{--bg:#05030f;--panel:#0b0720;--card:#120a2e;--card-hover:#1b1045;--ink:#f4f0ff;--muted:#a79bd6;--line:rgba(168,85,247,.35);
  --side:rgba(8,4,24,.94);--top:rgba(5,3,15,.8);--btn:#1b1045;--code:#0a0620;--hero1:#150a3a;--hero2:#07031a;--cyan:#22f5ff;--purple:#c026d3;--accent:#22d3ee;--accent2:#a855f7;
  --shadow:0 0 40px rgba(168,85,247,.25);--grad:linear-gradient(135deg,#22d3ee,#a855f7,#ec4899)}
[data-theme="neon"] body{background:radial-gradient(circle at 5% 0%,rgba(34,211,238,.22),transparent 32%),radial-gradient(circle at 95% 0%,rgba(236,72,153,.22),transparent 30%),var(--bg)}
[data-theme="neon"] .feature-card,[data-theme="neon"] .dash-tile,[data-theme="neon"] .panel,[data-theme="neon"] .stat{box-shadow:0 0 14px rgba(168,85,247,.22);border-color:rgba(168,85,247,.45)}
[data-theme="neon"] .dash-tile b,[data-theme="neon"] .page-title{text-shadow:0 0 12px rgba(34,211,238,.7)}
[data-theme="neon"] .btn,[data-theme="neon"] .primary-button{box-shadow:0 0 16px rgba(34,211,238,.45)}

/* style rules */
.feature-card,.dash-tile{border:1px solid color-mix(in srgb,var(--c,#888) 55%,transparent);background:color-mix(in srgb,var(--c,#888) 16%,var(--card));border-radius:18px}
.feature-card .feature-icon{background:color-mix(in srgb,var(--c,#888) 40%,transparent);color:var(--c);width:48px;height:48px;border-radius:14px;display:grid;place-items:center}
.feature-card:hover{box-shadow:0 0 18px color-mix(in srgb,var(--c,#888) 45%,transparent)}
.view-screen .page-title{color:var(--c,inherit)}
.view-screen .navbar{border-bottom:2px solid var(--c,transparent)}

/* one colour per function */
[data-act="go:files"],#screen-files{--c:#e23636}
[data-act="go:exam"],#screen-exam{--c:#36e28c}
[data-act="go:analytics"],#screen-analytics{--c:#e236e2}
[data-act="go:srs"],#screen-srs{--c:#8ce236}
[data-act="go:planner"],#screen-planner{--c:#3636e2}
[data-act="mode:student"]{--c:#e28c36}
[data-act="mode:stu_doubt"]{--c:#36e2e2}
[data-act="mode:stu_math"]{--c:#e2368c}
[data-act="mode:stu_notes"]{--c:#36e236}
[data-act="mode:stu_quiz"]{--c:#8c36e2}
[data-act="mode:stu_flash"]{--c:#e2e236}
[data-act="mode:stu_plan"]{--c:#368ce2}
[data-act="mode:stu_write"]{--c:#bc0f0f}
[data-act="mode:stu_exam"]{--c:#0fbc66}
[data-act="mode:stu_lang"]{--c:#bc0fbc}
[data-act="mode:stu_check"]{--c:#66bc0f}
[data-act="go:notebook"],#screen-notebook{--c:#0f0fbc}
[data-act="go:calendar"],#screen-calendar{--c:#bc660f}
[data-act="go:utils"],#screen-utils{--c:#0fbcbc}
[data-act="go:pdftools"],#screen-pdftools{--c:#bc0f66}
[data-act="aiq:eli5"]{--c:#0fbc0f}
[data-act="aiq:mindmap"]{--c:#650fbc}
[data-act="aiq:mnemonic"]{--c:#bcbc0f}
[data-act="aiq:viva"]{--c:#0f65bc}
[data-act="aiq:tldr"]{--c:#e67474}
[data-act="aiq:translate"]{--c:#74e6ad}
[data-act="aiq:essay"]{--c:#e674e6}
[data-act="aiq:pyq"]{--c:#ade674}
[data-act="mode:stu_career"]{--c:#7474e6}
[data-act="mode:chat"]{--c:#e6ad74}
[data-act="mode:search"]{--c:#74e6e6}
[data-act="go:research"],#screen-research{--c:#e674ad}
[data-act="mode:code"]{--c:#74e674}
[data-act="go:images"],#screen-images{--c:#ad74e6}
[data-act="mode:analyze"]{--c:#e6e674}
[data-act="mode:canvas"]{--c:#74ade6}
[data-act="go:student"],#screen-student{--c:#e30b0b}
[data-act="mode:excel"]{--c:#0be377}
[data-act="mode:dataentry"]{--c:#e30be3}
[data-act="mode:guided"]{--c:#77e30b}
.sheet{box-shadow:none}.sheet.show{box-shadow:0 -25px 80px rgba(0,0,0,.6)}
.toast{box-shadow:0 6px 16px -6px rgba(0,0,0,.35)}

/* sticky "Search this screen" bar */
.view-screen .navbar{top:-28px !important}
@media(max-width:700px){.view-screen .navbar{top:-18px !important}}






