/* Test Series Platform - styles */
:root{
  --bg:#0b0f17; --bg2:#111722; --card:#151c2a; --card2:#1b2435;
  --line:#243049; --text:#e8edf6; --muted:#8a97ad; --muted2:#5d6a82;
  --primary:#f59e0b; --primary2:#d97706; --accent:#10b981;
  --blue:#3b82f6; --red:#ef4444; --green:#10b981; --warn:#f59e0b;
  --radius:14px; --radius-sm:9px;
  --shadow:0 8px 30px rgba(0,0,0,.35);
  --font:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{background:radial-gradient(1200px 600px at 80% -10%,#15213a00 0,transparent 60%),linear-gradient(180deg,#0b0f17,#0d121d 40%,#0b0f17);color:var(--text);font-family:var(--font);font-size:15px;line-height:1.55;min-height:100vh}
a{color:inherit;text-decoration:none}
img{max-width:100%}

.container{max-width:1180px;margin:0 auto;padding:0 20px}
.row{display:flex;gap:16px;flex-wrap:wrap}
.grid{display:grid;gap:18px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}
@media(max-width:900px){.grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}}
@media(max-width:640px){.grid-3,.grid-4,.grid-2{grid-template-columns:1fr}.row{flex-direction:column}}

/* Header */
header.site{position:sticky;top:0;z-index:50;background:rgba(11,15,23,.82);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.nav{display:flex;align-items:center;justify-content:space-between;height:62px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:18px;letter-spacing:-.2px}
.brand .logo{width:34px;height:34px;border-radius:9px;background:linear-gradient(135deg,var(--primary),var(--primary2));display:grid;place-items:center;color:#0b0f17;font-weight:900;font-size:16px}
.nav-links{display:flex;align-items:center;gap:6px}
.nav-links a{padding:8px 14px;border-radius:9px;color:var(--muted);font-weight:500;transition:.15s}
.nav-links a:hover{color:var(--text);background:var(--card)}
.nav-links a.active{color:var(--primary)}
.nav-links a.btn-sm{background:var(--primary);color:#0b0f17;font-weight:700}
.nav-links a.btn-sm:hover{background:var(--primary2);color:#0b0f17}
.burger{display:none;background:none;border:0;color:var(--text);font-size:24px;cursor:pointer}
@media(max-width:760px){
  .burger{display:block}
  .nav-links{position:absolute;top:62px;left:0;right:0;flex-direction:column;background:var(--bg2);border-bottom:1px solid var(--line);padding:10px;gap:4px;display:none}
  .nav-links.open{display:flex}
}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 18px;border-radius:10px;font-weight:600;border:1px solid transparent;cursor:pointer;transition:.15s;font-size:14px;font-family:inherit}
.btn-primary{background:linear-gradient(135deg,var(--primary),var(--primary2));color:#0b0f17}
.btn-primary:hover{filter:brightness(1.08);transform:translateY(-1px);box-shadow:0 8px 20px rgba(245,158,11,.3)}
.btn-outline{background:transparent;border-color:var(--line);color:var(--text)}
.btn-outline:hover{border-color:var(--primary);color:var(--primary)}
.btn-ghost{background:var(--card);color:var(--text)}
.btn-ghost:hover{background:var(--card2)}
.btn-danger{background:var(--red);color:#fff}
.btn-danger:hover{filter:brightness(1.1)}
.btn-sm{padding:7px 13px;font-size:13px}
.btn-block{width:100%}
.btn:disabled{opacity:.5;cursor:not-allowed}

/* Cards */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px}
.card.hover:hover{transform:translateY(-3px);border-color:#33415f;box-shadow:var(--shadow);transition:.18s}
.series-card{display:flex;flex-direction:column;overflow:hidden}
.series-card .cover{height:130px;background:linear-gradient(135deg,#1f2a44,#10182b);display:flex;align-items:center;justify-content:center;position:relative}
.series-card .cover .ic{font-size:38px;opacity:.4}
.series-card .body{padding:18px;display:flex;flex-direction:column;gap:10px;flex:1}
.series-card h3{margin:0;font-size:17px;letter-spacing:-.2px}
.badge{display:inline-flex;align-items:center;gap:5px;padding:3px 10px;border-radius:999px;font-size:11px;font-weight:700;letter-spacing:.4px;text-transform:uppercase}
.badge-free{background:rgba(16,185,129,.15);color:var(--green)}
.badge-paid{background:rgba(245,158,11,.15);color:var(--primary)}
.badge-blue{background:rgba(59,130,246,.15);color:var(--blue)}

/* Hero */
.hero{padding:54px 0 36px;text-align:center}
.hero h1{font-size:40px;line-height:1.1;margin:0 0 14px;font-weight:800;letter-spacing:-1px}
.hero h1 .grad{background:linear-gradient(135deg,var(--primary),#fbbf24);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p{color:var(--muted);font-size:17px;max-width:620px;margin:0 auto 22px}
.hero .cta{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}

.section-title{display:flex;align-items:center;justify-content:space-between;margin:28px 0 16px}
.section-title h2{font-size:22px;font-weight:700;margin:0;letter-spacing:-.3px}
.section-title a{color:var(--primary);font-size:14px;font-weight:600}

/* Forms */
.form-card{max-width:440px;margin:40px auto}
.form-card.wide{max-width:720px}
.form-group{margin-bottom:16px}
.form-group label{display:block;margin-bottom:6px;font-size:13px;font-weight:600;color:var(--muted)}
.form-control{width:100%;padding:11px 14px;background:var(--bg2);border:1px solid var(--line);border-radius:9px;color:var(--text);font-family:inherit;font-size:14px;transition:.15s}
.form-control:focus{outline:0;border-color:var(--primary);box-shadow:0 0 0 3px rgba(245,158,11,.15)}
textarea.form-control{min-height:90px;resize:vertical}
select.form-control{appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%238a97ad' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 14px center;padding-right:34px}
.hint{font-size:12px;color:var(--muted2);margin-top:5px}

