/* en: compact tool chrome — 12-col grid + keycap hero, not bands or circles */
:root {
  --ink: #212121;
  --navy: #1A237E;
  --bar: #283593;
  --wash: #E8EAF6;
  --chip: #C5CAE9;
}

html { scroll-behavior: auto; }

body {
  margin: 0;
  background: var(--wash);
  color: var(--ink);
  font-family: "Helvetica Neue", Helvetica, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

.tool {
  display: grid;
  grid-template-columns: 200px 1fr;
  align-items: center;
  min-height: 48px;
  padding: 0 16px;
  background: var(--bar);
  color: #E8EAF6;
}

.tool strong {
  font-size: 0.95rem;
  letter-spacing: 0.03em;
}

.tool menu {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.tool a {
  display: inline-block;
  padding: 14px 10px;
  color: #C5CAE9;
  font-size: 0.8rem;
  text-decoration: none;
}

.tool a:hover {
  color: #FFFFFF;
  background: #1A237E;
}

.sheet {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 18px 20px;
  width: min(1180px, calc(100% - 40px));
  margin: 22px auto 48px;
}

.hero-copy {
  grid-column: 1 / 8;
  background: #FFFFFF;
  padding: 28px 28px 22px;
  border-top: 6px solid var(--navy);
}

.hero-copy h1 {
  margin: 0 0 14px;
  font-size: 1.75rem;
  line-height: 1.35;
  color: var(--navy);
}

.hero-copy p { margin: 0 0 10px; }

.hero-keys {
  grid-column: 8 / 13;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  align-content: center;
  padding: 20px;
  background: var(--navy);
}

.hero-keys svg {
  width: 100%;
  height: auto;
}

.panel {
  grid-column: 1 / -1;
  background: #FFFFFF;
  padding: 22px 24px 18px;
}

.panel h2 {
  margin: 0 0 12px;
  color: var(--navy);
  font-size: 1.28rem;
}

.panel p { margin: 0 0 12px; }

.keymap {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.keymap th,
.keymap td {
  padding: 9px 10px;
  border-bottom: 1px solid var(--chip);
  text-align: left;
  vertical-align: top;
}

.keymap thead th {
  background: var(--bar);
  color: #FFFFFF;
  font-weight: 600;
}

.keymap tbody tr:nth-child(odd) { background: var(--wash); }

.quad {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.quad article {
  background: #FFFFFF;
  padding: 14px 14px 12px;
  border-left: 4px solid var(--bar);
}

.quad svg {
  width: 26px;
  height: 26px;
  stroke: var(--bar);
  fill: none;
  stroke-width: 1.8;
}

.quad h3 {
  margin: 8px 0 6px;
  font-size: 0.98rem;
  color: var(--navy);
}

.quad p { margin: 0; font-size: 0.9rem; }

.steps3 {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: stretch;
  background: #FFFFFF;
}

.steps3 > div {
  padding: 18px 16px;
}

.steps3 h2 {
  grid-column: 1 / -1;
  margin: 0;
  padding: 16px 16px 0;
  color: var(--navy);
  font-size: 1.28rem;
}

.steps3 .intro {
  grid-column: 1 / -1;
  padding: 8px 16px 4px;
}

.steps3 .bridge {
  width: 28px;
  background: var(--chip);
  align-self: stretch;
}

.steps3 h3 {
  margin: 0 0 8px;
  font-size: 1rem;
}

.steps3 p { margin: 0; }

.split2 {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.split2 > div {
  padding: 20px 22px;
  background: #FFFFFF;
}

.split2 > div:last-child {
  background: var(--chip);
}

.split2 h2 {
  grid-column: auto;
  margin: 0 0 12px;
  color: var(--navy);
  font-size: 1.28rem;
}

.split2 h3 {
  margin: 0 0 8px;
  font-size: 1.02rem;
}

.faq-grid {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.faq-grid > h2 {
  grid-column: 1 / -1;
  margin: 8px 0 0;
  color: var(--navy);
}

.faq-grid article {
  background: #FFFFFF;
  padding: 14px 16px;
}

.faq-grid h3 {
  margin: 0 0 8px;
  font-size: 1rem;
  color: var(--navy);
}

.faq-grid p { margin: 0; }

.base {
  background: var(--navy);
  color: #E8EAF6;
  padding: 24px 20px 28px;
}

.base-in {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.base p { margin: 0 0 8px; font-size: 0.9rem; }

@media (max-width: 900px) {
  .tool { grid-template-columns: 1fr; padding: 8px 12px 4px; }
  .hero-copy, .hero-keys { grid-column: 1 / -1; }
  .quad, .faq-grid, .split2 { grid-template-columns: 1fr; }
  .steps3 { grid-template-columns: 1fr; }
  .steps3 .bridge { width: 100%; height: 8px; }
}