/* ===== Design tokens ===== */
:root {
  color-scheme: light;
  --bg: #f4f6fb;
  --bg-soft: #eef2f9;
  --card: #ffffff;
  --card-2: #f8fafc;
  --text: #0f172a;
  --text-2: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --line-strong: #cbd5e1;
  --primary: #2563eb;
  --primary-2: #0ea5e9;
  --primary-soft: #eff6ff;
  --success: #16a34a;
  --success-soft: #ecfdf5;
  --danger: #dc2626;
  --danger-soft: #fef2f2;
  --warning: #f59e0b;
  --warning-soft: #fffbeb;
  --violet: #7c3aed;
  --shadow: 0 18px 50px -24px rgba(15, 23, 42, .28);
  --shadow-sm: 0 8px 24px -16px rgba(15, 23, 42, .3);
  --radius: 22px;
  --radius-sm: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #080e1a;
  --bg-soft: #0d1626;
  --card: #111c30;
  --card-2: #16223a;
  --text: #e8eefc;
  --text-2: #c7d4ea;
  --muted: #93a4bf;
  --line: #22314b;
  --line-strong: #324565;
  --primary: #3b82f6;
  --primary-2: #22d3ee;
  --primary-soft: #14243f;
  --success: #34d399;
  --success-soft: #0d2b25;
  --danger: #f87171;
  --danger-soft: #311418;
  --warning: #fbbf24;
  --warning-soft: #302511;
  --violet: #a78bfa;
  --shadow: 0 24px 60px -28px rgba(0, 0, 0, .7);
  --shadow-sm: 0 10px 30px -18px rgba(0, 0, 0, .8);
}

/* ===== Base ===== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
  overflow-y: scroll;
  -webkit-tap-highlight-color: transparent;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(900px 500px at 8% -8%, rgba(37, 99, 235, .12), transparent 60%),
    radial-gradient(700px 450px at 100% 0%, rgba(6, 182, 212, .10), transparent 55%),
    radial-gradient(800px 600px at 50% 110%, rgba(124, 58, 237, .07), transparent 60%);
}
[data-theme="dark"] body::before {
  background:
    radial-gradient(900px 500px at 8% -8%, rgba(59, 130, 246, .18), transparent 60%),
    radial-gradient(700px 450px at 100% 0%, rgba(34, 211, 238, .10), transparent 55%),
    radial-gradient(800px 600px at 50% 110%, rgba(167, 139, 250, .09), transparent 60%);
}
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; border: 0; background: none; }
img { max-width: 100%; display: block; }
h1, h2, h3, h4, p { margin: 0; }
ul, ol { margin: 0; padding-left: 1.2em; }
::selection { background: rgba(37, 99, 235, .22); }
:focus-visible { outline: 3px solid rgba(37, 99, 235, .45); outline-offset: 2px; border-radius: 8px; }
.hidden { display: none !important; }
[hidden] { display: none !important; }

/* ===== Shell ===== */
.shell { width: min(1100px, 100%); margin: 0 auto; padding: 0 18px calc(104px + env(safe-area-inset-bottom)); }
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  padding: 10px 0;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(160%) blur(16px);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 65%, transparent);
}
.topbar-inner {
  width: min(1100px, 100%);
  margin: 0 auto;
  padding: 0 18px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.brand { display: flex; align-items: center; gap: 10px; min-width: 0; }
.brand img { width: 38px; height: 38px; border-radius: 11px; box-shadow: var(--shadow-sm); }
.brand-name { font-weight: 800; letter-spacing: -.02em; font-size: 16px; line-height: 1.1; white-space: nowrap; }
.brand-sub { font-size: 11px; color: var(--muted); font-weight: 600; letter-spacing: .04em; text-transform: uppercase; }
.top-actions { margin-left: auto; display: flex; align-items: center; gap: 8px; }
.streak-chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 7px 11px; border-radius: 999px;
  background: var(--warning-soft); color: #b45309;
  font-weight: 700; font-size: 13px; white-space: nowrap;
  border: 1px solid color-mix(in srgb, var(--warning) 25%, transparent);
}
[data-theme="dark"] .streak-chip { color: var(--warning); }
.icon-btn {
  width: 40px; height: 40px; border-radius: 12px;
  display: grid; place-items: center;
  color: var(--text-2); border: 1px solid var(--line);
  background: var(--card);
  transition: .18s ease;
}
.icon-btn:hover { border-color: var(--line-strong); transform: translateY(-1px); }
.icon-btn:active { transform: scale(.96); }
.icon {
  width: 20px;
  height: 20px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.icon-sm { width: 16px; height: 16px; }
.icon-lg { width: 26px; height: 26px; }

