/* ============================================================
   Revision Hub — global styles
   Dark theme, per-subject accent via --accent set on .app
   ============================================================ */

:root {
  --bg:        #0B0F14;
  --bg-2:      #121821;
  --panel:     #121821;
  --panel-2:   #1A2230;
  --line:      #28313e;
  --line-soft: #1c2531;
  --text:      #eef2f8;
  --text-dim:  #9aa6ba;
  --text-mute: #69748a;
  --accent:    #FFB74D;          /* warm amber — overridden per subject */
  --accent-ink:#0B0F14;
  --gold:      #FFC857;
  --blue:      #4F8CFF;
  --good:      #4ADE80;
  --bad:       #F87171;
  --warn:      #FFC857;
  --radius:    18px;
  --radius-sm: 12px;
  --shadow:    0 22px 60px rgba(0,0,0,.55);
  --ring:      0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent);
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
  --maxw:      1100px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  background:
    radial-gradient(950px 520px at 50% -16%, rgba(255,183,77,.09), transparent 62%),
    radial-gradient(720px 520px at 88% 4%, rgba(79,140,255,.05), transparent 60%),
    var(--bg);
  background-attachment: fixed;
  color: var(--text);
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

h1,h2,h3,h4 { font-family: 'Lexend', 'Inter', sans-serif; line-height: 1.15; margin: 0; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px;
  padding: 13px clamp(16px, 4vw, 40px);
  background: linear-gradient(180deg, rgba(14,17,27,.85), rgba(14,17,27,.62));
  backdrop-filter: blur(18px) saturate(1.3);
  -webkit-backdrop-filter: blur(18px) saturate(1.3);
  border-bottom: 1px solid var(--line-soft);
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-family: 'Lexend'; letter-spacing: -.02em; }
.brand-mark { color: var(--accent); font-size: 20px; transform: translateY(1px); }
.brand-name { font-size: 18px; }
.topnav { display: flex; gap: 6px; }
.topnav a {
  padding: 8px 14px; border-radius: 999px; font-weight: 600; font-size: 14px;
  color: var(--text-dim); transition: .15s;
}
.topnav a:hover { color: var(--text); background: var(--panel); }
.topnav a.active { color: var(--accent-ink); background: linear-gradient(135deg, color-mix(in srgb, var(--accent) 92%, white), var(--accent)); box-shadow: 0 4px 14px color-mix(in srgb, var(--accent) 30%, transparent); }

/* ---------- layout ---------- */
.app { flex: 1; width: 100%; max-width: var(--maxw); margin: 0 auto; padding: clamp(20px, 4vw, 40px); }
.footer {
  text-align: center; color: var(--text-mute); font-size: 13px;
  padding: 28px 16px 56px; border-top: 1px solid var(--line-soft); margin-top: 30px;
}

/* creator credit — fixed bottom-left */
.credit {
  position: fixed; left: 14px; bottom: 12px; z-index: 40;
  max-width: 46vw; font-size: 11.5px; line-height: 1.35; color: var(--text-mute);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  border: 1px solid var(--line-soft); border-radius: 10px;
  padding: 7px 11px; backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  pointer-events: none; user-select: none;
}
@media (max-width: 640px) { .credit { font-size: 10.5px; max-width: 70vw; left: 8px; bottom: 8px; } }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  padding: 11px 18px; border-radius: var(--radius-sm); border: 1px solid var(--line);
  background: var(--panel); color: var(--text); font-weight: 600; font-size: 14px;
  cursor: pointer; transition: .15s; white-space: nowrap;
}
.btn:hover { border-color: var(--accent); transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: transparent; box-shadow: 0 6px 18px color-mix(in srgb, var(--accent) 22%, transparent); }
.btn.primary:hover { filter: brightness(1.04); box-shadow: 0 8px 22px color-mix(in srgb, var(--accent) 30%, transparent); }
.btn.ghost { background: transparent; }
.btn.sm { padding: 7px 12px; font-size: 13px; }
.btn:disabled { opacity: .45; cursor: not-allowed; transform: none; }

.back {
  display: inline-flex; align-items: center; gap: 7px; color: var(--text-dim);
  font-weight: 600; font-size: 14px; margin-bottom: 18px; cursor: pointer;
}
.back:hover { color: var(--accent); }

/* ---------- hero ---------- */
.hero { margin-bottom: 34px; }
.hero h1 { font-size: clamp(30px, 5vw, 46px); letter-spacing: -.03em; }
.hero h1 .grad {
  background: linear-gradient(95deg, var(--accent), #b9c7ff 60%, #8defd0);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero p { color: var(--text-dim); max-width: 620px; margin-top: 12px; font-size: 16px; }

/* ---------- subject grid ---------- */
.grid { display: grid; gap: 18px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }

