/* ExamPrep — design tokens */
:root {
  --bg: #f6f4ef;
  --bg-elev: #ffffff;
  --bg-sunk: #eeebe4;
  --fg: #1d1c1a;
  --fg-muted: #6b675f;
  --fg-faint: #9a958b;
  --line: #e2ded5;
  --line-strong: #c9c4b9;
  --accent: #C96442;
  --accent-fg: #ffffff;
  --accent-soft: #f6e4dc;
  --ok: #2e7d4f;
  --ok-soft: #dff0e5;
  --bad: #b3261e;
  --bad-soft: #f8dcd9;
  --warn: #9a6a00;
  --warn-soft: #f8ecc8;
  --info: #2b5fa8;
  --info-soft: #dde8f8;
  --pdf: #5b4fcf;
  --pdf-soft: #e6e3fa;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(0,0,0,.05), 0 6px 20px -10px rgba(0,0,0,.18);
  --font: "Inter", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { --bg:#15161a; --bg-elev:#1e2026; --bg-sunk:#101115; --fg:#ecebe7; --fg-muted:#a3a39c; --fg-faint:#6f6f69; --line:#2c2f37; --line-strong:#3d414b; --accent:#e07a56; --accent-soft:#3a251d; --ok:#5ec489; --ok-soft:#1b2f23; --bad:#f07b73; --bad-soft:#3a1f1d; --warn:#e1b84a; --warn-soft:#332a14; --info:#7faaf0; --info-soft:#1c2838; --pdf:#a79cf5; --pdf-soft:#272443; --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px -12px rgba(0,0,0,.7); color-scheme: dark; }
}
:root[data-theme="dark"] { --bg:#15161a; --bg-elev:#1e2026; --bg-sunk:#101115; --fg:#ecebe7; --fg-muted:#a3a39c; --fg-faint:#6f6f69; --line:#2c2f37; --line-strong:#3d414b; --accent:#e07a56; --accent-soft:#3a251d; --ok:#5ec489; --ok-soft:#1b2f23; --bad:#f07b73; --bad-soft:#3a1f1d; --warn:#e1b84a; --warn-soft:#332a14; --info:#7faaf0; --info-soft:#1c2838; --pdf:#a79cf5; --pdf-soft:#272443; --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px -12px rgba(0,0,0,.7); color-scheme: dark; }

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body { background: var(--bg); color: var(--fg); font: 15px/1.55 var(--font); -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
button, input, select, textarea { font: inherit; color: inherit; }
h1, h2, h3, h4 { margin: 0 0 .4em; line-height: 1.25; letter-spacing: -.01em; }
h1 { font-size: 1.6rem; font-weight: 700; }
h2 { font-size: 1.2rem; font-weight: 650; }
h3 { font-size: 1rem; font-weight: 650; }
p { margin: 0 0 .8em; }
code, .mono { font-family: var(--mono); font-size: .9em; }
[hidden] { display: none !important; }
.muted { color: var(--fg-muted); }
.faint { color: var(--fg-faint); }
.small { font-size: .86rem; }
.boot { padding: 40px; text-align: center; color: var(--fg-muted); }

/* layout */
.app { min-height: 100%; display: flex; flex-direction: column; }
.topbar { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 14px; padding: 10px 16px; background: color-mix(in srgb, var(--bg-elev) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: -.01em; color: var(--fg); }
.brand:hover { text-decoration: none; }
.brand .logo { width: 28px; height: 28px; border-radius: 8px; background: var(--accent); display: grid; place-items: center; color: #fff; }
.nav { display: flex; gap: 4px; margin-left: 8px; }
.nav a { padding: 6px 10px; border-radius: 8px; color: var(--fg-muted); font-weight: 500; }
.nav a.active, .nav a:hover { background: var(--bg-sunk); color: var(--fg); text-decoration: none; }
.spacer { flex: 1; }
.userchip { display: flex; align-items: center; gap: 8px; color: var(--fg-muted); font-size: .9rem; }
.main { flex: 1; width: 100%; max-width: 1180px; margin: 0 auto; padding: 24px 16px 60px; }
.main.wide { max-width: 1400px; }
.main.narrow { max-width: 520px; }