/* ===== Bottom nav ===== */
.bottom-nav {
  position: fixed;
  z-index: 45;
  left: 50%;
  bottom: calc(14px + env(safe-area-inset-bottom));
  transform: translateX(-50%);
  width: min(560px, calc(100% - 24px));
  display: flex;
  gap: 2px;
  padding: 7px;
  border-radius: 22px;
  border: 1px solid color-mix(in srgb, var(--line) 80%, transparent);
  background: color-mix(in srgb, var(--card) 88%, transparent);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  box-shadow: 0 20px 50px -18px rgba(2, 6, 23, .35);
}
.nav-item {
  flex: 1;
  display: flex; flex-direction: column; align-items: center; gap: 3px;
  padding: 8px 4px 7px;
  border-radius: 16px;
  color: var(--muted);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: .01em;
  transition: .18s ease;
}
.nav-item .icon { width: 21px; height: 21px; }
.nav-item:hover { color: var(--text-2); background: var(--card-2); }
.nav-item.active { color: var(--primary); background: var(--primary-soft); }
body.in-session .topbar, body.in-session .bottom-nav { display: none; }

/* ===== Common ===== */
.page-head { display: flex; align-items: flex-end; gap: 14px; margin: 26px 0 18px; flex-wrap: wrap; }
.page-title { font-size: clamp(25px, 4vw, 34px); line-height: 1.08; letter-spacing: -.035em; font-weight: 850; }
.page-sub { color: var(--muted); font-size: 14px; line-height: 1.45; margin-top: 5px; }
.page-head .spacer { flex: 1; }
.section { margin-top: 26px; }
.section-head { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.section-title { font-size: 18px; letter-spacing: -.02em; font-weight: 800; }
.section-sub { color: var(--muted); font-size: 13px; }
.section-head .spacer { flex: 1; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}
.pad { padding: 20px; }
.muted { color: var(--muted); }
.small { font-size: 12.5px; }
.tiny { font-size: 11.5px; }
.strong { font-weight: 750; }
.row { display: flex; align-items: center; gap: 10px; }
.wrap { flex-wrap: wrap; }
.spacer { flex: 1; }
.stack { display: flex; flex-direction: column; gap: 10px; }
.grid { display: grid; gap: 14px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.divider { height: 1px; background: var(--line); margin: 16px 0; }
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 10px; border-radius: 999px;
  background: var(--card-2); border: 1px solid var(--line);
  color: var(--text-2); font-size: 12px; font-weight: 650; white-space: nowrap;
}
.chip.primary { background: var(--primary-soft); color: var(--primary); border-color: color-mix(in srgb, var(--primary) 24%, transparent); }
.chip.success { background: var(--success-soft); color: var(--success); border-color: color-mix(in srgb, var(--success) 24%, transparent); }
.chip.danger { background: var(--danger-soft); color: var(--danger); border-color: color-mix(in srgb, var(--danger) 24%, transparent); }
.chip.warning { background: var(--warning-soft); color: #b45309; border-color: color-mix(in srgb, var(--warning) 24%, transparent); }
[data-theme="dark"] .chip.warning { color: var(--warning); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 46px; padding: 11px 18px;
  border-radius: 14px;
  background: var(--card); border: 1px solid var(--line);
  color: var(--text); font-weight: 720; font-size: 14.5px;
  transition: .18s ease;
  user-select: none;
}
.btn:hover { border-color: var(--line-strong); transform: translateY(-1px); box-shadow: var(--shadow-sm); }
.btn:active { transform: scale(.985); }
.btn.primary { background: linear-gradient(135deg, var(--primary), var(--primary-2)); border-color: transparent; color: #fff; box-shadow: 0 12px 24px -12px rgba(37, 99, 235, .6); }
.btn.primary:hover { filter: brightness(1.05); }
.btn.success { background: var(--success); border-color: transparent; color: #fff; }
.btn.danger { background: var(--danger); border-color: transparent; color: #fff; }
.btn.soft { background: var(--primary-soft); color: var(--primary); border-color: color-mix(in srgb, var(--primary) 18%, transparent); }
.btn.ghost { background: transparent; }
.btn.sm { min-height: 38px; padding: 8px 13px; font-size: 13px; border-radius: 11px; }
.btn.lg { min-height: 54px; padding: 14px 22px; font-size: 16px; border-radius: 16px; }
.btn.block { width: 100%; }
.btn:disabled { opacity: .55; cursor: not-allowed; transform: none; box-shadow: none; }

.progress { height: 8px; border-radius: 999px; background: var(--bg-soft); overflow: hidden; }
.progress > i { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--primary), var(--primary-2)); transition: width .5s cubic-bezier(.2, .8, .2, 1); }
.progress.success > i { background: linear-gradient(90deg, #22c55e, #10b981); }
.progress.warning > i { background: linear-gradient(90deg, #f59e0b, #f97316); }
.progress.danger > i { background: linear-gradient(90deg, #ef4444, #f43f5e); }

