/* ============================================
   Xuanji (璇玑) — Product Landing Page
   配色体系：极夜黑 + 琥珀金暗金系
   ============================================ */

:root {
  --bg-deep: #08080C;
  --bg-surface: #0d0d12;
  --bg-card: #14141a;
  --bg-elevated: #1a1a22;
  --accent-primary: #D4A053;
  --accent-warm: #c68f3e;
  --accent-light: #e0b870;
  --color-jade: #34C88A;
  --color-cinnabar: #D94848;
  --color-steel: #5BA8CC;
  --text-primary: #F0EEE8;
  --text-secondary: #b8b0a8;
  --text-muted: #6a6560;
  --border-subtle: rgba(212, 160, 83, 0.08);
  --border-default: rgba(212, 160, 83, 0.15);

  --max-width: 960px;
  --nav-height: 64px;
  --radius-sm: 10px;
  --radius-md: 12px;
  --radius-lg: 14px;
  --radius-xl: 20px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Noto Serif SC', Georgia, 'Times New Roman', serif;

  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration: 0.3s;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

a { color: var(--accent-primary); text-decoration: none; transition: color var(--duration) var(--ease-out); }
a:hover { color: var(--accent-warm); }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

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

/* ============================================
   Navigation
   ============================================ */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; height: var(--nav-height); z-index: 1000;
  background: rgba(8, 8, 12, 0.88); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle); transition: background var(--duration) var(--ease-out);
}

.nav-container {
  max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
  height: 100%; display: flex; align-items: center; justify-content: space-between;
}

.nav-logo {
  display: flex; align-items: center; gap: 10px;
  color: var(--text-primary) !important; font-weight: 500; font-size: 15px;
}

.logo-sub { font-size: 11px; color: var(--accent-primary); font-weight: 500; letter-spacing: 0.15em; }

.nav-brand {
  display: flex; align-items: center; gap: 8px;
}

.nav-parent {
  font-size: 12px; color: var(--text-muted) !important; font-weight: 400;
  white-space: nowrap; letter-spacing: 0.02em;
}

.nav-parent:hover { color: var(--accent-primary) !important; }

.nav-sep {
  font-size: 14px; color: var(--text-muted); opacity: 0.35;
  line-height: 1; user-select: none;
}

.logo-img {
  width: 28px; height: 28px; object-fit: contain; display: block;
  border-radius: 6px; background: transparent;
}

.logo-img-large { width: 80px; height: 80px; border-radius: 14px; }

.nav-links { display: flex; gap: 28px; }

.nav-link {
  color: var(--text-secondary) !important; font-size: 14px; font-weight: 400;
  transition: color var(--duration) var(--ease-out); position: relative;
}

.nav-link::after {
  content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 1px;
  background: var(--accent-primary); transition: width var(--duration) var(--ease-out);
}

.nav-link:hover { color: var(--text-primary) !important; }
.nav-link:hover::after { width: 100%; }

.nav-toggle {
  display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 4px;
}

.nav-toggle span {
  width: 20px; height: 1.5px; background: var(--text-secondary); border-radius: 1px;
  transition: all var(--duration) var(--ease-out);
}

.nav-toggle.active span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: fixed; top: var(--nav-height); left: 0; right: 0;
    background: rgba(8, 8, 12, 0.98); backdrop-filter: blur(20px);
    flex-direction: column; align-items: center; padding: 24px 0; gap: 20px;
    border-bottom: 1px solid var(--border-subtle);
    transform: translateY(-100%); opacity: 0; pointer-events: none;
    transition: all var(--duration) var(--ease-out);
  }
  .nav-links.active { transform: translateY(0); opacity: 1; pointer-events: auto; }
}

/* ============================================
   Hero
   ============================================ */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  padding: calc(var(--nav-height) + 60px) 0 80px; overflow: hidden;
}

.hero-bg { position: absolute; inset: 0; pointer-events: none; }

.hero-glow {
  position: absolute; border-radius: 50%; filter: blur(120px);
}

.hero-glow-1 {
  width: 600px; height: 600px; top: -10%; right: -5%;
  background: radial-gradient(circle, rgba(212, 160, 83, 0.06), transparent 70%);
}

