:root {
  /* warm off-white base */
  --bg: #f6f2ec;
  --bg-card: #fbf8f3;
  --bg-elev: #ffffff;
  --line: #e7e0d4;
  --line-strong: #d6ccba;

  /* warm charcoals */
  --ink: #1c1a17;
  --ink-2: #3b3731;
  --ink-3: #6b6459;
  --ink-4: #a39a8b;

  /* single accent — burnt sienna */
  --accent: #c75a2a;
  --accent-soft: #f0d9c8;
  --accent-ink: #7a3315;

  --radius: 14px;
  --radius-sm: 10px;
}

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

body {
  font-family: "Noto Sans SC", -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-feature-settings: "ss01", "ss02";
  line-height: 1.5;
  transition: background 240ms ease, color 240ms ease;
}

::selection { background: var(--accent); color: #fff; }

.serif { font-family: "Instrument Serif", "Noto Serif SC", serif; font-weight: 400; letter-spacing: 0.005em; }
.mono { font-family: "JetBrains Mono", ui-monospace, monospace; }

/* ---- shell ---- */
.shell {
  max-width: 1180px;
  margin: 0 auto;
  padding: 22px 40px 0;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink);
}
.brand-mark {
  width: 34px; height: 34px;
  border-radius: 9px;
  background: var(--ink);
  color: var(--bg);
  display: grid;
  place-items: center;
  position: relative;
  box-shadow:
    0 1px 0 rgba(255,255,255,0.08) inset,
    0 10px 18px -14px rgba(28,26,23,0.6);
}
.brand-symbol {
  width: 100%;
  height: 100%;
  display: block;
}
.brand-name {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.brand-sub {
  font-size: 11px;
  color: var(--ink-3);
  margin-left: 4px;
  padding-left: 10px;
  border-left: 1px solid var(--line-strong);
  letter-spacing: 0.04em;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-link {
  font-size: 13.5px;
  color: var(--ink-3);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 8px;
  transition: color 160ms, background 160ms;
}
.nav-link:hover { color: var(--ink); background: var(--bg-card); }
.nav-cta {
  font-size: 13.5px;
  color: var(--bg);
  background: var(--ink);
  padding: 9px 16px;
  border-radius: 999px;
  text-decoration: none;
  margin-left: 6px;
  transition: transform 160ms;
}
.nav-cta:hover { transform: translateY(-1px); }

/* ---- hero ---- */
.hero {
  padding: 64px 0 32px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: start;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--ink-3);
  background: var(--bg-card);
  border: 1px solid var(--line);
  padding: 6px 12px 6px 8px;
  border-radius: 999px;
  margin-bottom: 24px;
}
.eyebrow-dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--accent) 18%, transparent);
}

h1.headline {
  font-size: clamp(40px, 5.6vw, 68px);
  line-height: 1.05;
  letter-spacing: -0.025em;
  font-weight: 600;
  margin: 0 0 20px;
  color: var(--ink);
}
h1.headline .accent {
  font-family: "Instrument Serif", "Noto Serif SC", serif;
  font-style: italic;
  font-weight: 400;
  color: var(--accent);
  letter-spacing: 0;
}

.lede {
  font-size: 17px;
  color: var(--ink-3);
  max-width: 480px;
  margin: 0 0 32px;
  line-height: 1.6;
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 20px 32px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}
.meta {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.meta-num {
  font-family: "Instrument Serif", serif;
  font-size: 30px;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.meta-num small {
  font-family: "Noto Sans SC", sans-serif;
  font-size: 13px;
  color: var(--ink-3);
  margin-left: 2px;
}
.meta-label {
  font-size: 12px;
  color: var(--ink-4);
  letter-spacing: 0.03em;
}

/* ---- input card ---- */
.composer {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow:
    0 1px 0 rgba(255,255,255,0.6) inset,
    0 14px 40px -22px rgba(45, 35, 20, 0.18);
}

.composer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.composer-title {
  font-size: 13px;
  color: var(--ink-2);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 10px;
}
.composer-title .badge {
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px;
  background: var(--ink);
  color: var(--bg);
  padding: 3px 7px;
  border-radius: 5px;
  letter-spacing: 0.04em;
}
.composer-meta {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  color: var(--ink-4);
  letter-spacing: 0.04em;
}

textarea.input {
  width: 100%;
  min-height: 168px;
  resize: vertical;
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  color: var(--ink);
  font-family: inherit;
  font-size: 15px;
  line-height: 1.65;
  outline: none;
  transition: border-color 160ms, box-shadow 160ms;
}
textarea.input::placeholder { color: var(--ink-4); }
textarea.input:focus {
  border-color: color-mix(in oklab, var(--accent) 60%, var(--line));
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--accent) 14%, transparent);
}