/* ===== Home hero ===== */
.hero {
  position: relative;
  overflow: hidden;
  border-radius: 28px;
  padding: 26px;
  color: #fff;
  background:
    radial-gradient(600px 300px at 10% -10%, rgba(255,255,255,.24), transparent 55%),
    linear-gradient(135deg, #1d4ed8 0%, #2563eb 45%, #0891b2 100%);
  box-shadow: 0 28px 60px -30px rgba(29, 78, 216, .75);
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 24px;
}
.hero::after {
  content: "";
  position: absolute; right: -60px; top: -90px;
  width: 300px; height: 300px; border-radius: 50%;
  border: 42px solid rgba(255,255,255,.08);
}
.hero-copy { position: relative; z-index: 1; flex: 1; min-width: 0; }
.hero-eyebrow { display: inline-flex; align-items: center; gap: 7px; font-size: 11.5px; font-weight: 750; letter-spacing: .09em; text-transform: uppercase; color: rgba(255,255,255,.78); }
.hero h1 { font-size: clamp(27px, 4.2vw, 40px); line-height: 1.04; letter-spacing: -.04em; margin: 10px 0 9px; font-weight: 850; }
.hero p { color: rgba(255,255,255,.82); font-size: 14px; line-height: 1.5; max-width: 48ch; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.hero .btn { border: 0; min-height: 45px; }
.hero .btn-primary-inv { background: #fff; color: #1d4ed8; box-shadow: 0 12px 25px -12px rgba(0,0,0,.4); }
.hero .btn-ghost-inv { background: rgba(255,255,255,.13); color: #fff; border: 1px solid rgba(255,255,255,.28); backdrop-filter: blur(6px); }
.hero .btn-ghost-inv:hover { background: rgba(255,255,255,.2); }
.hero-ring { position: relative; z-index: 1; width: 132px; height: 132px; flex: none; display: grid; place-items: center; }
.hero-ring svg { transform: rotate(-90deg); }
.hero-ring .ring-text { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 1px; }
.hero-ring .ring-value { font-size: 27px; font-weight: 850; letter-spacing: -.04em; }
.hero-ring .ring-label { font-size: 10px; text-transform: uppercase; letter-spacing: .08em; color: rgba(255,255,255,.7); font-weight: 700; }

/* ===== Stats mini ===== */
.stat-row { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 10px; margin-top: 14px; }
.stat-mini { padding: 14px 15px; }
.stat-mini .v { font-size: 21px; font-weight: 850; letter-spacing: -.03em; }
.stat-mini .l { color: var(--muted); font-size: 11.5px; font-weight: 650; margin-top: 2px; }

/* ===== Mode cards ===== */
.mode-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 12px; }
.mode-card {
  position: relative;
  text-align: left;
  padding: 17px;
  border-radius: 20px;
  border: 1px solid var(--line);
  background: var(--card);
  box-shadow: var(--shadow-sm);
  transition: .2s ease;
  overflow: hidden;
  min-height: 126px;
  display: flex; flex-direction: column;
}
.mode-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--line-strong); }
.mode-card:active { transform: scale(.99); }
.mode-ico { width: 42px; height: 42px; border-radius: 13px; display: grid; place-items: center; margin-bottom: 14px; }
.mode-ico.blue { background: var(--primary-soft); color: var(--primary); }
.mode-ico.green { background: var(--success-soft); color: var(--success); }
.mode-ico.orange { background: var(--warning-soft); color: #d97706; }
.mode-ico.red { background: var(--danger-soft); color: var(--danger); }
.mode-ico.violet { background: color-mix(in srgb, var(--violet) 12%, transparent); color: var(--violet); }
.mode-ico.cyan { background: color-mix(in srgb, #06b6d4 12%, transparent); color: #0891b2; }
.mode-title { font-weight: 800; font-size: 15.5px; letter-spacing: -.015em; }
.mode-desc { color: var(--muted); font-size: 12px; line-height: 1.4; margin-top: 3px; }
.mode-badge { position: absolute; top: 14px; right: 14px; }
.mode-card .arrow { position: absolute; right: 16px; bottom: 15px; color: var(--muted); opacity: .7; transition: .2s; }
.mode-card:hover .arrow { transform: translateX(3px); color: var(--primary); opacity: 1; }

/* ===== Continue / recent ===== */
.continue-card { display: flex; align-items: center; gap: 14px; padding: 16px; margin-top: 14px; border: 1px solid color-mix(in srgb, var(--primary) 24%, var(--line)); background: linear-gradient(135deg, var(--primary-soft), var(--card)); }
.continue-icon { width: 46px; height: 46px; border-radius: 14px; display: grid; place-items: center; background: var(--primary); color: #fff; flex: none; }
.recent-list { display: flex; flex-direction: column; gap: 8px; }
.recent-item { display: flex; align-items: center; gap: 12px; padding: 12px 14px; border: 1px solid var(--line); border-radius: 14px; background: var(--card); }
.recent-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--success); flex: none; box-shadow: 0 0 0 4px var(--success-soft); }
.recent-dot.fail { background: var(--danger); box-shadow: 0 0 0 4px var(--danger-soft); }