.hero-glow-2 {
  width: 500px; height: 500px; bottom: 15%; left: -8%;
  background: radial-gradient(circle, rgba(212, 160, 83, 0.04), transparent 70%);
}

.hero-content { position: relative; max-width: 600px; }

.hero-tag {
  font-size: 13px; color: var(--accent-primary); font-weight: 500;
  letter-spacing: 0.12em; margin-bottom: 20px;
  display: inline-block; padding: 4px 14px;
  background: rgba(212, 160, 83, 0.08); border-radius: 20px;
}

.hero-title {
  font-family: var(--font-serif); font-size: clamp(30px, 5vw, 48px);
  font-weight: 400; line-height: 1.35; letter-spacing: -0.02em; margin-bottom: 24px;
}

.hero-highlight {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-light));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

.hero-desc { font-size: 16px; color: var(--text-secondary); line-height: 1.8; margin-bottom: 36px; }

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 32px; }

.hero-meta { display: flex; align-items: center; gap: 12px; }
.meta-item {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13px; color: var(--text-muted);
}
.meta-divider { color: var(--text-muted); opacity: 0.3; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 28px; border-radius: var(--radius-sm); font-size: 14px; font-weight: 500;
  font-family: var(--font-sans); cursor: pointer; transition: all var(--duration) var(--ease-out);
  border: none; text-decoration: none !important;
}

.btn-primary { background: var(--accent-primary); color: #08080C !important; }
.btn-primary:hover { background: var(--accent-light); transform: translateY(-1px); box-shadow: 0 8px 24px rgba(212, 160, 83, 0.2); }

.btn-ghost { background: transparent; color: var(--text-secondary) !important; border: 1px solid var(--border-default); }
.btn-ghost:hover { border-color: var(--accent-primary); color: var(--accent-primary) !important; }

/* ============================================
   Sections (通用)
   ============================================ */
.section { padding: 100px 0; }

.section-header { text-align: center; margin-bottom: 60px; }

.section-tag {
  display: inline-block; font-size: 12px; color: var(--accent-primary); font-weight: 500;
  letter-spacing: 0.12em; margin-bottom: 12px; padding: 4px 14px;
  background: rgba(212, 160, 83, 0.08); border-radius: 20px;
}

.section-title {
  font-family: var(--font-serif); font-size: clamp(22px, 3.5vw, 30px);
  font-weight: 400; letter-spacing: -0.01em; margin-bottom: 16px; color: var(--text-primary);
}

.section-desc { font-size: 15px; color: var(--text-muted); max-width: 500px; margin: 0 auto; }

/* ============================================
   Pricing — 定价方案
   ============================================ */
.pricing { background: var(--bg-surface); }

.pricing-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
  max-width: 760px; margin: 0 auto;
}

.pricing-card {
  padding: 36px 28px; background: var(--bg-card); border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle); text-align: center;
  transition: all var(--duration) var(--ease-out); position: relative; overflow: hidden;
}

.pricing-card:hover { border-color: var(--border-default); transform: translateY(-3px); }

.pricing-card.featured {
  border-color: rgba(212, 160, 83, 0.25);
  box-shadow: 0 0 40px rgba(212, 160, 83, 0.06);
}

.pricing-card.featured::before {
  content: '推荐'; position: absolute; top: 14px; right: -28px;
  background: var(--accent-primary); color: #08080C; font-size: 10px; font-weight: 600;
  padding: 4px 36px; transform: rotate(45deg);
}

.pricing-duration { font-size: 13px; color: var(--text-muted); margin-bottom: 12px; }

.pricing-price {
  font-family: var(--font-serif); font-size: 36px; font-weight: 400;
  color: var(--accent-primary); margin-bottom: 4px; letter-spacing: -0.02em;
}

.pricing-price-note { font-size: 12px; color: var(--text-muted); margin-bottom: 20px; }

