:root {
  color-scheme: light;
  --canvas: #f4f6f8;
  --surface: #ffffff;
  --surface-soft: #f7f9fa;
  --surface-blue: #edf5fb;
  --hairline: #d7dde3;
  --hairline-strong: #b7c4cf;
  --ink: #18212c;
  --ink-soft: #35414d;
  --muted: #5d6874;
  --accent: #1769aa;
  --accent-deep: #115485;
  --success: #176b2c;
  --success-soft: #edf8f0;
  --warning: #9a5b00;
  --warning-soft: #fff4e2;
  --danger: #9f2d16;
  --danger-soft: #fff0e9;
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  line-height: 1.55;
  color: var(--ink);
  background: var(--canvas);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; }
button, a { font: inherit; }
button:focus-visible, a:focus-visible, [tabindex="-1"]:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}
button {
  min-height: 44px;
  padding: 10px 16px;
  color: #fff;
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 8px;
  font-weight: 650;
  cursor: pointer;
}
button:hover:not(:disabled) { background: var(--accent-deep); border-color: var(--accent-deep); }
button:disabled { color: #71808d; background: #e2e7eb; border-color: #d7dde3; cursor: not-allowed; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: 10px;
  left: 10px;
  padding: 10px 14px;
  color: #fff;
  background: var(--accent);
  border-radius: 8px;
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }

.application-shell {
  display: grid;
  grid-template-columns: minmax(230px, 270px) minmax(0, 1fr);
  gap: 24px;
  width: min(calc(100% - 32px), 1440px);
  margin: 0 auto;
  padding: 24px 0 64px;
}
.application-content { display: grid; gap: 18px; min-width: 0; }
.workspace-sidebar {
  position: sticky;
  top: 16px;
  display: grid;
  gap: 12px;
  align-content: start;
  min-width: 0;
  max-width: 100%;
  max-height: calc(100vh - 32px);
}
.sidebar-brand, .task-stage-navigation, .local-task-card {
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: 12px;
}
.sidebar-brand { display: flex; align-items: center; gap: 12px; }
.sidebar-brand div { display: grid; gap: 2px; min-width: 0; }
.sidebar-brand small, .local-task-card small { color: var(--muted); }
.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  color: #fff;
  background: var(--accent);
  border-radius: 10px;
  font-weight: 800;
}
.sidebar-label {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: .72rem;
  font-weight: 750;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.task-stage-navigation { min-width: 0; max-width: 100%; overflow: hidden; }
.task-stage-navigation ol { display: grid; gap: 6px; min-width: 0; max-width: 100%; margin: 0; padding: 0; list-style: none; }
.stage-item a {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 10px;
  align-items: center;
  min-height: 48px;
  padding: 7px 8px;
  color: var(--ink-soft);
  border-radius: 8px;
  text-decoration: none;
}
.stage-item a:hover, .stage-item a[aria-current="step"] { background: var(--surface-blue); }
.stage-marker {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  color: var(--muted);
  background: var(--surface-soft);
  border: 1px solid var(--hairline);
  border-radius: 8px;
  font-size: .78rem;
  font-weight: 750;
}
.stage-current .stage-marker { color: #fff; background: var(--accent); border-color: var(--accent); }
.stage-complete .stage-marker { color: var(--success); background: var(--success-soft); border-color: #add4b7; }
.stage-stale .stage-marker { color: var(--danger); background: var(--danger-soft); border-color: #efb8a8; }
.stage-copy { display: grid; min-width: 0; }
.stage-copy strong { font-size: .9rem; }
.stage-copy small { color: var(--muted); font-size: .76rem; }
.local-task-card { display: grid; gap: 4px; }

.workspace-header {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(300px, .8fr);
  gap: 24px;
  align-items: start;
  padding: 6px 2px;
}
.workspace-title h1 { margin: 0 0 10px; font-size: clamp(2rem, 4vw, 2.85rem); line-height: 1.1; letter-spacing: -.035em; }
.workspace-title > p:last-child { max-width: 680px; margin-bottom: 0; color: var(--muted); }
.eyebrow { margin: 0 0 7px; color: var(--accent); font-size: .78rem; font-weight: 750; letter-spacing: .06em; }
.task-summary {
  display: grid;
  gap: 9px;
  margin: 0;
  padding: 18px;
  background: var(--surface-blue);
  border: 1px solid #d3e2ee;
  border-radius: 12px;
}
.task-summary div { display: grid; grid-template-columns: 82px minmax(0, 1fr); gap: 10px; }
.task-summary dt { color: var(--muted); font-size: .88rem; font-weight: 700; }
.task-summary dd { margin: 0; overflow-wrap: anywhere; font-size: .92rem; }

.demo-disclosure {
  display: flex;
  justify-content: space-between;
  gap: 22px;
  align-items: center;
  padding: 16px 18px;
  color: #24402d;
  background: var(--success-soft);
  border: 1px solid #b8dbc1;
  border-radius: 12px;
}
.demo-disclosure p { margin: 4px 0 0; color: #476050; }
.secondary-button {
  color: var(--accent-deep);
  background: var(--surface);
  border-color: #8eacc3;
}
.secondary-button:hover:not(:disabled) { color: #fff; background: var(--accent-deep); }
.demo-disclosure .secondary-button { flex: 0 0 auto; }
.stale-banner {
  display: grid;
  gap: 4px;
  padding: 16px 18px;
  color: var(--danger);
  background: var(--danger-soft);
  border: 1px solid #efb8a8;
  border-left: 5px solid var(--danger);
  border-radius: 10px;
}