/* ===== Set chips / tickets ===== */
.chips-scroll { display: flex; gap: 8px; overflow-x: auto; padding: 2px 2px 8px; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
.chips-scroll::-webkit-scrollbar { display: none; }
.chip-btn {
  flex: none; padding: 9px 14px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--card);
  color: var(--text-2); font-size: 12.5px; font-weight: 700; white-space: nowrap;
  transition: .18s ease;
}
.chip-btn:hover { border-color: var(--line-strong); }
.chip-btn.active { background: var(--text); color: var(--bg); border-color: var(--text); }
.set-summary { display: flex; align-items: flex-start; gap: 14px; padding: 17px; margin: 6px 0 16px; }
.set-summary .spacer { flex: 1; }
.ticket-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(76px, 1fr)); gap: 9px; }
.ticket-tile {
  position: relative;
  aspect-ratio: 1 / 1;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--card);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px;
  padding: 6px;
  transition: .16s ease;
  overflow: hidden;
}
.ticket-tile:hover { transform: translateY(-2px); border-color: var(--line-strong); box-shadow: var(--shadow-sm); }
.ticket-tile .num { font-size: 17px; font-weight: 850; letter-spacing: -.03em; }
.ticket-tile .best { font-size: 9.5px; color: var(--muted); font-weight: 700; }
.ticket-tile .status-dot { position: absolute; top: 7px; right: 7px; width: 7px; height: 7px; border-radius: 50%; background: var(--line-strong); }
.ticket-tile.passed { border-color: color-mix(in srgb, var(--success) 40%, var(--line)); background: linear-gradient(180deg, var(--success-soft), var(--card)); }
.ticket-tile.passed .status-dot { background: var(--success); }
.ticket-tile.failed { border-color: color-mix(in srgb, var(--danger) 32%, var(--line)); }
.ticket-tile.failed .status-dot { background: var(--danger); }
.ticket-tile.current { outline: 3px solid rgba(37,99,235,.35); }
.ticket-toolbar { display: flex; align-items: center; gap: 9px; flex-wrap: wrap; margin-bottom: 14px; }
.search-wrap { position: relative; flex: 1; min-width: 170px; }
.search-wrap .icon { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); color: var(--muted); }
.input {
  width: 100%; min-height: 44px; padding: 10px 12px 10px 38px;
  border-radius: 13px; border: 1px solid var(--line);
  background: var(--card); outline: none;
  transition: .18s;
}
.input:focus { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(37,99,235,.12); }
.input::placeholder { color: var(--muted); }

/* ===== Theme / chapter lists ===== */
.theme-list { display: grid; gap: 10px; }
.theme-card { padding: 16px; display: flex; gap: 14px; align-items: flex-start; transition: .18s; }
.theme-card:hover { border-color: var(--line-strong); box-shadow: var(--shadow-sm); }
.theme-num { width: 42px; height: 42px; border-radius: 13px; flex: none; display: grid; place-items: center; background: var(--primary-soft); color: var(--primary); font-weight: 850; font-size: 16px; }
.theme-main { flex: 1; min-width: 0; }
.theme-title { font-weight: 800; font-size: 14.5px; letter-spacing: -.01em; }
.theme-desc { font-size: 12px; color: var(--muted); margin-top: 3px; line-height: 1.4; }
.theme-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.chapter-list { display: grid; gap: 8px; }
.chapter-item { display: flex; align-items: center; gap: 12px; padding: 13px 14px; border: 1px solid var(--line); border-radius: 14px; background: var(--card); transition: .16s; }
.chapter-item:hover { border-color: var(--line-strong); background: var(--card-2); }
.chapter-num { width: 36px; height: 36px; border-radius: 11px; background: var(--card-2); border: 1px solid var(--line); display: grid; place-items: center; font-weight: 800; font-size: 13px; flex: none; }
.chapter-main { flex: 1; min-width: 0; }
.chapter-title { font-weight: 700; font-size: 13.5px; line-height: 1.25; }
.chapter-sub { font-size: 11.5px; color: var(--muted); margin-top: 2px; }