.pricing-features { list-style: none; margin-bottom: 28px; text-align: left; }

.pricing-features li {
  font-size: 13px; color: var(--text-secondary); padding: 6px 0;
  border-bottom: 1px solid var(--border-subtle); line-height: 1.5;
}

.pricing-features li:last-child { border-bottom: none; }

.pricing-btn {
  display: inline-block; width: 100%; padding: 12px 0; border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 500; cursor: pointer; transition: all var(--duration) var(--ease-out);
  text-decoration: none; border: none; font-family: var(--font-sans);
}

.pricing-btn-primary { background: var(--accent-primary); color: #08080C !important; }
.pricing-btn-primary:hover { background: var(--accent-light); }

.pricing-btn-outline { background: transparent; color: var(--accent-primary) !important; border: 1px solid var(--border-default); }
.pricing-btn-outline:hover { border-color: var(--accent-primary); }

.pricing-free-note {
  text-align: center; margin-top: 28px; font-size: 13px; color: var(--text-muted);
  max-width: 500px; margin-left: auto; margin-right: auto;
}

@media (max-width: 768px) {
  .pricing-grid { grid-template-columns: 1fr; max-width: 340px; }
  .pricing-card.featured::before { display: none; }
}

/* ============================================
   Core Features — 核心功能（7项）
   ============================================ */
.features { background: var(--bg-surface); }

.feature-item {
  display: flex; gap: 24px; padding: 32px 28px;
  background: var(--bg-card); border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle); margin-bottom: 16px;
  transition: all var(--duration) var(--ease-out);
}

.feature-item:hover {
  border-color: var(--border-default); transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.feature-item-number {
  flex-shrink: 0; font-family: var(--font-serif);
  font-size: 28px; color: var(--accent-primary); opacity: 0.5;
  line-height: 1; width: 40px;
}

.feature-item-body { flex: 1; min-width: 0; }

.feature-item-title {
  font-family: var(--font-serif); font-size: 18px; font-weight: 400;
  color: var(--text-primary); margin-bottom: 8px; letter-spacing: -0.01em;
}

.feature-item-desc { font-size: 14px; color: var(--text-secondary); line-height: 1.7; margin-bottom: 14px; }

/* 文件类型表格 */
.file-type-table {
  border: 1px solid var(--border-subtle); border-radius: var(--radius-md);
  overflow: hidden; max-width: 520px;
}

.file-type-row {
  display: grid; grid-template-columns: 32px 80px 1fr; gap: 12px;
  padding: 10px 16px; align-items: center;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 13px; color: var(--text-secondary);
}

.file-type-row:last-child { border-bottom: none; }
.file-type-icon { text-align: center; font-size: 16px; }
.file-type-name { color: var(--accent-primary); font-weight: 500; }
.file-type-formats { color: var(--text-muted); }

/* 局域网同步能力表 */
.lan-cap-table {
  border: 1px solid var(--border-subtle); border-radius: var(--radius-md);
  overflow: hidden; max-width: 480px;
}

.lan-cap-item {
  display: flex; justify-content: space-between; gap: 16px;
  padding: 10px 16px; border-bottom: 1px solid var(--border-subtle);
  font-size: 13px;
}

.lan-cap-item:last-child { border-bottom: none; }
.lan-cap-label { color: var(--accent-primary); font-weight: 500; flex-shrink: 0; }
.lan-cap-value { color: var(--text-secondary); text-align: right; }

@media (max-width: 640px) {
  .feature-item { flex-direction: column; gap: 12px; }
  .feature-item-number { width: auto; }
  .file-type-row { grid-template-columns: 24px 1fr; gap: 8px; }
  .file-type-name { grid-column: 2; }
  .file-type-formats { grid-column: 2; }
  .lan-cap-item { flex-direction: column; gap: 4px; }
  .lan-cap-value { text-align: left; }
}

/* ============================================
   Media — 极致影音体验
   ============================================ */
.media { background: var(--bg-deep); }

.media-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
  max-width: 800px; margin: 0 auto;
}

.media-card {
  padding: 28px 24px; background: var(--bg-card);
  border-radius: var(--radius-lg); border: 1px solid var(--border-subtle);
  transition: all var(--duration) var(--ease-out);
}

