:root {
  color-scheme: light dark;
  --bg: #f6f7fb;
  --panel: #ffffff;
  --panel-2: #f0f2f7;
  --text: #171923;
  --muted: #697083;
  --line: #dfe3eb;
  --primary: #5357e8;
  --primary-2: #7377ff;
  --accent: #13a37f;
  --danger: #d84a4a;
  --warning: #d28a14;
  --shadow: 0 18px 60px rgba(24, 30, 65, .10);
  --radius: 18px;
  --radius-sm: 12px;
  --max: 1180px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c1018;
    --panel: #131925;
    --panel-2: #1a2231;
    --text: #f3f5fb;
    --muted: #9aa4b6;
    --line: #2a3446;
    --primary: #7c82ff;
    --primary-2: #979cff;
    --accent: #4bd0aa;
    --danger: #ff7474;
    --warning: #ffb74d;
    --shadow: 0 18px 60px rgba(0,0,0,.28);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", sans-serif; line-height: 1.55; }
a { color: inherit; }
button, input, select, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: fixed; top: -60px; left: 16px; z-index: 1000; background: var(--text); color: var(--bg); padding: 10px 14px; border-radius: 10px; transition: top .2s; }
.skip-link:focus { top: 16px; }

.shell { width: min(var(--max), calc(100% - 32px)); margin-inline: auto; }
.topbar { position: sticky; top: 0; z-index: 50; display: flex; justify-content: space-between; align-items: center; gap: 18px; padding: 14px max(16px, calc((100vw - var(--max))/2)); background: color-mix(in srgb, var(--bg) 86%, transparent); backdrop-filter: blur(16px); border-bottom: 1px solid color-mix(in srgb, var(--line) 80%, transparent); }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; min-width: 0; }
.brand-mark { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 12px; background: linear-gradient(135deg, var(--primary), var(--accent)); color: white; box-shadow: var(--shadow); }
.brand strong { display: block; letter-spacing: -.02em; }
.brand small { display: block; color: var(--muted); font-size: 12px; }
.top-actions { display: flex; gap: 8px; align-items: center; }

.button { border: 1px solid transparent; border-radius: 12px; padding: 10px 14px; cursor: pointer; text-decoration: none; display: inline-flex; align-items: center; justify-content: center; gap: 7px; font-weight: 700; transition: transform .15s, border-color .15s, background .15s, opacity .15s; }
.button:hover { transform: translateY(-1px); }
.button:focus-visible, .tab:focus-visible, .chip:focus-visible, .icon-button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible { outline: 3px solid color-mix(in srgb, var(--primary) 36%, transparent); outline-offset: 2px; }
.button.primary { background: var(--primary); color: #fff; }
.button.primary:hover { background: var(--primary-2); }
.button.secondary { background: color-mix(in srgb, var(--primary) 12%, var(--panel)); border-color: color-mix(in srgb, var(--primary) 38%, var(--line)); color: var(--text); }
.button.ghost { background: transparent; border-color: var(--line); color: var(--text); }
.button.compact { padding: 8px 11px; border-radius: 10px; font-size: 14px; }
.button[aria-pressed="true"] { background: color-mix(in srgb, var(--primary) 15%, var(--panel)); border-color: var(--primary); }
.file-button input { display: none; }
.icon-button { border: 1px solid var(--line); background: transparent; color: var(--text); border-radius: 999px; width: 38px; height: 38px; font-size: 24px; line-height: 1; cursor: pointer; }
.link-button { border: 0; background: transparent; color: var(--primary); font-weight: 700; cursor: pointer; }