/* cards & buttons */
.card { background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; box-shadow: var(--shadow); }
.card + .card { margin-top: 16px; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 9px 14px; border-radius: 10px; border: 1px solid var(--line-strong); background: var(--bg-elev); color: var(--fg); font-weight: 550; cursor: pointer; transition: background .12s, transform .05s, border-color .12s; white-space: nowrap; }
.btn:hover { background: var(--bg-sunk); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-fg); }
.btn.primary:hover { filter: brightness(1.06); background: var(--accent); }
.btn.danger { color: var(--bad); border-color: color-mix(in srgb, var(--bad) 40%, var(--line-strong)); }
.btn.ghost { border-color: transparent; background: transparent; }
.btn.ghost:hover { background: var(--bg-sunk); }
.btn.sm { padding: 5px 10px; font-size: .86rem; border-radius: 8px; }
.btn.icon { padding: 7px; width: 36px; height: 36px; }
.btn-row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 14px; }
.field label { font-size: .86rem; font-weight: 600; color: var(--fg-muted); }
input[type=text], input[type=password], input[type=number], input[type=search], select, textarea { padding: 9px 12px; border-radius: 10px; border: 1px solid var(--line-strong); background: var(--bg-elev); width: 100%; outline: none; }
input:focus, select:focus, textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.check { display: flex; align-items: center; gap: 10px; padding: 6px 0; cursor: pointer; }
.check input { width: 18px; height: 18px; accent-color: var(--accent); }
.badge { display: inline-flex; align-items: center; gap: 5px; padding: 2px 9px; border-radius: 999px; font-size: .76rem; font-weight: 650; letter-spacing: .01em; background: var(--bg-sunk); color: var(--fg-muted); white-space: nowrap; }
.badge.ok { background: var(--ok-soft); color: var(--ok); }
.badge.bad { background: var(--bad-soft); color: var(--bad); }
.badge.warn { background: var(--warn-soft); color: var(--warn); }
.badge.info { background: var(--info-soft); color: var(--info); }
.badge.pdf { background: var(--pdf-soft); color: var(--pdf); }
.badge.accent { background: var(--accent-soft); color: var(--accent); }
.alert { padding: 12px 14px; border-radius: 10px; border: 1px solid; font-size: .92rem; margin-bottom: 14px; }
.alert.bad { background: var(--bad-soft); border-color: color-mix(in srgb, var(--bad) 30%, transparent); color: var(--bad); }
.alert.warn { background: var(--warn-soft); border-color: color-mix(in srgb, var(--warn) 30%, transparent); color: var(--warn); }
.alert.info { background: var(--info-soft); border-color: color-mix(in srgb, var(--info) 30%, transparent); color: var(--info); }
.alert.ok { background: var(--ok-soft); border-color: color-mix(in srgb, var(--ok) 30%, transparent); color: var(--ok); }
.toast { position: fixed; left: 50%; bottom: 28px; transform: translateX(-50%); background: var(--fg); color: var(--bg); padding: 10px 16px; border-radius: 10px; font-size: .9rem; z-index: 100; box-shadow: var(--shadow); max-width: 90vw; }
.grid { display: grid; gap: 16px; }
.grid.cols-2 { grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.stat { padding: 14px 16px; border-radius: var(--radius-sm); background: var(--bg-sunk); }
.stat .v { font-size: 1.6rem; font-weight: 700; letter-spacing: -.02em; line-height: 1.1; }
.stat .l { font-size: .8rem; color: var(--fg-muted); margin-top: 4px; }
table { width: 100%; border-collapse: collapse; font-size: .92rem; }
th, td { text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--line); vertical-align: middle; }
th { font-size: .78rem; text-transform: uppercase; letter-spacing: .05em; color: var(--fg-muted); font-weight: 650; }
tr:hover td { background: color-mix(in srgb, var(--bg-sunk) 50%, transparent); }
.bar { height: 8px; border-radius: 99px; background: var(--bg-sunk); overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--accent); border-radius: 99px; transition: width .4s; }
.bar.ok > i { background: var(--ok); }
.bar.bad > i { background: var(--bad); }

/* auth */
.auth-wrap { min-height: 100vh; display: grid; place-items: center; padding: 24px 16px; }
.auth-card { width: 100%; max-width: 400px; }
.auth-card .brand { justify-content: center; margin-bottom: 18px; font-size: 1.1rem; }

/* exam cards */
.exam-card { position: relative; overflow: hidden; display: flex; flex-direction: column; gap: 10px; }
.exam-card::before { content: ""; position: absolute; inset: 0 0 auto 0; height: 4px; background: var(--exam-accent, var(--accent)); }
.exam-card .code { font-family: var(--mono); font-size: .78rem; color: var(--fg-muted); }
.exam-card .meta { display: flex; gap: 14px; flex-wrap: wrap; color: var(--fg-muted); font-size: .86rem; }