/* ===== Question screen ===== */
.session-wrap { width: min(820px, 100%); margin: 0 auto; padding: 18px 0 120px; }
.session-top { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.session-top .spacer { flex: 1; }
.timer {
  display: inline-flex; align-items: center; gap: 6px;
  font-variant-numeric: tabular-nums;
  padding: 7px 12px; border-radius: 999px;
  background: var(--card); border: 1px solid var(--line);
  font-weight: 750; font-size: 13px;
}
.timer.warn { color: var(--danger); border-color: color-mix(in srgb, var(--danger) 30%, transparent); background: var(--danger-soft); }
.session-title { font-weight: 800; font-size: 14px; letter-spacing: -.01em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.session-progress { display: flex; gap: 5px; margin: 0 0 16px; }
.session-progress .seg { flex: 1; height: 5px; border-radius: 99px; background: var(--line); overflow: hidden; }
.session-progress .seg.done > i { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), var(--primary-2)); }
.session-progress .seg.current { background: color-mix(in srgb, var(--primary) 35%, var(--line)); }
.q-card { padding: 20px; }
.q-head { display: flex; align-items: center; gap: 9px; margin-bottom: 14px; flex-wrap: wrap; }
.q-num { font-weight: 800; font-size: 13px; color: var(--primary); background: var(--primary-soft); padding: 6px 11px; border-radius: 999px; }
.q-image {
  position: relative; border-radius: 16px; overflow: hidden;
  background: #e9eef7; border: 1px solid var(--line);
  margin-bottom: 16px; cursor: zoom-in;
  display: block; width: 100%; padding: 0; text-align: left;
}
[data-theme="dark"] .q-image { background: #dbe4f0; border-color: #26364f; }
.q-image img { width: 100%; aspect-ratio: 4 / 3; object-fit: contain; }
.q-image .zoom-hint { position: absolute; right: 10px; bottom: 10px; background: rgba(15,23,42,.65); color: #fff; padding: 6px 9px; border-radius: 9px; font-size: 11px; font-weight: 650; display: flex; align-items: center; gap: 5px; backdrop-filter: blur(4px); }
.q-text { font-size: clamp(18px, 2.6vw, 23px); line-height: 1.32; letter-spacing: -.025em; font-weight: 800; margin-bottom: 17px; }
.answers { display: flex; flex-direction: column; gap: 9px; }
.answer {
  display: flex; align-items: flex-start; gap: 12px;
  width: 100%; text-align: left;
  padding: 13px 14px;
  border-radius: 14px; border: 1.5px solid var(--line);
  background: var(--card);
  transition: .15s ease;
  font-size: 14.5px; line-height: 1.35;
}
.answer:hover:not(:disabled) { border-color: var(--line-strong); background: var(--card-2); transform: translateX(2px); }
.answer .letter {
  width: 27px; height: 27px; border-radius: 8px; flex: none;
  display: grid; place-items: center;
  background: var(--card-2); border: 1px solid var(--line);
  font-size: 12px; font-weight: 800; color: var(--muted);
}
.answer.selected { border-color: var(--primary); background: var(--primary-soft); }
.answer.selected .letter { background: var(--primary); border-color: var(--primary); color: #fff; }
.answer.correct { border-color: var(--success); background: var(--success-soft); }
.answer.correct .letter { background: var(--success); border-color: var(--success); color: #fff; }
.answer.wrong { border-color: var(--danger); background: var(--danger-soft); }
.answer.wrong .letter { background: var(--danger); border-color: var(--danger); color: #fff; }
.answer:disabled { cursor: default; }
.answer.dim { opacity: .55; }
.answer .ans-mark { margin-left: auto; flex: none; display: grid; place-items: center; width: 22px; height: 22px; border-radius: 50%; }
.answer.correct .ans-mark { color: var(--success); }
.answer.wrong .ans-mark { color: var(--danger); }

.explain { margin-top: 16px; border-radius: 16px; border: 1px solid var(--line); overflow: hidden; animation: rise .25s ease both; }
.explain-head { display: flex; align-items: center; gap: 9px; padding: 12px 15px; font-weight: 800; font-size: 13.5px; }
.explain.ok .explain-head { background: var(--success-soft); color: var(--success); }
.explain.bad .explain-head { background: var(--danger-soft); color: var(--danger); }
.explain-body { padding: 15px; background: var(--card); font-size: 13.5px; line-height: 1.55; color: var(--text-2); }
.explain-body p { margin: 0 0 9px; }
.explain-body p:last-child { margin-bottom: 0; }
.explain-body img { border-radius: 12px; margin: 10px 0; border: 1px solid var(--line); max-height: 320px; object-fit: contain; width: auto; }
.explain-body ul, .explain-body ol { margin: 7px 0 9px; }
.explain-body li { margin: 3px 0; }
.explain-body a { color: var(--primary); text-decoration: underline; }
.ref-list { display: flex; flex-wrap: wrap; gap: 6px; padding: 0 15px 14px; background: var(--card); }
.ref-btn { font-size: 11.5px; font-weight: 700; padding: 5px 9px; border-radius: 8px; background: var(--card-2); border: 1px solid var(--line); color: var(--text-2); }
.ref-btn:hover { border-color: var(--primary); color: var(--primary); }
.session-footer { display: flex; align-items: center; gap: 10px; margin-top: 16px; }
.session-footer .spacer { flex: 1; }
.session-footer .btn { min-width: 120px; }
.exam-dots { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 14px; }
.exam-dot { width: 30px; height: 30px; border-radius: 9px; border: 1px solid var(--line); background: var(--card); font-size: 11.5px; font-weight: 750; color: var(--muted); display: grid; place-items: center; }
.exam-dot.answered { background: var(--primary-soft); border-color: color-mix(in srgb, var(--primary) 35%, var(--line)); color: var(--primary); }
.exam-dot.current { background: var(--primary); border-color: var(--primary); color: #fff; }
.q-tools { margin-left: auto; display: flex; gap: 6px; }
.star-btn { width: 38px; height: 38px; border-radius: 11px; border: 1px solid var(--line); background: var(--card); display: grid; place-items: center; color: var(--muted); }
.star-btn:hover { color: var(--warning); border-color: color-mix(in srgb, var(--warning) 40%, var(--line)); }
.star-btn.on { color: var(--warning); background: var(--warning-soft); border-color: color-mix(in srgb, var(--warning) 35%, transparent); }

