:root {
  --navy: #0b2e59; --navy-2: #273171; --ink: #0f172a; --muted: #475569; --line: #e2e8f0;
  --bg: #f8fafc; --card: #fff; --accent: #e67e22; --accent-ink: #fff; --sky: #0284c7;
  --ok: #15803d; --ok-bg: #dcfce7; --bad: #b91c1c; --bad-bg: #fee2e2; --sel: #e0f2fe;
  --radius: 14px; --shadow: 0 1px 2px rgba(15, 23, 42, .06), 0 4px 16px rgba(15, 23, 42, .06);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; font: 16px/1.55 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; color: var(--ink); background: var(--bg); }
a { color: var(--navy-2); }
button { font: inherit; cursor: pointer; }
.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }

.top { background: #fff; border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 5; }
.top-in { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 64px; }
.logo img { height: 44px; width: auto; max-width: 58vw; display: block; object-fit: contain; }
.top-nav { display: flex; align-items: center; gap: 18px; font-weight: 600; font-size: 15px; }
.top-nav a { text-decoration: none; color: var(--navy); }
.btn-sm { background: var(--accent); color: #fff !important; padding: 8px 14px; border-radius: 999px; }
@media (max-width: 640px) { .top-nav a:not(.btn-sm) { display: none; } .logo img { height: 36px; } }

main { padding: 24px 16px 48px; min-height: 60vh; }
.loading { color: var(--muted); }
.hero { background: linear-gradient(135deg, var(--navy), var(--navy-2)); color: #fff; border-radius: var(--radius); padding: 28px 24px; margin-bottom: 24px; }
.hero h1 { margin: 0 0 6px; font-size: clamp(24px, 4vw, 34px); line-height: 1.2; }
.hero p { margin: 0; opacity: .9; max-width: 640px; }
.hero .stats { display: flex; flex-wrap: wrap; gap: 8px 22px; margin-top: 16px; font-size: 14px; }
.hero .stats b { font-size: 20px; display: block; color: #facc15; }

h2 { font-size: 20px; margin: 28px 0 12px; color: var(--navy); }
.crumbs { font-size: 14px; color: var(--muted); margin-bottom: 12px; display: flex; flex-wrap: wrap; gap: 6px; }
.crumbs a { color: var(--muted); }
.grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); text-decoration: none; color: inherit; display: block; }
a.card:hover, a.card:focus-visible { border-color: var(--navy-2); }
.card h3 { margin: 0 0 4px; font-size: 17px; color: var(--navy); }
.card p { margin: 0; color: var(--muted); font-size: 14px; }
.card .meta { margin-top: 10px; font-size: 13px; color: var(--muted); display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.tag { display: inline-block; font-size: 12px; font-weight: 600; padding: 2px 8px; border-radius: 999px; background: #eef2ff; color: var(--navy-2); }
.tag.el { background: #fff7ed; color: #9a3412; }
.tag.gen { background: #f1f5f9; color: #334155; }
.tag.done { background: var(--ok-bg); color: var(--ok); }
.prog-head { display: flex; gap: 14px; align-items: center; }
.prog-badge { width: 52px; height: 52px; border-radius: 12px; background: var(--navy); color: #fff; display: grid; place-items: center; font-weight: 700; flex: none; }

.subject-head { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); margin-bottom: 16px; }
.subject-head h1 { margin: 2px 0 8px; font-size: clamp(20px, 3.4vw, 28px); color: var(--navy); line-height: 1.25; }
.subject-head .code { font-size: 13px; color: var(--muted); letter-spacing: .04em; }
.units { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.unit { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; display: flex; align-items: center; gap: 14px; }
.unit .n { width: 38px; height: 38px; flex: none; border-radius: 10px; background: #eef2ff; color: var(--navy-2); display: grid; place-items: center; font-weight: 700; font-size: 14px; }
.unit .t { flex: 1; min-width: 0; }
.unit .t b { display: block; font-weight: 600; }
.unit .t span { font-size: 13px; color: var(--muted); }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; min-height: 44px; padding: 10px 18px; border-radius: 10px; border: 1px solid transparent; font-weight: 600; text-decoration: none; }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-navy { background: var(--navy); color: #fff; }
.btn-ghost { background: #fff; border-color: var(--line); color: var(--navy); }
.btn:disabled { opacity: .45; cursor: default; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
@media (max-width: 560px) { .unit { flex-wrap: wrap; } .unit .btn { width: 100%; } }