.subject-card {
  position: relative; overflow: hidden;
  background:
    radial-gradient(120% 90% at 100% 0%, color-mix(in srgb, var(--c, var(--accent)) 12%, transparent), transparent 60%),
    linear-gradient(160deg, var(--panel), var(--bg-2));
  border: 1px solid var(--line-soft); border-radius: var(--radius);
  padding: 22px; cursor: pointer; transition: transform .2s cubic-bezier(.2,.7,.2,1), border-color .2s, box-shadow .2s;
  display: flex; flex-direction: column; gap: 14px; min-height: 168px;
}
.subject-card::before {
  content: ""; position: absolute; inset: 0 auto 0 0; width: 4px;
  background: var(--c, var(--accent));
}
.subject-card:hover { transform: translateY(-4px); border-color: var(--c, var(--accent)); box-shadow: var(--shadow); }
.subject-card .sc-top { display: flex; align-items: center; gap: 14px; }
.subject-card .sc-icon {
  width: 52px; height: 52px; flex: none; display: grid; place-items: center;
  font-size: 26px; border-radius: 14px;
  background: color-mix(in srgb, var(--c) 18%, transparent);
  border: 1px solid color-mix(in srgb, var(--c) 35%, transparent);
}
.subject-card h3 { font-size: 19px; letter-spacing: -.01em; }
.subject-card .sc-sub { color: var(--text-mute); font-size: 13px; margin-top: 3px; }
.subject-card .sc-meta { margin-top: auto; display: flex; gap: 8px; flex-wrap: wrap; }
.badge {
  font-size: 11.5px; font-weight: 700; letter-spacing: .03em; text-transform: uppercase;
  padding: 4px 10px; border-radius: 999px;
  background: color-mix(in srgb, var(--c, var(--accent)) 16%, transparent);
  color: color-mix(in srgb, var(--c, var(--accent)) 90%, white);
  border: 1px solid color-mix(in srgb, var(--c, var(--accent)) 30%, transparent);
}
.badge.plain { background: var(--panel-2); color: var(--text-dim); border-color: var(--line); }

/* ---------- subject header ---------- */
.subject-head {
  display: flex; align-items: center; gap: 18px; margin-bottom: 26px;
  padding-bottom: 22px; border-bottom: 1px solid var(--line-soft);
}
.subject-head .sh-icon {
  width: 64px; height: 64px; flex: none; display: grid; place-items: center; font-size: 32px;
  border-radius: 18px; background: color-mix(in srgb, var(--accent) 18%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
}
.subject-head h1 { font-size: clamp(24px, 4vw, 34px); letter-spacing: -.02em; }
.subject-head .sh-meta { color: var(--text-dim); margin-top: 6px; display: flex; gap: 8px; flex-wrap: wrap; }

/* ---------- topic list ---------- */
.section-label { font-size: 13px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--text-mute); margin: 8px 0 14px; }
.topic-grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
.topic-card {
  background: var(--panel); border: 1px solid var(--line-soft); border-radius: var(--radius-sm);
  padding: 18px; cursor: pointer; transition: .15s; display: flex; flex-direction: column; gap: 8px;
}
.topic-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.topic-card h4 { font-size: 16px; }
.topic-card .tc-stats { display: flex; gap: 12px; color: var(--text-mute); font-size: 12.5px; margin-top: 6px; }
.topic-card .tc-stats b { color: var(--text-dim); font-weight: 600; }

/* ---------- tabs ---------- */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin: 8px 0 26px; padding: 5px; background: var(--bg-2); border: 1px solid var(--line-soft); border-radius: 14px; width: fit-content; }
.tab { padding: 9px 16px; border-radius: 10px; font-weight: 600; font-size: 14px; color: var(--text-dim); cursor: pointer; transition: .15s; }
.tab:hover { color: var(--text); }
.tab.active { background: var(--accent); color: var(--accent-ink); }

/* ---------- panel ---------- */
.panel { background: var(--panel); border: 1px solid var(--line-soft); border-radius: var(--radius); padding: clamp(18px, 3vw, 30px); }
.panel-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 18px; flex-wrap: wrap; }
.muted { color: var(--text-dim); }
.center { text-align: center; }
.empty { text-align: center; color: var(--text-mute); padding: 50px 20px; }

