/* OSEE Platform — base styles */
:root{
  --primary:#1e3a8a; --accent:#f59e0b;
  --ink:#0f172a; --ink-2:#334155; --muted:#64748b; --line:#e2e8f0; --soft:#f1f5f9; --bg:#f8fafc; --white:#fff;
  --ok:#16a34a; --ok-bg:#dcfce7; --warn:#b45309; --warn-bg:#fef3c7; --bad:#dc2626; --bad-bg:#fee2e2; --info:#1d4ed8; --info-bg:#dbeafe;
  --r-sm:10px; --r:14px; --r-lg:22px;
  --shadow:0 1px 2px rgba(15,23,42,.06),0 4px 16px rgba(15,23,42,.06);
  --shadow-lg:0 10px 40px rgba(15,23,42,.12);
  --font:'Inter',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.6;font-size:15px}
img{max-width:100%;height:auto}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.25;margin:0 0 .6em;letter-spacing:-.01em}
h1{font-size:2rem}h2{font-size:1.5rem}h3{font-size:1.15rem}
p{margin:0 0 1em}
hr{border:0;border-top:1px solid var(--line);margin:1.5rem 0}
code{background:var(--soft);padding:2px 6px;border-radius:6px;font-size:.9em}
.container{width:100%;max-width:1180px;margin:0 auto;padding:0 20px}
.narrow{max-width:720px}
.center{text-align:center}
.pad-xl{padding-top:64px;padding-bottom:64px}
.muted{color:var(--muted)} .small{font-size:.86rem}
.mt-0{margin-top:0}.mt{margin-top:16px}.mt-lg{margin-top:32px}.mb-0{margin-bottom:0}.mb{margin-bottom:16px}
.flex{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.between{justify-content:space-between}
.grow{flex:1}
.hide{display:none!important}
.text-right{text-align:right}
.nowrap{white-space:nowrap}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:11px 20px;border-radius:999px;border:1px solid var(--primary);background:var(--primary);color:#fff;font-weight:600;font-size:.95rem;cursor:pointer;text-decoration:none!important;transition:.15s;font-family:inherit;line-height:1.2}
.btn:hover{filter:brightness(1.1);transform:translateY(-1px)}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
.btn-sm{padding:7px 14px;font-size:.85rem}
.btn-lg{padding:14px 28px;font-size:1.05rem}
.btn-ghost{background:transparent;color:var(--primary)}
.btn-light{background:#fff;color:var(--ink);border-color:var(--line)}
.btn-accent{background:var(--accent);border-color:var(--accent);color:#1f1300}
.btn-danger{background:var(--bad);border-color:var(--bad)}
.btn-ok{background:var(--ok);border-color:var(--ok)}
.btn-block{width:100%}
.link-btn{background:none;border:0;color:var(--primary);cursor:pointer;font:inherit;padding:0}
.link-danger{color:var(--bad)}
.icon-btn{display:inline-grid;place-items:center;width:38px;height:38px;border-radius:12px;color:var(--ink-2);border:1px solid var(--line);background:#fff}

/* Header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.header-inner{display:flex;align-items:center;gap:24px;height:70px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none!important}
.brand-logo{height:44px;width:auto}
.brand-mark{width:40px;height:40px;border-radius:12px;background:var(--primary);color:#fff;display:grid;place-items:center;font-weight:800;font-size:1.2rem;position:relative}
.brand-mark::after{content:"";position:absolute;right:-3px;bottom:-3px;width:12px;height:12px;border-radius:50%;background:var(--accent);border:2px solid #fff}
.brand-text{display:flex;flex-direction:column;line-height:1.1}
.brand-text b{font-size:1.1rem;letter-spacing:.02em}
.brand-text small{color:var(--muted);font-size:.72rem}
.brand-light .brand-text b{color:#fff}.brand-light .brand-text small{color:#cbd5e1}
.main-nav{display:flex;gap:4px;margin-left:auto}
.main-nav a{color:var(--ink-2);padding:8px 14px;border-radius:999px;font-weight:500;font-size:.93rem}
.main-nav a:hover,.main-nav a.active{background:var(--soft);color:var(--primary);text-decoration:none}
.header-actions{display:flex;align-items:center;gap:10px}
.cart-link{position:relative;color:var(--ink-2);display:grid;place-items:center;width:40px;height:40px;border-radius:12px}
.cart-link:hover{background:var(--soft)}
.badge-dot{position:absolute;top:2px;right:0;background:var(--accent);color:#1f1300;font-size:.7rem;font-weight:700;min-width:18px;height:18px;border-radius:9px;display:grid;place-items:center;padding:0 4px}
.nav-toggle{display:none;background:none;border:0;width:40px;height:40px;cursor:pointer;flex-direction:column;justify-content:center;gap:5px;padding:8px}
.nav-toggle span{display:block;height:2px;background:var(--ink);border-radius:2px}

