:root {
  --bg: #f7f8fc;
  --bg-alt: #eef2ff;
  --text: #111827;
  --text-soft: #4b5563;
  --line: #dbe2f0;
  --brand: #3b82f6;
  --brand-strong: #1d4ed8;
  --surface: #ffffff;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(17, 24, 39, 0.08);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
}

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

.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

.header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(247, 248, 252, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 24px;
  line-height: 1;
  letter-spacing: 0.3px;
}

.logo-icon {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  object-fit: cover;
  display: block;
}

.nav nav {
  display: flex;
  gap: 18px;
  color: var(--text-soft);
}

.nav nav a[aria-current="page"] {
  color: var(--brand-strong);
  font-weight: 700;
}

.hero {
  padding: 78px 0 58px;
}

.eyebrow {
  display: inline-block;
  margin: 0;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 13px;
  color: var(--brand-strong);
  background: #dbeafe;
}

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

h1 {
  margin-top: 16px;
  font-size: clamp(34px, 5vw, 54px);
  line-height: 1.12;
}

.hero-desc {
  margin-top: 18px;
  max-width: 760px;
  color: var(--text-soft);
  font-size: 18px;
  line-height: 1.7;
}

.hero-note {
  margin-top: 10px;
  color: #6b7280;
  font-size: 14px;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 10px;
  border: 1px solid transparent;
  font-weight: 600;
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
}

.btn-github {
  color: #fff;
  background: #24292f;
  border-color: #24292f;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.btn-github:hover {
  background: #32383f;
  border-color: #32383f;
}

.btn-nav {
  min-height: 36px;
  padding: 0 12px;
  font-size: 14px;
}

.btn-ghost {
  border-color: var(--line);
  background: var(--surface);
}

.tags {
  margin-top: 20px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
}

.tags li {
  font-size: 13px;
  color: #374151;
  background: #eef2ff;
  border: 1px solid #dbe2f0;
  border-radius: 999px;
  padding: 5px 10px;
}

.platform-strip {
  padding: 30px 0;
  background: linear-gradient(135deg, #eff6ff 0%, #ffffff 50%, #f5f3ff 100%);
}

.platform-header {
  text-align: center;
  margin-bottom: 16px;
}

.platform-header p {
  font-size: 14px;
  color: #9ca3af;
}

.platform-icons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 12px;
  max-width: 900px;
  margin: 0 auto;
}

.platform-icon {
  min-width: 88px;
  min-height: 82px;
  border-radius: 999px;
  border: 1px solid #d1d5db;
  background: #ffffff;
  color: #4b5563;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 600;
  padding: 10px 12px;
  opacity: 0.9;
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.platform-icon:hover {
  opacity: 1;
  transform: translateY(-1px);
}

.platform-icon-img {
  width: 34px;
  height: 34px;
  object-fit: contain;
  display: block;
}

.platform-icon-plus {
  min-width: 46px;
  min-height: 46px;
  width: 46px;
  border-style: dashed;
  padding: 0;
}

.section {
  padding: 64px 0;
}

.section h2 {
  font-size: clamp(28px, 4vw, 40px);
  margin-bottom: 20px;
}

.section-alt {
  background: var(--bg-alt);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

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

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
}

.card h3 {
  font-size: 20px;
  margin-bottom: 10px;
}

.card p {
  color: var(--text-soft);
  line-height: 1.65;
}

.steps {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 14px;
}

.steps h3 {
  margin-bottom: 8px;
}

.steps p {
  color: var(--text-soft);
}

.list {
  margin: 0;
  padding-left: 20px;
  color: var(--text-soft);
  display: grid;
  gap: 8px;
}

.why-modules {
  display: grid;
  gap: 14px;
}

.why-module {
  background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);
  border: 1px solid #d8e4ff;
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 18px 20px;
}

.why-module h3 {
  font-size: clamp(20px, 2.5vw, 27px);
  line-height: 1.2;
  margin-bottom: 8px;
}

.why-module p {
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.65;
  color: var(--text-soft);
}

.why-module:nth-child(1) {
  background: linear-gradient(135deg, #eff6ff 0%, #ffffff 100%);
  border-color: #bfdbfe;
}

.why-module:nth-child(2) {
  background: linear-gradient(135deg, #f0fdf4 0%, #ffffff 100%);
  border-color: #bbf7d0;
}

.why-module:nth-child(3) {
  background: linear-gradient(135deg, #f5f3ff 0%, #ffffff 100%);
  border-color: #ddd6fe;
}

.why-module:nth-child(4) {
  background: linear-gradient(135deg, #fff7ed 0%, #ffffff 100%);
  border-color: #fed7aa;
}

.why-module:nth-child(5) {
  background: linear-gradient(135deg, #ecfeff 0%, #ffffff 100%);
  border-color: #a5f3fc;
}

.faq {
  display: grid;
  gap: 10px;
}

.faq details {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px 14px;
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
}

.faq p {
  margin-top: 10px;
  color: var(--text-soft);
}

.cta {
  text-align: center;
}

.cta p {
  margin-top: 10px;
  color: var(--text-soft);
}

.cta .cta-row {
  justify-content: center;
}

.author-notes {
  max-width: 860px;
}

.author-notes-content {
  margin-top: 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
}

.author-notes-content p {
  margin-top: 0;
  margin-bottom: 14px;
  color: var(--text-soft);
  font-size: 17px;
  line-height: 1.9;
}

.author-notes-content p:last-child {
  margin-bottom: 0;
}

.dandan-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.dandan-card {
  margin: 0;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: #fff;
}

.dandan-card img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  object-position: top;
  display: block;
}

.footer {
  border-top: 1px solid var(--line);
  background: #fff;
}

.footer-wrap {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--text-soft);
}

@media (max-width: 860px) {
  .grid,
  .grid-3,
  .dandan-grid {
    grid-template-columns: 1fr;
  }

  .nav nav {
    display: none;
  }

  .hero {
    padding-top: 48px;
  }

  .section {
    padding: 52px 0;
  }

  .footer-wrap {
    padding: 14px 0;
    flex-direction: column;
    align-items: flex-start;
  }
}