:root {
  --bg: #f6f7fb; --surface: #ffffff; --surface-2: #eef1f7; --text: #141a2a; --muted: #5d6680; --border: #dbe0ea;
  --accent: #ff9900; --accent-ink: #1b1300; --brand: #232f3e; --link: #1d5fd1;
  --good: #16a34a; --good-bg: #e7f7ec; --bad: #dc2626; --bad-bg: #fdecec; --mid: #d97706; --star: #a16207; --star-bg: #fef6dc;
  --shadow: 0 1px 2px rgba(20,26,42,.06), 0 4px 16px rgba(20,26,42,.06);
  --c-compute: #f58536; --c-storage: #3f8624; --c-database: #3b48cc; --c-network: #8c4fff; --c-security: #dd344c;
  --c-ai: #01a88d; --c-analytics: #7a3cd6; --c-integration: #e7157b; --c-mgmt: #c925d1; --c-billing: #2e8b57;
  --c-migration: #0f7b8f; --c-devtools: #4b5bdc; --c-concept: #64748b;
  --radius: 14px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e121b; --surface: #161c29; --surface-2: #1e2636; --text: #e8ecf5; --muted: #9aa4bc; --border: #2a3448;
    --brand: #0b0f17; --link: #7fb0ff; --good: #34d17a; --good-bg: #10301f; --bad: #ff6b6b; --bad-bg: #3a1618; --mid: #f0a43a; --star: #f6c453; --star-bg: #33280c;
    --shadow: 0 1px 2px rgba(0,0,0,.4), 0 4px 16px rgba(0,0,0,.3);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0e121b; --surface: #161c29; --surface-2: #1e2636; --text: #e8ecf5; --muted: #9aa4bc; --border: #2a3448;
  --brand: #0b0f17; --link: #7fb0ff; --good: #34d17a; --good-bg: #10301f; --bad: #ff6b6b; --bad-bg: #3a1618; --mid: #f0a43a; --star: #f6c453; --star-bg: #33280c;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
a { color: var(--link); }
h1 { font-size: clamp(1.5rem, 3vw, 2.1rem); line-height: 1.2; margin: .2em 0 .4em; }
h2 { font-size: 1.3rem; margin: 0 0 .5em; }
h3 { font-size: 1.05rem; margin: 1.4em 0 .5em; }
.container { max-width: 1100px; margin: 0 auto; padding: 0 16px; }
main.container { padding-top: 20px; padding-bottom: 40px; min-height: 70vh; }
.muted { color: var(--muted); }
.hidden { display: none !important; }
.lead { font-size: 1.1rem; color: var(--muted); max-width: 60ch; }
.loading { padding: 40px 0; text-align: center; color: var(--muted); }
.foot { color: var(--muted); font-size: .8rem; padding-bottom: 24px; }

/* top bar */
.topbar { background: var(--brand); color: #fff; display: flex; align-items: center; gap: 16px; padding: 10px 16px; flex-wrap: wrap; position: sticky; top: 0; z-index: 20; }
.topbar a { color: #fff; text-decoration: none; }
.brand { font-weight: 800; font-size: 1.15rem; display: flex; gap: 8px; align-items: center; }
.links { display: flex; gap: 14px; }
.links a { opacity: .85; } .links a:hover { opacity: 1; text-decoration: underline; }
.me { margin-left: auto; display: flex; align-items: center; gap: 12px; font-size: .9rem; flex-wrap: wrap; }
.xp { display: inline-flex; gap: 6px; align-items: center; }
.mini-bar { display: inline-block; width: 60px; height: 6px; background: rgba(255,255,255,.2); border-radius: 4px; overflow: hidden; }
.mini-bar span { display: block; height: 100%; background: var(--accent); }
.demo-pill { background: var(--accent); color: var(--accent-ink); padding: 2px 10px; border-radius: 99px; font-weight: 700; font-size: .78rem; }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; font: inherit; font-weight: 600; padding: 10px 18px; border-radius: 10px; border: 1px solid var(--border); background: var(--surface); color: var(--text); cursor: pointer; text-decoration: none; min-height: 44px; }
.btn:hover:not(:disabled) { border-color: var(--muted); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover:not(:disabled) { filter: brightness(1.05); border-color: var(--accent); }
.btn.ghost { background: transparent; color: inherit; border-color: rgba(255,255,255,.35); }
.btn.small { padding: 6px 12px; min-height: 36px; font-size: .9rem; }
.btn.big { padding: 14px 26px; font-size: 1.05rem; }
.icon-btn { border: 1px solid var(--border); background: var(--surface); color: var(--text); border-radius: 8px; width: 36px; height: 36px; cursor: pointer; }
.icon-btn:disabled { opacity: .35; }
:focus-visible { outline: 3px solid var(--link); outline-offset: 2px; }

.panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); margin-top: 24px; }
.section-title { margin-top: 32px; }
.back { display: inline-block; margin-bottom: 8px; text-decoration: none; font-weight: 600; }

/* sign in */
.signin { text-align: center; padding: 60px 0; display: grid; justify-items: center; gap: 8px; }
.signin-art { font-size: 72px; }

/* home */
.hero { display: flex; justify-content: space-between; gap: 20px; align-items: center; flex-wrap: wrap; background: linear-gradient(135deg, var(--surface), var(--surface-2)); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.hero-stats { display: flex; gap: 12px; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 10px 16px; text-align: center; min-width: 92px; }
.stat b { display: block; font-size: 1.5rem; }
.stat span { font-size: .8rem; color: var(--muted); }
.exam-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; }
.exam-card { position: relative; display: flex; flex-direction: column; gap: 10px; background: var(--surface); border: 1px solid var(--border); border-top: 6px solid var(--exam); border-radius: var(--radius); padding: 18px; color: var(--text); text-decoration: none; box-shadow: var(--shadow); transition: transform .15s; }
.exam-card:hover { transform: translateY(-3px); }
.exam-card h3 { margin: 0; }
.exam-card .btn { margin-top: auto; align-self: flex-start; }
.exam-card-top { display: flex; justify-content: space-between; gap: 10px; align-items: center; }
.exam-code { font-weight: 800; color: var(--exam); letter-spacing: .03em; }
.exam-facts { list-style: none; margin: 0; padding: 0; font-size: .9rem; }
.exam-clf { --exam: #ff9900; } .exam-aif { --exam: #01a88d; } .exam-saa { --exam: #3b48cc; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .exam-saa { --exam: #8f9aff; } }
.due-pill { position: absolute; top: 12px; right: 110px; background: var(--bad); color: #fff; font-size: .75rem; font-weight: 700; padding: 2px 8px; border-radius: 99px; }
.badges { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 10px; }
.badge { background: var(--surface); border: 1px dashed var(--border); border-radius: 12px; padding: 12px; text-align: center; display: grid; gap: 2px; opacity: .55; filter: grayscale(1); }
.badge.got { opacity: 1; filter: none; border-style: solid; border-color: var(--accent); }
.badge-icon { font-size: 28px; }
.badge small { color: var(--muted); font-size: .75rem; }
.steps li { margin-bottom: 6px; }

/* rings and bars */
.ring-track { fill: none; stroke: var(--surface-2); stroke-width: 9; }
.ring-fill { fill: none; stroke: var(--bad); stroke-width: 9; stroke-linecap: round; transition: stroke-dasharray .8s; }
.ring-fill.mid { stroke: var(--mid); } .ring-fill.good { stroke: var(--good); }
.ring-text { font-weight: 800; font-size: 18px; fill: var(--text); }
.bar { height: 12px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
.bar span { display: block; height: 100%; background: var(--link); border-radius: 99px; transition: width .6s; }
.bar.good span { background: var(--good); } .bar.mid span { background: var(--mid); } .bar.low span { background: var(--bad); }

/* exam hub */
.exam-head { display: flex; gap: 24px; align-items: center; background: var(--surface); border: 1px solid var(--border); border-left: 6px solid var(--exam); border-radius: var(--radius); padding: 20px; flex-wrap: wrap; }
.exam-head h1 { margin: 0; }
.domains { display: grid; gap: 10px; }
.domain-row { display: grid; grid-template-columns: minmax(200px, 1.2fr) 2fr auto; gap: 14px; align-items: center; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 10px 14px; }
.domains.compact .domain-row { grid-template-columns: minmax(180px, 1fr) 2fr; }
.domain-name { display: grid; }
.domain-name small { color: var(--muted); }
.mode-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 12px; }
.mode-tile { position: relative; display: grid; gap: 4px; align-content: start; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; text-decoration: none; color: var(--text); box-shadow: var(--shadow); transition: transform .15s, border-color .15s; min-height: 130px; }
.mode-tile:hover { transform: translateY(-3px); border-color: var(--accent); }
.mode-tile.disabled { opacity: .55; box-shadow: none; }
.mode-tile small { color: var(--muted); }
.mode-icon { font-size: 30px; }
.count { position: absolute; top: 12px; right: 12px; background: var(--surface-2); border-radius: 99px; padding: 0 9px; font-size: .8rem; font-weight: 700; }

