:root {
  --bg: #f4f1ec;
  --surface: #ffffff;
  --ink: #1f1a2e;
  --muted: #6b647a;
  --accent: #d64550;
  --accent-dark: #8b1f28;
  --accent-soft: #ffede3;
  --jade: #1b9aaa;
  --gold: #f0a202;
  --shadow: 0 20px 60px rgba(9, 9, 13, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
}

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

img {
  max-width: 100%;
  display: block;
}

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(244, 241, 236, 0.92);
  backdrop-filter: blur(10px);
  box-shadow: 0 10px 30px rgba(20, 20, 25, 0.08);
  z-index: 1000;
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.brand svg {
  width: 36px;
  height: 36px;
}

.nav-links {
  display: flex;
  gap: 18px;
  align-items: center;
}

.nav-link {
  font-size: 14px;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: 999px;
  transition: background 0.3s ease, color 0.3s ease;
  color: var(--muted);
}

.nav-link:hover,
.nav-link.active {
  background: var(--ink);
  color: #fff;
}

.nav-toggle {
  display: none;
  width: 34px;
  height: 34px;
  border-radius: 6px;
  border: 1px solid rgba(31, 26, 46, 0.2);
  background: transparent;
  position: relative;
}

.nav-toggle span,
.nav-toggle::before,
.nav-toggle::after {
  content: "";
  position: absolute;
  left: 8px;
  right: 8px;
  height: 2px;
  background: var(--ink);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle span {
  top: 16px;
}

.nav-toggle::before {
  top: 10px;
}

.nav-toggle::after {
  bottom: 10px;
}

.nav-toggle.open::before {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle.open::after {
  transform: translateY(-6px) rotate(-45deg);
}

.nav-toggle.open span {
  opacity: 0;
}

main {
  padding-top: 96px;
}

section {
  padding: 80px 24px;
}

.section-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.section-head {
  margin-bottom: 48px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--jade);
}

.section-tag::before {
  content: "";
  width: 32px;
  height: 2px;
  background: var(--jade);
}

.section-head h2 {
  font-size: 36px;
  margin: 12px 0 16px;
}

.section-head p {
  color: var(--muted);
  max-width: 720px;
}

.hero {
  background: radial-gradient(circle at top left, #fff5f2, var(--bg));
}

.hero-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 40px;
  align-items: center;
}

.hero-note {
  text-transform: uppercase;
  color: var(--accent);
  letter-spacing: 0.3em;
  font-size: 13px;
}

.hero h1 {
  font-size: 48px;
  line-height: 1.2;
  margin: 16px 0;
}

.hero p {
  color: var(--muted);
}

.hero-actions {
  margin-top: 24px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  border: none;
  border-radius: 38px;
  padding: 14px 26px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.3s ease;
}

.btn-primary {
  background: linear-gradient(120deg, var(--accent) 0%, var(--accent-dark) 100%);
  color: #fff;
  box-shadow: 0 12px 24px rgba(214, 69, 80, 0.35);
}

.btn-secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid rgba(31, 26, 46, 0.2);
}

.btn:hover {
  transform: translateY(-2px);
}

.hero-panel {
  background: var(--surface);
  border-radius: 28px;
  padding: 32px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.hero-panel::after {
  content: "";
  position: absolute;
  top: -20%;
  right: -10%;
  width: 220px;
  height: 220px;
  background: radial-gradient(circle, rgba(214, 69, 80, 0.25), transparent 65%);
}

.hero-panel h3 {
  margin: 0 0 8px;
  font-size: 22px;
}

.hero-panel ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(120px, 1fr));
  gap: 16px;
}

.hero-panel li strong {
  display: block;
  font-size: 26px;
}

.hero-panel li span {
  color: var(--muted);
  font-size: 13px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--surface);
  border-radius: 20px;
  padding: 24px;
  border: 1px solid rgba(31, 26, 46, 0.08);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: var(--accent-soft);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
}

.feature-card h3 {
  margin: 0 0 10px;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
}

.feature-panels {
  margin-top: 48px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-panel-item {
  background: var(--surface);
  border-radius: 24px;
  padding: 28px;
  border: 1px solid rgba(31, 26, 46, 0.05);
}

.feature-panel-item h4 {
  margin: 0 0 12px;
  font-size: 22px;
}

.feature-panel-item p {
  margin: 0 0 12px;
  color: var(--muted);
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.platform-card {
  background: var(--surface);
  border-radius: 24px;
  padding: 24px;
  border: 1px solid rgba(31, 26, 46, 0.08);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.platform-card header {
  display: flex;
  align-items: center;
  gap: 12px;
}

.platform-card ul {
  padding-left: 18px;
  margin: 0 0 12px;
  color: var(--muted);
}

.platform-card .version {
  font-weight: 600;
  color: var(--jade);
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.review-card {
  background: var(--surface);
  border-radius: 22px;
  padding: 24px;
  border: 1px solid rgba(31, 26, 46, 0.08);
}

.review-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.stars svg {
  width: 16px;
  height: 16px;
  color: var(--gold);
}

.review-card p {
  margin: 0;
  color: var(--muted);
}

.security-badges {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

.security-badge {
  background: var(--surface);
  border-radius: 20px;
  padding: 20px;
  border: 1px solid rgba(31, 26, 46, 0.08);
}

.security-badge h4 {
  margin: 10px 0 6px;
}

.security-badge p {
  margin: 0;
  color: var(--muted);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 24px;
  background: var(--surface);
  border-radius: 16px;
  overflow: hidden;
}

.compare-table th,
.compare-table td {
  padding: 14px 18px;
  border-bottom: 1px solid rgba(31, 26, 46, 0.06);
  text-align: left;
}

.compare-table th {
  background: var(--accent-soft);
}

.version-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.version-card {
  background: var(--surface);
  border-radius: 24px;
  padding: 28px;
  border: 2px solid rgba(31, 26, 46, 0.08);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.version-card .price {
  font-size: 36px;
  font-weight: 700;
}

.version-card ul {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}

.version-card .tag {
  display: inline-flex;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
}

.faq-list {
  display: grid;
  gap: 16px;
}

.faq-item {
  background: var(--surface);
  border-radius: 18px;
  border: 1px solid rgba(31, 26, 46, 0.08);
  overflow: hidden;
}

.faq-item button {
  width: 100%;
  background: transparent;
  border: none;
  padding: 20px 24px;
  font-size: 18px;
  text-align: left;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

.faq-item .answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  padding: 0 24px;
  color: var(--muted);
}

.faq-item.open .answer {
  max-height: 400px;
  padding-bottom: 20px;
}

.faq-item svg {
  width: 18px;
  height: 18px;
  transition: transform 0.3s ease;
}

.faq-item.open svg {
  transform: rotate(45deg);
}

footer {
  padding: 40px 24px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

.tablet-stack .hero-grid {
  grid-template-columns: 1fr;
}

.nav-links.show {
  display: flex;
}

@keyframes spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 900px) {
  .nav-links {
    position: absolute;
    top: 64px;
    right: 24px;
    flex-direction: column;
    background: var(--surface);
    padding: 16px;
    border-radius: 18px;
    box-shadow: var(--shadow);
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
}