/* ---------- flashcards ---------- */
.fc-stage { display: flex; flex-direction: column; align-items: center; gap: 20px; }
.flashcard { width: 100%; max-width: 560px; height: 320px; perspective: 1600px; cursor: pointer; }
.flashcard-inner { position: relative; width: 100%; height: 100%; transition: transform .55s cubic-bezier(.2,.7,.2,1); transform-style: preserve-3d; }
.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }
.fc-face {
  position: absolute; inset: 0; backface-visibility: hidden; border-radius: var(--radius);
  padding: 30px; display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; border: 1px solid var(--line);
}
.fc-front { background: linear-gradient(160deg, var(--panel-2), var(--bg-2)); }
.fc-back { background: linear-gradient(160deg, color-mix(in srgb, var(--accent) 14%, var(--panel-2)), var(--bg-2)); transform: rotateY(180deg); border-color: color-mix(in srgb, var(--accent) 40%, var(--line)); }
.fc-tag { font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--text-mute); margin-bottom: 14px; }
.fc-text { font-size: clamp(17px, 2.6vw, 22px); font-weight: 500; line-height: 1.45; }
.fc-back .fc-text { font-size: clamp(15px, 2.3vw, 19px); }
.fc-hint { color: var(--text-mute); font-size: 13px; margin-top: 16px; }
.fc-controls { display: flex; align-items: center; gap: 12px; }
.fc-count { color: var(--text-dim); font-size: 14px; min-width: 70px; text-align: center; font-variant-numeric: tabular-nums; }

/* ---------- quiz ---------- */
.quiz-wrap { max-width: 640px; margin: 0 auto; }
.quiz-progress { height: 7px; border-radius: 999px; background: var(--bg-2); overflow: hidden; margin-bottom: 22px; }
.quiz-progress > i { display: block; height: 100%; background: var(--accent); transition: width .3s; }
.qmeta { display: flex; justify-content: space-between; color: var(--text-dim); font-size: 13px; margin-bottom: 12px; }
.qtext { font-size: clamp(18px, 3vw, 23px); font-weight: 600; line-height: 1.4; margin-bottom: 22px; }
.options { display: flex; flex-direction: column; gap: 11px; }
.option {
  text-align: left; padding: 15px 18px; border-radius: 12px; border: 1px solid var(--line);
  background: var(--panel-2); color: var(--text); font-size: 15px; cursor: pointer; transition: .14s;
  display: flex; align-items: center; gap: 12px;
}
.option:hover:not(:disabled) { border-color: var(--accent); }
.option .opt-key { width: 26px; height: 26px; flex: none; display: grid; place-items: center; border-radius: 7px; background: var(--bg-2); font-weight: 700; font-size: 13px; color: var(--text-dim); }
.option.correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 14%, var(--panel-2)); }
.option.correct .opt-key { background: var(--good); color: #062018; }
.option.wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 14%, var(--panel-2)); }
.option.wrong .opt-key { background: var(--bad); color: #2a0810; }
.option:disabled { cursor: default; }
.explain { margin-top: 18px; padding: 14px 16px; border-radius: 12px; background: var(--bg-2); border: 1px solid var(--line-soft); font-size: 14px; color: var(--text-dim); }
.explain b { color: var(--text); }
.quiz-foot { display: flex; justify-content: flex-end; margin-top: 20px; }
.score-ring { font-size: 54px; font-weight: 800; font-family: 'Lexend'; }
.score-ring small { display: block; font-size: 15px; color: var(--text-dim); font-weight: 500; font-family: 'Inter'; margin-top: 4px; }

/* ---------- revision notes ---------- */
.notes-panel { max-width: 820px; }
.note-toc {
  background: var(--bg-2); border: 1px solid var(--line-soft); border-radius: 12px;
  padding: 16px 18px; margin: 6px 0 26px;
}
.toc-links { display: flex; flex-wrap: wrap; gap: 8px; }
.toc-link {
  font-size: 13px; font-weight: 600; color: var(--text-dim); cursor: pointer;
  padding: 6px 12px; border-radius: 999px; background: var(--panel-2); border: 1px solid var(--line-soft); transition: .14s;
}
.toc-link:hover { color: var(--accent); border-color: var(--accent); }

.notes { display: flex; flex-direction: column; gap: 26px; }
.note-sec { scroll-margin-top: 80px; }
.note-h {
  font-size: 19px; letter-spacing: -.01em; padding-bottom: 8px;
  border-bottom: 2px solid color-mix(in srgb, var(--accent) 45%, transparent);
  margin-bottom: 14px;
}
.note-h strong { color: var(--accent); font-weight: 800; }
.note-intro { color: var(--text-dim); margin: 0 0 12px; font-size: 15px; }
.note-list { margin: 0; padding-left: 0; list-style: none; display: flex; flex-direction: column; gap: 9px; }
.note-list li {
  position: relative; padding-left: 22px; font-size: 15.5px; line-height: 1.6; color: var(--text);
}
.note-list li::before {
  content: ""; position: absolute; left: 4px; top: 10px; width: 7px; height: 7px; border-radius: 2px;
  background: var(--accent); transform: rotate(45deg);
}
.note-list li strong { color: #fff; font-weight: 700; }
.note-foot { margin-top: 30px; padding-top: 20px; border-top: 1px dashed var(--line); display: flex; align-items: center; justify-content: space-between; gap: 14px; flex-wrap: wrap; }
.note-foot p { margin: 0; }