.hero { padding: 76px 0 46px; display: grid; grid-template-columns: 1.4fr .8fr; gap: 48px; align-items: center; }
.hero-copy h1 { font-size: clamp(42px, 6vw, 76px); line-height: .98; letter-spacing: -.055em; margin: 12px 0 22px; max-width: 900px; }
.hero-copy p { color: var(--muted); max-width: 760px; font-size: 18px; }
.eyebrow { font-size: 12px; text-transform: uppercase; letter-spacing: .13em; font-weight: 800; color: var(--accent); }
.hero-actions, .button-row { display: flex; gap: 10px; align-items: center; margin-top: 24px; }
.button-row.wrap { flex-wrap: wrap; }
.hero-panel { background: radial-gradient(circle at 10% 10%, color-mix(in srgb, var(--primary) 15%, transparent), transparent 40%), var(--panel); border: 1px solid var(--line); border-radius: 28px; padding: 24px; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; box-shadow: var(--shadow); }
.stat { border: 1px solid var(--line); border-radius: 16px; padding: 20px; background: color-mix(in srgb, var(--panel-2) 72%, transparent); }
.stat strong { display: block; font-size: 34px; letter-spacing: -.04em; }
.stat span { color: var(--muted); font-size: 13px; }
.privacy-note { grid-column: 1 / -1; display: flex; gap: 9px; align-items: center; color: var(--muted); padding: 6px 4px; font-size: 13px; }

.quickstart { padding: 30px 0 60px; }
.section-heading h2 { font-size: clamp(28px, 4vw, 46px); letter-spacing: -.035em; line-height: 1.08; margin: 8px 0; max-width: 900px; }
.section-heading p { color: var(--muted); max-width: 820px; }
.compact-heading h2 { font-size: 30px; }
.inline-heading { display: flex; align-items: end; justify-content: space-between; }
.steps { display: grid; grid-template-columns: repeat(3,1fr); gap: 14px; margin-top: 22px; }
.steps article, .feature-grid article { border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; background: var(--panel); }
.steps article > span, .feature-grid article > span { color: var(--primary); font-weight: 900; font-size: 13px; }
.steps h3, .feature-grid h3 { margin: 10px 0 6px; }
.steps p, .feature-grid p { color: var(--muted); margin: 0; }

.workspace { padding: 10px 0 78px; }
.tabs { display: flex; gap: 8px; overflow-x: auto; padding: 6px; background: var(--panel); border: 1px solid var(--line); border-radius: 16px; position: sticky; top: 76px; z-index: 20; box-shadow: 0 8px 24px rgba(0,0,0,.05); }
.tab { flex: 0 0 auto; border: 0; background: transparent; color: var(--muted); padding: 10px 15px; border-radius: 11px; font-weight: 800; cursor: pointer; }
.tab.active { color: #fff; background: var(--text); }
.output-language-bar { margin-top: 12px; display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 13px 16px; background: color-mix(in srgb, var(--primary) 7%, var(--panel)); border: 1px solid color-mix(in srgb, var(--primary) 25%, var(--line)); border-radius: 15px; }
.output-language-copy { min-width: 0; }
.output-language-copy strong { display: block; }
.output-language-copy small { display: block; color: var(--muted); margin-top: 2px; }
.output-language-bar select { min-width: 228px; padding: 9px 34px 9px 11px; }
.tab-panel { padding-top: 24px; }

.library-toolbar { display: flex; justify-content: space-between; gap: 12px; align-items: center; }
.search-box { flex: 1; min-width: 240px; max-width: 620px; display: flex; align-items: center; gap: 10px; background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 0 12px; }
.search-box input { border: 0; outline: 0; background: transparent; color: var(--text); width: 100%; padding: 12px 0; }
kbd { color: var(--muted); border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 6px; padding: 1px 6px; font-size: 12px; }
.toolbar-actions { display: flex; gap: 8px; }
.filter-block { margin: 18px 0; border: 1px solid var(--line); border-radius: 16px; background: var(--panel); padding: 14px 16px; }
.filter-row { display: flex; gap: 14px; align-items: flex-start; padding: 6px 0; }
.filter-label { width: 58px; flex: 0 0 auto; color: var(--muted); font-size: 13px; font-weight: 800; padding-top: 6px; }
.chips { display: flex; flex-wrap: wrap; gap: 7px; }
.chip { border: 1px solid var(--line); background: var(--panel-2); color: var(--muted); border-radius: 999px; padding: 6px 10px; cursor: pointer; font-size: 13px; font-weight: 700; }
.chip.active { color: var(--text); border-color: var(--primary); background: color-mix(in srgb, var(--primary) 13%, var(--panel)); }
.results-line { display: flex; justify-content: space-between; color: var(--muted); font-size: 13px; margin: 14px 2px; }
.prompt-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 14px; }
.prompt-card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; min-height: 228px; display: flex; flex-direction: column; transition: transform .15s, border-color .15s, box-shadow .15s; }
.prompt-card:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--primary) 50%, var(--line)); box-shadow: 0 10px 30px rgba(0,0,0,.06); }
.card-top { display: flex; justify-content: space-between; gap: 10px; }
.badges { display: flex; gap: 6px; flex-wrap: wrap; }
.badge { padding: 4px 8px; border-radius: 999px; background: var(--panel-2); color: var(--muted); font-size: 11px; font-weight: 800; }
.badge.age { color: var(--primary); background: color-mix(in srgb, var(--primary) 12%, var(--panel)); }
.badge.score-good { color: var(--accent); }
.favorite-button { border: 0; background: transparent; color: var(--muted); cursor: pointer; font-size: 20px; }
.favorite-button.active { color: var(--warning); }
.prompt-card h3 { margin: 14px 0 6px; font-size: 20px; letter-spacing: -.02em; }
.prompt-card p { color: var(--muted); margin: 0; font-size: 14px; }
.card-actions { margin-top: auto; padding-top: 18px; display: flex; gap: 8px; }
.card-actions .button { flex: 1; }
.empty-state { border: 1px dashed var(--line); border-radius: var(--radius); padding: 44px; text-align: center; color: var(--muted); background: color-mix(in srgb, var(--panel) 70%, transparent); }
.empty-state strong { color: var(--text); display: block; margin-bottom: 6px; }