/* study layout */
.study { display: grid; grid-template-columns: 300px 1fr; gap: 18px; align-items: start; }
.study > *, .two > * { min-width: 0; }
.sidebar { position: sticky; top: 70px; max-height: calc(100vh - 86px); display: flex; flex-direction: column; gap: 10px; }
.sidebar .card { padding: 12px; }
.qgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(38px, 1fr)); gap: 5px; overflow: auto; padding: 2px; max-height: 44vh; }
.qdot { aspect-ratio: 1; border-radius: 8px; border: 1px solid var(--line-strong); background: var(--bg-elev); font-size: .78rem; font-weight: 600; cursor: pointer; display: grid; place-items: center; position: relative; color: var(--fg-muted); }
.qdot:hover { border-color: var(--accent); }
.qdot.cur { outline: 2px solid var(--accent); outline-offset: 1px; color: var(--fg); }
.qdot.ok { background: var(--ok-soft); color: var(--ok); border-color: transparent; }
.qdot.bad { background: var(--bad-soft); color: var(--bad); border-color: transparent; }
.qdot.answered { background: var(--info-soft); color: var(--info); border-color: transparent; }
.qdot.flag::after { content: ""; position: absolute; top: 3px; right: 3px; width: 6px; height: 6px; border-radius: 50%; background: var(--warn); }
.qdot.bm::before { content: ""; position: absolute; bottom: 3px; right: 3px; width: 6px; height: 6px; border-radius: 2px; background: var(--accent); }
.filters { display: flex; flex-direction: column; gap: 6px; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { padding: 4px 10px; border-radius: 999px; border: 1px solid var(--line-strong); background: var(--bg-elev); font-size: .8rem; cursor: pointer; color: var(--fg-muted); }
.chip.on { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
.legend { display: flex; flex-wrap: wrap; gap: 10px; font-size: .76rem; color: var(--fg-muted); }
.legend i { display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 4px; vertical-align: -1px; }

/* question */
.qhead { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 10px; }
.qnum { font-family: var(--mono); font-size: .85rem; color: var(--fg-muted); }
.stem { font-size: 1.04rem; line-height: 1.6; margin: 6px 0 16px; }
.opts { display: flex; flex-direction: column; gap: 8px; }
.opt { display: grid; grid-template-columns: 34px 1fr auto; gap: 12px; align-items: start; padding: 12px 14px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg-elev); cursor: pointer; transition: border-color .12s, background .12s; }
.opt:hover { border-color: var(--line-strong); background: var(--bg-sunk); }
.opt .letter { width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center; font-weight: 700; background: var(--bg-sunk); color: var(--fg-muted); font-size: .9rem; }
.opt.sel { border-color: var(--accent); background: var(--accent-soft); }
.opt.sel .letter { background: var(--accent); color: var(--accent-fg); }
.opt.correct { border-color: var(--ok); background: var(--ok-soft); }
.opt.correct .letter { background: var(--ok); color: #fff; }
.opt.wrong { border-color: var(--bad); background: var(--bad-soft); }
.opt.wrong .letter { background: var(--bad); color: #fff; }
.opt.missed { border-color: var(--ok); border-style: dashed; }
.opt.locked { cursor: default; }
.opt .tags { display: flex; gap: 6px; align-items: center; }
.hs-table { width: 100%; border-collapse: separate; border-spacing: 0 8px; }
.hs-table td { border: none; padding: 10px 12px; background: var(--bg-elev); vertical-align: middle; }
.hs-table tr td:first-child { border-radius: 10px 0 0 10px; border: 1px solid var(--line); border-right: none; }
.hs-table tr td:last-child { border-radius: 0 10px 10px 0; border: 1px solid var(--line); border-left: none; white-space: nowrap; }
.hs-table tr.correct td { background: var(--ok-soft); }
.hs-table tr.wrong td { background: var(--bad-soft); }
.seg { display: inline-flex; flex-wrap: wrap; border: 1px solid var(--line-strong); border-radius: 8px; overflow: hidden; }
.seg button { padding: 6px 10px; border: none; background: var(--bg-elev); cursor: pointer; font-size: .86rem; border-right: 1px solid var(--line-strong); color: var(--fg-muted); }
.seg button:last-child { border-right: none; }
.seg button.on { background: var(--accent); color: var(--accent-fg); }
.seg button:disabled { cursor: default; }