.quick {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}
.chip {
  font-size: 12.5px;
  color: var(--ink-2);
  background: var(--bg-elev);
  border: 1px solid var(--line);
  padding: 7px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 160ms;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.chip:hover {
  border-color: var(--ink-2);
  color: var(--ink);
  transform: translateY(-1px);
}
.chip svg { width: 12px; height: 12px; opacity: 0.6; }

/* options row */
.options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px dashed var(--line);
}
.opt {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 10px 12px;
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}
.opt-label {
  font-size: 12px;
  color: var(--ink-3);
  letter-spacing: 0.02em;
}
.seg {
  display: inline-flex;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 2px;
  gap: 2px;
}
.seg button {
  appearance: none;
  border: 0;
  background: transparent;
  font-family: inherit;
  font-size: 12px;
  color: var(--ink-3);
  padding: 5px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 140ms;
}
.seg button:hover { color: var(--ink); }
.seg button.on {
  background: var(--ink);
  color: var(--bg);
}

.actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
}
.btn-primary {
  flex: 1;
  appearance: none;
  border: 0;
  background: var(--ink);
  color: var(--bg);
  font-family: inherit;
  font-size: 14.5px;
  font-weight: 500;
  padding: 14px 20px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  letter-spacing: 0.02em;
  transition: transform 160ms, background 160ms, box-shadow 160ms;
  position: relative;
  overflow: hidden;
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 28px -14px rgba(28,26,23,0.55);
}
.btn-primary .arrow {
  transition: transform 200ms;
}
.btn-primary:hover .arrow { transform: translateX(3px); }

.btn-ghost {
  appearance: none;
  border: 1px solid var(--line);
  background: var(--bg-elev);
  color: var(--ink-2);
  font-family: inherit;
  font-size: 13px;
  padding: 13px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 160ms;
}
.btn-ghost:hover { border-color: var(--ink-2); color: var(--ink); }

.privacy {
  margin-top: 14px;
  font-size: 12px;
  color: var(--ink-4);
  display: flex;
  align-items: center;
  gap: 8px;
  line-height: 1.6;
}
.privacy a { color: var(--ink-2); text-decoration: underline; text-underline-offset: 3px; text-decoration-color: var(--line-strong); }
.privacy a:hover { text-decoration-color: var(--accent); color: var(--accent); }
.privacy svg { width: 13px; height: 13px; flex-shrink: 0; color: var(--ink-3); }

/* ---- preview strip / how it works ---- */
.strip {
  margin-top: 56px;
  padding: 28px 0 64px;
  border-top: 1px solid var(--line);
}
.strip-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 12px;
}
.strip-title {
  font-family: "Instrument Serif", serif;
  font-size: 28px;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.strip-title em { color: var(--accent); }
.strip-sub {
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px;
  color: var(--ink-4);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}
.step {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  position: relative;
  overflow: hidden;
  min-height: 168px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}
.step-num {
  font-family: "Instrument Serif", serif;
  font-size: 13px;
  color: var(--ink-3);
}
.step-title {
  font-size: 17px;
  font-weight: 500;
  color: var(--ink);
  margin: 6px 0 8px;
  letter-spacing: -0.005em;
}
.step-body {
  font-size: 13.5px;
  color: var(--ink-3);
  line-height: 1.6;
  max-width: 28ch;
}
.step-vis {
  margin-top: 20px;
  height: 38px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--bg-elev);
  display: flex;
  align-items: center;
  padding: 0 12px;
  gap: 8px;
  overflow: hidden;
}
.step-vis .ln {
  height: 6px;
  border-radius: 3px;
  background: var(--line-strong);
}
.step-vis .ln.a { width: 26%; }
.step-vis .ln.b { width: 18%; background: var(--accent); }
.step-vis .ln.c { width: 32%; }
.step-vis .ln.d { width: 14%; }
.step-vis.b { gap: 4px; flex-wrap: wrap; padding: 7px 10px; align-content: center; }
.step-vis.b .pill {
  height: 18px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  border-radius: 4px;
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  padding: 0 6px;
  display: inline-flex;
  align-items: center;
}
.step-vis.c { padding: 6px 10px; flex-direction: column; align-items: stretch; gap: 4px; height: auto; }
.step-vis.c .row {
  height: 5px;
  border-radius: 2px;
  background: var(--line-strong);
}
.step-vis.c .row:nth-child(1) { width: 80%; background: var(--ink-2); }
.step-vis.c .row:nth-child(2) { width: 95%; }
.step-vis.c .row:nth-child(3) { width: 70%; }
.step-vis.c .row:nth-child(4) { width: 88%; }