/* play */
.play-top { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.play-title { font-size: 1.3rem; margin: 0; flex: 1; }
.play-meta { display: flex; gap: 12px; font-weight: 700; }
.clock { font-variant-numeric: tabular-nums; } .clock.low { color: var(--bad); animation: pulse 1s infinite; }
.combo { color: var(--accent); }
.play-progress { display: flex; align-items: center; gap: 10px; margin: 12px 0; }
.play-progress .bar { flex: 1; }
.play-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); animation: rise .25s ease-out; }
.play-head { display: flex; gap: 8px; flex-wrap: wrap; }
.type-pill, .domain-pill, .ai-pill { font-size: .78rem; font-weight: 700; padding: 3px 10px; border-radius: 99px; background: var(--surface-2); }
.ai-pill { background: #7c3aed; color: #fff; }
.q { font-size: 1.12rem; font-weight: 600; margin: 12px 0 4px; }
.hint { color: var(--muted); font-size: .9rem; margin: 4px 0 12px; }
.actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 16px; flex-wrap: wrap; }
.feedback { margin-top: 16px; border-radius: 12px; padding: 12px 16px; animation: rise .25s; }
.feedback.good { background: var(--good-bg); border: 1px solid var(--good); }
.feedback.bad { background: var(--bad-bg); border: 1px solid var(--bad); }
.feedback p { margin: 4px 0 0; }
.play-footer { margin-top: 14px; }

/* chips */
.chip { font: inherit; font-size: .92rem; display: inline-flex; align-items: center; gap: 8px; padding: 6px 12px 6px 6px; border-radius: 10px; border: 1px solid var(--border); background: var(--surface); color: var(--text); cursor: grab; touch-action: none; user-select: none; min-height: 40px; box-shadow: 0 1px 0 var(--border); transition: transform .1s, box-shadow .1s; }
.chip.txt { padding: 8px 12px; text-align: left; }
.chip:hover { transform: translateY(-1px); box-shadow: 0 3px 8px rgba(0,0,0,.12); }
.chip.selected { outline: 3px solid var(--accent); outline-offset: 1px; }
.chip.dragging { opacity: .35; }
.chip.ghost { position: fixed; left: 0; top: 0; z-index: 100; pointer-events: none; transform-origin: 0 0; box-shadow: 0 10px 24px rgba(0,0,0,.25); cursor: grabbing; }
.mono { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 7px; font-size: .72rem; font-weight: 800; color: #fff; background: var(--cat, var(--c-concept)); flex: none; }
.cat-compute { --cat: var(--c-compute); } .cat-storage { --cat: var(--c-storage); } .cat-database { --cat: var(--c-database); }
.cat-network { --cat: var(--c-network); } .cat-security { --cat: var(--c-security); } .cat-ai { --cat: var(--c-ai); }
.cat-analytics { --cat: var(--c-analytics); } .cat-integration { --cat: var(--c-integration); } .cat-mgmt { --cat: var(--c-mgmt); }
.cat-billing { --cat: var(--c-billing); } .cat-migration { --cat: var(--c-migration); } .cat-devtools { --cat: var(--c-devtools); } .cat-concept { --cat: var(--c-concept); }
.chip.svc { border-left: 4px solid var(--cat); }
.chip.right { border-color: var(--good); background: var(--good-bg); }
.chip.wrong { border-color: var(--bad); background: var(--bad-bg); }
.belongs { color: var(--bad); font-weight: 700; }

.board { display: grid; gap: 10px; }
.board.locked .chip { cursor: default; }
.tray-label { font-size: .8rem; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
.tray { display: flex; flex-wrap: wrap; gap: 8px; min-height: 56px; padding: 10px; border: 2px dashed var(--border); border-radius: 12px; background: var(--surface-2); }
[data-drop].over { outline: 3px dashed var(--accent); outline-offset: 2px; }
.picking [data-drop]:not(.tray) { box-shadow: 0 0 0 2px var(--accent) inset; }