/* marks on PDF pages (annot.js) */

/* reader view (view.js) */
.vw-lab{margin:10px 0 4px;font-size:12px}

/* packs + meaning card (packs.js, view.js) */

/* document scanner (scanner.js) */
body.sc-open{overflow:hidden}
.sc{position:fixed;inset:0;z-index:350;background:#05070b;color:#fff;display:flex;flex-direction:column}
.sc.hidden,.sc-pane.hidden,.sc-bar.hidden{display:none}
.sc-top{display:flex;align-items:center;gap:8px;padding:calc(8px + env(safe-area-inset-top,0px)) 12px 8px}
.sc-stage{position:relative;flex:1;min-height:0}
.sc-pane{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;overflow:hidden}
#sc-video{width:100%;height:100%;object-fit:contain;background:#000}
#sc-over{position:absolute;left:0;top:0;pointer-events:none}
.sc-msg{position:absolute;left:0;right:0;bottom:10px;text-align:center;font-size:14px;padding:0 16px;text-shadow:0 1px 4px #000}
.sc-note{font-size:13px;color:#cbd5e1;padding:0 12px;height:40px;display:flex;align-items:center;text-align:center}
#sc-crop{touch-action:none}
#sc-prev{background:#fff;box-shadow:0 4px 24px rgba(0,0,0,.6)}
#sc-list{justify-content:flex-start;align-items:stretch;overflow-y:auto;padding:12px}
.sc-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
.sc-card{background:#111827;border-radius:10px;overflow:hidden}.sc-card img{width:100%;display:block;aspect-ratio:3/4;object-fit:contain;background:#1f2937}
.sc-cardbar{display:flex;align-items:center;gap:2px;padding:4px 6px}.sc-cardbar b{margin-right:auto}
.sc-bar{display:flex;align-items:center;justify-content:center;gap:8px;padding:10px 12px calc(10px + env(safe-area-inset-bottom,0px));flex-wrap:wrap;background:#0b1018}
.sc-shutter{width:68px;height:68px;border-radius:50%;border:5px solid #fff;background:#38bdf8;padding:0;flex:none}
.sc-filters,.sc-row{display:flex;gap:6px;flex-wrap:wrap;justify-content:center;width:100%}
.sc-slider{display:flex;align-items:center;gap:6px;flex:1 1 140px}.sc-slider input{flex:1}

/* search words boxed on the page (find.js) */

/* ===== 3D cards on every screen except Home (own colour per card) ===== */
.view-screen:not(#screen-home) .feature-card{background:linear-gradient(180deg,color-mix(in srgb,var(--c,#3b82f6) 78%,#fff),color-mix(in srgb,var(--c,#3b82f6) 62%,#000))!important;border:0!important;border-radius:18px;box-shadow:0 6px 0 rgba(0,0,0,.35),0 16px 24px -8px rgba(0,0,0,.55),inset 0 2px 0 rgba(255,255,255,.55),inset 0 -4px 0 rgba(0,0,0,.18)!important;transition:transform .15s ease,box-shadow .15s ease}
.view-screen:not(#screen-home) .feature-card:hover{transform:translateY(-4px)}
.view-screen:not(#screen-home) .feature-card:active{transform:translateY(4px);box-shadow:0 2px 0 rgba(0,0,0,.35),0 6px 12px -6px rgba(0,0,0,.5),inset 0 2px 0 rgba(255,255,255,.4)!important}
.view-screen:not(#screen-home) .feature-card h3{color:#fff;font-weight:800;text-shadow:0 2px 0 rgba(0,0,0,.35)}
.view-screen:not(#screen-home) .feature-card p{color:rgba(255,255,255,.92);text-shadow:0 1px 2px rgba(0,0,0,.5)}
.view-screen:not(#screen-home) .feature-card .feature-icon{background:rgba(255,255,255,.28)!important;border-radius:14px;box-shadow:inset 0 2px 0 rgba(255,255,255,.5),0 2px 4px rgba(0,0,0,.25)}
/* ===== /3D cards ===== */

/* history of this tool: clock handle on the left, list slides out from the left */
#screen-chat{position:relative}
#bh-tab{position:absolute;left:0;top: 76px;z-index:30;width:30px;height:56px;border:1px solid var(--line);border-left:0;border-radius:0 12px 12px 0;background:var(--panel);color:var(--ink);cursor:pointer;opacity:.9;padding:0;font-size:16px}
#box-history{position:absolute;top:0;left:0;bottom:0;z-index:40;box-sizing:border-box;width:min(320px,85%);background:var(--panel);border-right:1px solid var(--line);box-shadow:8px 0 30px rgba(0,0,0,.35);transform:translateX(-102%);visibility:hidden;transition:transform .2s ease,visibility 0s .2s;display:flex;flex-direction:column;padding:12px;gap:8px;will-change:transform}
#box-history.open{transform:none;visibility:visible;transition:transform .2s ease}
.bh-head{display:flex;align-items:center;justify-content:space-between}
#bh-list{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:6px}

/* ===== PDF Reader Phase 5.1 (annot, view, packs, scanner) ===== */
/* marks on PDF pages (annot.js) */
/* reader view (view.js) */
.vw-lab{margin:10px 0 4px;font-size:12px}
/* packs + meaning card (packs.js, view.js) */
/* document scanner (scanner.js) */
body.sc-open{overflow:hidden}
.sc{position:fixed;inset:0;z-index:350;background:#05070b;color:#fff;display:flex;flex-direction:column}
.sc.hidden,.sc-pane.hidden,.sc-bar.hidden{display:none}
.sc-top{display:flex;align-items:center;gap:8px;padding:calc(8px + env(safe-area-inset-top,0px)) 12px 8px}
.sc-stage{position:relative;flex:1;min-height:0}
.sc-pane{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;overflow:hidden}
#sc-video{width:100%;height:100%;object-fit:contain;background:#000}
#sc-over{position:absolute;left:0;top:0;pointer-events:none}
.sc-msg{position:absolute;left:0;right:0;bottom:10px;text-align:center;font-size:14px;padding:0 16px;text-shadow:0 1px 4px #000}
.sc-note{font-size:13px;color:#cbd5e1;padding:0 12px;height:40px;display:flex;align-items:center;text-align:center}
#sc-crop{touch-action:none}
#sc-prev{background:#fff;box-shadow:0 4px 24px rgba(0,0,0,.6)}
#sc-list{justify-content:flex-start;align-items:stretch;overflow-y:auto;padding:12px}
.sc-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
.sc-card{background:#111827;border-radius:10px;overflow:hidden}.sc-card img{width:100%;display:block;aspect-ratio:3/4;object-fit:contain;background:#1f2937}
.sc-cardbar{display:flex;align-items:center;gap:2px;padding:4px 6px}.sc-cardbar b{margin-right:auto}
.sc-bar{display:flex;align-items:center;justify-content:center;gap:8px;padding:10px 12px calc(10px + env(safe-area-inset-bottom,0px));flex-wrap:wrap;background:#0b1018}
.sc-shutter{width:68px;height:68px;border-radius:50%;border:5px solid #fff;background:#38bdf8;padding:0;flex:none}
.sc-filters,.sc-row{display:flex;gap:6px;flex-wrap:wrap;justify-content:center;width:100%}
.sc-slider{display:flex;align-items:center;gap:6px;flex:1 1 140px}.sc-slider input{flex:1}
/* search words boxed on the page (find.js) */
/* ===== /PDF Reader Phase 5.1 ===== */