/* ===== Result ===== */
.result-wrap { width: min(820px, 100%); margin: 0 auto; padding: 26px 0 110px; }
.result-hero { text-align: center; padding: 28px 20px; position: relative; overflow: hidden; }
.result-hero::before { content: ""; position: absolute; inset: 0; background: radial-gradient(500px 220px at 50% 0%, rgba(37,99,235,.12), transparent 70%); pointer-events: none; }
.result-circle { width: 150px; height: 150px; margin: 0 auto 14px; position: relative; display: grid; place-items: center; }
.result-circle svg { transform: rotate(-90deg); }
.result-circle .inner { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; }
.result-circle .pct { font-size: 34px; font-weight: 850; letter-spacing: -.05em; }
.result-circle .lbl { font-size: 10px; text-transform: uppercase; letter-spacing: .09em; color: var(--muted); font-weight: 750; }
.result-title { font-size: clamp(24px, 4vw, 33px); font-weight: 850; letter-spacing: -.035em; }
.result-sub { color: var(--muted); font-size: 13.5px; margin-top: 5px; }
.result-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 9px; margin-top: 20px; }
.result-stats { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 9px; margin-top: 18px; }
.result-stat { padding: 13px; border-radius: 14px; background: var(--card-2); border: 1px solid var(--line); text-align: center; }
.result-stat .v { font-weight: 850; font-size: 18px; }
.result-stat .l { font-size: 10.5px; color: var(--muted); font-weight: 650; }
.review-list { display: flex; flex-direction: column; gap: 8px; }
.review-item { border: 1px solid var(--line); border-radius: 14px; background: var(--card); overflow: hidden; }
.review-item summary { list-style: none; cursor: pointer; padding: 13px 15px; display: flex; align-items: center; gap: 10px; }
.review-item summary::-webkit-details-marker { display: none; }
.review-item summary .q-idx { width: 27px; height: 27px; border-radius: 8px; background: var(--card-2); border: 1px solid var(--line); display: grid; place-items: center; font-size: 11.5px; font-weight: 800; flex: none; }
.review-item summary .txt { flex: 1; font-size: 13px; font-weight: 650; line-height: 1.35; }
.review-item.ok summary .q-idx { background: var(--success-soft); color: var(--success); border-color: transparent; }
.review-item.bad summary .q-idx { background: var(--danger-soft); color: var(--danger); border-color: transparent; }
.review-body { padding: 0 15px 15px 52px; font-size: 12.5px; line-height: 1.5; color: var(--text-2); }
.review-body .your { color: var(--danger); font-weight: 650; }
.review-body .right { color: var(--success); font-weight: 650; }
.review-body .comment { margin-top: 8px; color: var(--muted); }
.review-body img { margin-top: 10px; border-radius: 10px; border: 1px solid var(--line); max-height: 220px; object-fit: contain; }

/* ===== Lists / mistakes ===== */
.q-list { display: flex; flex-direction: column; gap: 8px; }
.q-list-item { display: flex; gap: 12px; align-items: flex-start; padding: 14px; border-radius: 15px; border: 1px solid var(--line); background: var(--card); transition: .16s; }
.q-list-item:hover { border-color: var(--line-strong); box-shadow: var(--shadow-sm); }
.q-list-item .thumb { width: 74px; height: 55px; border-radius: 9px; object-fit: cover; background: var(--bg-soft); border: 1px solid var(--line); flex: none; }
.q-list-item .body { flex: 1; min-width: 0; }
.q-list-item .text { font-size: 13.5px; font-weight: 650; line-height: 1.35; }
.q-list-item .meta { display: flex; flex-wrap: wrap; gap: 7px; align-items: center; margin-top: 7px; color: var(--muted); font-size: 11.5px; }
.empty { text-align: center; padding: 46px 20px; }
.empty .ico { width: 64px; height: 64px; border-radius: 20px; margin: 0 auto 14px; display: grid; place-items: center; background: var(--card-2); color: var(--muted); }
.empty h3 { font-size: 18px; font-weight: 800; letter-spacing: -.02em; }
.empty p { color: var(--muted); font-size: 13px; margin-top: 5px; line-height: 1.5; }
.empty .btn { margin-top: 16px; }