/* architecture builder */
.diagram { overflow-x: auto; padding: 6px 2px; background-image: radial-gradient(var(--border) 1px, transparent 1px); background-size: 16px 16px; border-radius: 12px; border: 1px solid var(--border); }
.flow { display: flex; align-items: stretch; gap: 0; flex-wrap: wrap; padding: 12px; row-gap: 14px; }
.node { display: grid; gap: 6px; align-content: start; min-width: 150px; max-width: 220px; flex: 1; background: var(--surface); border: 2px solid var(--border); border-radius: 12px; padding: 10px; }
.node.fixed { flex: 0 0 auto; min-width: 100px; background: var(--surface-2); border-style: solid; place-content: center; text-align: center; font-weight: 700; }
.node.slot { border-style: dashed; cursor: pointer; }
.node-label { font-size: .8rem; font-weight: 700; color: var(--muted); text-transform: uppercase; letter-spacing: .03em; }
.hole { min-height: 44px; border-radius: 10px; background: var(--surface-2); display: flex; align-items: center; justify-content: center; }
.hole:empty::before { content: 'Drop service'; color: var(--muted); font-size: .8rem; }
.hole .chip { width: 100%; }
.node.right { border-color: var(--good); border-style: solid; background: var(--good-bg); }
.node.wrong { border-color: var(--bad); border-style: solid; background: var(--bad-bg); }
.arrow { align-self: center; width: 30px; height: 2px; background: var(--muted); position: relative; flex: none; margin: 0 2px; }
.arrow::after { content: ''; position: absolute; right: -1px; top: -5px; border: 6px solid transparent; border-left-color: var(--muted); border-right: 0; }
.correction { font-size: .85rem; color: var(--good); font-weight: 700; }

/* sort */
.buckets { display: grid; grid-template-columns: repeat(var(--cols, 2), minmax(0, 1fr)); gap: 10px; }
.bucket { border: 2px solid var(--border); border-radius: 12px; background: var(--surface); min-height: 140px; display: flex; flex-direction: column; }
.bucket-title { font-weight: 800; padding: 8px 12px; border-bottom: 1px solid var(--border); background: var(--surface-2); border-radius: 10px 10px 0 0; }
.bucket-body { display: flex; flex-wrap: wrap; gap: 6px; padding: 10px; flex: 1; align-content: flex-start; }

/* rank */
.rank-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.rank-row { display: flex; align-items: center; gap: 10px; background: var(--surface-2); border: 1px solid var(--border); border-radius: 12px; padding: 6px 10px; flex-wrap: wrap; }
.rank-row .chip { flex: 1; }
.rank-num { width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; background: var(--brand); color: #fff; font-weight: 800; font-size: .85rem; flex: none; }
.rank-btns { display: flex; gap: 4px; }
.rank-row.right { border-color: var(--good); background: var(--good-bg); }
.rank-row.wrong { border-color: var(--bad); background: var(--bad-bg); }
.rank-end { font-size: .85rem; font-weight: 700; color: var(--muted); }

/* match */
.match-meta { display: flex; justify-content: flex-end; font-weight: 700; color: var(--muted); }
.match-grid { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr); gap: 12px; margin-top: 8px; }
.match-col { display: grid; gap: 8px; align-content: start; }
.match-tile { font: inherit; text-align: left; display: flex; gap: 8px; align-items: center; padding: 10px 12px; border-radius: 10px; border: 2px solid var(--border); background: var(--surface); color: var(--text); cursor: pointer; min-height: 48px; }
.match-tile.l { font-weight: 700; }
.match-tile.selected { border-color: var(--accent); background: var(--surface-2); }
.match-tile.paired { border-color: hsl(var(--pair-hue) 65% 50%); background: hsl(var(--pair-hue) 70% 50% / .14); cursor: default; }
.match-tile:disabled { color: var(--text); }
.shake { animation: shake .4s; border-color: var(--bad) !important; }