/* Tables */
.table{width:100%;border-collapse:collapse}
.table th,.table td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--line);font-size:14px}
.table th{color:var(--muted);font-weight:600;font-size:12px;text-transform:uppercase;letter-spacing:.4px}
.table tr:hover td{background:rgba(255,255,255,.02)}

/* Flash */
.flash{padding:12px 16px;border-radius:10px;margin:14px 0;font-size:14px;font-weight:500}
.flash-success{background:rgba(16,185,129,.12);border:1px solid rgba(16,185,129,.3);color:#4ad6a3}
.flash-error{background:rgba(239,68,68,.12);border:1px solid rgba(239,68,68,.3);color:#f48a8a}

/* Tabs */
.tabs{display:flex;gap:4px;border-bottom:1px solid var(--line);margin-bottom:22px;overflow-x:auto}
.tabs a{padding:11px 16px;color:var(--muted);font-weight:600;border-bottom:2px solid transparent;white-space:nowrap}
.tabs a.active{color:var(--primary);border-color:var(--primary)}

/* Test taking */
.test-shell{display:grid;grid-template-columns:1fr 260px;gap:20px}
@media(max-width:900px){.test-shell{grid-template-columns:1fr}}
.question-box{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px}
.q-num{font-size:13px;color:var(--primary);font-weight:700;margin-bottom:8px}
.opt{display:flex;align-items:center;gap:12px;padding:13px 16px;border:1px solid var(--line);border-radius:10px;margin-bottom:9px;cursor:pointer;transition:.15s}
.opt:hover{border-color:var(--primary);background:var(--card2)}
.opt input{accent-color:var(--primary);width:17px;height:17px}
.opt.selected{border-color:var(--primary);background:rgba(245,158,11,.07)}
.pane{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;height:fit-content;position:sticky;top:80px}
.timer{font-size:26px;font-weight:800;color:var(--primary);text-align:center;font-variant-numeric:tabular-nums}
.pq-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:6px;margin:14px 0}
.pq{aspect-ratio:1;border-radius:7px;display:grid;place-items:center;font-size:13px;font-weight:700;background:var(--bg2);border:1px solid var(--line);cursor:pointer}
.pq.answered{background:var(--accent);color:#0b0f17;border-color:var(--accent)}
.pq.current{outline:2px solid var(--primary);outline-offset:1px}

/* Result */
.score-card{text-align:center;padding:30px}
.score-circle{width:130px;height:130px;border-radius:50%;display:grid;place-items:center;margin:0 auto 16px;font-size:34px;font-weight:800;background:conic-gradient(var(--primary) var(--p,0%),var(--line) 0);position:relative}
.score-circle span{position:absolute;width:104px;height:104px;border-radius:50%;background:var(--card);display:grid;place-items:center}
.review-q{background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:16px;margin-bottom:12px}
.review-q .correct{color:var(--green)}
.review-q .wrong{color:var(--red)}

/* Admin layout */
.admin-wrap{display:grid;grid-template-columns:220px 1fr;gap:0;min-height:calc(100vh - 62px)}
.admin-side{background:var(--bg2);border-right:1px solid var(--line);padding:18px 12px}
.admin-side a{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:9px;color:var(--muted);font-weight:500;margin-bottom:2px}
.admin-side a:hover,.admin-side a.active{background:var(--card);color:var(--text)}
.admin-side a.active{color:var(--primary)}
.admin-main{padding:26px}
@media(max-width:760px){.admin-wrap{grid-template-columns:1fr}.admin-side{display:none}}

.stat{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px}
.stat .n{font-size:30px;font-weight:800;letter-spacing:-1px}
.stat .l{color:var(--muted);font-size:13px;margin-top:4px}

footer.site{border-top:1px solid var(--line);padding:26px 0;color:var(--muted2);font-size:13px;text-align:center;margin-top:40px}

.empty{text-align:center;padding:50px 20px;color:var(--muted)}
.empty .ic{font-size:42px;opacity:.4;margin-bottom:10px}

.muted{color:var(--muted)}
.small{font-size:13px}
.right{text-align:right}
.center{text-align:center}
.mt{margin-top:18px}.mt2{margin-top:32px}
.mb{margin-bottom:18px}
.flex{display:flex;align-items:center;gap:10px}
.between{justify-content:space-between}
.wrap{flex-wrap:wrap}
.gap-sm{gap:6px}
.feature-list{list-style:none;padding:0;margin:0}
.feature-list li{padding:8px 0;border-bottom:1px dashed var(--line);display:flex;gap:10px;align-items:flex-start}
.feature-list li:last-child{border-bottom:0}
.feature-list .tick{color:var(--accent);font-weight:800}
.pill{padding:3px 10px;border-radius:999px;background:var(--bg2);border:1px solid var(--line);font-size:12px;color:var(--muted)}

details.acc{border:1px solid var(--line);border-radius:10px;margin-bottom:8px;background:var(--bg2)}
details.acc summary{padding:12px 16px;cursor:pointer;font-weight:600;list-style:none}
details.acc summary::-webkit-details-marker{display:none}
details.acc[open] summary{border-bottom:1px solid var(--line)}
details.acc .acc-body{padding:14px 16px}
.sol-correct{border-left:3px solid var(--green);padding-left:12px}
.sol-wrong{border-left:3px solid var(--red);padding-left:12px}