/* ---------- diagrams (inline SVG, theme-aware) ---------- */
.dgm-fig { margin: 16px 0 4px; }
.dgm {
  background: var(--bg-2); border: 1px solid var(--line-soft); border-radius: 12px;
  padding: 16px; overflow-x: auto;
}
.dgm svg { width: 100%; height: auto; display: block; max-width: 560px; margin: 0 auto; }
.dgm-cap { color: var(--text-mute); font-size: 13px; text-align: center; margin-top: 8px; }
/* SVG helper classes referenced by diagrams.js */
.dgm .d-box   { fill: var(--panel); stroke: var(--line); stroke-width: 1.5; }
.dgm .d-box-a { fill: color-mix(in srgb, var(--accent) 16%, var(--panel)); stroke: var(--accent); stroke-width: 1.5; }
.dgm .d-stroke{ stroke: var(--accent); stroke-width: 2; fill: none; }
.dgm .d-line  { stroke: var(--text-mute); stroke-width: 1.5; fill: none; }
.dgm .d-fill  { fill: var(--accent); }
.dgm .d-fill2 { fill: var(--text-mute); }
.dgm .d-dash  { stroke: var(--text-mute); stroke-width: 1.5; fill: none; stroke-dasharray: 4 4; }
.dgm .d-lbl   { fill: var(--text); font: 600 13px 'Inter', sans-serif; }
.dgm .d-lbl-a { fill: var(--accent); font: 700 13px 'Inter', sans-serif; }
.dgm .d-sub   { fill: var(--text-mute); font: 11px 'Inter', sans-serif; }
.dgm .d-axis  { stroke: var(--text-dim); stroke-width: 1.5; }

/* ---------- past papers ---------- */
.link-list { display: flex; flex-direction: column; gap: 10px; }
.link-row {
  display: flex; align-items: center; justify-content: space-between; gap: 14px;
  padding: 14px 16px; border-radius: 12px; background: var(--panel-2); border: 1px solid var(--line-soft); transition: .14s;
}
.link-row:hover { border-color: var(--accent); }
.link-row .lr-main { display: flex; align-items: center; gap: 12px; min-width: 0; }
.link-row .lr-ico { font-size: 18px; }
.link-row .lr-title { font-weight: 600; }
.link-row .lr-sub { color: var(--text-mute); font-size: 12.5px; }
.link-row .arrow { color: var(--text-mute); }

/* ---------- battle ---------- */
.battle-wrap { max-width: 720px; margin: 0 auto; }
.field { display: flex; flex-direction: column; gap: 7px; margin-bottom: 16px; }
.field label { font-size: 13px; font-weight: 600; color: var(--text-dim); }
.input {
  padding: 13px 15px; border-radius: 11px; border: 1px solid var(--line); background: var(--bg-2);
  color: var(--text); font-size: 15px; font-family: inherit; transition: .14s; width: 100%;
}
.input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent); }
.input.code { letter-spacing: .35em; text-transform: uppercase; font-weight: 700; text-align: center; font-size: 22px; }
.row { display: flex; gap: 12px; flex-wrap: wrap; }
.row > * { flex: 1; min-width: 140px; }
.divider-or { display: flex; align-items: center; gap: 14px; color: var(--text-mute); font-size: 13px; margin: 22px 0; }
.divider-or::before, .divider-or::after { content: ""; height: 1px; flex: 1; background: var(--line-soft); }

.vs-board { display: grid; grid-template-columns: 1fr auto 1fr; gap: 14px; align-items: stretch; margin-bottom: 22px; }
.player-card { background: var(--panel-2); border: 1px solid var(--line-soft); border-radius: 14px; padding: 18px; text-align: center; transition: .2s; }
.player-card.me { border-color: var(--accent); }
.player-card.lead { box-shadow: 0 0 0 2px var(--good) inset; }
.player-card .pc-name { font-weight: 700; font-size: 17px; display: flex; align-items: center; justify-content: center; gap: 7px; }
.player-card .pc-score { font-size: 46px; font-weight: 800; font-family: 'Lexend'; margin: 6px 0; }
.player-card .pc-status { font-size: 12.5px; color: var(--text-mute); min-height: 16px; }
.vs-mid { display: grid; place-items: center; font-weight: 800; color: var(--text-mute); font-family: 'Lexend'; }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--text-mute); display: inline-block; }
.dot.on { background: var(--good); box-shadow: 0 0 8px var(--good); }

.pill { display: inline-flex; align-items: center; gap: 7px; padding: 7px 13px; border-radius: 999px; background: var(--bg-2); border: 1px solid var(--line-soft); font-size: 13px; font-weight: 600; }
.room-code-show { font-family: 'Lexend'; font-weight: 800; letter-spacing: .3em; color: var(--accent); }

.config-warn {
  background: color-mix(in srgb, var(--warn) 12%, var(--panel)); border: 1px solid color-mix(in srgb, var(--warn) 40%, transparent);
  border-radius: 12px; padding: 16px 18px; margin-bottom: 20px; font-size: 14px; color: var(--text);
}
.config-warn b { color: var(--warn); }
.config-warn code { background: var(--bg); padding: 2px 6px; border-radius: 5px; font-size: 13px; }

