* { box-sizing: border-box; }

:root {
  color-scheme: dark;
  --bg: #0B1821;
  --surface: #132A35;
  --surface-raised: #1A3441;
  --text: #EEF3F2;
  --muted: #A9BBC0;
  --border: #36515D;
  --accent: #D85A32;
  --accent-strong: #B94322;
  --accent-soft: #F0AA92;
  --accent-button-text: #0B1821;
  --accent-button-hover-text: #FFFFFF;
  --success: #86C8A2;
  --radius: 8px;
}

:root[data-theme="mist"] {
  color-scheme: light;
  --bg: #F1F4F4;
  --surface: #E2E9EA;
  --surface-raised: #FAFBFA;
  --text: #132A36;
  --muted: #526872;
  --border: #B1C0C4;
  --accent: #A84224;
  --accent-strong: #96361D;
  --accent-soft: #8F3E28;
  --accent-button-text: #FFFFFF;
  --accent-button-hover-text: #FFFFFF;
  --success: #286A46;
}

html, body, main, section, .tool-item, .media-placeholder { min-width: 0; }
html {
  font-family: "Microsoft YaHei", "Noto Sans CJK SC", "PingFang SC", system-ui, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}
body { margin: 0; background: var(--bg); }
a, button { min-width: 44px; min-height: 44px; }
a { color: var(--accent); }
a:hover { color: var(--accent-strong); }
button {
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-raised);
  color: var(--text);
  font: inherit;
  cursor: pointer;
}
button:hover:not(:disabled) { border-color: var(--accent); }
button:disabled { cursor: not-allowed; opacity: .58; }
:where(a, button):focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }
[hidden], .hidden { display: none !important; }
img { display: block; max-width: 100%; height: auto; }
figure { margin: 0; }

.skip-link {
  position: absolute; top: 8px; left: 16px; z-index: 3;
  padding: 8px 12px; border: 1px solid var(--accent); border-radius: var(--radius);
  background: var(--surface-raised); color: var(--text); transform: translateY(-160%);
}
.skip-link:focus-visible { transform: translateY(0); }
.site-header, main, .footer { width: min(calc(100% - 40px), 1360px); margin: 0 auto; }
.site-header {
  min-height: 70px; display: flex; flex-wrap: nowrap; align-items: center; gap: 16px;
  border-bottom: 1px solid var(--border);
}
.brand {
  display: grid; align-content: center; gap: 0; min-width: 0; margin-right: auto;
  color: var(--text); text-decoration: none;
}
.brand strong { font-size: 1.15rem; letter-spacing: -.02em; }
.brand span, .site-header nav, .footer small, .tool-kicker, .section-kicker, .section-note, .hero-kicker { color: var(--muted); }
.brand span { font-size: .83rem; }
.site-header nav { display: flex; align-items: center; gap: 8px; }
.site-header nav a { display: inline-flex; align-items: center; padding: 0 8px; color: var(--text); text-decoration: none; }
.theme-toggle { white-space: nowrap; }
#auth-section { display: flex; align-items: center; justify-content: flex-end; gap: 8px; min-width: 0; }
.auth-state { display: flex; align-items: center; justify-content: flex-end; gap: 8px; flex-wrap: wrap; }
.auth-state .welcome-msg { max-width: 22rem; overflow-wrap: anywhere; font-weight: 600; }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 8px 14px; border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); text-decoration: none; }
.btn-primary { border-color: var(--accent); background: var(--accent); color: var(--accent-button-text); }
.btn-primary:hover { border-color: var(--accent-strong); background: var(--accent-strong); color: var(--accent-button-hover-text); }
.btn-outline { background: var(--surface-raised); }
.btn-danger-text { color: var(--accent-soft); }
.btn-sm { min-height: 40px; padding: 6px 12px; font-size: .92rem; }
.status-message { display: flex; align-items: center; gap: 8px; color: var(--muted); }
.status-error, .usage-error { color: var(--accent-soft); }
.auth-hint { width: 100%; color: var(--accent-soft); font-size: .9rem; }
.loading-spinner { display: inline-block; width: 18px; height: 18px; border: 2px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

main { padding: 16px 0 40px; }
section { margin: 0 0 40px; }
.hero { min-height: 190px; max-height: 240px; display: flex; flex-direction: column; align-items: flex-start; justify-content: center; gap: 8px; padding: 16px 0; }
.hero p, .hero h1 { margin: 0; }
.hero h1 { max-width: 18ch; font-size: clamp(2rem, 4.2vw, 3.2rem); line-height: 1.2; }
.hero-copy { max-width: 52rem; color: var(--muted); }
.hero-actions { display: flex; align-items: center; gap: 8px; }
.hero-actions a { display: inline-flex; align-items: center; padding: 8px 14px; border: 1px solid var(--accent); border-radius: var(--radius); background: var(--accent); color: var(--accent-button-text); text-decoration: none; }
.hero-actions a:hover { border-color: var(--accent-strong); background: var(--accent-strong); color: var(--accent-button-hover-text); }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin-bottom: 12px; }
.section-heading h2 { margin: 0; font-size: 1.5rem; line-height: 1.3; }
.section-kicker { margin: 0 0 4px; font-size: .78rem; letter-spacing: .08em; text-transform: uppercase; }
.section-note { margin: 0; font-size: .9rem; }