/* ===== Flashcards 3D ===== */
.fcx-prog { height: 8px; border-radius: 99px; background: #e7e3fb; overflow: hidden; margin: 8px 0 12px; }
.fcx-prog span { display: block; height: 100%; width: 0; border-radius: 99px; background: linear-gradient(90deg, #7c5cff, #22c7a9); transition: width .3s; }
.fcx-card { display: block; width: 100%; height: 260px; padding: 0; border: 0; background: none; font: inherit; cursor: pointer; perspective: 1000px; -webkit-tap-highlight-color: transparent; }
.fcx-inner { position: relative; display: block; width: 100%; height: 100%; transform-style: preserve-3d; transition: transform .45s; will-change: transform; }
.fcx-item.flipped .fcx-inner { transform: rotateY(180deg); }
.fcx-face { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; padding: 18px; border-radius: 22px; text-align: center; backface-visibility: hidden; -webkit-backface-visibility: hidden; box-shadow: 0 8px 22px rgba(60, 40, 140, .18); }
.fcx-front { background: linear-gradient(160deg, #ffffff, #efeaff); color: #1e1b4b; border: 2px solid #d9d0ff; }
.fcx-back { background: linear-gradient(160deg, #4f3fd1, #2f2a8f); color: #fff; transform: rotateY(180deg); }
.fcx-tag { padding: 3px 12px; border-radius: 99px; font-weight: 700; letter-spacing: .06em; background: #6d4aff; color: #fff; }
.fcx-back .fcx-tag { background: rgba(255, 255, 255, .22); }
.fcx-q, .fcx-a { font-size: clamp(20px, 5vw, 26px); font-weight: 700; line-height: 1.3; max-height: 150px; overflow-y: auto; word-break: break-word; }
.fcx-a { font-weight: 600; }
.fcx-hint { opacity: .7; font-size: 14px; }
.fcx-nav { display: flex; gap: 8px; justify-content: space-between; margin: 12px 0 8px; }
.fcx-nav .stu-btn { flex: 1; min-height: 44px; }
.fcx-rate { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin: 8px 0; }
.fcx-r { min-height: 56px; padding: 8px 2px; border: 0; border-radius: 14px; color: #fff; font-weight: 700; font-size: 14px; line-height: 1.3; cursor: pointer; }
.fcx-again { background: #d63a3f; }
.fcx-hard { background: #c2570c; }
.fcx-good { background: #0f8f6f; }
.fcx-easy { background: #5b3fd9; }
.fcx-r:active { transform: scale(.97); }
@media (prefers-reduced-motion: reduce) { .fcx-inner, .fcx-prog span { transition: none; } }

.fcx-prog{height:8px;background:rgba(124,92,255,.18);border-radius:99px;overflow:hidden;margin:8px 0}
.fcx-prog span{display:block;height:100%;width:0;background:linear-gradient(90deg,#22d3ee,#34d399);border-radius:99px;transition:width .3s}
.fcx-stage{perspective:1000px;margin:10px 0}
.fcx-card{display:block;width:100%;padding:0;border:0;background:none;cursor:pointer;font:inherit;color:inherit}
.fcx-inner{display:grid;position:relative;min-height:220px;transform-style:preserve-3d;transition:transform .45s;will-change:transform}
.fcx-item.flipped .fcx-inner{transform:rotateY(180deg)}
.fcx-face{grid-area:1/1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;padding:24px 18px;border-radius:20px;text-align:center;font-size:1.4rem;font-weight:700;line-height:1.4;backface-visibility:hidden;-webkit-backface-visibility:hidden;box-shadow:0 10px 24px rgba(60,40,140,.22)}
.fcx-front{background:linear-gradient(135deg,#fff,#ece8ff);color:#2b2160}
.fcx-back{background:linear-gradient(135deg,#7c5cff,#a855f7);color:#fff;transform:rotateY(180deg)}
.fcx-tag{padding:3px 12px;border-radius:99px;background:rgba(124,92,255,.18);font-size:.7rem;letter-spacing:.08em}
.fcx-back .fcx-tag{background:rgba(255,255,255,.25)}
.fcx-hint{font-weight:400;opacity:.7;font-size:.85rem}
.fcx-nav{display:flex;gap:8px;justify-content:center;margin:10px 0}
.fcx-rate{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin:10px 0}
.fcx-rate.hidden{display:none}
.fcx-r{border:0;border-radius:14px;padding:12px 4px;color:#fff;font-weight:700;font-size:.9rem;cursor:pointer;box-shadow:0 4px 10px rgba(0,0,0,.18)}
.fcx-again{background:#ef4f6a}.fcx-hard{background:#f59e3b}.fcx-good{background:#34c28a}.fcx-easy{background:#8b5cf6}
@media (prefers-reduced-motion:reduce){.fcx-inner,.fcx-prog span{transition:none}}

   .hidden{display:none!important}

/* ===== Reader: ek patti upar, neeche saaf (rdui) ===== */
/* ===== /Reader rdui ===== */

/* ===== Reader: pura book ek ke neeche ek (scroll) ===== */
/* ===== /Reader scroll ===== */

/* ===== Student Suite merged tiles (hub sheet) ===== */
.hub-head{display:flex;align-items:center;gap:12px;margin-bottom:12px}
.hub-head b{display:block;font-size:16px}.hub-head small{color:var(--muted);font-size:12px}
.hub-hi{font-size:26px}.hub-x{margin-left:auto;width:34px;height:34px;border-radius:50%;background:var(--card);border:1px solid var(--line);color:inherit}
.hub-list{display:grid;grid-template-columns:1fr;gap:8px}
.hub-item{display:flex;align-items:center;gap:12px;padding:12px;border-radius:14px;text-align:left;width:100%;background:var(--card);border:1px solid var(--line);color:inherit}
.hub-item:hover{background:var(--card-hover)}.hub-item:active{transform:scale(.98)}
.hub-ic{flex:none;width:42px;height:42px;border-radius:12px;display:grid;place-items:center;font-size:20px;background:color-mix(in srgb,var(--c,#888) 38%,transparent)}
.hub-tx b{display:block;font-size:14px}.hub-tx small{display:block;color:var(--muted);font-size:12px;margin-top:2px}
@media(min-width:560px){.hub-list{grid-template-columns:1fr 1fr}}
[data-act="hub:ask_explain"]{--c:#e28c36}
[data-act="hub:solve_check"]{--c:#36e2e2}
[data-act="hub:quiz_exam_prep"]{--c:#8c36e2}
[data-act="hub:write_language"]{--c:#bc0fbc}
[data-act="hub:flashcards_revision"]{--c:#e2e236}
[data-act="hub:planner"]{--c:#368ce2}
[data-act="hub:backup"]{--c:#7a8aa0}
[data-act="backup"]{--c:#7a8aa0}
[data-act="export-xlsx"]{--c:#36e28c}
[data-act="restore"]{--c:#e28c36}
[data-act="aiq:tldr"]{--c:#e2c636}
[data-act="aiq:pyq"]{--c:#36a8e2}
[data-act="aiq:viva"]{--c:#e25a36}
[data-act="aiq:essay"]{--c:#a8e236}
[data-act="aiq:translate"]{--c:#36e2c6}
/* ===== /Student Suite merged tiles ===== */