/* ===== Stats ===== */
.stat-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 10px; }
.stat-card { padding: 16px; }
.stat-card .l { font-size: 11px; text-transform: uppercase; letter-spacing: .07em; font-weight: 750; color: var(--muted); }
.stat-card .v { font-size: 27px; font-weight: 850; letter-spacing: -.04em; margin-top: 5px; }
.stat-card .s { font-size: 11.5px; color: var(--muted); margin-top: 2px; }
.chart { display: flex; align-items: flex-end; gap: 6px; height: 112px; padding: 8px 2px 0; }
.chart-col { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 5px; height: 100%; justify-content: flex-end; }
.chart-bar { width: 100%; border-radius: 6px 6px 3px 3px; background: linear-gradient(180deg, var(--primary), var(--primary-2)); min-height: 3px; transition: .3s; }
.chart-bar.zero { background: var(--line); }
.chart-label { font-size: 9px; color: var(--muted); font-weight: 650; white-space: nowrap; }
.bar-list { display: flex; flex-direction: column; gap: 12px; }
.bar-row .top { display: flex; align-items: center; gap: 8px; font-size: 12.5px; margin-bottom: 5px; }
.bar-row .top .name { font-weight: 650; flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bar-row .top .val { color: var(--muted); font-weight: 700; font-size: 11.5px; }
.history { display: flex; flex-direction: column; gap: 8px; }
.history-item { display: flex; align-items: center; gap: 11px; padding: 12px 13px; border: 1px solid var(--line); border-radius: 13px; }
.history-item .ico { width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center; flex: none; }
.history-item .ico.ok { background: var(--success-soft); color: var(--success); }
.history-item .ico.bad { background: var(--danger-soft); color: var(--danger); }
.history-item .main { flex: 1; min-width: 0; }
.history-item .t { font-size: 12.5px; font-weight: 700; }
.history-item .s { font-size: 11px; color: var(--muted); margin-top: 1px; }

/* ===== Rules ===== */
.rules-layout { display: grid; grid-template-columns: 280px 1fr; gap: 18px; align-items: start; margin-top: 8px; }
.rules-side { position: sticky; top: 76px; max-height: calc(100vh - 100px); overflow: auto; padding: 10px; }
.rules-side a { display: block; padding: 9px 10px; border-radius: 9px; color: var(--text-2); font-size: 12.5px; font-weight: 600; line-height: 1.3; }
.rules-side a:hover { background: var(--card-2); color: var(--text); }
.rules-side a.active { background: var(--primary-soft); color: var(--primary); }
.rules-content { padding: 24px; font-size: 14px; line-height: 1.6; }
.rules-content h1 { font-size: 25px; letter-spacing: -.03em; line-height: 1.15; margin-bottom: 12px; }
.rules-content h2 { font-size: 19px; letter-spacing: -.02em; margin: 20px 0 8px; }
.rules-content h3 { font-size: 16px; margin: 16px 0 7px; }
.rules-content h4 { font-size: 14px; margin: 14px 0 6px; }
.rules-content p { margin: 0 0 10px; color: var(--text-2); }
.rules-content section.rule { padding: 10px 12px; border-left: 3px solid var(--line-strong); background: var(--card-2); border-radius: 0 10px 10px 0; margin: 8px 0; }
.rules-content .rule-number { font-weight: 850; color: var(--primary); margin-right: 4px; }
.rules-content a { color: var(--primary); text-decoration: underline; }
.rules-content img { border-radius: 12px; border: 1px solid var(--line); margin: 10px 0; }
.rules-content ul, .rules-content ol { margin: 7px 0 12px; color: var(--text-2); }

