:root{
  --blue:#1d4ed8; --blue-dark:#1736a8; --blue-50:#eef3ff; --blue-100:#dde7ff;
  --ink:#0f1729; --muted:#5b6b86; --line:#e6ebf3; --bg:#f4f7fc;
  --card:#ffffff; --ok:#0f9d58; --warn:#e8a008; --bad:#e03e3e;
  --radius:14px; --shadow:0 1px 2px rgba(16,33,80,.04),0 8px 24px rgba(16,33,80,.06);
  --shadow-sm:0 1px 3px rgba(16,33,80,.07);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0; background:var(--bg); color:var(--ink);
  font-family:'Plus Jakarta Sans',system-ui,sans-serif;
  font-size:15px; line-height:1.6; -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4,h5,.brand{font-family:'Lexend','Plus Jakarta Sans',sans-serif;font-weight:600;letter-spacing:-.01em}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
.container-narrow{max-width:1180px;margin:0 auto;padding:0 18px}

/* ---------- Navbar ---------- */
.topbar{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
.topbar .inner{display:flex;align-items:center;gap:22px;height:62px}
.brand{display:flex;align-items:center;gap:10px;font-size:20px;color:var(--ink);font-weight:700}
.brand:hover{text-decoration:none}
.brand .logo{width:34px;height:34px;border-radius:9px;background:linear-gradient(135deg,var(--blue),#3b82f6);
  color:#fff;display:grid;place-items:center;font-weight:800;font-family:'Lexend';font-size:17px}
.brand .sub{font-size:11px;color:var(--muted);font-weight:500;font-family:'Plus Jakarta Sans'}
.nav-links{display:flex;gap:6px;margin-left:auto;align-items:center}
.nav-links a{color:var(--muted);padding:8px 13px;border-radius:9px;font-weight:500;font-size:14px}
.nav-links a:hover{background:var(--blue-50);color:var(--blue);text-decoration:none}
.nav-links a.active{color:var(--blue);background:var(--blue-50)}

/* ---------- Buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:7px;border:1px solid transparent;border-radius:10px;
  padding:9px 17px;font-weight:600;font-size:14px;cursor:pointer;transition:.15s;font-family:inherit}
.btn:hover{text-decoration:none;transform:translateY(-1px)}
.btn-primary{background:var(--blue);color:#fff}
.btn-primary:hover{background:var(--blue-dark);color:#fff}
.btn-light{background:#fff;border-color:var(--line);color:var(--ink)}
.btn-light:hover{border-color:var(--blue);color:var(--blue)}
.btn-ghost{background:var(--blue-50);color:var(--blue)}
.btn-danger{background:var(--bad);color:#fff}
.btn-success{background:var(--ok);color:#fff}
.btn-sm{padding:6px 12px;font-size:13px;border-radius:8px}
.btn-block{width:100%;justify-content:center}

/* ---------- Cards / layout ---------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-sm)}
.card-pad{padding:22px}
.grid{display:grid;gap:18px}
.dash-layout{display:grid;grid-template-columns:240px 1fr;gap:24px;align-items:start;padding:24px 0}
.sidebar{position:sticky;top:86px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:10px;box-shadow:var(--shadow-sm)}
.sidebar a{display:flex;align-items:center;gap:11px;padding:10px 13px;border-radius:9px;color:var(--muted);font-weight:500;font-size:14px;margin-bottom:2px}
.sidebar a:hover{background:var(--blue-50);color:var(--blue);text-decoration:none}
.sidebar a.active{background:var(--blue);color:#fff}
.sidebar .group{font-size:11px;text-transform:uppercase;letter-spacing:.06em;color:#9aa7bd;padding:12px 13px 6px;font-weight:700}

/* ---------- Stat cards ---------- */
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:16px}
.stat{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;box-shadow:var(--shadow-sm)}
.stat .label{color:var(--muted);font-size:13px;font-weight:500}
.stat .value{font-family:'Lexend';font-size:28px;font-weight:700;margin-top:4px}
.stat .ic{width:40px;height:40px;border-radius:11px;background:var(--blue-50);color:var(--blue);
  display:grid;place-items:center;float:right;font-size:18px}

/* ---------- Tables ---------- */
table.tbl{width:100%;border-collapse:collapse;font-size:14px}
table.tbl th{text-align:left;color:var(--muted);font-weight:600;font-size:12.5px;text-transform:uppercase;
  letter-spacing:.04em;padding:11px 12px;border-bottom:2px solid var(--line)}
table.tbl td{padding:12px;border-bottom:1px solid var(--line)}
table.tbl tr:hover td{background:#fafbfe}

/* ---------- Forms ---------- */
label{font-weight:600;font-size:13.5px;display:block;margin-bottom:6px;color:#33415c}
.input,select,textarea{width:100%;padding:10px 13px;border:1px solid var(--line);border-radius:10px;
  font-size:14px;font-family:inherit;background:#fff;color:var(--ink);transition:.15s}
.input:focus,select:focus,textarea:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px var(--blue-100)}
.field{margin-bottom:16px}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:14px}

/* ---------- Badges / pills ---------- */
.badge{display:inline-block;padding:3px 10px;border-radius:999px;font-size:12px;font-weight:600}
.badge.blue{background:var(--blue-50);color:var(--blue)}
.badge.green{background:#e6f6ee;color:var(--ok)}
.badge.red{background:#fdeaea;color:var(--bad)}
.badge.gray{background:#eef1f6;color:var(--muted)}
.badge.amber{background:#fdf3df;color:#a76d00}