/* Flash */
.flash-wrap{max-width:1180px;margin:16px auto 0;padding:0 20px}
.dash .flash-wrap{padding:0;margin:0 0 16px}
.alert{position:relative;padding:12px 40px 12px 16px;border-radius:var(--r-sm);margin-bottom:10px;font-size:.93rem;border:1px solid transparent}
.alert-success{background:var(--ok-bg);color:#14532d;border-color:#bbf7d0}
.alert-error{background:var(--bad-bg);color:#7f1d1d;border-color:#fecaca}
.alert-info{background:var(--info-bg);color:#1e3a8a;border-color:#bfdbfe}
.alert-warn{background:var(--warn-bg);color:#78350f;border-color:#fde68a}
.alert-x{position:absolute;right:10px;top:8px;background:none;border:0;font-size:1.2rem;cursor:pointer;color:inherit;opacity:.6}

/* Hero */
.hero{background:radial-gradient(1200px 500px at 85% -10%,color-mix(in srgb,var(--accent) 30%,transparent),transparent),linear-gradient(135deg,var(--primary),color-mix(in srgb,var(--primary) 70%,#000));color:#fff;padding:80px 0 90px;overflow:hidden}
.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:center}
.hero h1{font-size:clamp(2rem,4.2vw,3.2rem);font-weight:800;line-height:1.1;margin-bottom:18px}
.hero p.lead{font-size:1.12rem;color:#dbeafe;max-width:560px}
.hero .eyebrow{display:inline-block;background:rgba(255,255,255,.14);padding:6px 14px;border-radius:999px;font-size:.82rem;font-weight:600;margin-bottom:18px}
.hero-card{background:#fff;color:var(--ink);border-radius:var(--r-lg);padding:26px;box-shadow:var(--shadow-lg)}
.hero-card h3{margin-bottom:6px}
.hero-stats{display:flex;gap:28px;margin-top:30px;flex-wrap:wrap}
.hero-stats b{display:block;font-size:1.6rem}
.hero-stats span{color:#bfdbfe;font-size:.85rem}

/* Sections */
.section{padding:64px 0}
.section-alt{background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.section-head{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:28px;flex-wrap:wrap}
.section-head h2{margin:0}
.kicker{color:var(--accent);font-weight:700;font-size:.8rem;text-transform:uppercase;letter-spacing:.08em;display:block;margin-bottom:6px;filter:brightness(.85)}
.page-hero{background:linear-gradient(135deg,var(--primary),color-mix(in srgb,var(--primary) 75%,#000));color:#fff;padding:48px 0}
.page-hero h1{margin:0 0 6px}.page-hero p{color:#dbeafe;margin:0}