/* ===== Reader (Phase 6) ===== */
.view-screen.reader-screen{padding:0}
.view-screen.reader-screen.active{display:flex;flex-direction:column}
.rd-pg{width:70px;padding:6px 8px;text-align:center}
.rd-body{flex:1;min-height:0;overflow:auto;padding:12px;background:var(--code)}
.rd-canvas-wrap{display:flex;justify-content:flex-start;margin:0 auto;width:max-content;max-width:none}
.rd-canvas-wrap canvas,.rd-img{background:#fff;box-shadow:0 4px 24px rgba(0,0,0,.35);max-width:none}
.rd-img{max-width:100%;height:auto}
.rd-text{max-width:760px;margin:0 auto;white-space:pre-wrap;line-height:1.75;font-size:16px}
.rd-tools{display:flex;gap:8px;flex-wrap:wrap;align-items:center;padding:8px 12px;border-top:1px solid var(--line);background:var(--panel)}
.rd-tools .select{width:auto;padding:4px 8px}
.rd-notes{border-top:1px solid var(--line);padding:8px 12px;background:var(--panel);max-height:40vh;overflow:auto}
.rd-notes summary{cursor:pointer;font-weight:600}
.rd-bms{display:flex;gap:6px;flex-wrap:wrap;margin:8px 0}
.fc-deck{margin-top:8px;width:100%}
.rd-search{max-height:45vh}
.rd-search .input{margin:8px 0}
.rd-text mark{background:#facc15;color:#000;border-radius:3px;padding:0 2px}
.rd-canvas-wrap{position:relative}
.mk-ov{position:absolute;left:0;top:0;pointer-events:none;background:transparent!important;box-shadow:none!important}
.rd-marks{display:flex;align-items:center;gap:6px;padding:6px 12px;border-bottom:1px solid var(--line);background:var(--panel);overflow-x:auto;-webkit-overflow-scrolling:touch}
.rd-marks>*{flex:none}
.rd-marks .select{width:auto;padding:4px 8px}
.mk-sep{width:1px;height:22px;background:var(--line)}
.mk-dot{width:24px;height:24px;border-radius:50%;border:2px solid var(--line);padding:0}
.mk-dot.on{border-color:var(--ink);transform:scale(1.15)}
.mk-dot.sm{width:12px;height:12px;border-width:1px;flex:none;align-self:center}
#rd-body{touch-action:pan-x pan-y}
#rd-body canvas:not(.mk-ov):not(.fh-ov),#rd-body .rd-img{filter:brightness(var(--rd-bright,1))}
#rd-body.th-sepia{background:#e8dcc0}
#rd-body.th-sepia canvas:not(.mk-ov):not(.fh-ov),#rd-body.th-sepia .rd-img{filter:sepia(.65) contrast(.95) brightness(var(--rd-bright,1))}
#rd-body.th-night{background:#05080c}
#rd-body.th-night canvas:not(.mk-ov):not(.fh-ov),#rd-body.th-night .rd-img{filter:invert(.92) hue-rotate(180deg) brightness(var(--rd-bright,1))}
#rd-body.th-comfort canvas:not(.mk-ov):not(.fh-ov),#rd-body.th-comfort .rd-img{filter:sepia(.28) saturate(.9) brightness(calc(var(--rd-bright,1) * .96))}
#rd-zoom{min-width:44px;text-align:center;font-size:12px}
.rd-thumbs{display:grid;grid-template-columns:repeat(auto-fill,minmax(84px,1fr));gap:8px;margin-top:8px}
.th-item{display:flex;flex-direction:column;align-items:center;gap:3px;padding:4px;border-radius:8px;border:2px solid transparent;background:transparent;color:var(--muted);font-size:12px}
.th-item canvas{width:100%;height:auto;aspect-ratio:96/136;background:#fff;border-radius:3px;box-shadow:0 2px 8px rgba(0,0,0,.3)}
.th-item.on{border-color:var(--accent);color:var(--ink)}
#rd-zoom{min-width:38px}
#screen-reader{position:relative}
.rd-dict-card{position:absolute;left:8px;right:8px;bottom:8px;z-index:6;background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:10px 40px 10px 12px;box-shadow:0 8px 28px rgba(0,0,0,.45);max-height:34vh;overflow:auto}
.rd-dict-card>.icon-btn{position:absolute;top:4px;right:4px}
.fh-ov{position:absolute;left:0;top:0;pointer-events:none;background:transparent!important;box-shadow:none!important}
.rd-hitbar{display:flex;align-items:center;gap:4px;padding:4px 12px;background:var(--panel);border-bottom:1px solid var(--line);font-size:13px}
.rd-hitbar.hidden{display:none}
#rd-hit-info{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
#screen-reader.reader-screen{padding:0}
#screen-reader.active{position:fixed;inset:0;z-index:160;display:block;background:var(--bg);overflow:hidden;animation:none}
#screen-reader .rd-body{position:absolute;inset:0;flex:none;min-height:0;padding:0;overflow:auto;-webkit-overflow-scrolling:touch;overscroll-behavior:contain;touch-action:pan-x pan-y;background:#3a3f48}
.rd-top{position:absolute;left:0;right:0;top:0;z-index:30;display:flex;align-items:center;gap:2px;padding:calc(6px + env(safe-area-inset-top,0px)) 6px 6px;background:var(--panel);border-bottom:1px solid var(--line);box-shadow:0 2px 12px rgba(0,0,0,.25);transition:transform .22s ease}
.rd-top.hidden{display:none}
.rd-ib{width:44px;height:44px;flex:none;border-radius:50%;display:grid;place-items:center;font-size:20px;background:transparent;border:0;color:var(--ink);cursor:pointer}
.rd-ib.sm{width:36px;height:36px;font-size:15px}
.rd-ib:active{background:var(--card-hover)}
.rd-ttl{flex:1;min-width:0;padding:0 4px}
.rd-name{font-weight:700;font-size:15px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.rd-subt{font-size:12px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.rd-find{flex:1;min-width:70px;height:40px;border-radius:20px;border:1px solid var(--line);background:var(--card);color:var(--ink);padding:0 14px;font-size:15px;outline:none}
.rd-searchbar .rd-hitbar{display:flex;align-items:center;gap:0;flex:none;padding:0;background:none;border:0}
.rd-searchbar .rd-hitbar.hidden{display:none}
#rd-hit-info{max-width:92px;font-size:11px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;flex:none;padding-right:2px}
.pv-list{position:relative;box-sizing:border-box;min-width:100%;padding:calc(64px + env(safe-area-inset-top,0px)) 8px 200px}
.pv{position:relative;width:var(--pw,595px);height:var(--ph,842px);margin:0 auto 10px;background:#fff;box-shadow:0 2px 14px rgba(0,0,0,.45);overflow:hidden;contain:strict}   /* every box has a fixed size: the browser lays each page out on its own (fast with 5000 pages) */