.tool-grid, .utility-grid { display: grid; min-width: 0; }
.tool-grid { height: 500px; grid-template-columns: repeat(12, minmax(0, 1fr)); grid-template-rows: repeat(3, minmax(0, 1fr)); gap: 12px; }
.tool-grid .tool-nh { grid-column: 1 / 5; grid-row: 1 / 3; }
.tool-grid .motion-media { grid-column: 5 / 9; grid-row: 1 / 3; }
.tool-grid .tool-outline { grid-column: 9 / 11; grid-row: 1; }
.tool-grid .tool-expansion { grid-column: 11 / 13; grid-row: 1; }
.tool-grid .tool-bible { grid-column: 9 / 11; grid-row: 2; }
.tool-grid .tool-coach { grid-column: 11 / 13; grid-row: 2; }
.tool-grid .tool-doctor { grid-column: 1 / 13; grid-row: 3; display: grid; grid-template-columns: minmax(64px, .7fr) minmax(0, 1.2fr) minmax(0, 2fr) auto; align-items: center; gap: 12px; padding: 12px 16px; }
.tool-item, .media-placeholder, #usage-content {
  padding: 16px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface);
}
.tool-item {
  display: flex; flex-direction: column; align-items: flex-start; gap: 8px;
  min-height: 0; min-width: 0; overflow-wrap: anywhere; color: var(--text); text-decoration: none;
}
.tool-item:hover, .tool-item:focus-visible { color: var(--text); border-color: var(--accent); }
.tool-item.locked, .tool-item[aria-disabled="true"] { opacity: .72; cursor: not-allowed; }
.tool-item p { margin: 0; }
.tool-item h3 { margin: 0; font-size: 1.1rem; line-height: 1.35; }
.tool-item .tool-kicker { font-size: .78rem; letter-spacing: .04em; }
.tool-item .tool-description { color: var(--muted); }
.tool-item .tool-action { display: inline-flex; align-items: center; min-height: 44px; margin-top: auto; padding: 6px 12px; border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); }
.tool-item:hover .tool-action { border-color: var(--accent); }
.tool-nh { border-color: var(--accent); background: var(--surface-raised); }
.tool-grid .tool-outline, .tool-grid .tool-expansion, .tool-grid .tool-bible, .tool-grid .tool-coach { gap: 4px; padding: 12px; font-size: .92rem; }
.tool-grid .tool-outline h3, .tool-grid .tool-expansion h3, .tool-grid .tool-bible h3, .tool-grid .tool-coach h3 { font-size: 1rem; }
.tool-grid .tool-outline .tool-description, .tool-grid .tool-expansion .tool-description, .tool-grid .tool-bible .tool-description, .tool-grid .tool-coach .tool-description { line-height: 1.4; }
.tool-doctor .tool-action { justify-self: start; }
.motion-media { position: relative; display: grid; grid-template-rows: minmax(0, 1fr) auto; grid-template-columns: minmax(0, 1fr); align-content: start; gap: 12px; overflow: hidden; background: var(--surface-raised); }
.motion-media img { width: 100%; height: 100%; min-height: 0; object-fit: cover; }
.motion-media figcaption { color: var(--muted); }
.motion-media::after { content: ""; grid-column: 1; grid-row: 1; align-self: stretch; justify-self: stretch; z-index: 1; margin: 12px; border: 1px solid var(--accent-soft); box-shadow: inset 0 0 0 1px var(--surface-raised); background: transparent; pointer-events: none; }
.utility-rail { margin-top: 40px; }
.utility-grid { grid-template-columns: 1fr; gap: 12px; }
.utility-grid .tool-item { display: grid; grid-template-columns: minmax(72px, auto) minmax(12rem, 1fr) minmax(14rem, 2fr) auto; align-items: center; gap: 12px; }
.utility-grid .tool-item .tool-action { margin-top: 0; }

