:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #17202a;
  --muted: #64748b;
  --line: #dbe2ea;
  --blue: #1769e0;
  --blue-dark: #0e3f8f;
  --green: #0f8a5f;
  --amber: #b15d00;
  --shadow: 0 12px 30px rgba(20, 35, 54, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
}

a {
  color: inherit;
  text-decoration: none;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
  padding: 14px clamp(20px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 220px;
}

.brand-mark {
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 8px;
  background: var(--blue);
  color: #fff;
  font-weight: 800;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 12px;
}

.topnav {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f9fbfd;
}

.topnav a {
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.topnav a:hover {
  background: #eaf2ff;
  color: var(--blue);
}

main {
  padding: 34px clamp(20px, 5vw, 72px) 60px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(300px, 0.75fr);
  gap: 28px;
  align-items: stretch;
}

.hero-copy {
  padding: clamp(28px, 5vw, 56px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 820px;
  margin-bottom: 18px;
  font-size: clamp(34px, 4.6vw, 64px);
  line-height: 1.05;
  letter-spacing: 0;
}

.lead {
  max-width: 760px;
  color: #3f4f63;
  font-size: 17px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.primary-button,
.secondary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 7px;
  font-weight: 800;
}

.primary-button {
  background: var(--blue);
  color: #fff;
}

.secondary-button {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--blue-dark);
}

.hero-panel {
  display: grid;
  grid-template-rows: repeat(3, 1fr);
  gap: 12px;
}

.metric {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.metric span {
  color: var(--muted);
  font-weight: 700;
}

.metric strong {
  color: var(--blue);
  font-size: 42px;
}

.section {
  margin-top: 48px;
}

.section-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 18px;
}

.section-header h2 {
  margin-bottom: 0;
  font-size: clamp(26px, 3vw, 38px);
}

.hint {
  max-width: 520px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.featured-tool {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 22px;
  align-items: center;
  padding: 26px;
  border: 1px solid #b9d1f4;
  border-radius: 8px;
  background: #f9fcff;
}

.featured-tool h3 {
  margin-bottom: 10px;
  font-size: 24px;
}

.featured-tool p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.7;
}

.status {
  display: inline-flex;
  margin-bottom: 12px;
  padding: 4px 9px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 900;
}

.status.online {
  background: #e8f8f1;
  color: var(--green);
}

.tool-grid,
.phase-grid,
.contact-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-top: 14px;
}

.contact-grid {
  grid-template-columns: minmax(260px, 0.8fr) minmax(0, 1.2fr);
}

.tool-card,
.phase-card,
.contact-card {
  min-height: 208px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.tool-card {
  cursor: pointer;
}

.tool-card:hover,
.tool-card:focus {
  border-color: #94bdf4;
  outline: none;
  box-shadow: 0 12px 26px rgba(23, 105, 224, 0.12);
}

.tool-card.active {
  border-color: #c8d9f2;
  background: #fbfdff;
}

.day,
.phase-card span {
  display: inline-flex;
  margin-bottom: 14px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 900;
}

.tool-card h3,
.phase-card h3 {
  margin-bottom: 10px;
  font-size: 18px;
}

.tool-card p,
.phase-card p {
  color: var(--muted);
  line-height: 1.65;
}

.path {
  display: block;
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  color: #58677b;
  font-family: Consolas, "Courier New", monospace;
  font-size: 12px;
  overflow-wrap: anywhere;
}

.phase-card strong {
  display: block;
  margin-top: 18px;
  color: #26364a;
  line-height: 1.55;
}

.contact-card {
  min-height: 180px;
  background: #fbfdff;
}

.contact-card span {
  display: inline-flex;
  margin-bottom: 14px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 900;
}

.contact-card strong {
  display: block;
  margin-bottom: 12px;
  color: var(--blue-dark);
  font-size: clamp(26px, 3vw, 42px);
}

.contact-card p {
  color: var(--muted);
  line-height: 1.7;
}

.contact-card.action {
  display: grid;
  align-content: start;
  justify-items: start;
}

.tree {
  margin: 0;
  padding: 24px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #111827;
  color: #dbeafe;
  line-height: 1.7;
}

.tree code {
  font-family: Consolas, "Courier New", monospace;
  font-size: 14px;
}

.rules {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 14px;
}

.rules p {
  margin: 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--muted);
  line-height: 1.7;
}

.rules strong {
  color: var(--text);
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(20px, 5vw, 72px);
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 1100px) {
  .hero,
  .featured-tool {
    grid-template-columns: 1fr;
  }

  .tool-grid,
  .phase-grid,
  .contact-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .topbar,
  .section-header,
  .footer {
    align-items: stretch;
    flex-direction: column;
  }

  .topnav {
    overflow-x: auto;
  }

  main {
    padding-top: 22px;
  }

  .hero-copy {
    padding: 26px 20px;
  }

  h1 {
    font-size: 34px;
  }

  .tool-grid,
  .phase-grid,
  .contact-grid,
  .rules {
    grid-template-columns: 1fr;
  }

  .primary-button,
  .secondary-button {
    width: 100%;
  }
}