.split-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.builder-card, .preview-card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; min-width: 0; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 18px; }
.form-grid label { display: grid; gap: 6px; color: var(--muted); font-size: 13px; font-weight: 800; }
.form-grid label.wide { grid-column: 1 / -1; }
input, select, textarea { color: var(--text); background: var(--panel-2); border: 1px solid var(--line); border-radius: 11px; }
.form-grid input, .form-grid select, .form-grid textarea { padding: 10px 11px; width: 100%; }
.toggle-row { margin-top: 14px; color: var(--muted); font-size: 13px; }
.toggle-row label { display: flex; gap: 8px; align-items: center; }
.preview-head { display: flex; align-items: start; justify-content: space-between; gap: 12px; }
.preview-head h2 { margin: 4px 0 14px; }
.score-badge { min-width: 54px; height: 54px; border-radius: 16px; display: grid; place-items: center; background: var(--panel-2); border: 1px solid var(--line); font-weight: 900; }
.prompt-editor { width: 100%; min-height: 380px; resize: vertical; padding: 14px; line-height: 1.55; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 13px; }
.prompt-editor.tall { min-height: 500px; }
.lint-mini { margin-top: 12px; color: var(--muted); font-size: 13px; }

.chain-header { display: flex; justify-content: space-between; gap: 24px; align-items: end; }
.chain-list { display: grid; gap: 12px; margin-top: 20px; }
.chain-item { display: grid; grid-template-columns: 52px 1fr auto; gap: 12px; align-items: start; background: var(--panel); border: 1px solid var(--line); border-radius: 16px; padding: 14px; }
.chain-number { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; background: var(--panel-2); font-weight: 900; color: var(--primary); }
.chain-item textarea { width: 100%; min-height: 130px; padding: 10px; resize: vertical; }
.chain-controls { display: grid; gap: 6px; }
.chain-controls button { width: 34px; height: 34px; border-radius: 9px; border: 1px solid var(--line); background: transparent; color: var(--text); cursor: pointer; }
.grow { flex: 1; }

.score-panel { display: flex; gap: 16px; align-items: center; padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.big-score { width: 88px; height: 88px; display: grid; place-items: center; border-radius: 22px; background: var(--panel-2); border: 1px solid var(--line); font-size: 30px; font-weight: 950; }
.score-panel p { color: var(--muted); margin: 4px 0 0; }
.lint-results { display: grid; gap: 8px; margin-top: 16px; }
.lint-row { display: grid; grid-template-columns: 28px 1fr auto; gap: 8px; align-items: start; padding: 12px; border-radius: 12px; background: var(--panel-2); border: 1px solid var(--line); }
.lint-row .status { font-weight: 950; }
.lint-row.pass .status { color: var(--accent); }
.lint-row.warn .status { color: var(--warning); }
.lint-row strong { display: block; }
.lint-row small { color: var(--muted); }
.lint-row .points { color: var(--muted); font-size: 12px; }