.task-page-navigation {
  padding: 6px;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: 10px;
}
.task-page-navigation button {
  min-width: 150px;
  color: var(--accent-deep);
  background: transparent;
  border-color: transparent;
}
.task-page-navigation button:hover:not(:disabled) { color: var(--accent-deep); background: var(--surface-blue); border-color: transparent; }
.task-page-navigation button[aria-current="page"] { color: #fff; background: var(--accent); border-color: var(--accent); }
.workspace-page { display: grid; gap: 18px; }
.workspace-stage-heading { padding: 8px 2px 2px; }
.workspace-stage-heading h2 { margin: 0; font-size: 1.6rem; }
#materials, #plan, #research, #outline, #draft { scroll-margin-top: 18px; }

.workspace-panel, .panel {
  padding: 26px;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  box-shadow: 0 7px 22px rgb(18 39 58 / 5%);
}
.panel-heading { display: flex; justify-content: space-between; gap: 18px; align-items: flex-start; margin-bottom: 14px; }
.panel-heading h2 { margin: 0; font-size: 1.35rem; letter-spacing: -.015em; }
.panel-intro { max-width: 820px; margin: 0 0 18px; color: var(--muted); }
.status-badge {
  display: inline-flex;
  padding: 5px 9px;
  color: var(--muted);
  background: #edf1f4;
  border-radius: 999px;
  font-size: .78rem;
  font-weight: 750;
  white-space: nowrap;
}
.status-current { color: var(--accent-deep); background: var(--surface-blue); }
.status-complete { color: var(--success); background: var(--success-soft); }
.status-stale { color: var(--danger); background: var(--danger-soft); }
.panel-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 18px; }
.source-list { display: grid; gap: 9px; margin: 18px 0 0; padding: 0; list-style: none; }
.source-list li { display: flex; justify-content: space-between; gap: 16px; padding: 12px 14px; background: var(--surface-soft); border-radius: 8px; }
.source-list span { color: var(--muted); overflow-wrap: anywhere; text-align: right; }
.lexical-note { margin: 18px 0 0; padding: 12px 14px; color: #65450a; background: #fff8df; border-left: 4px solid #c58b00; }

.plan-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin-top: 18px; }
.plan-block { padding: 16px; background: var(--surface-soft); border-radius: 8px; }
.plan-block h3 { margin: 0 0 9px; font-size: 1rem; }
.plan-block ol, .plan-block ul { margin: 0; padding-left: 20px; }
.audit-summary, .gap-summary { margin-top: 18px; padding: 16px; background: var(--surface-soft); border-radius: 9px; }
.audit-summary h3, .gap-summary h3 { margin: 0 0 10px; }
.audit-summary ol, .gap-summary ul { margin-bottom: 0; }
.audit-summary p { color: var(--success); font-weight: 650; }
.evidence-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin-top: 18px; }
.evidence-card { padding: 17px; border: 1px solid var(--hairline); border-left: 5px solid var(--accent); border-radius: 10px; background: var(--surface); }
.evidence-selected { border-color: #92c4a0; border-left-color: var(--success); background: #fbfefc; }
.evidence-card-heading { display: flex; justify-content: space-between; gap: 12px; }
.evidence-card p { overflow-wrap: anywhere; }
.evidence-relevance { padding: 10px 12px; color: #244766; background: #eef6ff; border-radius: 7px; }
.evidence-location { color: var(--muted); font-size: .9rem; }
.evidence-toggle { width: 100%; margin-top: 4px; }
.evidence-confirmation { display: grid; gap: 10px; margin-top: 18px; padding: 16px; background: var(--surface-soft); border-radius: 9px; }
.evidence-confirmation p { margin: 0; color: var(--muted); }
.evidence-confirmation button { justify-self: start; }

.outline-preview { margin-top: 18px; padding: 17px; background: var(--surface-soft); border: 1px solid var(--hairline); border-radius: 9px; }
.outline-preview ol { margin-bottom: 0; }
.stale-label { margin: 0 0 14px; padding: 10px 12px; color: var(--danger); background: var(--danger-soft); border-radius: 8px; font-weight: 750; }
.draft-preview { max-height: 440px; margin: 18px 0; padding: 18px; overflow: auto; white-space: pre-wrap; overflow-wrap: anywhere; color: #24313d; background: var(--surface-soft); border: 1px solid var(--hairline); border-radius: 9px; font: inherit; }
.download-link, .primary-action {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 16px;
  color: #fff;
  background: var(--success);
  border-radius: 8px;
  font-weight: 700;
  text-decoration: none;
}
.download-link[aria-disabled="true"] { color: #71808d; background: #e2e7eb; cursor: not-allowed; }

.page-shell { width: min(calc(100% - 32px), 900px); margin: 0 auto; padding: 48px 0; }
.panel { margin-top: 18px; }
.step { margin: 0; color: var(--accent); font-size: .78rem; font-weight: 750; letter-spacing: .08em; }

@media (max-width: 960px) {
  .application-shell { grid-template-columns: minmax(0, 1fr); }
  .workspace-sidebar { position: static; max-height: none; }
  .task-stage-navigation ol { display: flex; width: 100%; overflow-x: auto; }
  .stage-item { flex: 0 0 180px; min-width: 0; }
  .workspace-header { grid-template-columns: 1fr; }
}

@media (max-width: 680px) {
  .application-shell { width: min(calc(100% - 20px), 1440px); padding-top: 10px; }
  .workspace-panel, .panel { padding: 19px; }
  .demo-disclosure { align-items: stretch; flex-direction: column; }
  .demo-disclosure .secondary-button { width: 100%; }
  .task-page-navigation { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .task-page-navigation button { min-width: 0; }
  .plan-grid, .evidence-grid { grid-template-columns: 1fr; }
  .panel-heading, .source-list li { align-items: stretch; flex-direction: column; }
  .source-list span { text-align: left; }
  .panel-actions { display: grid; }
  .panel-actions button { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}