/* Cards & grids */
.grid{display:grid;gap:20px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--r-lg);padding:24px;box-shadow:var(--shadow)}
.card-flat{box-shadow:none}
.card h2:first-child,.card h3:first-child{margin-top:0}
.item-card{background:#fff;border:1px solid var(--line);border-radius:var(--r-lg);overflow:hidden;display:flex;flex-direction:column;transition:.2s;color:inherit}
.item-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);text-decoration:none}
.item-thumb{aspect-ratio:16/9;background:linear-gradient(135deg,color-mix(in srgb,var(--primary) 85%,#fff),var(--primary));display:grid;place-items:center;color:#fff;font-weight:800;font-size:1.6rem;position:relative;overflow:hidden}
.item-thumb img{width:100%;height:100%;object-fit:cover}
.item-thumb .tag{position:absolute;top:12px;left:12px;background:rgba(255,255,255,.95);color:var(--primary);font-size:.72rem;font-weight:700;padding:4px 10px;border-radius:999px}
.item-body{padding:18px;display:flex;flex-direction:column;gap:8px;flex:1}
.item-body h3{margin:0;font-size:1.05rem;color:var(--ink)}
.item-body p{margin:0;color:var(--muted);font-size:.9rem}
.item-foot{display:flex;justify-content:space-between;align-items:center;margin-top:auto;padding-top:10px}
.price{font-weight:800;color:var(--primary);font-size:1.05rem}
.price-free{color:var(--ok)}
.feature{display:flex;gap:14px;align-items:flex-start}
.feature-ico{flex:none;width:46px;height:46px;border-radius:14px;background:color-mix(in srgb,var(--primary) 10%,#fff);color:var(--primary);display:grid;place-items:center}
.feature h3{margin:0 0 4px;font-size:1rem}.feature p{margin:0;color:var(--muted);font-size:.9rem}
.cta-band{background:var(--accent);border-radius:var(--r-lg);padding:36px;display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap;color:#1f1300}
.cta-band h2{margin:0}

/* Forms */
.form label,label.field{display:block;font-weight:600;font-size:.88rem;margin-bottom:14px;color:var(--ink-2)}
input[type=text],input[type=email],input[type=password],input[type=number],input[type=url],input[type=tel],input[type=date],input[type=datetime-local],input[type=color],input[type=search],select,textarea,input:not([type]){
  display:block;width:100%;margin-top:6px;padding:11px 14px;border:1px solid var(--line);border-radius:var(--r-sm);font:inherit;font-weight:400;color:var(--ink);background:#fff;transition:.15s}
input[type=color]{height:44px;padding:4px}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px color-mix(in srgb,var(--primary) 18%,transparent)}
textarea{min-height:110px;resize:vertical}
input[type=file]{display:block;margin-top:6px;font-size:.88rem;max-width:100%}
.check{display:flex!important;gap:10px;align-items:center;font-weight:500!important}
.check input{width:18px;height:18px;margin:0}
.help{display:block;color:var(--muted);font-weight:400;font-size:.8rem;margin-top:4px}
.form-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:8px}
.inline-form{display:inline}
.input-group{display:flex;gap:8px}
.input-group input{margin-top:0}
fieldset{border:1px solid var(--line);border-radius:var(--r);padding:16px 18px;margin:0 0 16px}
legend{font-weight:700;padding:0 6px}
.checklist{list-style:none;padding:0}.checklist li{padding:4px 0}.checklist .ok{color:var(--ok)}.checklist .bad{color:var(--bad)}

/* Rich editor */
.rte{border:1px solid var(--line);border-radius:var(--r-sm);background:#fff;margin-top:6px;overflow:hidden}
.rte-bar{display:flex;gap:2px;flex-wrap:wrap;padding:6px;border-bottom:1px solid var(--line);background:var(--soft)}
.rte-bar button{border:0;background:transparent;border-radius:8px;padding:5px 9px;cursor:pointer;font:600 .85rem var(--font);color:var(--ink-2)}
.rte-bar button:hover{background:#fff}
.rte-area{min-height:160px;padding:12px 14px;outline:none;font-weight:400;color:var(--ink)}
.rte-area:empty::before{content:attr(data-placeholder);color:var(--muted)}
.rte-small .rte-area{min-height:70px}

/* Tables */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--r);background:#fff}
table.table{width:100%;border-collapse:collapse;font-size:.9rem}
.table th{background:var(--soft);text-align:left;font-weight:600;color:var(--ink-2);padding:11px 14px;white-space:nowrap;font-size:.82rem;text-transform:uppercase;letter-spacing:.03em}
.table td{padding:12px 14px;border-top:1px solid var(--line);vertical-align:middle}
.table tr:hover td{background:#fafcff}
.table .actions{white-space:nowrap;text-align:right}
.table .actions > *{margin-left:6px}

