:root{
  --blue-900:#0b2a5b; --blue-800:#123a7a; --blue-700:#1a4fa0; --blue-600:#2166cc;
  --blue-500:#2f7de1; --blue-100:#dbe9fb; --blue-50:#eef5fe;
  --white:#ffffff; --ink:#12233f; --muted:#5b6b85; --line:#dbe4f0;
  --ok:#12805c; --ok-bg:#e3f6ef; --err:#c0392b; --err-bg:#fdecea;
  --radius:14px; --shadow:0 10px 30px rgba(11,42,91,.10);
}
*{box-sizing:border-box}
body{margin:0;font-family:"Segoe UI",system-ui,-apple-system,Roboto,Arial,sans-serif;background:var(--blue-50);color:var(--ink);min-height:100vh}
a{color:var(--blue-600);text-decoration:none}
a:hover{text-decoration:underline}

/* ---------- AUTH ---------- */
.auth-body{display:flex;align-items:center;justify-content:center;padding:24px;
  background:linear-gradient(160deg,var(--blue-900) 0%,var(--blue-700) 55%,var(--blue-500) 100%)}
.auth-card{background:var(--white);border-radius:20px;box-shadow:0 25px 60px rgba(0,20,60,.35);
  padding:36px 34px;width:100%;max-width:420px;animation:rise .5s ease}
@keyframes rise{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:none}}
.brand{display:flex;align-items:center;gap:12px;font-size:26px;font-weight:800;color:var(--blue-800);margin-bottom:22px}
.brand small{font-size:13px;font-weight:600;color:var(--muted)}
.brand-badge{background:linear-gradient(135deg,var(--blue-700),var(--blue-500));color:#fff;width:44px;height:44px;
  border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:24px;box-shadow:0 6px 14px rgba(33,102,204,.4)}
.form label{display:block;font-size:13px;font-weight:600;color:var(--muted);margin:12px 0 4px}
.form input{width:100%;padding:12px 14px;border:1.5px solid var(--line);border-radius:10px;font-size:15px;transition:.2s;background:#fbfdff}
.form input:focus{outline:none;border-color:var(--blue-500);box-shadow:0 0 0 3px var(--blue-100)}
.form h3{margin:18px 0 4px;color:var(--blue-800);font-size:16px;border-bottom:2px solid var(--blue-100);padding-bottom:6px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 22px;border-radius:10px;border:none;
  font-size:15px;font-weight:700;cursor:pointer;transition:.2s;text-decoration:none}
.btn.primary{background:linear-gradient(135deg,var(--blue-700),var(--blue-500));color:#fff;box-shadow:0 6px 16px rgba(33,102,204,.35)}
.btn.primary:hover{transform:translateY(-2px);box-shadow:0 10px 22px rgba(33,102,204,.45)}
.btn.ghost{background:var(--blue-100);color:var(--blue-800)}
.btn.danger{background:var(--err-bg);color:var(--err)}
.btn.block{width:100%;margin-top:16px}
.alert{padding:12px 16px;border-radius:10px;margin:12px 0;font-size:14px;font-weight:600}
.alert.ok{background:var(--ok-bg);color:var(--ok)}
.alert.err{background:var(--err-bg);color:var(--err)}
.auth-links{text-align:center;margin-top:18px;font-size:14px;color:var(--muted)}

/* ---------- LAYOUT ---------- */
.topbar{background:linear-gradient(90deg,var(--blue-900),var(--blue-700));color:#fff;position:sticky;top:0;z-index:50;box-shadow:0 4px 16px rgba(11,42,91,.3)}
.topbar-inner{max-width:1180px;margin:auto;display:flex;align-items:center;gap:18px;padding:12px 20px}
.topbar .brand{margin:0;font-size:20px;color:#fff}
.topbar .brand-badge{width:36px;height:36px;font-size:19px;background:rgba(255,255,255,.18)}
.nav{display:flex;gap:4px;flex:1;flex-wrap:wrap}
.nav a{color:#cfe1fa;padding:8px 13px;border-radius:8px;font-weight:600;font-size:14px}
.nav a:hover,.nav a.active{background:rgba(255,255,255,.16);color:#fff;text-decoration:none}
.user-chip{display:flex;align-items:center;gap:10px;font-size:14px;font-weight:600}
.user-chip .avatar{width:34px;height:34px;border-radius:50%;background:rgba(255,255,255,.2);display:flex;align-items:center;justify-content:center;font-weight:800}
.hamburger{display:none;background:none;border:none;color:#fff;font-size:24px;cursor:pointer}
.container{max-width:1180px;margin:26px auto;padding:0 20px}