/* mcq + tf */
.options { display: grid; gap: 8px; margin-top: 10px; }
.option { font: inherit; text-align: left; display: flex; gap: 12px; align-items: flex-start; padding: 12px 14px; border: 2px solid var(--border); background: var(--surface); color: var(--text); border-radius: 12px; cursor: pointer; }
.option:hover:not(:disabled) { border-color: var(--muted); }
.option.chosen { border-color: var(--link); background: var(--surface-2); }
.option.right { border-color: var(--good); background: var(--good-bg); }
.option.wrong { border-color: var(--bad); background: var(--bad-bg); }
.option:disabled { cursor: default; color: var(--text); }
.opt-key { flex: none; width: 26px; height: 26px; border-radius: 7px; display: grid; place-items: center; background: var(--surface-2); font-weight: 800; font-size: .85rem; }
.tf-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 14px; }
.tf-btn { font: inherit; font-size: 1.2rem; font-weight: 800; padding: 22px; border-radius: 14px; border: 2px solid var(--border); background: var(--surface); color: var(--text); cursor: pointer; }
.tf-btn.true:hover:not(:disabled) { border-color: var(--good); } .tf-btn.false:hover:not(:disabled) { border-color: var(--bad); }
.tf-btn.right { background: var(--good-bg); border-color: var(--good); } .tf-btn.wrong { background: var(--bad-bg); border-color: var(--bad); }
.tf-btn:disabled { color: var(--text); cursor: default; }

/* tutor */
.tutor { margin-top: 12px; display: grid; gap: 8px; }
.tutor-btn { justify-self: start; border-color: #7c3aed; color: #7c3aed; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .tutor-btn { color: #c4b5fd; border-color: #8b5cf6; } }
.tutor-msg { background: var(--surface); border: 1px solid var(--border); border-left: 4px solid #7c3aed; border-radius: 10px; padding: 10px 14px; white-space: pre-line; }
.tutor-msg p { margin: 0 0 8px; } .tutor-msg p:last-child { margin: 0; }
.tutor-msg.you { border-left-color: var(--link); font-weight: 600; }
.tutor-msg.err { border-left-color: var(--bad); }
.tutor-msg.loading { color: var(--muted); }
.tutor-form { display: flex; gap: 8px; }
.tutor-input { flex: 1; font: inherit; padding: 8px 12px; border-radius: 10px; border: 1px solid var(--border); background: var(--surface); color: var(--text); min-height: 40px; min-width: 0; }

/* results */
.results { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
.results-score { display: flex; gap: 24px; align-items: center; flex-wrap: wrap; }
.results-score h2 { margin: 0 0 4px; font-size: 1.6rem; }
.xp-gain { display: inline-block; font-size: 1.5rem; color: var(--accent); }
.misses { display: grid; gap: 8px; }
.miss { border: 1px solid var(--border); border-radius: 10px; padding: 10px 14px; background: var(--surface-2); }
.miss summary { cursor: pointer; font-weight: 600; }

/* leaderboard + mentor */
.leaders { list-style: none; padding: 0; display: grid; gap: 8px; max-width: 640px; }
.leaders li { display: grid; grid-template-columns: 44px 1fr auto auto; gap: 12px; align-items: center; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 10px 14px; }
.leaders li.top1 { border-color: #f5c518; } .leaders .place { font-size: 1.3rem; text-align: center; font-weight: 800; }
.lb-xp { font-weight: 800; }
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); }
.roster { width: 100%; border-collapse: collapse; font-size: .92rem; }
.roster th, .roster td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
.roster th { background: var(--surface-2); white-space: nowrap; }
.ready-chip { font-weight: 800; padding: 2px 8px; border-radius: 99px; background: var(--bad-bg); color: var(--bad); }
.ready-chip.mid { background: rgba(217,119,6,.15); color: var(--mid); } .ready-chip.good { background: var(--good-bg); color: var(--good); }

/* toast + confetti */
.toast { position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 20px); opacity: 0; background: var(--brand); color: #fff; padding: 10px 18px; border-radius: 10px; z-index: 200; transition: .25s; max-width: calc(100vw - 32px); box-shadow: var(--shadow); }
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.toast.good { background: var(--good); } .toast.bad { background: var(--bad); }
.confetti { position: fixed; inset: 0; pointer-events: none; z-index: 150; overflow: hidden; }
.confetti i { position: absolute; top: -12px; width: 9px; height: 14px; border-radius: 2px; animation: fall linear forwards; }