.toast { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); background: var(--panel); border: 1px solid var(--line); padding: 12px 18px; border-radius: 12px; box-shadow: var(--shadow); font-size: 14px; z-index: 100; opacity: 0; transition: .25s; pointer-events: none; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(-4px); }

/* ---------- add-card editor ---------- */
.editor { margin-top: 22px; border-top: 1px dashed var(--line); padding-top: 20px; }
.editor textarea.input { resize: vertical; min-height: 64px; }
details.editor-d summary { cursor: pointer; font-weight: 600; color: var(--text-dim); list-style: none; }
details.editor-d summary::-webkit-details-marker { display: none; }
details.editor-d summary::before { content: "＋ "; color: var(--accent); }
details.editor-d[open] summary::before { content: "－ "; }

/* ---------- difficulty chips + badges ---------- */
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.chip {
  padding: 7px 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--panel-2);
  color: var(--text-dim); font-weight: 600; font-size: 13px; cursor: pointer; transition: .14s;
}
.chip:hover { color: var(--text); border-color: var(--accent); }
.chip.active { background: var(--accent); color: var(--accent-ink); border-color: transparent; }
.chip.edge-easy:not(.active)   { box-shadow: inset 3px 0 0 var(--good); }
.chip.edge-medium:not(.active) { box-shadow: inset 3px 0 0 var(--warn); }
.chip.edge-hard:not(.active)   { box-shadow: inset 3px 0 0 var(--bad); }

.lvl-badge {
  position: absolute; top: 14px; right: 16px; font-size: 11px; font-weight: 700; letter-spacing: .04em;
  text-transform: uppercase; padding: 3px 9px; border-radius: 999px; border: 1px solid var(--line);
}
.lvl-easy   { color: var(--good); border-color: color-mix(in srgb, var(--good) 45%, transparent); background: color-mix(in srgb, var(--good) 12%, transparent); }
.lvl-medium { color: var(--warn); border-color: color-mix(in srgb, var(--warn) 45%, transparent); background: color-mix(in srgb, var(--warn) 12%, transparent); }
.lvl-hard   { color: var(--bad);  border-color: color-mix(in srgb, var(--bad) 45%, transparent);  background: color-mix(in srgb, var(--bad) 12%, transparent); }

.btn.rate-good { border-color: color-mix(in srgb, var(--good) 50%, var(--line)); color: var(--good); }
.btn.rate-good:hover { background: color-mix(in srgb, var(--good) 14%, transparent); }
.btn.rate-bad  { border-color: color-mix(in srgb, var(--bad) 50%, var(--line)); color: var(--bad); }
.btn.rate-bad:hover { background: color-mix(in srgb, var(--bad) 14%, transparent); }

/* ---------- dashboard ---------- */
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; }
.stat-card { background: var(--panel); border: 1px solid var(--line-soft); border-radius: var(--radius-sm); padding: 18px; }
.stat-big { font-family: 'Lexend'; font-weight: 800; font-size: 30px; letter-spacing: -.02em; }
.stat-label { color: var(--text-mute); font-size: 13px; margin-top: 4px; }

.dash-list { display: flex; flex-direction: column; }
.dash-row {
  display: flex; align-items: center; justify-content: space-between; gap: 14px;
  padding: 13px 14px; border-radius: 10px; cursor: pointer; transition: .12s;
}
.dash-row:hover { background: var(--panel-2); }
.dash-row-main { display: flex; align-items: center; gap: 12px; min-width: 0; }
.dash-ico { font-size: 20px; }
.dash-topic { font-weight: 600; }
.dash-sub { color: var(--text-mute); font-size: 12.5px; }
.dash-row-right { display: flex; align-items: center; gap: 12px; flex: 0 0 auto; }
.mbar { width: 120px; height: 8px; border-radius: 999px; background: var(--bg-2); overflow: hidden; }
.mbar-fill { display: block; height: 100%; transition: width .4s; }
.dash-pct { font-variant-numeric: tabular-nums; font-weight: 700; font-size: 14px; min-width: 42px; text-align: right; }
.band-low  { background: var(--bad);  color: var(--bad); }
.band-mid  { background: var(--warn); color: var(--warn); }
.band-high { background: var(--good); color: var(--good); }
.band-none { background: var(--line); color: var(--text-mute); }
.dash-sub-block { background: var(--panel); border: 1px solid var(--line-soft); border-radius: var(--radius-sm); padding: 14px 16px; margin-bottom: 12px; }
.dash-sub-block summary { cursor: pointer; font-weight: 700; font-family: 'Lexend'; list-style: none; display: flex; align-items: center; gap: 4px; }
.dash-sub-block summary::-webkit-details-marker { display: none; }
.dash-sub-avg { margin-left: auto; font-family: 'Inter'; font-weight: 600; font-size: 13px; color: var(--text-mute); }
@media (max-width: 560px) { .mbar { width: 70px; } }