.pv>canvas.pg{display:block;width:100%;height:100%}
.pv:empty::before{content:attr(data-n);position:absolute;inset:0;display:grid;place-items:center;color:#9aa3af;font-size:22px}
.textLayer{position:absolute;inset:0;overflow:hidden;line-height:1;text-size-adjust:none;transform-origin:0 0;z-index:2}
.textLayer :is(span,br){color:transparent;position:absolute;white-space:pre;cursor:text;transform-origin:0 0}
.textLayer ::selection{background:rgba(59,130,246,.38)}
.fh-ov{z-index:1}
.mk-ov{z-index:3}
.rd-alt{box-sizing:border-box;padding:calc(64px + env(safe-area-inset-top,0px)) 14px 200px;max-width:780px;margin:0 auto}
.rd-alt:empty{display:none}
.rd-alt .rd-text{background:var(--panel);padding:18px;border-radius:12px}
#rd-body.alt .pv-list{display:none}
#rd-body.rd-single{scroll-snap-type:y mandatory}
#rd-body.rd-single .pv{scroll-snap-align:center}
#rd-body.rd-single.zoomed{scroll-snap-type:none}
.rd-bottom{position:absolute;left:0;right:0;bottom:0;z-index:30;background:var(--panel);border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom,0px);box-shadow:0 -2px 12px rgba(0,0,0,.25);transition:transform .22s ease}
.rd-immersive .rd-top{transform:translateY(-115%)}
.rd-immersive .rd-bottom{transform:translateY(115%)}
.rd-slide{display:flex;align-items:center;gap:8px;padding:6px 12px 2px}
.rd-pg{width:60px;text-align:center;padding:5px 4px;border-radius:8px;border:1px solid var(--line);background:var(--card);color:var(--ink);font-size:14px;-moz-appearance:textfield}
.rd-slider{flex:1;min-width:0;accent-color:var(--accent)}
.rd-tot{font-size:13px;color:var(--muted);min-width:48px}
.rd-nav{display:flex;justify-content:space-around;padding:2px 4px 6px}
.rd-nav button{flex:1;display:flex;flex-direction:column;align-items:center;gap:1px;background:none;border:0;color:var(--muted);font-size:11px;padding:4px 0;cursor:pointer}
.rd-nav .ic{font-size:20px;color:var(--ink);line-height:1.2}
.rd-nav button.on .ic,.rd-nav button.on{color:var(--accent)}
.rd-marks{display:flex;align-items:center;gap:2px;padding:4px 8px;overflow-x:auto;border-bottom:1px solid var(--line);background:var(--panel)}
.rd-marks.hidden{display:none}
.rd-marks>*{flex:none}
.mk-b{display:flex;flex-direction:column;align-items:center;gap:0;background:none;border:0;color:var(--ink);font-size:18px;padding:3px 9px;border-radius:10px;min-width:46px;cursor:pointer}
.mk-b small{font-size:10px;color:var(--muted)}
.mk-b.on{background:rgba(59,130,246,.25)}
.mk-b.done{color:var(--accent)}
.rd-chip{position:absolute;left:50%;transform:translateX(-50%);bottom:calc(150px + env(safe-area-inset-bottom,0px));z-index:25;background:rgba(15,23,42,.9);color:#fff;padding:6px 15px;border-radius:999px;font-size:13px;font-weight:600;opacity:0;pointer-events:none;transition:opacity .2s}
.rd-chip.show{opacity:1;pointer-events:auto}
.rd-immersive .rd-chip{bottom:calc(26px + env(safe-area-inset-bottom,0px))}
.rd-comment .rd-chip{bottom:calc(214px + env(safe-area-inset-bottom,0px))}
.rd-selbar{position:fixed;z-index:200;display:flex;flex-wrap:wrap;max-width:94vw;gap:1px;background:#0f172a;color:#fff;border-radius:12px;padding:4px;box-shadow:0 8px 28px rgba(0,0,0,.55)}
.rd-selbar.hidden{display:none}
.rd-selbar button{background:none;border:0;color:#fff;padding:9px 11px;font-size:13px;border-radius:8px;cursor:pointer}
.rd-selbar button:active{background:rgba(255,255,255,.15)}
.rd-speed{position:absolute;left:12px;bottom:calc(150px + env(safe-area-inset-bottom,0px));z-index:25;display:flex;align-items:center;gap:8px;background:var(--panel);border:1px solid var(--line);padding:4px 10px;border-radius:999px}
.rd-speed.hidden{display:none}
.rd-speed .select{width:auto;padding:2px 6px}
.rd-scrim{position:absolute;inset:0;z-index:40;background:rgba(0,0,0,.45)}
.rd-scrim.hidden{display:none}
.rd-sheet{position:absolute;left:0;right:0;bottom:0;z-index:50;background:var(--panel);border-radius:18px 18px 0 0;max-height:74%;display:flex;flex-direction:column;box-shadow:0 -10px 40px rgba(0,0,0,.5);padding-bottom:env(safe-area-inset-bottom,0px)}
.rd-sheet.hidden{display:none}
.rd-sh-head{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:10px 12px 6px}
.rd-sh-body{overflow:auto;padding:6px 14px 18px;-webkit-overflow-scrolling:touch;min-height:120px}
.rd-tabs{display:flex;gap:6px;overflow-x:auto}
.rd-tabs button{flex:none;padding:7px 12px;border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--muted);font-size:13px;cursor:pointer}
.rd-tabs button.on{background:var(--accent);color:#fff;border-color:transparent}
.rd-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.rd-grid button{display:flex;flex-direction:column;align-items:center;gap:6px;padding:14px 6px;border-radius:12px;background:var(--card);border:1px solid var(--line);color:var(--ink);font-size:12px;text-align:center;cursor:pointer}
.rd-grid .ic{font-size:24px}
.rd-zoomlab{min-width:56px;text-align:center;font-weight:700}
#screen-reader .rd-dict-card{z-index:60;bottom:calc(150px + env(safe-area-inset-bottom,0px))}
.textLayer,.textLayer span{-webkit-user-select:text;user-select:text}
.pv-list.armed{touch-action:pan-y}
#rd-body.tooling .pv .textLayer span{cursor:text}
.th-item .th-box{width:100%;aspect-ratio:96/136;background:#fff;border-radius:3px;box-shadow:0 2px 8px rgba(0,0,0,.3);overflow:hidden}
.th-item .th-box canvas{display:block;width:100%;height:100%;box-shadow:none;border-radius:0;aspect-ratio:auto}
.textLayer .endOfContent{display:block;position:absolute;inset:100% 0 0;z-index:0;cursor:default;-webkit-user-select:none;user-select:none}
.textLayer.selecting .endOfContent{top:0}
.textLayer span.markedContent{top:0;height:0}
.textLayer br::selection{background:transparent}
/* ===== /Reader (Phase 6) ===== */