/* Badges */
.badge{display:inline-block;padding:3px 10px;border-radius:999px;font-size:.75rem;font-weight:600;white-space:nowrap}
.badge-ok{background:var(--ok-bg);color:#166534}.badge-warn{background:var(--warn-bg);color:#92400e}.badge-bad{background:var(--bad-bg);color:#991b1b}
.badge-info{background:var(--info-bg);color:#1e40af}.badge-muted{background:var(--soft);color:var(--muted)}
.chip{display:inline-block;background:var(--soft);color:var(--ink-2);padding:4px 12px;border-radius:999px;font-size:.8rem;font-weight:500}

/* Pager */
.pager{display:flex;gap:6px;margin-top:18px;flex-wrap:wrap}
.pager a{min-width:36px;height:36px;display:grid;place-items:center;border-radius:10px;border:1px solid var(--line);background:#fff;color:var(--ink-2)}
.pager a.active{background:var(--primary);color:#fff;border-color:var(--primary)}

/* Empty */
.empty{text-align:center;padding:48px 20px;background:#fff;border:1px dashed var(--line);border-radius:var(--r-lg)}
.empty-ico{width:56px;height:56px;border-radius:16px;background:var(--soft);display:grid;place-items:center;margin:0 auto 12px;color:var(--muted)}
.big-404{font-size:5rem;font-weight:800;color:var(--primary);line-height:1}

/* Footer */
.site-footer{background:#0b1222;color:#e2e8f0;padding:56px 0 20px;margin-top:40px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:40px}
.site-footer h4{color:#fff;margin-bottom:12px}
.site-footer a{display:block;color:#cbd5e1;margin-bottom:8px;font-size:.92rem}
.muted-light{color:#94a3b8;font-size:.92rem}
.footer-bottom{border-top:1px solid #1e293b;margin-top:36px;padding-top:18px;color:#64748b;font-size:.85rem}

/* Detail pages */
.detail-grid{display:grid;grid-template-columns:1fr 360px;gap:32px;align-items:start}
.sticky{position:sticky;top:90px}
.prose{color:var(--ink-2)}
.prose h2,.prose h3{color:var(--ink);margin-top:1.4em}
.prose img{border-radius:var(--r)}
.prose blockquote{border-left:4px solid var(--accent);margin:0;padding:6px 16px;background:var(--soft);border-radius:0 10px 10px 0}
.prose table{border-collapse:collapse;width:100%}.prose td,.prose th{border:1px solid var(--line);padding:6px 10px}
.meta-list{list-style:none;padding:0;margin:0 0 18px}
.meta-list li{display:flex;justify-content:space-between;padding:9px 0;border-bottom:1px solid var(--line);font-size:.92rem}
.meta-list li span:first-child{color:var(--muted)}
.curr-sec{border:1px solid var(--line);border-radius:var(--r);margin-bottom:10px;overflow:hidden;background:#fff}
.curr-sec summary{padding:13px 16px;font-weight:600;cursor:pointer;background:var(--soft);list-style:none;display:flex;justify-content:space-between}
.curr-sec ul{list-style:none;margin:0;padding:0}
.curr-sec li{padding:10px 16px;border-top:1px solid var(--line);display:flex;gap:10px;align-items:center;font-size:.92rem}
.curr-sec li .grow{color:var(--ink-2)}

