/* Home page */
.hero { padding: 3.5rem 0 4rem; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr); gap: 3rem; align-items: start; }
.hero h1 { font-size: var(--fs-hero); font-weight: 600; letter-spacing: 0.01em; }
.hero h1 .line { display: inline-block; }
@media (min-width: 561px) { .hero h1 .line { white-space: nowrap; } }
.hero-sub { margin-top: 1.25rem; font-size: var(--fs-md); color: var(--muted); max-width: 30em; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 2rem; }
.hero-facts { list-style: none; padding: 0; margin: 2.5rem 0 0; display: grid; gap: 0.6rem; border-top: 1px solid var(--line); padding-top: 1.25rem; }
.hero-facts li { display: grid; grid-template-columns: 7.5em 1fr; color: var(--muted); }
.hero-facts strong { color: var(--ink); font-weight: 600; }

/* Demo panel */
.demo { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-md); padding: 1.25rem; display: grid; gap: 1rem; }
.demo-head h2 { font-size: var(--fs-md); font-weight: 600; }
.demo-note { color: var(--muted); font-size: var(--fs-sm); }
.demo-req { font-size: 0.82rem; }
.demo-table table { font-size: 0.86rem; }

/* Shenzhen as a tile map: west on the left, coast along the bottom row. */
.district-map {
  display: grid; gap: 4px;
  grid-template-columns: 1.15fr 1fr 1fr 1fr 1fr 1fr;
  grid-template-rows: 54px 54px;
  grid-template-areas:
    "baoan guangming longhua longgang longgang pingshan"
    "baoan nanshan  futian  luohu   yantian  dapeng";
}
.tile {
  font: inherit; font-size: 0.95rem; cursor: pointer;
  border: 1px solid var(--line-strong); border-radius: 3px;
  background: repeating-linear-gradient(135deg, #f7f9fb 0 6px, #eef2f6 6px 7px);
  color: var(--ink); min-height: 44px;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease;
}
.tile:hover { border-color: var(--ink); background: var(--ink-soft); }
.tile[aria-pressed="true"] { background: var(--ink); color: #fff; border-color: var(--ink); font-weight: 600; }
.t-baoan { grid-area: baoan; }
.t-guangming { grid-area: guangming; }
.t-longhua { grid-area: longhua; }
.t-longgang { grid-area: longgang; }
.t-pingshan { grid-area: pingshan; }
.t-nanshan { grid-area: nanshan; }
.t-futian { grid-area: futian; }
.t-luohu { grid-area: luohu; }
.t-yantian { grid-area: yantian; }
.t-dapeng { grid-area: dapeng; }

/* Datasets as a definition list with rules, not cards */
.datasets { margin: 2.25rem 0 0; display: grid; }
.datasets > div { display: grid; grid-template-columns: 10rem 1fr; gap: 1.5rem; padding: 1.25rem 0; border-top: 1px solid var(--line); }
.datasets > div:last-child { border-bottom: 1px solid var(--line); }
.datasets dt { font-weight: 600; color: var(--ink); font-size: var(--fs-md); }
.datasets dd { margin: 0; display: grid; grid-template-columns: 1fr 11rem; gap: 1.5rem; }
.datasets .range { color: var(--muted); font-size: var(--fs-sm); text-align: right; padding-top: 0.15rem; }

/* Steps: a real sequence, so numbered */
.start-grid { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: 3rem; align-items: start; }
.steps { list-style: none; counter-reset: step; padding: 0; margin: 1.5rem 0 0; display: grid; gap: 1.5rem; }
.steps li { counter-increment: step; display: grid; grid-template-columns: 2.5rem 1fr; column-gap: 0.75rem; }
.steps li::before {
  content: counter(step); grid-row: span 2;
  width: 2rem; height: 2rem; display: grid; place-items: center;
  border: 1.5px solid var(--seal); color: var(--seal); border-radius: 3px; font-weight: 700;
}
.steps h3 { font-size: var(--fs-md); }
.steps p { color: var(--muted); }

.code-tabs { display: grid; gap: 0; }
.tabs { display: flex; gap: 2px; }
.tabs [role="tab"] {
  font: inherit; font-size: var(--fs-sm); cursor: pointer; min-height: 40px; padding: 0 1rem;
  border: 0; border-radius: var(--r-sm) var(--r-sm) 0 0; background: var(--ink-soft); color: var(--ink);
}
.tabs [role="tab"][aria-selected="true"] { background: var(--code-bg); color: #fff; }
.code-tabs .code { border-top-left-radius: 0; }

/* FAQ */
.faq-grid { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: 3rem; }
.faq details { border-top: 1px solid var(--line); padding: 0.9rem 0; }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; font-weight: 600; color: var(--ink); list-style: none; display: flex; justify-content: space-between; gap: 1rem; min-height: 28px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-weight: 400; }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin-top: 0.5rem; color: var(--muted); max-width: 38em; }

@media (max-width: 960px) {
  .hero-grid, .start-grid, .faq-grid { grid-template-columns: 1fr; gap: 2rem; }
  .datasets dd { grid-template-columns: 1fr; gap: 0.25rem; }
  .datasets .range { text-align: left; }
}
@media (max-width: 560px) {
  .datasets > div { grid-template-columns: 1fr; gap: 0.4rem; }
  .district-map { grid-template-rows: 48px 48px; }
  .tile { font-size: 0.85rem; }
  .hero-facts li { grid-template-columns: 6.5em 1fr; }
}