/* ---------- battle: N-player board, timer, results ---------- */
.score-grid { display: grid; gap: 12px; grid-template-columns: repeat(2, 1fr); margin-bottom: 22px; }
.score-grid.n3, .score-grid.n5, .score-grid.n6 { grid-template-columns: repeat(3, 1fr); }
.score-grid.n4 { grid-template-columns: repeat(2, 1fr); }
@media (min-width: 620px) { .score-grid.n4 { grid-template-columns: repeat(4, 1fr); } }
.score-grid .player-card .pc-score { font-size: 38px; }

.qtimer { height: 6px; border-radius: 999px; background: var(--bg-2); overflow: hidden; margin-bottom: 16px; }
.qtimer.hidden { display: none; }
.qtimer-fill { display: block; height: 100%; width: 100%; background: var(--accent); transition: width 1s linear; }
.qtimer-num { font-variant-numeric: tabular-nums; font-weight: 700; color: var(--text-dim); }

.result-list { max-width: 380px; margin: 18px auto 0; display: flex; flex-direction: column; gap: 8px; }
.result-row { display: flex; align-items: center; gap: 12px; padding: 11px 14px; border-radius: 10px; background: var(--panel-2); border: 1px solid var(--line-soft); }
.result-row.me { border-color: var(--accent); }
.result-rank { font-family: 'Lexend'; font-weight: 800; color: var(--text-mute); width: 34px; }
.result-name { font-weight: 600; flex: 1; text-align: left; }
.result-score { font-family: 'Lexend'; font-weight: 800; font-size: 18px; }

/* ---------- marker (essay) practice ---------- */
.marker-q { margin-top: 8px; padding: 18px; border-radius: 12px; background: var(--bg-2); border: 1px solid var(--line-soft); }
.marker-marks { display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: .04em; text-transform: uppercase; color: var(--accent); background: color-mix(in srgb, var(--accent) 14%, transparent); border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent); padding: 3px 10px; border-radius: 999px; }
.marker-qtext { font-size: 18px; font-weight: 600; line-height: 1.45; margin-top: 10px; }

.mark-result { margin-top: 22px; display: flex; flex-direction: column; gap: 14px; }
.mark-badge { display: flex; align-items: baseline; gap: 12px; padding: 16px 20px; border-radius: 14px; border: 1px solid var(--line); background: var(--panel-2); }
.mark-badge.band-high { border-color: color-mix(in srgb, var(--good) 50%, transparent); background: color-mix(in srgb, var(--good) 12%, var(--panel-2)); }
.mark-badge.band-mid  { border-color: color-mix(in srgb, var(--warn) 50%, transparent); background: color-mix(in srgb, var(--warn) 12%, var(--panel-2)); }
.mark-badge.band-low  { border-color: color-mix(in srgb, var(--bad) 50%, transparent);  background: color-mix(in srgb, var(--bad) 12%, var(--panel-2)); }
.mark-score { font-family: 'Lexend'; font-weight: 800; font-size: 32px; }
.mark-sub { color: var(--text-dim); font-size: 14px; }

.mark-sec { padding: 14px 16px; border-radius: 12px; background: var(--panel-2); border: 1px solid var(--line-soft); border-left-width: 4px; }
.mark-sec h4 { font-size: 14px; margin-bottom: 8px; font-family: 'Inter'; }
.mark-sec.good  { border-left-color: var(--good); }
.mark-sec.warn  { border-left-color: var(--warn); }
.mark-sec.bad   { border-left-color: var(--bad); }
.mark-sec.info  { border-left-color: var(--accent); }
.mark-sec.model { border-left-color: var(--good); background: var(--bg-2); }
.mark-list { margin: 0; padding-left: 20px; display: flex; flex-direction: column; gap: 6px; }
.mark-list li { font-size: 14.5px; line-height: 1.5; }
.model-text { margin: 0; font-size: 14.5px; line-height: 1.6; color: var(--text); white-space: pre-wrap; }
.mark-disclaimer { color: var(--text-mute); font-size: 12.5px; text-align: center; padding-top: 4px; }

/* ---------- accounts / ranks / leaderboard ---------- */
.rank-badge { display: inline-flex; align-items: center; gap: 5px; font-weight: 700; font-size: 12.5px; padding: 4px 11px; border-radius: 999px;
  color: var(--rc, var(--accent)); background: color-mix(in srgb, var(--rc, var(--accent)) 14%, transparent);
  border: 1px solid color-mix(in srgb, var(--rc, var(--accent)) 38%, transparent); white-space: nowrap; }
.rank-badge.big { font-size: 15px; padding: 6px 14px; }