/* Dashboard */
.dash{background:var(--bg)}
.dash-shell{display:flex;min-height:100vh}
.dash-side{width:264px;flex:none;background:#fff;border-right:1px solid var(--line);padding:18px 14px;position:sticky;top:0;height:100vh;overflow-y:auto}
.dash-side .brand{padding:4px 8px 18px}
.side-group{font-size:.7rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);font-weight:700;padding:14px 12px 6px}
.side-nav a{display:flex;align-items:center;gap:10px;padding:9px 12px;border-radius:12px;color:var(--ink-2);font-weight:500;font-size:.92rem;margin-bottom:2px}
.side-nav a:hover{background:var(--soft);text-decoration:none}
.side-nav a.active{background:color-mix(in srgb,var(--primary) 10%,#fff);color:var(--primary);font-weight:600}
.dash-main{flex:1;min-width:0;display:flex;flex-direction:column}
.dash-top{display:flex;align-items:center;gap:16px;padding:14px 28px;background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}
.dash-title{font-size:1.25rem;margin:0}
.dash-top-actions{margin-left:auto;display:flex;align-items:center;gap:10px}
.dash-user{display:flex;align-items:center;gap:10px}
.avatar{width:38px;height:38px;border-radius:12px;background:var(--primary);color:#fff;display:grid;place-items:center;font-weight:700}
.dash-user-meta{display:flex;flex-direction:column;line-height:1.2}
.dash-user-meta small{color:var(--muted);font-size:.75rem}
.dash-content{padding:28px;max-width:1280px;width:100%}
.dash-toggle{display:none}
.side-backdrop{display:none}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px;margin-bottom:24px}
.stat{background:#fff;border:1px solid var(--line);border-radius:var(--r-lg);padding:18px 20px}
.stat span{color:var(--muted);font-size:.85rem;display:block}
.stat b{font-size:1.7rem;display:block;margin-top:4px;letter-spacing:-.02em}
.stat small{color:var(--muted)}
.toolbar{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-bottom:16px}
.toolbar form{display:flex;gap:8px;flex-wrap:wrap}
.toolbar input,.toolbar select{margin-top:0;width:auto;min-width:180px;padding:9px 12px}
.progress{height:8px;background:var(--soft);border-radius:999px;overflow:hidden}
.progress > i{display:block;height:100%;background:linear-gradient(90deg,var(--primary),color-mix(in srgb,var(--primary) 60%,var(--accent)));border-radius:999px}
.list-row{display:flex;gap:16px;align-items:center;padding:16px;border:1px solid var(--line);border-radius:var(--r);background:#fff;margin-bottom:10px}
.list-thumb{width:110px;aspect-ratio:16/9;border-radius:10px;background:var(--primary);flex:none;overflow:hidden;color:#fff;display:grid;place-items:center;font-weight:800}
.list-thumb img{width:100%;height:100%;object-fit:cover}
.tabs{display:flex;gap:4px;border-bottom:1px solid var(--line);margin-bottom:18px;flex-wrap:wrap}
.tabs a{padding:10px 16px;color:var(--muted);font-weight:600;border-bottom:2px solid transparent;margin-bottom:-1px}
.tabs a.active{color:var(--primary);border-color:var(--primary);text-decoration:none}

/* Question bank editor */
.qsec{background:#fff;border:1px solid var(--line);border-radius:var(--r-lg);margin-bottom:20px;overflow:hidden}
.qsec-head{display:flex;gap:12px;align-items:center;justify-content:space-between;padding:16px 20px;background:var(--soft);flex-wrap:wrap}
.qsec-body{padding:16px 20px}
.qgroup{border:1px dashed #cbd5e1;border-radius:var(--r);padding:12px 14px;margin:12px 0;background:#fcfdff}
.qitem{display:flex;gap:12px;padding:10px 0;border-top:1px solid var(--line);align-items:flex-start}
.qitem:first-child{border-top:0}
.qnum{flex:none;width:30px;height:30px;border-radius:9px;background:var(--soft);display:grid;place-items:center;font-weight:700;font-size:.85rem}
.qtext{flex:1;min-width:0;font-size:.92rem}
.qtext .opts{color:var(--muted);font-size:.85rem;margin-top:4px}
.qtext .opts b{color:var(--ok)}
.opt-row{display:grid;grid-template-columns:44px 1fr;gap:10px;align-items:center;margin-bottom:8px}
.opt-row .opt-key{display:flex;align-items:center;gap:4px;font-weight:700}
.opt-row input[type=text]{margin-top:0}