/* ---- footer ---- */
footer.footer {
  border-top: 1px solid var(--line);
  padding: 24px 0 36px;
  margin-top: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12.5px;
  color: var(--ink-3);
}
.footer-left { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.footer a { color: var(--ink-2); text-decoration: none; }
.footer a:hover { color: var(--accent); }
.footer-icon {
  width: 30px; height: 30px;
  border-radius: 50%;
  border: 1px solid var(--line);
  display: grid;
  place-items: center;
  color: var(--ink-3);
  transition: all 160ms;
}
.footer-icon:hover { color: var(--ink); border-color: var(--ink-2); }

/* ---- responsive ---- */
@media (max-width: 880px) {
  .shell { padding: 18px 22px 0; }
  .hero { grid-template-columns: 1fr; gap: 36px; padding: 36px 0 24px; }
  .steps { grid-template-columns: 1fr; }
  .options { grid-template-columns: 1fr; }
  .nav-link { display: none; }
}

/* subtle entry */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}
.fade { animation: fadeUp 600ms ease both; }
.fade.d1 { animation-delay: 80ms; }
.fade.d2 { animation-delay: 160ms; }
.fade.d3 { animation-delay: 240ms; }

/* ===================== RESULT VIEW ===================== */
.result-wrap {
  display: none;
  padding: 32px 0 24px;
}
.result-wrap.active { display: block; animation: fadeUp 360ms ease both; }

/* hide the rest when showing result */
body.showing-result .hero,
body.showing-result .strip { display: none; }

.result-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 14px;
}
.result-back {
  appearance: none;
  border: 1px solid var(--line);
  background: var(--bg-card);
  color: var(--ink-2);
  font-family: inherit;
  font-size: 13px;
  padding: 9px 14px 9px 11px;
  border-radius: 999px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 160ms;
}
.result-back:hover { border-color: var(--ink-2); color: var(--ink); transform: translateX(-2px); }

.result-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: "JetBrains Mono", monospace;
  font-size: 11.5px;
  color: var(--ink-3);
  letter-spacing: 0.06em;
  padding: 7px 12px;
  border-radius: 999px;
  background: var(--bg-card);
  border: 1px solid var(--line);
}
.result-status .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--accent);
  animation: pulse 1.2s ease-in-out infinite;
}
.result-status.done .dot {
  background: #4a8d4a;
  animation: none;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%      { opacity: 0.4; transform: scale(0.7); }
}

.result-grid {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 28px;
  align-items: start;
}

/* sidebar */
.result-side {
  position: sticky;
  top: 24px;
}
.side-card {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
}
.side-title {
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px;
  color: var(--ink-4);
  letter-spacing: 0.08em;
  margin-bottom: 12px;
}
.toc-item {
  display: block;
  width: 100%;
  text-align: left;
  appearance: none;
  border: 0;
  background: transparent;
  font-family: inherit;
  font-size: 13px;
  color: var(--ink-3);
  padding: 8px 10px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 140ms;
  border-left: 2px solid transparent;
}
.toc-item:hover { background: var(--bg-elev); color: var(--ink); }
.toc-item.locked { opacity: 0.35; }
.toc-item.active {
  color: var(--ink);
  border-left-color: var(--accent);
  background: var(--bg-elev);
  font-weight: 500;
}

.side-meta {
  margin-top: 12px;
  padding: 16px;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 12px;
  color: var(--ink-3);
  line-height: 1.7;
}
.side-meta .row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}
.side-meta .row + .row { margin-top: 4px; }
.side-meta .row b { color: var(--ink); font-weight: 500; font-family: "JetBrains Mono", monospace; font-size: 11.5px; }

/* main paper */
.paper {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 44px 56px 48px;
  min-height: 540px;
  position: relative;
  box-shadow: 0 18px 50px -28px rgba(45,35,20,0.18);
}
.paper-head {
  border-bottom: 1px solid var(--line);
  padding-bottom: 18px;
  margin-bottom: 24px;
}
.paper-eyebrow {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}
.paper-title {
  font-size: 30px;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.02em;
  margin: 0 0 10px;
  line-height: 1.2;
}
.paper-meta {
  display: flex;
  gap: 18px;
  font-size: 12px;
  color: var(--ink-3);
  flex-wrap: wrap;
}
.paper-meta span { display: inline-flex; align-items: center; gap: 6px; }
.paper-meta svg { width: 12px; height: 12px; opacity: 0.7; }