/* ===== Modal / sheet ===== */
.overlay { position: fixed; inset: 0; z-index: 100; display: flex; align-items: flex-end; justify-content: center; padding: 0; background: rgba(2, 6, 23, .52); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); animation: fade .18s ease both; }
.overlay.center { align-items: center; padding: 18px; }
.sheet {
  width: min(560px, 100%); max-height: min(88vh, 820px); overflow: auto;
  background: var(--card); border-radius: 24px 24px 0 0;
  border: 1px solid var(--line); border-bottom: 0;
  box-shadow: 0 -20px 60px -20px rgba(2,6,23,.4);
  padding: 18px 18px calc(22px + env(safe-area-inset-bottom));
  animation: slideUp .24s cubic-bezier(.2,.8,.2,1) both;
}
.overlay.center .sheet { border-radius: 24px; border-bottom: 1px solid var(--line); padding-bottom: 20px; animation: pop .2s ease both; }
.sheet-head { display: flex; align-items: flex-start; gap: 12px; margin-bottom: 14px; }
.sheet-head .spacer { flex: 1; }
.sheet-title { font-size: 19px; font-weight: 850; letter-spacing: -.025em; }
.sheet-sub { font-size: 12.5px; color: var(--muted); margin-top: 3px; line-height: 1.4; }
.sheet-actions { display: flex; flex-direction: column; gap: 8px; margin-top: 16px; }
.sheet-actions .btn { width: 100%; justify-content: flex-start; }
.sheet-close { width: 34px; height: 34px; border-radius: 10px; border: 1px solid var(--line); display: grid; place-items: center; color: var(--muted); flex: none; }
.sheet-body { font-size: 13.5px; line-height: 1.55; color: var(--text-2); }
.sheet-body img { border-radius: 10px; border: 1px solid var(--line); margin: 8px 0; }
.grabber { width: 42px; height: 5px; border-radius: 99px; background: var(--line-strong); margin: 0 auto 14px; }
.overlay.center .grabber { display: none; }
.lightbox { position: fixed; inset: 0; z-index: 120; background: rgba(2,6,23,.92); display: grid; place-items: center; padding: 20px; animation: fade .16s ease both; }
.lightbox img { max-width: 100%; max-height: 100%; border-radius: 10px; box-shadow: 0 30px 80px rgba(0,0,0,.5); }
.lightbox .close { position: absolute; top: 18px; right: 18px; width: 42px; height: 42px; border-radius: 50%; background: rgba(255,255,255,.12); color: #fff; display: grid; place-items: center; }
.toast { position: fixed; z-index: 200; left: 50%; bottom: calc(92px + env(safe-area-inset-bottom)); transform: translateX(-50%) translateY(14px); background: var(--text); color: var(--bg); padding: 10px 16px; border-radius: 999px; font-size: 12.5px; font-weight: 700; opacity: 0; pointer-events: none; transition: .22s ease; box-shadow: 0 14px 40px rgba(0,0,0,.3); max-width: calc(100% - 40px); text-align: center; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ===== Loading ===== */
.loading-screen { position: fixed; inset: 0; z-index: 300; background: var(--bg); display: grid; place-items: center; transition: opacity .3s; }
.loading-screen.done { opacity: 0; pointer-events: none; }
.loader { display: flex; flex-direction: column; align-items: center; gap: 14px; color: var(--muted); font-size: 13px; font-weight: 650; }
.loader img { width: 62px; height: 62px; border-radius: 18px; box-shadow: var(--shadow); animation: pulse 1.4s ease-in-out infinite; }
.spinner { width: 22px; height: 22px; border-radius: 50%; border: 3px solid var(--line); border-top-color: var(--primary); animation: spin .8s linear infinite; }

/* ===== Animations ===== */
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@keyframes slideUp { from { transform: translateY(30px); opacity: .6; } to { transform: none; opacity: 1; } }
@keyframes pop { from { transform: scale(.97); opacity: 0; } to { transform: none; opacity: 1; } }
@keyframes pulse { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.05); } }
.view-in { animation: rise .28s cubic-bezier(.2,.8,.2,1) both; }

/* ===== Responsive ===== */
@media (min-width: 640px) {
  .mode-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }
  .stat-grid { grid-template-columns: repeat(4, minmax(0,1fr)); }
  .q-card { padding: 26px; }
  .result-hero { padding: 36px 28px; }
}
@media (min-width: 860px) {
  .shell { padding-left: 28px; padding-right: 28px; }
  .topbar-inner { padding-left: 28px; padding-right: 28px; }
  .hero { padding: 34px 38px; }
  .hero-ring { width: 160px; height: 160px; }
  .hero-ring .ring-value { font-size: 33px; }
  .ticket-grid { grid-template-columns: repeat(auto-fill, minmax(86px, 1fr)); }
}
@media (max-width: 700px) {
  .rules-layout { grid-template-columns: 1fr; }
  .rules-side { position: static; max-height: 260px; }
}
@media (max-width: 560px) {
  .hero { flex-direction: column; align-items: stretch; gap: 18px; padding: 22px; }
  .hero-ring { width: 112px; height: 112px; align-self: flex-start; }
  .hero-ring .ring-value { font-size: 23px; }
  .stat-mini { padding: 12px; }
  .stat-mini .v { font-size: 19px; }
  .mode-card { min-height: 118px; }
  .session-title { max-width: 40vw; }
  .q-text { font-size: 18px; }
  .answer { font-size: 14px; }
  .result-actions .btn { flex: 1; }
  .brand-sub { display: none; }
  .streak-chip span { display: none; }
  .streak-chip { padding: 7px 9px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}