/* Course player */
.player{display:grid;grid-template-columns:320px 1fr;min-height:calc(100vh - 70px)}
.player-side{background:#fff;border-right:1px solid var(--line);overflow-y:auto;max-height:calc(100vh - 70px);position:sticky;top:70px}
.player-side .ps-head{padding:18px;border-bottom:1px solid var(--line)}
.player-side .curr-sec{border-radius:0;border-left:0;border-right:0;margin:0}
.player-side li a{color:var(--ink-2);display:flex;gap:10px;align-items:center;width:100%}
.player-side li.current{background:color-mix(in srgb,var(--primary) 8%,#fff)}
.player-side li.current a{color:var(--primary);font-weight:600}
.lesson-done{color:var(--ok)}
.player-main{padding:28px 36px;max-width:980px}
.video-frame{position:relative;aspect-ratio:16/9;border-radius:var(--r);overflow:hidden;background:#000}
.video-frame iframe,.video-frame video{position:absolute;inset:0;width:100%;height:100%;border:0}
.pdf-frame{width:100%;height:75vh;border:1px solid var(--line);border-radius:var(--r)}
.dot{width:20px;height:20px;border-radius:50%;border:2px solid var(--line);flex:none;display:grid;place-items:center;font-size:.7rem}
.dot.done{background:var(--ok);border-color:var(--ok);color:#fff}

/* Exam */
.exam-body{background:#eef2f7;min-height:100vh}
.exam-top{position:sticky;top:0;z-index:30;background:var(--primary);color:#fff;display:flex;align-items:center;gap:16px;padding:10px 20px}
.exam-top .ex-title{font-weight:700}
.exam-top .ex-sec{opacity:.85;font-size:.9rem}
.timer{margin-left:auto;background:rgba(255,255,255,.15);padding:7px 14px;border-radius:999px;font-weight:700;font-variant-numeric:tabular-nums;font-size:1.05rem}
.timer.low{background:var(--bad);animation:pulse 1s infinite}
@keyframes pulse{50%{opacity:.7}}
.exam-wrap{display:grid;grid-template-columns:1fr 280px;gap:20px;padding:20px;max-width:1400px;margin:0 auto}
.exam-stage{display:grid;grid-template-columns:1fr;gap:20px;min-width:0}
.exam-stage.split{grid-template-columns:1fr 1fr}
.ex-panel{background:#fff;border-radius:var(--r-lg);padding:24px;border:1px solid var(--line);min-width:0}
.ex-passage{max-height:calc(100vh - 150px);overflow:auto;font-size:.98rem;line-height:1.75}
.ex-q-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}
.ex-qnum{font-weight:800;color:var(--primary)}
.ex-prompt{font-size:1.03rem;margin-bottom:18px}
.ex-prompt u{text-decoration-thickness:2px}
.ex-opts{display:flex;flex-direction:column;gap:10px}
.ex-opt{display:flex;gap:12px;align-items:flex-start;padding:13px 16px;border:2px solid var(--line);border-radius:var(--r);cursor:pointer;transition:.12s;background:#fff}
.ex-opt:hover{border-color:color-mix(in srgb,var(--primary) 40%,#fff)}
.ex-opt.sel{border-color:var(--primary);background:color-mix(in srgb,var(--primary) 6%,#fff)}
.ex-opt input{display:none}
.ex-key{flex:none;width:30px;height:30px;border-radius:50%;border:2px solid var(--line);display:grid;place-items:center;font-weight:700;font-size:.85rem}
.ex-opt.sel .ex-key{background:var(--primary);border-color:var(--primary);color:#fff}
.ex-nav{display:flex;justify-content:space-between;gap:10px;margin-top:22px;flex-wrap:wrap}
.ex-side{display:flex;flex-direction:column;gap:16px}
.ex-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:6px}
.ex-grid button{aspect-ratio:1;border-radius:10px;border:1px solid var(--line);background:#fff;font-weight:600;cursor:pointer;font-size:.82rem;position:relative}
.ex-grid button.ans{background:var(--primary);color:#fff;border-color:var(--primary)}
.ex-grid button.cur{outline:3px solid var(--accent);outline-offset:1px}
.ex-grid button.flag::after{content:"";position:absolute;top:3px;right:3px;width:7px;height:7px;border-radius:50%;background:var(--accent)}
.ex-legend{display:flex;gap:12px;flex-wrap:wrap;font-size:.75rem;color:var(--muted);margin-top:10px}
.ex-legend i{display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:4px;vertical-align:-1px}
.cam-box{position:relative;border-radius:var(--r);overflow:hidden;background:#0f172a;aspect-ratio:4/3}
.cam-box video{width:100%;height:100%;object-fit:cover;transform:scaleX(-1)}
.cam-box .cam-status{position:absolute;left:8px;bottom:8px;background:rgba(0,0,0,.6);color:#fff;font-size:.72rem;padding:3px 8px;border-radius:999px}
.audio-box{display:flex;align-items:center;gap:12px;background:var(--soft);border-radius:var(--r);padding:12px 14px;margin-bottom:16px}
.audio-box .play{width:44px;height:44px;border-radius:50%;border:0;background:var(--primary);color:#fff;cursor:pointer;flex:none;font-size:1rem}
.audio-box .play:disabled{background:#94a3b8;cursor:not-allowed}
.audio-box .bar{flex:1;height:6px;background:#cbd5e1;border-radius:999px;overflow:hidden}
.audio-box .bar i{display:block;height:100%;width:0;background:var(--primary)}
.audio-box small{color:var(--muted)}
.rec-box{border:2px dashed var(--line);border-radius:var(--r);padding:18px;text-align:center}
.rec-dot{display:inline-block;width:12px;height:12px;border-radius:50%;background:var(--bad);margin-right:6px;animation:pulse 1s infinite}
.essay-area{min-height:280px;font-size:1rem;line-height:1.7}
.word-count{font-size:.8rem;color:var(--muted);text-align:right;margin-top:4px}
.overlay{position:fixed;inset:0;background:rgba(15,23,42,.85);z-index:100;display:grid;place-items:center;padding:20px}
.overlay .card{max-width:480px;text-align:center}
.save-state{font-size:.78rem;opacity:.85}