.usage-section { margin-top: 40px; }
#usage-content { overflow-x: auto; }
.usage-state { min-height: 6rem; display: flex; align-items: center; justify-content: center; gap: 10px; flex-wrap: wrap; text-align: center; color: var(--muted); }
.usage-table { width: 100%; min-width: 680px; border-collapse: collapse; }
.usage-meta { padding: 0 0 12px; color: var(--muted); }
.usage-table th, .usage-table td { padding: 12px; text-align: left; border-bottom: 1px solid var(--border); }
.usage-table th { color: var(--muted); font-size: .84rem; font-weight: 600; }
.usage-table td { font-size: .94rem; }
.usage-table tfoot td { border-top: 1px solid var(--border); font-weight: 700; }
.usage-table .usage-value { color: var(--accent-soft); text-align: right; font-variant-numeric: tabular-nums; }
.usage-table .usage-label { font-weight: 500; }
.footer { padding: 16px 0 32px; border-top: 1px solid var(--border); text-align: center; }

@media (max-width: 1024px) {
  .tool-grid { display: flex; flex-direction: column; height: auto; gap: 12px; }
  .tool-grid > * { width: 100%; height: auto; min-height: auto; }
  .tool-grid .tool-doctor { display: flex; flex-direction: column; align-items: flex-start; gap: 8px; padding: 16px; }
  .motion-media img { width: 100%; height: 260px; object-fit: cover; }
}

@media (max-width: 900px) {
  .site-header { flex-wrap: wrap; padding: 10px 0; }
  .brand { flex: 1 1 180px; }
  #auth-section { flex: 1 1 100%; justify-content: flex-start; order: 4; }
  .site-header nav { order: 2; }
  .theme-toggle { order: 3; }
}
@media (max-width: 760px) {
  section { margin-bottom: 24px; }
  .site-header, main, .footer { width: min(calc(100% - 32px), 1360px); }
  .site-header { row-gap: 8px; }
  .site-header nav { width: 100%; order: 4; }
  #auth-section { width: 100%; order: 3; }
  .theme-toggle { margin-left: auto; }
  main { padding-top: 12px; }
  .hero { min-height: 150px; max-height: none; justify-content: flex-start; gap: 6px; padding: 8px 0 12px; }
  .hero h1 { max-width: none; font-size: clamp(2rem, 9vw, 2.5rem); }
  .hero-copy { font-size: .95rem; line-height: 1.45; }
  .section-heading { align-items: start; }
  .tool-grid { display: flex; flex-direction: column; height: auto; gap: 12px; }
  .tool-grid > * { width: 100%; height: auto; min-height: auto; }
  .tool-grid .tool-doctor { display: flex; flex-direction: column; align-items: flex-start; gap: 8px; padding: 16px; }
  .motion-media img { width: 100%; height: 200px; object-fit: cover; }
  .utility-rail { margin-top: 24px; }
  .utility-grid .tool-item { grid-template-columns: 1fr; align-items: start; }
  .usage-table { min-width: 620px; }
}

@media (prefers-reduced-motion: no-preference) {
  @keyframes editorial-desk-ken-burns {
    from { opacity: .94; transform: translate(-1.2%, -1%) scale(1.04); }
    to { opacity: 1; transform: translate(1.2%, 1%) scale(1.09); }
  }
  @keyframes writing-card-arrival {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
  }
  .motion-media img { transform-origin: center; animation: editorial-desk-ken-burns 19s ease-in-out alternate infinite; }
  #novel-tools-grid .tool-item { animation: writing-card-arrival .6s cubic-bezier(.22, .61, .36, 1) both; }
  #novel-tools-grid [data-tool-id="nh"] { --tool-order: 0; animation-delay: calc(var(--tool-order) * 60ms); }
  #novel-tools-grid [data-tool-id="outline"] { --tool-order: 1; animation-delay: calc(var(--tool-order) * 60ms); }
  #novel-tools-grid [data-tool-id="expansion"] { --tool-order: 2; animation-delay: calc(var(--tool-order) * 60ms); }
  #novel-tools-grid [data-tool-id="bible"] { --tool-order: 3; animation-delay: calc(var(--tool-order) * 60ms); }
  #novel-tools-grid [data-tool-id="coach"] { --tool-order: 4; animation-delay: calc(var(--tool-order) * 60ms); }
  #novel-tools-grid [data-tool-id="doctor"] { --tool-order: 5; animation-delay: calc(var(--tool-order) * 60ms); }
  .tool-item { transition: transform 180ms ease-out, border-color 180ms ease-out; }
  .tool-item:hover, .tool-item:focus-visible { transform: translateY(-3px); }
  button:active { transform: translateY(1px); transition: transform 160ms ease-out; }
}
@media (prefers-reduced-motion: reduce) {
  .motion-media img, .tool-item, button, .loading-spinner { animation: none !important; transform: none !important; transition-duration: .01ms !important; }
}