.why { padding: 10px 0 80px; }
.feature-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 14px; margin-top: 24px; }
.footer { border-top: 1px solid var(--line); padding: 28px 0 46px; display: flex; justify-content: space-between; gap: 20px; color: var(--muted); }
.footer strong { color: var(--text); }
.footer p { max-width: 640px; margin: 5px 0 0; }
.footer-links { display: flex; flex-wrap: wrap; gap: 16px; align-items: start; }

.prompt-dialog { width: min(900px, calc(100% - 28px)); max-height: 90vh; border: 1px solid var(--line); border-radius: 22px; padding: 0; background: var(--panel); color: var(--text); box-shadow: var(--shadow); }
.prompt-dialog::backdrop { background: rgba(0,0,0,.62); backdrop-filter: blur(4px); }
.dialog-shell { padding: 22px; }
.dialog-head { display: flex; justify-content: space-between; gap: 16px; }
.dialog-head h2 { margin: 10px 0 4px; font-size: 28px; }
.dialog-head p { color: var(--muted); margin: 0; }
.compare-bar { display: flex; gap: 7px; margin: 16px 0 10px; flex-wrap: wrap; }
.dialog-editor { min-height: 360px; }
.dialog-actions { display: flex; align-items: center; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.source-details { margin-top: 14px; border-top: 1px solid var(--line); padding-top: 12px; color: var(--muted); font-size: 13px; }
.source-details summary { cursor: pointer; font-weight: 800; color: var(--text); }
.source-details a { color: var(--primary); word-break: break-all; }
.toast { position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 24px); opacity: 0; pointer-events: none; background: var(--text); color: var(--bg); padding: 10px 14px; border-radius: 999px; font-weight: 800; z-index: 200; transition: .2s; box-shadow: var(--shadow); }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 960px) {
  .hero { grid-template-columns: 1fr; padding-top: 52px; }
  .hero-panel { max-width: 620px; }
  .prompt-grid { grid-template-columns: repeat(2,1fr); }
  .split-layout { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: repeat(2,1fr); }
  .chain-header { display: block; }
  .top-actions .button.ghost:not(#langBtn):not(#installBtn) { display: none; }
}

@media (max-width: 640px) {
  .shell { width: min(100% - 20px, var(--max)); }
  .topbar { padding: 10px; }
  .brand strong { font-size: 14px; }
  .brand small { display: none; }
  .top-actions { gap: 6px; }
  .top-actions .button.primary { font-size: 0; width: 42px; height: 38px; padding: 0; }
  .top-actions .button.primary::after { content: "↗"; font-size: 17px; }
  .output-language-bar { align-items: stretch; flex-direction: column; gap: 10px; }
  .output-language-bar select { min-width: 0; width: 100%; }
  .hero { padding-top: 38px; gap: 24px; }
  .hero-copy h1 { font-size: clamp(40px, 13vw, 58px); }
  .hero-copy p { font-size: 16px; }
  .hero-actions { align-items: stretch; }
  .hero-actions .button { flex: 1; }
  .steps, .prompt-grid, .feature-grid { grid-template-columns: 1fr; }
  .tabs { top: 62px; }
  .library-toolbar { align-items: stretch; flex-direction: column; }
  .toolbar-actions { overflow-x: auto; }
  .filter-row { display: block; }
  .filter-label { display: block; width: auto; padding: 0 0 7px; }
  .form-grid { grid-template-columns: 1fr; }
  .form-grid label.wide { grid-column: auto; }
  .chain-item { grid-template-columns: 42px 1fr; }
  .chain-controls { grid-column: 1 / -1; grid-template-columns: repeat(3,34px); justify-content: end; }
  .footer { flex-direction: column; }
  .dialog-actions .grow { display: none; }
  .dialog-actions .button { flex: 1 1 40%; }
  .prompt-dialog { width: calc(100% - 12px); }
  .dialog-shell { padding: 16px; }
}

/* Original project handoff affordance — intentionally not a Google trademark/logo. */
.notebook-launch { gap: .45rem; }