/* Result */
.score-hero{text-align:center;padding:36px 20px;background:linear-gradient(135deg,var(--primary),color-mix(in srgb,var(--primary) 70%,#000));color:#fff;border-radius:var(--r-lg);margin-bottom:24px}
.score-hero .big{font-size:4rem;font-weight:800;line-height:1;margin:10px 0}
.score-hero .lvl{display:inline-block;background:var(--accent);color:#1f1300;font-weight:700;border-radius:999px;padding:4px 14px}
.sec-scores{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:14px}
.sec-score{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:16px;text-align:center}
.sec-score b{display:block;font-size:1.8rem;color:var(--primary)}
.review-q{border:1px solid var(--line);border-radius:var(--r);padding:14px 16px;margin-bottom:10px;background:#fff}
.review-q.right{border-left:4px solid var(--ok)}.review-q.wrong{border-left:4px solid var(--bad)}

/* Certificate */
.cert-page{background:#e5e7eb;padding:30px 10px;min-height:100vh}
.cert-toolbar{max-width:1100px;margin:0 auto 16px;display:flex;gap:10px;justify-content:space-between;flex-wrap:wrap}
.certificate{width:1100px;max-width:100%;aspect-ratio:1.414/1;margin:0 auto;background:#fff;position:relative;padding:56px 70px;box-shadow:var(--shadow-lg);overflow:hidden;font-family:var(--font)}
.certificate::before{content:"";position:absolute;inset:18px;border:2px solid var(--primary);border-radius:6px;pointer-events:none}
.certificate::after{content:"";position:absolute;inset:26px;border:1px solid color-mix(in srgb,var(--accent) 70%,#fff);border-radius:4px;pointer-events:none}
.cert-corner{position:absolute;width:260px;height:260px;border-radius:50%;background:color-mix(in srgb,var(--primary) 8%,#fff);right:-90px;top:-90px}
.cert-corner.b{left:-110px;bottom:-110px;right:auto;top:auto;background:color-mix(in srgb,var(--accent) 14%,#fff)}
.cert-inner{position:relative;z-index:1;height:100%;display:flex;flex-direction:column}
.cert-head{display:flex;justify-content:space-between;align-items:center}
.cert-title{text-align:center;margin-top:18px}
.cert-title h1{font-size:2.6rem;letter-spacing:.18em;color:var(--primary);margin:0;font-weight:800}
.cert-title p{letter-spacing:.3em;color:var(--muted);font-size:.85rem;margin:4px 0 0;text-transform:uppercase}
.cert-name{text-align:center;font-size:2.4rem;font-weight:700;margin:22px 0 6px;color:var(--ink);font-family:Georgia,'Times New Roman',serif;font-style:italic}
.cert-line{width:420px;max-width:80%;height:2px;background:var(--accent);margin:0 auto 14px}
.cert-desc{text-align:center;color:var(--ink-2);max-width:720px;margin:0 auto}
.cert-scores{display:flex;justify-content:center;gap:14px;margin:18px 0 0;flex-wrap:wrap}
.cert-scores div{border:1px solid var(--line);border-radius:12px;padding:8px 16px;text-align:center;min-width:120px}