/* PDF reader speed: the frosted-glass blur behind the app chrome is recomputed on every scrolled frame
   (measured: it doubled the frame time). The reader covers that chrome, so it is switched off there. */
body[data-screen="reader"] *{-webkit-backdrop-filter:none!important;backdrop-filter:none!important}

/* ================= Spreadsheet: Excel AI + Data Entry (features/apps/excel_ai/sheet.js) ================= */
.view-screen.sheet-screen.active{display:block}
.xs{--xg:#107c41;--xg2:#0b5e30;--xgrid:rgba(127,127,127,.22);--xhead:rgba(127,127,127,.09);--xsel:rgba(16,124,65,.10);
  display:flex;flex-direction:column;height:calc(100dvh - 128px);min-height:480px;border-radius:18px;overflow:hidden;background:var(--panel);border:1px solid var(--line);box-shadow:0 10px 30px rgba(15,23,42,.08);color:var(--ink);font-family:var(--font)}
.xs-ribbon{display:flex;align-items:center;gap:10px;padding:8px 10px;background:linear-gradient(100deg,var(--xg2),var(--xg));color:#fff;flex-wrap:wrap}
.xs-ib{width:34px;height:34px;border:0;border-radius:10px;background:rgba(255,255,255,.16);color:inherit;font-size:18px;cursor:pointer;flex:none}
.xs-ib:hover{background:rgba(255,255,255,.28)}.xs-ib.sm{width:28px;height:28px;font-size:14px;background:rgba(127,127,127,.15);color:var(--ink)}
.xs-brand{display:flex;align-items:baseline;gap:8px;margin-right:6px}.xs-brand b{font-size:17px}.xs-brand small{opacity:.8;font-size:11px}.xs-logo{font-size:18px}
.xs-tools{display:flex;align-items:center;gap:2px;flex-wrap:wrap;margin-left:auto}
.xs-tools button{display:flex;flex-direction:column;align-items:center;gap:1px;min-width:52px;padding:4px 6px;border:0;border-radius:9px;background:none;color:#fff;font:600 15px var(--font);cursor:pointer;line-height:1.1}
.xs-tools button span{font-size:10.5px;font-weight:600;opacity:.92}.xs-tools button:hover{background:rgba(255,255,255,.16)}
.xs-tools .xs-ai-btn{background:rgba(255,255,255,.2)}.xs-sep{width:1px;height:28px;background:rgba(255,255,255,.3);margin:0 4px}
.xs-fbar{display:flex;align-items:center;gap:6px;padding:6px 8px;border-bottom:1px solid var(--line);background:var(--panel)}
.xs-namebox{width:92px;flex:none;padding:6px 8px;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink);font:600 13px var(--mono);text-align:center}
.xs-fx{flex:none;font:italic 700 14px Georgia,serif;color:var(--xg);padding:0 4px}
#xs-fn{flex:none;width:44px;padding:5px 2px;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink);font-weight:700;cursor:pointer}
.xs-formula{flex:1;min-width:0;padding:7px 10px;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink);font:14px var(--mono)}
.xs-formula:focus,.xs-namebox:focus{outline:2px solid var(--xg);outline-offset:-1px}
.xs-main{flex:1;min-height:0;display:flex}
.xs-grid{position:relative;flex:1;min-width:0;overflow:auto;outline:none;background:var(--panel)}
.xs-table{border-collapse:separate;border-spacing:0;table-layout:fixed;font:13.5px/1.2 var(--font);user-select:none}
.xs-table th,.xs-table td{border-right:1px solid var(--xgrid);border-bottom:1px solid var(--xgrid);height:26px;padding:0 6px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.xs-table td{width:104px;min-width:104px;max-width:600px;background:var(--panel);color:var(--ink);cursor:cell}
.xs-table td.num{text-align:right;font-variant-numeric:tabular-nums}.xs-table td.bool{text-align:center}.xs-table td.err{color:#dc2626;font-weight:700;text-align:center}
.xs-table thead th{position:sticky;top:0;z-index:3;background:var(--panel);background-image:linear-gradient(var(--xhead),var(--xhead));color:var(--muted);font-weight:600;font-size:12px;text-align:center;width:104px;min-width:104px;cursor:s-resize}
.xs-table tbody th{position:sticky;left:0;z-index:2;width:46px;min-width:46px;background:var(--panel);background-image:linear-gradient(var(--xhead),var(--xhead));color:var(--muted);font-weight:600;font-size:12px;text-align:center;cursor:e-resize}
.xs-table thead th.xs-corner{left:0;z-index:4;width:46px;min-width:46px;cursor:pointer}
.xs-table th.xs-hl{background-image:linear-gradient(rgba(16,124,65,.18),rgba(16,124,65,.18));color:var(--xg);border-bottom:2px solid var(--xg)}
.xs-table tbody th.xs-hl{border-bottom:1px solid var(--xgrid);border-right:2px solid var(--xg)}
.xs-rz{position:absolute;right:-3px;top:0;bottom:0;width:7px;cursor:col-resize;z-index:5}
.xs-table td.xs-in{background-image:linear-gradient(var(--xsel),var(--xsel))}
.xs-table td.xs-cur{box-shadow:inset 0 0 0 2px var(--xg);background-image:none}
.xs-editor{position:absolute;z-index:6;box-sizing:border-box;padding:0 6px;border:2px solid var(--xg);background:var(--panel);color:var(--ink);font:13.5px var(--font);outline:none;box-shadow:0 4px 14px rgba(0,0,0,.18)}
.xs-more{display:block;margin:10px 0 18px 54px;padding:6px 14px;border:1px dashed var(--line);border-radius:9px;background:none;color:var(--muted);cursor:pointer;font:inherit;font-size:12px}
.xs-panel{width:330px;flex:none;border-left:1px solid var(--line);padding:12px;overflow:auto;display:flex;flex-direction:column;gap:10px;background:var(--bg)}
.xs.no-panel .xs-panel,.xs-panel.hidden{display:none}
.xs-p-head{display:flex;align-items:center;justify-content:space-between;gap:8px}.xs-p-head b{font-size:15px}
.xs-panel textarea,.xs-panel input{width:100%;box-sizing:border-box;padding:9px 11px;border:1px solid var(--line);border-radius:11px;background:var(--panel);color:var(--ink);font:13.5px var(--font);resize:vertical}
.xs-panel textarea:focus,.xs-panel input:focus{outline:2px solid var(--xg);outline-offset:-1px}
.xs-p-row{display:flex;align-items:center;gap:8px;flex-wrap:wrap}.xs-p-note{color:var(--muted);font-size:12px;margin:0}
.xs-btn{border:0;border-radius:11px;background:var(--xg);color:#fff;font:700 13.5px var(--font);padding:9px 16px;cursor:pointer}
.xs-btn:hover{background:var(--xg2)}.xs-btn.alt{background:rgba(127,127,127,.16);color:var(--ink)}.xs-btn.sm{padding:6px 10px;font-weight:600;font-size:12.5px;text-align:left}
.xs-chips{display:flex;flex-wrap:wrap;gap:6px}.xs-chip{border:1px solid var(--line);background:var(--panel);color:var(--ink);border-radius:99px;padding:6px 10px;font:12.5px var(--font);cursor:pointer;text-align:left}
.xs-chip:hover{border-color:var(--xg);color:var(--xg)}
.xs-p-out:empty{display:none}.xs-ans{font-size:13.5px;line-height:1.5}.xs-ans .code pre{font-size:12px}
.xs-ins{display:flex;flex-direction:column;gap:6px;margin-top:8px}.xs-ins code{font-family:var(--mono);background:rgba(255,255,255,.18);padding:1px 4px;border-radius:4px}
.xs-warn{padding:10px 12px;border-radius:11px;background:rgba(245,158,11,.13);color:#b45309;font-size:13px}.xs-think{color:var(--muted);font-size:13px;display:flex;align-items:center;gap:8px}
.xs-foot{display:flex;align-items:center;gap:10px;border-top:1px solid var(--line);background:var(--panel);min-height:36px;padding:0 8px}
.xs-tabs{display:flex;gap:2px;overflow:auto;flex:1;min-width:0}
.xs-tab{border:0;border-bottom:3px solid transparent;background:none;color:var(--muted);font:600 13px var(--font);padding:7px 14px;cursor:pointer;white-space:nowrap;border-radius:8px 8px 0 0}
.xs-tab.on{color:var(--xg);border-bottom-color:var(--xg);background:var(--xsel)}.xs-tab.add{font-size:16px;padding:4px 12px}
.xs-status{flex:none;font-size:12.5px;color:var(--muted);white-space:nowrap}.xs-status b{color:var(--ink);margin-right:10px}
@media (max-width:900px){
  .xs{height:calc(100dvh - 96px);border-radius:14px}
  .xs-tools{flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none;width:100%;margin-left:0}.xs-tools::-webkit-scrollbar{display:none}
  .xs-tools button{min-width:44px;padding:4px;flex:none}.xs-tools button span{display:none}.xs-brand small{display:none}
  .xs-main{flex-direction:column}.xs-panel{width:auto;max-height:42%;border-left:0;border-top:1px solid var(--line)}
  .xs-table td,.xs-table thead th{width:88px;min-width:88px}.xs-status{display:none}
}