@keyframes fall { to { top: 105vh; transform: rotate(720deg); } }
@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-6px); } 75% { transform: translateX(6px); } }
@keyframes pulse { 50% { opacity: .5; } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }

@media (max-width: 720px) {
  .topbar { gap: 8px 14px; }
  .me { margin-left: 0; width: 100%; justify-content: space-between; }
  .domain-row, .domains.compact .domain-row { grid-template-columns: 1fr; gap: 6px; }
  .domain-row .btn { justify-self: start; }
  .flow { flex-direction: column; align-items: stretch; }
  .node { max-width: none; }
  .arrow { width: 2px; height: 22px; margin: 2px auto; }
  .arrow::after { right: -5px; top: auto; bottom: -1px; border: 6px solid transparent; border-top-color: var(--muted); border-bottom: 0; }
  .buckets { grid-template-columns: 1fr 1fr; }
  .match-grid { grid-template-columns: 1fr 1fr; gap: 8px; }
  .match-tile { font-size: .88rem; padding: 8px; }
  .hero-stats { width: 100%; } .stat { flex: 1; min-width: 0; }
  .due-pill { position: static; align-self: flex-start; }
  .leaders li { grid-template-columns: 36px 1fr auto; } .leaders li > span:nth-child(3) { display: none; }
}
.flow.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 12px; }
.flow.grid .node { max-width: none; }
@media (max-width: 720px) {
  /* Keep the palette in reach while the diagram scrolls past on phones. */
  .board > .tray { position: sticky; bottom: 8px; z-index: 5; box-shadow: 0 -6px 18px rgba(0,0,0,.12); background: var(--surface); max-height: 30vh; overflow-y: auto; gap: 6px; padding: 8px; }
  .board > .tray .chip { font-size: .82rem; min-height: 34px; padding: 3px 8px 3px 3px; }
  .board > .tray .chip.txt { padding: 6px 8px; }
  .board > .tray .mono { width: 22px; height: 22px; font-size: .65rem; }
  .flow { padding: 8px; }
  .node { padding: 8px; }
  .node.fixed { padding: 6px; }
}

/* high-yield stars */
.star-pill { font-size: .78rem; font-weight: 700; padding: 3px 10px; border-radius: 99px; background: var(--star-bg); color: var(--star); border: 1px solid var(--star); }
.games-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.star-toggle { display: inline-flex; align-items: center; gap: 6px; font-weight: 600; color: var(--star); cursor: pointer; min-height: 44px; }
.star-toggle input { width: 18px; height: 18px; accent-color: var(--star); }
.star-note { margin-top: -4px; font-size: .9rem; }

/* retry and per-option notes */
.retry-pill { font-size: .78rem; font-weight: 700; padding: 3px 10px; border-radius: 99px; background: var(--surface-2); color: var(--link); margin-left: 8px; }
.feedback.retry { background: var(--surface-2); border: 1px solid var(--mid); }
.feedback.retry .actions { margin-top: 10px; }
.option.struck { opacity: .55; }
.option.struck .opt-body > span:first-child { text-decoration: line-through; }
.opt-body { display: grid; gap: 4px; }
.why { display: block; color: var(--muted); font-size: .88rem; line-height: 1.4; }
.option.right .why, .option.wrong .why { color: var(--text); }
.answer-key { list-style: none; padding: 0; margin: 8px 0; display: grid; gap: 6px; }
.answer-key li { padding: 8px 12px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); display: grid; gap: 2px; }
.answer-key li.right { border-color: var(--good); background: var(--good-bg); }

/* test date countdown */
.countdown { margin-top: 16px; padding: 16px 20px; }
.countdown.urgent { border-color: var(--mid); }
.countdown-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.countdown-row > div:not(.countdown-num) { flex: 1 1 220px; }
.countdown-row p { margin: 2px 0 0; }
.countdown-num { font-size: 2.6rem; font-weight: 800; line-height: 1; min-width: 72px; text-align: center; color: var(--link); font-variant-numeric: tabular-nums; }
.countdown.urgent .countdown-num { color: var(--mid); }
.countdown-text { display: grid; gap: 2px; }
.countdown-form label { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.date-input { font: inherit; padding: 8px 10px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--text); min-height: 44px; }
.countdown-fact { font-weight: 600; color: var(--link); }