/* ---------- Flash ---------- */
.flash{padding:12px 16px;border-radius:11px;margin-bottom:12px;font-weight:500;font-size:14px;display:flex;gap:9px;align-items:center}
.flash.success{background:#e6f6ee;color:#0b7a43}
.flash.danger{background:#fdeaea;color:#b91c1c}
.flash.warning{background:#fdf3df;color:#92600a}
.flash.info{background:var(--blue-50);color:var(--blue-dark)}

/* ---------- Auth ---------- */
.auth-wrap{min-height:calc(100vh - 62px);display:grid;place-items:center;padding:30px 16px}
.auth-card{width:100%;max-width:430px;background:#fff;border:1px solid var(--line);border-radius:18px;padding:34px;box-shadow:var(--shadow)}

/* ---------- Landing ---------- */
.hero{background:radial-gradient(1200px 500px at 80% -10%,#dbe7ff 0%,transparent 60%),
  linear-gradient(180deg,#fff,#f4f7fc);padding:70px 0 50px;border-bottom:1px solid var(--line)}
.hero h1{font-size:46px;line-height:1.08;margin:0 0 16px}
.hero h1 span{color:var(--blue)}
.hero p{font-size:18px;color:var(--muted);max-width:560px}
.hero-stats{display:flex;gap:40px;margin-top:34px}
.hero-stats .n{font-family:'Lexend';font-size:30px;font-weight:700;color:var(--blue)}
.hero-stats .l{font-size:13px;color:var(--muted)}
.section{padding:56px 0}
.section h2{font-size:30px;text-align:center;margin-bottom:8px}
.section .lead{text-align:center;color:var(--muted);margin-bottom:36px}
.plan-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:22px;max-width:760px;margin:0 auto}
.plan{background:#fff;border:1.5px solid var(--line);border-radius:18px;padding:30px;position:relative;transition:.18s}
.plan:hover{border-color:var(--blue);transform:translateY(-4px);box-shadow:var(--shadow)}
.plan.featured{border-color:var(--blue);box-shadow:var(--shadow)}
.plan .price{font-family:'Lexend';font-size:42px;font-weight:700;margin:8px 0}
.plan .price small{font-size:15px;color:var(--muted);font-weight:500}
.plan ul{list-style:none;padding:0;margin:18px 0}
.plan li{padding:7px 0 7px 26px;position:relative;color:#33415c;font-size:14px}
.plan li:before{content:"✓";position:absolute;left:0;color:var(--ok);font-weight:800}
.ribbon{position:absolute;top:18px;right:18px;background:var(--blue);color:#fff;font-size:11px;
  font-weight:700;padding:4px 11px;border-radius:999px;text-transform:uppercase}

/* ---------- Test taking ---------- */
.exam-top{position:sticky;top:0;z-index:40;background:#fff;border-bottom:1px solid var(--line);
  display:flex;align-items:center;gap:16px;padding:12px 20px}
.timer{font-family:'Lexend';font-weight:700;font-size:18px;background:var(--blue-50);color:var(--blue);
  padding:7px 14px;border-radius:10px}
.timer.danger{background:#fdeaea;color:var(--bad)}
.exam-grid{display:grid;grid-template-columns:1fr 260px;gap:20px;padding:20px;max-width:1200px;margin:0 auto}
.opt{display:flex;gap:12px;align-items:flex-start;padding:14px 16px;border:1.5px solid var(--line);
  border-radius:12px;margin-bottom:11px;cursor:pointer;transition:.12s}
.opt:hover{border-color:var(--blue);background:var(--blue-50)}
.opt.selected{border-color:var(--blue);background:var(--blue-50)}
.opt .key{width:26px;height:26px;border-radius:50%;border:1.5px solid var(--line);display:grid;place-items:center;
  font-weight:700;font-size:13px;flex-shrink:0}
.opt.selected .key{background:var(--blue);color:#fff;border-color:var(--blue)}
.opt.correct{border-color:var(--ok);background:#e6f6ee}
.opt.correct .key{background:var(--ok);color:#fff;border-color:var(--ok)}
.opt.wrong{border-color:var(--bad);background:#fdeaea}
.opt.wrong .key{background:var(--bad);color:#fff;border-color:var(--bad)}
.palette{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}
.palette button{aspect-ratio:1;border:1px solid var(--line);background:#fff;border-radius:8px;font-weight:600;
  cursor:pointer;font-size:13px;color:var(--ink)}
.palette button.answered{background:var(--ok);color:#fff;border-color:var(--ok)}
.palette button.review{background:var(--warn);color:#fff;border-color:var(--warn)}
.palette button.current{outline:2px solid var(--blue);outline-offset:1px}

.muted{color:var(--muted)}
.text-center{text-align:center}
.flex{display:flex;align-items:center;gap:10px}
.between{justify-content:space-between}
.mt{margin-top:18px}.mb{margin-bottom:18px}
hr{border:none;border-top:1px solid var(--line);margin:18px 0}
footer.site{background:#0f1729;color:#c7d2e4;padding:30px 0;margin-top:50px;font-size:14px}
footer.site a{color:#9fc0ff}

@media(max-width:860px){
  .dash-layout{grid-template-columns:1fr}
  .sidebar{position:static;display:flex;flex-wrap:wrap;gap:4px}
  .sidebar .group{width:100%}
  .exam-grid{grid-template-columns:1fr}
  .hero h1{font-size:34px}
  .nav-links{gap:2px}
  .nav-links a{padding:7px 9px;font-size:13px}
}