.hero{background:linear-gradient(120deg,var(--blue-800),var(--blue-500));border-radius:20px;color:#fff;
  padding:34px 32px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:18px;box-shadow:var(--shadow)}
.hero h1{margin:0 0 8px;font-size:28px}
.hero p{margin:0;opacity:.9}
.grid{display:grid;gap:20px;margin-top:22px}
.grid.cols-4{grid-template-columns:repeat(4,1fr)}
.grid.cols-3{grid-template-columns:repeat(3,1fr)}
.grid.cols-2{grid-template-columns:repeat(2,1fr)}
.card{background:var(--white);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px;border:1px solid var(--line)}
.stat-num{font-size:32px;font-weight:800;color:var(--blue-700)}
.stat-label{color:var(--muted);font-size:13px;font-weight:600}
.subject-card{text-align:center;transition:.25s;cursor:pointer;display:block;color:var(--ink)}
.subject-card:hover{transform:translateY(-5px);box-shadow:0 16px 34px rgba(11,42,91,.16);text-decoration:none}
.subject-card .ico{font-size:38px}
.subject-card h4{margin:10px 0 4px;color:var(--blue-800)}
.subject-card small{color:var(--muted)}
.progress{height:8px;background:var(--blue-100);border-radius:99px;overflow:hidden;margin-top:12px}
.progress i{display:block;height:100%;background:linear-gradient(90deg,var(--blue-600),var(--blue-500));border-radius:99px}

table{width:100%;border-collapse:collapse;font-size:14px}
th{background:var(--blue-800);color:#fff;padding:11px 12px;text-align:left}
th:first-child{border-radius:10px 0 0 0}th:last-child{border-radius:0 10px 0 0}
td{padding:11px 12px;border-bottom:1px solid var(--line)}
tr:hover td{background:var(--blue-50)}
.pill{display:inline-block;padding:4px 12px;border-radius:99px;font-size:12px;font-weight:700}
.pill.ok{background:var(--ok-bg);color:var(--ok)}
.pill.err{background:var(--err-bg);color:var(--err)}

/* ---------- EXAM ---------- */
.exam-shell{display:grid;grid-template-columns:1fr 300px;gap:22px;align-items:start}
.q-card .q-meta{display:flex;gap:10px;align-items:center;margin-bottom:14px;flex-wrap:wrap}
.q-num{background:var(--blue-700);color:#fff;padding:5px 14px;border-radius:99px;font-weight:700;font-size:13px}
.q-year{background:var(--blue-100);color:var(--blue-800);padding:5px 14px;border-radius:99px;font-weight:700;font-size:13px}
.q-text{font-size:18px;line-height:1.65;font-weight:600;margin-bottom:20px}
.opts{display:grid;gap:10px}
.opt{display:flex;gap:12px;align-items:flex-start;padding:14px 16px;border:1.5px solid var(--line);border-radius:12px;cursor:pointer;transition:.15s;background:#fbfdff}
.opt:hover{border-color:var(--blue-500);background:var(--blue-50)}
.opt.sel{border-color:var(--blue-600);background:var(--blue-100);box-shadow:0 0 0 3px var(--blue-100)}
.opt .letter{font-weight:800;color:var(--blue-700);min-width:22px}
.opt.correct{border-color:var(--ok);background:var(--ok-bg)}
.opt.wrong{border-color:var(--err);background:var(--err-bg)}
.solution{margin-top:18px;background:var(--blue-50);border-left:4px solid var(--blue-600);border-radius:8px;padding:14px 16px;font-size:14.5px;line-height:1.6}
.exam-side .timer{font-size:30px;font-weight:800;color:var(--blue-800);text-align:center}
.palette{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;margin-top:16px}
.palette button{aspect-ratio:1;border-radius:8px;border:1.5px solid var(--line);background:#fff;font-weight:700;cursor:pointer;font-size:13px}
.palette button.answered{background:var(--blue-600);color:#fff;border-color:var(--blue-600)}
.palette button.current{outline:3px solid var(--blue-300,#9cc2f2)}
.exam-actions{display:flex;gap:10px;margin-top:18px;flex-wrap:wrap}

.result-ring{width:170px;height:170px;border-radius:50%;margin:auto;display:flex;flex-direction:column;align-items:center;justify-content:center;
  background:conic-gradient(var(--blue-600) var(--p,0%), var(--blue-100) 0)}
.result-ring>div{background:#fff;width:130px;height:130px;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center}
.result-ring b{font-size:34px;color:var(--blue-800)}
.result-ring span{font-size:12px;color:var(--muted);font-weight:700}

@media(max-width:900px){
  .grid.cols-4{grid-template-columns:repeat(2,1fr)}
  .grid.cols-3{grid-template-columns:repeat(2,1fr)}
  .exam-shell{grid-template-columns:1fr}
  .exam-side{order:-1}
}
@media(max-width:640px){
  .nav{display:none;position:absolute;top:100%;left:0;right:0;background:var(--blue-900);flex-direction:column;padding:10px}
  .nav.open{display:flex}
  .hamburger{display:block;margin-left:auto}
  .user-chip .uname{display:none}
  .grid.cols-2,.grid.cols-3,.grid.cols-4{grid-template-columns:1fr}
  .hero h1{font-size:22px}
  .auth-card{padding:26px 20px}
  .q-text{font-size:16px}
  .palette{grid-template-columns:repeat(8,1fr)}
  .container{margin:16px auto}
  table{font-size:12.5px}
  .topbar-inner{padding:10px 14px}
}