.cert-scores small{display:block;color:var(--muted);font-size:.72rem;text-transform:uppercase;letter-spacing:.06em}
.cert-scores b{font-size:1.35rem;color:var(--primary)}
.cert-scores .total{background:var(--primary);border-color:var(--primary)}.cert-scores .total b,.cert-scores .total small{color:#fff}
.cert-foot{margin-top:auto;display:flex;justify-content:space-between;align-items:flex-end}
.cert-sign{text-align:center;min-width:220px}
.cert-sign img{max-height:70px}
.cert-sign .line{border-top:1px solid var(--ink);margin-top:6px;padding-top:6px;font-weight:600}
.cert-qr{display:flex;gap:12px;align-items:flex-end;font-size:.78rem;color:var(--muted)}
.cert-qr #qr img,.cert-qr #qr canvas{display:block}
.verify-box{max-width:560px;margin:0 auto}
.verify-result{border-radius:var(--r-lg);padding:24px;margin-top:20px}
.verify-result.ok{background:var(--ok-bg);border:1px solid #bbf7d0}
.verify-result.bad{background:var(--bad-bg);border:1px solid #fecaca}

@media print{
  @page{size:A4 landscape;margin:0}
  body{background:#fff!important}
  .no-print,.cert-toolbar,.site-header,.site-footer{display:none!important}
  .cert-page{padding:0;background:#fff}
  .certificate{box-shadow:none;width:100%;height:100vh;aspect-ratio:auto;-webkit-print-color-adjust:exact;print-color-adjust:exact}
}

/* Responsive */
@media (max-width:1024px){
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .detail-grid{grid-template-columns:1fr}
  .exam-wrap{grid-template-columns:1fr}
  .exam-stage.split{grid-template-columns:1fr}
  .ex-passage{max-height:none}
  .player{grid-template-columns:1fr}
  .player-side{position:static;max-height:none;border-right:0;border-bottom:1px solid var(--line)}
}
@media (max-width:860px){
  .hero-grid,.grid-3,.footer-grid{grid-template-columns:1fr}
  .grid-2{grid-template-columns:1fr}
  .nav-toggle{display:flex;margin-left:auto}
  .main-nav{display:none;position:absolute;top:70px;left:0;right:0;background:#fff;flex-direction:column;padding:12px 20px;border-bottom:1px solid var(--line);box-shadow:var(--shadow)}
  body.nav-open .main-nav{display:flex}
  .header-actions .btn-ghost{display:none}
  .dash-side{position:fixed;left:-280px;z-index:60;transition:.2s;height:100vh}
  body.side-open .dash-side{left:0}
  body.side-open .side-backdrop{display:block;position:fixed;inset:0;background:rgba(15,23,42,.4);z-index:55}
  .dash-toggle{display:flex}
  .dash-content{padding:18px}
  .dash-top{padding:12px 16px}
  .dash-user-meta{display:none}
  .player-main{padding:20px}
  .certificate{padding:28px 30px;aspect-ratio:auto}
  .cert-title h1{font-size:1.6rem}.cert-name{font-size:1.6rem}
}
@media (max-width:560px){
  .grid-4{grid-template-columns:1fr}
  .list-row{flex-direction:column;align-items:flex-start}
  .list-thumb{width:100%}
}
.site-footer a.brand{display:flex;margin-bottom:12px}