/* ================= Tool start screens (chat modes) ================= */
.welcome.wl{max-width:880px;margin:22px auto 30px;text-align:left;padding:0 6px}
.wl-hero{display:flex;align-items:center;gap:20px;padding:24px 26px;border-radius:24px;color:#fff;background:linear-gradient(120deg,var(--wa),var(--wb));box-shadow:0 18px 40px -18px var(--wa);position:relative;overflow:hidden}
.wl-hero::after{content:"";position:absolute;right:-60px;top:-60px;width:220px;height:220px;border-radius:50%;background:rgba(255,255,255,.12)}
.wl-ic{flex:none;width:76px;height:76px;border-radius:22px;display:grid;place-items:center;font-size:40px;background:rgba(255,255,255,.2);box-shadow:inset 0 0 0 1px rgba(255,255,255,.35)}
.wl-tx{position:relative;z-index:1;min-width:0}.wl-tx h2{margin:0;font-size:clamp(22px,3vw,30px);line-height:1.15;color:#fff}.wl-tx p{margin:6px 0 0;opacity:.95;font-size:14.5px;line-height:1.45}
.wl-can{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}.wl-can span{background:rgba(255,255,255,.2);border-radius:99px;padding:4px 10px;font-size:12px;font-weight:600}
.wl-can .wl-web{background:rgba(255,255,255,.95);color:var(--wa)}
.wl-pick{display:flex;flex-wrap:wrap;gap:8px;margin:16px 0 0}
.wl-pk{border:1.5px solid var(--line);background:var(--panel);color:var(--ink);border-radius:14px;padding:10px 16px;font:600 14px var(--font);cursor:pointer}
.wl-pk:hover{border-color:var(--wa);color:var(--wa)}
.wl-lbl,.mini-lbl{margin:20px 0 8px;font-size:12px;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
.wl-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:10px}
.wl-card{display:flex;align-items:flex-start;gap:12px;text-align:left;padding:14px 16px;border-radius:18px;border:1px solid var(--line);background:var(--panel);color:var(--ink);font:500 14px/1.4 var(--font);cursor:pointer;transition:transform .15s,box-shadow .15s,border-color .15s}
.wl-card i{font-style:normal;font-size:20px;flex:none;width:36px;height:36px;border-radius:12px;display:grid;place-items:center;background:color-mix(in srgb,var(--wa) 14%,transparent)}
.wl-card span{flex:1}.wl-card b{color:var(--muted);font-weight:400}
.wl-card:hover{transform:translateY(-2px);border-color:var(--wa);box-shadow:0 10px 24px -14px var(--wa)}
.wl-tip{margin:18px 0 0;font-size:12.5px;color:var(--muted);text-align:center}
@media (max-width:640px){.wl-hero{flex-direction:column;align-items:flex-start;padding:20px}.wl-ic{width:60px;height:60px;font-size:32px}}