/* Test */
.test { max-width: 720px; margin: 0 auto; }
.test-top { display: flex; justify-content: space-between; align-items: center; gap: 10px; font-size: 14px; color: var(--muted); margin-bottom: 8px; }
.bar { height: 6px; background: var(--line); border-radius: 99px; overflow: hidden; margin-bottom: 18px; }
.bar i { display: block; height: 100%; background: var(--accent); transition: width .2s; }
.qcard { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow); }
.qcard h2 { margin: 0 0 18px; font-size: 19px; color: var(--ink); line-height: 1.45; }
.opts { display: grid; gap: 10px; }
.opt { text-align: left; width: 100%; min-height: 52px; padding: 12px 14px; border: 1.5px solid var(--line); background: #fff; border-radius: 12px; display: flex; gap: 12px; align-items: center; font-size: 16px; color: var(--ink); }
.opt:hover { border-color: #94a3b8; }
.opt .k { width: 30px; height: 30px; flex: none; border-radius: 8px; background: #f1f5f9; display: grid; place-items: center; font-weight: 700; font-size: 14px; color: var(--muted); }
.opt.sel { border-color: var(--sky); background: var(--sel); }
.opt.sel .k { background: var(--sky); color: #fff; }
.test-nav { display: flex; justify-content: space-between; gap: 10px; margin-top: 16px; }
.dots { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 18px; justify-content: center; }
.dots button { width: 32px; height: 32px; border-radius: 8px; border: 1px solid var(--line); background: #fff; font-size: 13px; color: var(--muted); }
.dots button.ans { background: #eef2ff; color: var(--navy-2); border-color: #c7d2fe; }
.dots button.cur { outline: 2px solid var(--accent); outline-offset: 1px; }
.hint { text-align: center; font-size: 13px; color: var(--muted); margin-top: 10px; }
@media (max-width: 560px) { .hint { display: none; } }

/* Details form */
.form { max-width: 560px; margin: 0 auto; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); }
.form h1 { margin: 0 0 6px; font-size: 24px; color: var(--navy); }
.form p.sub { margin: 0 0 18px; color: var(--muted); }
.field { margin-bottom: 14px; }
.field label { display: block; font-weight: 600; font-size: 14px; margin-bottom: 6px; }
.field input, .field select { width: 100%; min-height: 48px; padding: 10px 12px; border: 1.5px solid var(--line); border-radius: 10px; font: inherit; font-size: 16px; background: #fff; color: var(--ink); }
.field input:focus, .field select:focus { outline: none; border-color: var(--sky); }
.check { display: flex; gap: 10px; align-items: flex-start; font-size: 14px; color: var(--muted); margin: 6px 0 16px; }
.check input { width: 20px; height: 20px; margin-top: 2px; flex: none; }
.err { color: var(--bad); font-size: 14px; margin: 0 0 12px; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form .btn { width: 100%; }

/* Results */
.score { background: linear-gradient(135deg, var(--navy), var(--navy-2)); color: #fff; border-radius: var(--radius); padding: 24px; display: flex; gap: 22px; align-items: center; flex-wrap: wrap; }
.ring { --p: 0; width: 120px; height: 120px; border-radius: 50%; flex: none; display: grid; place-items: center; background: conic-gradient(#facc15 calc(var(--p) * 1%), rgba(255,255,255,.18) 0); }
.ring span { width: 94px; height: 94px; border-radius: 50%; background: var(--navy); display: grid; place-items: center; font-size: 28px; font-weight: 800; }
.score h1 { margin: 0 0 4px; font-size: 24px; }
.score p { margin: 0; opacity: .9; }
.review { margin-top: 22px; display: grid; gap: 12px; }
.rv { background: var(--card); border: 1px solid var(--line); border-left: 4px solid var(--ok); border-radius: 12px; padding: 14px 16px; }
.rv.wrong { border-left-color: var(--bad); }
.rv.skip { border-left-color: #94a3b8; }
.rv h3 { margin: 0 0 8px; font-size: 16px; font-weight: 600; }
.rv .a { font-size: 14px; margin: 2px 0; }
.rv .a.ok { color: var(--ok); }
.rv .a.bad { color: var(--bad); }
.rv .why { font-size: 14px; color: var(--muted); margin-top: 6px; }
.filter { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 22px; }
.filter button { border: 1px solid var(--line); background: #fff; border-radius: 999px; padding: 6px 14px; font-size: 14px; color: var(--muted); }
.filter button.on { background: var(--navy); color: #fff; border-color: var(--navy); }
.cta { margin-top: 24px; background: #fff7ed; border: 1px solid #fed7aa; border-radius: var(--radius); padding: 18px 20px; }
.cta h3 { margin: 0 0 4px; color: #9a3412; }
.cta p { margin: 0 0 10px; color: #7c2d12; }

.about { padding-bottom: 40px; color: var(--ink); }
.about h2 { margin-top: 0; }
.about h3 { font-size: 17px; color: var(--navy); margin: 22px 0 8px; }
.about ul, .about ol { padding-left: 22px; }
.about li { margin: 4px 0; }
.about p { margin: 8px 0; }

.foot { border-top: 1px solid var(--line); background: #fff; color: var(--muted); font-size: 13px; padding: 18px 0; }
.foot p { margin: 4px 0; }