.profile-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 22px; padding-bottom: 20px; border-bottom: 1px solid var(--line-soft); }
.profile-id { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.profile-name { font-family: 'Lexend'; font-weight: 800; font-size: 26px; letter-spacing: -.02em; }

.friend-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 11px 4px; border-bottom: 1px solid var(--line-soft); }
.friend-row:last-child { border-bottom: none; }
.friend-name { font-weight: 600; }

.lb-row { display: grid; grid-template-columns: 48px 1fr auto auto auto; gap: 12px; align-items: center; padding: 12px 14px; border-radius: 10px; }
.lb-row:nth-child(odd) { background: var(--panel-2); }
.lb-row.me { box-shadow: inset 0 0 0 1px var(--accent); }
.lb-pos { font-family: 'Lexend'; font-weight: 800; color: var(--text-mute); }
.lb-name { font-weight: 600; min-width: 0; overflow: hidden; text-overflow: ellipsis; }
.lb-elo { font-family: 'Lexend'; font-weight: 800; font-variant-numeric: tabular-nums; }
.lb-record { font-size: 13px; }
@media (max-width: 560px) { .lb-row { grid-template-columns: 36px 1fr auto; } .lb-row .rank-badge, .lb-record { display: none; } }

.elo-banner { display: flex; align-items: center; justify-content: center; gap: 14px; padding: 12px 16px; border-radius: 12px; margin-bottom: 16px; font-weight: 700;
  border: 1px solid var(--line); background: var(--panel-2); }
.elo-banner.up   { border-color: color-mix(in srgb, var(--good) 50%, transparent); background: color-mix(in srgb, var(--good) 12%, var(--panel-2)); }
.elo-banner.down { border-color: color-mix(in srgb, var(--bad) 50%, transparent);  background: color-mix(in srgb, var(--bad) 12%, var(--panel-2)); }
.elo-outcome { font-family: 'Lexend'; font-size: 17px; }
.elo-delta { font-family: 'Lexend'; font-weight: 800; }
.topnav a.active[data-nav="account"], .topnav a.active[data-nav="leaderboard"] { color: var(--accent-ink); }

/* ---------- premium design system: frosted glass + mono numbers ---------- */
.panel { background: color-mix(in srgb, var(--panel) 84%, transparent); backdrop-filter: blur(12px) saturate(1.1); -webkit-backdrop-filter: blur(12px) saturate(1.1); }
.card-glass {
  background: color-mix(in srgb, var(--panel-2) 70%, transparent);
  border: 1px solid color-mix(in srgb, #ffffff 8%, var(--line-soft));
  border-radius: var(--radius); padding: clamp(18px, 3vw, 28px);
  backdrop-filter: blur(16px) saturate(1.2); -webkit-backdrop-filter: blur(16px) saturate(1.2);
  box-shadow: 0 16px 44px rgba(0,0,0,.45), inset 0 1px 0 rgba(255,255,255,.05);
}
.mono, .stat-big, .pc-score, .mark-score, .lb-elo, .lb-pos, .score-ring,
.fc-count, .result-score, .result-rank, .qtimer-num, .dash-pct { font-family: var(--font-mono); font-feature-settings: "tnum"; }
.brand-mark { color: var(--gold); }

/* ---------- excuse generator ---------- */
.excuse-card { text-align: left; }
.excuse-line { font-size: 18px; line-height: 1.5; font-weight: 500; color: var(--text); min-height: 54px; }

/* ---------- achievement badges ---------- */
.badge-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; }
.badge-card {
  background: color-mix(in srgb, var(--panel-2) 60%, transparent); border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm); padding: 16px; text-align: center; opacity: .55; filter: grayscale(.5); transition: .2s;
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
}
.badge-card.got { opacity: 1; filter: none; border-color: color-mix(in srgb, var(--gold) 45%, transparent); box-shadow: 0 0 0 1px color-mix(in srgb, var(--gold) 25%, transparent), 0 10px 26px rgba(0,0,0,.35); }
.badge-icon { font-size: 30px; margin-bottom: 8px; }
.badge-name { font-weight: 700; font-size: 13.5px; }
.badge-desc { color: var(--text-mute); font-size: 11.5px; margin-top: 4px; line-height: 1.35; }