/* explanations */
.explain { margin-top: 18px; display: grid; gap: 14px; }
.verdict { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; padding: 12px 14px; border-radius: 10px; font-weight: 600; }
.verdict.ok { background: var(--ok-soft); color: var(--ok); }
.verdict.bad { background: var(--bad-soft); color: var(--bad); }
.verdict.neutral { background: var(--bg-sunk); color: var(--fg); }
.panel { border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.panel > header { display: flex; align-items: center; gap: 10px; padding: 10px 14px; background: var(--bg-sunk); font-weight: 650; font-size: .92rem; }
.panel > .body { padding: 12px 14px; }
.panel.claude > header { background: var(--accent-soft); color: var(--accent); }
.panel.pdf > header { background: var(--pdf-soft); color: var(--pdf); }
.key { font-size: 1rem; line-height: 1.55; padding: 12px 14px; border-left: 3px solid var(--accent); background: var(--bg-sunk); border-radius: 0 8px 8px 0; margin-bottom: 10px; }
.optexp { display: grid; grid-template-columns: 30px 1fr; gap: 10px; padding: 8px 0; border-top: 1px dashed var(--line); font-size: .92rem; }
.optexp:first-child { border-top: none; }
.optexp .l { font-weight: 700; font-family: var(--mono); font-size: .85rem; }
.optexp .l.ok { color: var(--ok); } .optexp .l.bad { color: var(--bad); }
.diff { padding: 12px 14px; border-radius: 10px; background: var(--warn-soft); border: 1px solid color-mix(in srgb, var(--warn) 35%, transparent); }
.diff h4 { color: var(--warn); margin-bottom: 6px; }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.toolbar { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-bottom: 14px; }
.kbd { font-family: var(--mono); font-size: .75rem; padding: 1px 6px; border: 1px solid var(--line-strong); border-bottom-width: 2px; border-radius: 5px; color: var(--fg-muted); }

/* exam */
.exam-top { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-bottom: 14px; }
.timer { font-family: var(--mono); font-size: 1.05rem; font-weight: 600; padding: 6px 12px; border-radius: 8px; background: var(--bg-sunk); }
.timer.low { background: var(--bad-soft); color: var(--bad); }
.progress-line { height: 6px; background: var(--bg-sunk); border-radius: 99px; overflow: hidden; margin-bottom: 14px; }
.progress-line i { display: block; height: 100%; background: var(--accent); }
.result-hero { text-align: center; padding: 28px 16px; }
.score-ring { width: 150px; height: 150px; margin: 0 auto 14px; position: relative; }
.score-ring svg { transform: rotate(-90deg); }
.score-ring .num { position: absolute; inset: 0; display: grid; place-items: center; font-size: 2rem; font-weight: 700; letter-spacing: -.03em; }
.domain-row { display: grid; grid-template-columns: 1fr 120px 60px; gap: 12px; align-items: center; padding: 6px 0; font-size: .9rem; }
.review-list .item { display: grid; grid-template-columns: 44px 1fr auto; gap: 12px; padding: 10px 12px; border-top: 1px solid var(--line); cursor: pointer; align-items: center; }
.review-list .item:hover { background: var(--bg-sunk); }
.modal-bg { position: fixed; inset: 0; background: rgba(0,0,0,.45); display: grid; place-items: center; z-index: 50; padding: 16px; }
.modal { width: 100%; max-width: 520px; max-height: 90vh; overflow: auto; }

/* responsive */
@media (max-width: 900px) {
  .study, .study[style] { grid-template-columns: 1fr !important; }
  .hs-table tr td:last-child { white-space: normal; }
  .hs-table { border-spacing: 0 8px; }
  .hs-table tr { display: grid; }
  .hs-table tr td:first-child { border-radius: 10px 10px 0 0; border-right: 1px solid var(--line); border-bottom: none; }
  .hs-table tr td:last-child { border-radius: 0 0 10px 10px; border-left: 1px solid var(--line); border-top: none; padding-top: 0; }
  .topbar { padding: 8px 12px; gap: 8px; }
  .userchip { display: none; }
  .main { padding: 14px 12px 50px; }
  .grid.cols-3 { gap: 8px; }
  .stat { padding: 10px 12px; } .stat .v { font-size: 1.3rem; }
  .sidebar { position: static; max-height: none; }
  .qgrid { max-height: 160px; }
  .two { grid-template-columns: 1fr; }
  .nav { display: none; }
  .domain-row { grid-template-columns: 1fr 80px 50px; }
}
@media print { .topbar, .sidebar, .toolbar, .btn { display: none !important; } .main { max-width: none; } }