/* typed body */
.typed {
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-2);
  white-space: normal;
  word-break: break-word;
  min-height: 200px;
}
.typed h2 {
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.005em;
  margin: 26px 0 10px;
  padding-top: 6px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.typed h2::before {
  content: "";
  width: 4px; height: 16px;
  background: var(--accent);
  border-radius: 2px;
  flex-shrink: 0;
}
.typed h2:first-child { margin-top: 0; }
.typed p { margin: 0 0 12px; }
.typed ul, .typed ol { margin: 4px 0 14px; padding-left: 22px; }
.typed li { margin-bottom: 6px; }
.typed li::marker { color: var(--accent); }
.typed strong { color: var(--ink); font-weight: 600; }
.typed em { color: var(--ink-3); font-style: normal; background: var(--accent-soft); padding: 1px 5px; border-radius: 3px; }

.caret {
  display: inline-block;
  width: 8px;
  height: 1.1em;
  background: var(--accent);
  vertical-align: -2px;
  margin-left: 1px;
  animation: blink 900ms steps(2, jump-none) infinite;
  border-radius: 1px;
}
@keyframes blink { 50% { opacity: 0; } }
.typed.done .caret { display: none; }

/* error banner inside paper */
.err-banner {
  margin: 0 0 16px;
  padding: 10px 14px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  border: 1px solid color-mix(in oklab, var(--accent) 50%, var(--accent-soft));
  border-radius: var(--radius-sm);
  font-size: 13px;
  line-height: 1.5;
}

/* result actions */
.result-actions {
  display: flex;
  gap: 10px;
  margin-top: 22px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  flex-wrap: wrap;
  justify-content: space-between;
}
.result-actions .group { display: flex; gap: 8px; flex-wrap: wrap; }
.act-btn {
  appearance: none;
  border: 1px solid var(--line);
  background: var(--bg-card);
  color: var(--ink-2);
  font-family: inherit;
  font-size: 13px;
  padding: 10px 14px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  transition: all 160ms;
}
.act-btn:hover { border-color: var(--ink-2); color: var(--ink); transform: translateY(-1px); }
.act-btn:disabled,
.act-btn:disabled:hover {
  border-color: var(--line);
  color: var(--ink-3);
  cursor: not-allowed;
  opacity: 0.5;
  transform: none;
}
.act-btn svg { width: 13px; height: 13px; }
.act-btn.primary {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}
.act-btn.primary:hover { background: var(--ink-2); }
.act-btn.primary:disabled,
.act-btn.primary:disabled:hover {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--bg);
}
.act-btn.copied {
  background: #2f6b3e;
  color: #fff;
  border-color: #2f6b3e;
}

@media (max-width: 880px) {
  /* 单列 + 用 contents 解包 aside,让 TOC / paper / side-meta 三者可独立排序 */
  .result-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
  }
  .result-side {
    display: contents;
  }

  /* TOC:压缩成横向滚动的胶囊条,放在顶部 */
  .side-card {
    order: 1;
    padding: 10px 12px;
  }
  .side-title { display: none; }
  #toc {
    display: flex;
    gap: 6px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  #toc::-webkit-scrollbar { display: none; }
  .toc-item {
    flex-shrink: 0;
    width: auto;
    padding: 7px 12px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: var(--bg-elev);
    font-size: 12px;
  }
  .toc-item.active {
    border-color: var(--accent);
    background: var(--accent-soft);
    color: var(--accent-ink);
    font-weight: 500;
  }

  /* 周报正文:中间,主视觉焦点 */
  .paper {
    order: 2;
    padding: 28px 22px 32px;
  }
  .paper-title { font-size: 24px; }

  /* 元信息:压缩成单行小条,放在底部 */
  .side-meta {
    order: 3;
    margin-top: 0;
    padding: 10px 14px;
    display: flex;
    flex-wrap: wrap;
    gap: 6px 18px;
    font-size: 11.5px;
    line-height: 1.4;
  }
  .side-meta .row {
    flex-direction: row;
    align-items: baseline;
    gap: 6px;
    justify-content: flex-start;
  }
  .side-meta .row + .row { margin-top: 0; }
  .side-meta .row b { font-size: 11.5px; }
}