/* v1.3 discovery-first layout: put the working area before the tutorial. */
main { display: flex; flex-direction: column; }
.hero { order: 1; padding: 42px 0 28px; gap: 32px; }
.hero-copy h1 { font-size: clamp(40px, 5.2vw, 64px); max-width: 820px; }
.hero-copy p { max-width: 720px; }
.hero-panel { padding: 18px; border-radius: 24px; }
.workspace { order: 2; padding: 10px 0 48px; }
.quickstart { order: 3; padding: 34px 0 64px; }
.why { order: 4; }

.collection-strip {
  display: grid;
  grid-template-columns: minmax(180px, .32fr) minmax(0, 1fr);
  gap: 18px;
  align-items: center;
  margin-bottom: 18px;
  padding: 17px 18px;
  border: 1px solid color-mix(in srgb, var(--primary) 28%, var(--line));
  border-radius: 18px;
  background:
    radial-gradient(circle at 8% 0%, color-mix(in srgb, #bca7ff 22%, transparent), transparent 42%),
    radial-gradient(circle at 92% 100%, color-mix(in srgb, #70dbc5 18%, transparent), transparent 38%),
    var(--panel);
}
.collection-copy p { margin: 5px 0 0; color: var(--muted); font-size: 13px; }
.collection-chips { justify-content: flex-end; }
.collection-chip { border-color: color-mix(in srgb, var(--primary) 20%, var(--line)); }
.collection-chip.active { box-shadow: 0 7px 20px color-mix(in srgb, var(--primary) 22%, transparent); }

.prompt-card {
  overflow: hidden;
  isolation: isolate;
  background:
    radial-gradient(circle at 100% 0%, color-mix(in srgb, var(--card-accent, var(--primary)) 8%, transparent), transparent 38%),
    var(--panel);
  border-top-color: color-mix(in srgb, var(--card-accent, var(--primary)) 42%, var(--line));
}
.prompt-card[data-vibe="dreamy"] { --card-accent: #9b7bea; }
.prompt-card[data-vibe="animated"] { --card-accent: #ff6f91; }
.prompt-card[data-vibe="adventure"] { --card-accent: #27a78c; }
.prompt-card[data-vibe="playful"] { --card-accent: #e8a328; }
.prompt-card[data-vibe="cinematic"] { --card-accent: #4d6fd7; }
.prompt-card[data-vibe="elegant"] { --card-accent: #b4677d; }
.prompt-card[data-vibe="editorial"] { --card-accent: #e45d4e; }
.prompt-card[data-vibe="calm"] { --card-accent: #63a687; }
.prompt-card[data-vibe="performance"] { --card-accent: #d64f83; }
.prompt-card[data-vibe="cultural"] { --card-accent: #148c76; }
.badge.vibe { color: var(--card-accent, var(--primary)); background: color-mix(in srgb, var(--card-accent, var(--primary)) 11%, var(--panel)); }
.badge-new { color: #fff; background: linear-gradient(135deg, #7a5df0, #d85c9b); letter-spacing: .06em; }
.badge.score-good { color: #087d68; background: color-mix(in srgb, #1bb89b 10%, var(--panel)); }

.load-more-row { display: flex; justify-content: center; margin: 22px 0 4px; }
.load-more-row .button { min-width: 180px; }
.reference-tip {
  margin: 12px 0 0;
  padding: 11px 13px;
  border: 1px solid color-mix(in srgb, var(--accent) 28%, var(--line));
  border-radius: 12px;
  color: var(--muted);
  background: color-mix(in srgb, var(--accent) 6%, var(--panel));
  font-size: 13px;
  line-height: 1.5;
}

@media (max-width: 960px) {
  .hero { padding-top: 34px; }
  .collection-strip { grid-template-columns: 1fr; }
  .collection-chips { justify-content: flex-start; }
}

@media (max-width: 640px) {
  .hero { padding-top: 26px; padding-bottom: 18px; }
  .hero-copy h1 { font-size: clamp(38px, 12vw, 52px); }
  .hero-panel { display: none; }
  .collection-strip { padding: 14px; margin-bottom: 14px; }
  .collection-chips { flex-wrap: nowrap; overflow-x: auto; padding-bottom: 4px; }
  .collection-chip { flex: 0 0 auto; }
  .quickstart { padding-top: 24px; }
}