/* ---------- boss battle ---------- */
.boss-arena { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.boss-side { position: relative; overflow: hidden; text-align: center; padding: 20px 16px; border-radius: var(--radius);
  background: color-mix(in srgb, var(--panel-2) 70%, transparent); border: 1px solid var(--line-soft); backdrop-filter: blur(10px); }
.boss-side.me { border-color: color-mix(in srgb, var(--blue) 40%, transparent); }
.boss-face { font-size: 46px; line-height: 1; margin-bottom: 8px; }
.boss-name { font-weight: 700; font-family: 'Lexend'; margin-bottom: 12px; }
.hp-row { display: flex; align-items: center; gap: 10px; }
.hp-row .mono { font-size: 13px; min-width: 56px; text-align: right; }
.hpbar { flex: 1; height: 12px; border-radius: 999px; background: var(--bg); overflow: hidden; border: 1px solid var(--line-soft); }
.hpfill { display: block; height: 100%; width: 100%; transition: width .4s cubic-bezier(.2,.7,.2,1); }
.hpfill.hp-high { background: var(--good); }
.hpfill.hp-mid  { background: var(--gold); }
.hpfill.hp-low  { background: var(--bad); }
.float-hit { position: absolute; left: 50%; top: 30%; transform: translateX(-50%); font-family: var(--font-mono); font-weight: 700; font-size: 22px; pointer-events: none;
  animation: floatup .9s ease-out forwards; }
.float-hit.good { color: var(--good); } .float-hit.bad { color: var(--bad); }
@keyframes floatup { from { opacity: 1; transform: translate(-50%, 0); } to { opacity: 0; transform: translate(-50%, -40px); } }
@media (max-width: 560px) { .boss-arena { grid-template-columns: 1fr; } }
.boss-side { transition: box-shadow .2s; }
.boss-hit { animation: bosshit .42s ease; }
@keyframes bosshit { 0%,100%{transform:translateX(0)} 20%{transform:translateX(-7px)} 40%{transform:translateX(6px)} 60%{transform:translateX(-4px)} 80%{transform:translateX(3px)} }
.boss-side.boss-hit:not(.me) { box-shadow: 0 0 0 2px color-mix(in srgb, var(--gold) 55%, transparent), 0 0 28px color-mix(in srgb, var(--gold) 26%, transparent); }
.boss-side.me.boss-hit { box-shadow: 0 0 0 2px color-mix(in srgb, var(--bad) 55%, transparent), 0 0 28px color-mix(in srgb, var(--bad) 26%, transparent); }
.boss-face { transition: transform .15s; display: inline-block; }
.combo-pill { display: block; width: 100%; text-align: center; margin: 14px 0 0; font-family: var(--font-mono); font-weight: 700; font-size: 15px; color: var(--gold); letter-spacing: .03em; animation: comboPop .3s ease; }
.combo-pill.hidden { display: none; }
@keyframes comboPop { from { transform: scale(.7); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.badge-prog { margin-top: 6px; font-size: 11px; color: var(--gold); font-weight: 600; }

/* ---------- 3D study house ---------- */
.house-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 16px; margin-bottom: 16px; flex-wrap: wrap; }
.house-title { font-size: clamp(24px, 4vw, 34px); letter-spacing: -.02em; }
.house-stage {
  position: relative; width: 100%; min-height: 420px; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--line-soft);
  background: radial-gradient(120% 100% at 50% 0%, #121821, #0b0f14 70%);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.04), 0 22px 60px rgba(0,0,0,.5);
}
.house-canvas { display: block; width: 100%; touch-action: none; }
.house-loading { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; }
.spinner { width: 30px; height: 30px; border-radius: 50%; border: 3px solid var(--line); border-top-color: var(--accent); animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.house-label {
  position: absolute; transform: translate(-50%, -130%); pointer-events: none; z-index: 5;
  background: color-mix(in srgb, var(--panel) 88%, transparent); border: 1px solid var(--line);
  border-radius: 10px; padding: 7px 11px; font-size: 12.5px; line-height: 1.3; white-space: nowrap;
  backdrop-filter: blur(8px); box-shadow: 0 8px 22px rgba(0,0,0,.45);
}
.house-label b { display: block; } .house-label span { color: var(--text-mute); font-size: 11.5px; }

/* ---------- motion / 3D (fx.js) ---------- */
@media (prefers-reduced-motion: no-preference) {
  .fx-reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s cubic-bezier(.2,.75,.2,1); }
  .fx-in { opacity: 1; transform: none; }
}
.subject-card, .topic-card { will-change: transform; transition: transform .25s cubic-bezier(.2,.75,.2,1), border-color .2s, box-shadow .25s; }
.subject-card:hover, .topic-card:hover { box-shadow: 0 18px 50px rgba(0,0,0,.5); }
.subject-card .sc-icon, .topic-card h4 { transform: translateZ(20px); }     /* lift on tilt */
/* refined left accent: a soft glow instead of a hard bar */
.subject-card::before { width: 3px; border-radius: 0 3px 3px 0; opacity: .85; box-shadow: 0 0 16px var(--c, var(--accent)); }
.btn { transition: transform .12s cubic-bezier(.2,.75,.2,1), border-color .15s, box-shadow .2s, background .15s; }
.btn:active { transform: translateY(1px) scale(.99); }

@media (max-width: 560px) {
  .vs-board { grid-template-columns: 1fr; }
  .vs-mid { padding: 4px 0; }
  .tabs { width: 100%; }
  .flashcard { height: 280px; }
}