/* ================= Images, Research, Tools ================= */
.style-chips{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:12px}
.st-chip{border:1.5px solid var(--line);background:var(--panel);color:var(--ink);border-radius:99px;padding:7px 14px;font:600 13px var(--font);cursor:pointer}
.st-chip.on{border-color:var(--accent);background:color-mix(in srgb,var(--accent) 12%,var(--panel));color:var(--accent)}
.img-empty{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:6px;min-height:220px;border:2px dashed var(--line);border-radius:20px;color:var(--muted);text-align:center;padding:20px}
.img-empty span{font-size:44px}.img-empty b{color:var(--ink);font-size:16px}.img-empty small{max-width:360px}
.idea-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:10px}
.idea{display:flex;align-items:center;gap:12px;text-align:left;padding:14px;border-radius:18px;border:1px solid var(--line);background:var(--panel);color:var(--ink);font:600 14px/1.35 var(--font);cursor:pointer;font-size:24px;transition:transform .15s,border-color .15s}
.idea span{font-size:14px}.idea:hover{transform:translateY(-2px);border-color:var(--accent)}
.steps3{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:16px}
.steps3>div{display:flex;flex-direction:column;gap:2px;padding:14px;border-radius:18px;background:var(--panel);border:1px solid var(--line)}
.steps3 i{font-style:normal;width:28px;height:28px;border-radius:9px;display:grid;place-items:center;background:var(--grad);color:#fff;font-weight:800;margin-bottom:6px}
.steps3 b{font-size:14px}.steps3 small{color:var(--muted);font-size:12.5px}
@media (max-width:640px){.steps3{grid-template-columns:1fr}}
.tools-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:14px;align-items:start}
.tools-grid .panel{margin:0}
.tool-h{display:flex;align-items:center;justify-content:space-between;gap:10px}
.badge-off{font-size:11px;font-weight:800;padding:3px 10px;border-radius:99px;background:rgba(34,197,94,.14);color:#16a34a}
.calc-out{margin-top:10px;min-height:44px;display:flex;flex-direction:column;align-items:flex-end;padding:8px 12px;border-radius:14px;background:var(--bg);font-variant-numeric:tabular-nums}
.calc-out small{color:var(--muted);font-size:12px;max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.calc-out b{font-size:26px;line-height:1.2}
.calc-out.bad{align-items:flex-start;color:#dc2626;font-size:13px;justify-content:center}.calc-out:empty{display:none}
.calc-keys{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;margin-top:12px}
.calc-keys button{height:46px;border-radius:14px;border:1px solid var(--line);background:var(--panel);color:var(--ink);font:700 18px var(--font);cursor:pointer}
.calc-keys button:active{transform:translateY(1px)}.calc-keys .op{color:var(--accent)}.calc-keys .fn{background:var(--bg);color:var(--muted)}
.calc-hist{display:flex;flex-direction:column;gap:4px;margin-top:10px}.calc-hist:empty{display:none}
.calc-hist button{display:flex;justify-content:space-between;gap:10px;border:0;background:none;color:var(--muted);font:13px var(--font);padding:6px 4px;border-bottom:1px dashed var(--line);cursor:pointer;text-align:left}
.calc-hist button b{color:var(--ink)}
.uc-row{display:flex;gap:8px;margin-top:10px}.uc-row .input{min-width:0}.uc-row input{flex:1}.uc-row select{flex:1}
.uc-eq{text-align:center;color:var(--muted);font-weight:800;margin-top:8px}
.uc-out{flex:1;display:flex;align-items:center;padding:0 12px;border-radius:14px;background:var(--bg);font-size:20px;font-weight:800;min-height:46px;overflow:auto}

/* big gradient shortcut buttons (Revision screen -> Flash Card app) */
.cta-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:12px;margin:0 0 14px}
.cta{display:grid;grid-template-columns:auto 1fr;grid-template-rows:auto auto;column-gap:14px;align-items:center;text-align:left;padding:16px 18px;border:0;border-radius:20px;color:#fff;background:linear-gradient(120deg,var(--ca),var(--cb));box-shadow:0 14px 30px -16px var(--ca);cursor:pointer;font-family:var(--font);transition:transform .15s}
.cta span{grid-row:1/3;font-size:32px;width:52px;height:52px;border-radius:16px;display:grid;place-items:center;background:rgba(255,255,255,.2)}
.cta b{font-size:16px}.cta small{opacity:.92;font-size:12.5px}.cta:hover{transform:translateY(-2px)}