.media-card:hover {
  border-color: var(--border-default); transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.media-card-wide { grid-column: 1 / -1; }

.media-icon { font-size: 28px; display: block; margin-bottom: 14px; }

.media-title {
  font-family: var(--font-serif); font-size: 16px; font-weight: 400;
  color: var(--accent-primary); margin-bottom: 12px;
}

.media-list { list-style: none; padding: 0; }

.media-list li {
  font-size: 13px; color: var(--text-secondary); line-height: 1.8;
  padding-left: 16px; position: relative;
}

.media-list li::before {
  content: '·'; position: absolute; left: 4px; color: var(--accent-primary); opacity: 0.5;
}

@media (max-width: 768px) {
  .media-grid { grid-template-columns: 1fr; max-width: 400px; }
  .media-card-wide { grid-column: 1; }
}

/* ============================================
   Vault — 全类型保险箱
   ============================================ */
.vault { background: var(--bg-surface); }

.vault-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
  max-width: 800px; margin: 0 auto; margin-bottom: 32px;
}

.vault-card {
  text-align: center; padding: 28px 20px; background: var(--bg-card);
  border-radius: var(--radius-md); border: 1px solid var(--border-subtle);
  transition: all var(--duration) var(--ease-out);
}

.vault-card:hover {
  border-color: var(--border-default); transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.vault-card-icon { font-size: 28px; display: block; margin-bottom: 12px; }

.vault-card-title {
  font-family: var(--font-serif); font-size: 15px; font-weight: 400;
  color: var(--text-primary); margin-bottom: 8px;
}

.vault-card-desc { font-size: 12px; color: var(--text-muted); line-height: 1.6; }

.vault-note {
  text-align: center; font-size: 13px; color: var(--text-secondary);
  max-width: 600px; margin: 0 auto;
}

@media (max-width: 768px) {
  .vault-grid { grid-template-columns: repeat(2, 1fr); max-width: 480px; }
}

@media (max-width: 400px) {
  .vault-grid { grid-template-columns: 1fr; max-width: 280px; }
}

/* ============================================
   Security Architecture — 安全架构
   ============================================ */
.security-arch { background: var(--bg-deep); }

.arch-table {
  max-width: 640px; margin: 0 auto; margin-bottom: 32px;
  border: 1px solid var(--border-subtle); border-radius: var(--radius-lg);
  overflow: hidden;
}

.arch-row {
  display: grid; grid-template-columns: 120px 1fr;
  gap: 16px; padding: 14px 20px; align-items: center;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 14px;
}

.arch-row:last-child { border-bottom: none; }

.arch-header-row {
  background: var(--bg-card);
  font-weight: 500; color: var(--accent-primary);
}

.arch-layer { color: var(--accent-primary); font-weight: 500; }
.arch-detail { color: var(--text-secondary); }

.arch-pledge {
  text-align: center; font-size: 15px; color: var(--accent-primary);
  font-weight: 500; letter-spacing: 0.02em;
}

@media (max-width: 640px) {
  .arch-row { grid-template-columns: 1fr; gap: 4px; padding: 12px 16px; }
}

/* ============================================
   Taglines — 短文案卡片
   ============================================ */
.taglines { background: var(--bg-surface); }

.tagline-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px;
  max-width: 760px; margin: 0 auto;
}

.tagline-card {
  padding: 20px 22px; background: var(--bg-card);
  border-radius: var(--radius-md); border: 1px solid var(--border-subtle);
  font-size: 14px; color: var(--text-secondary); line-height: 1.7;
  font-style: italic; transition: all var(--duration) var(--ease-out);
}

.tagline-card:hover {
  border-color: var(--border-default); transform: translateY(-2px);
  color: var(--text-primary);
}

@media (max-width: 640px) {
  .tagline-grid { grid-template-columns: 1fr; max-width: 400px; }
}

/* ============================================
   Audiences — 写给不同的人
   ============================================ */
.audiences { background: var(--bg-deep); }

.audience-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px;
  max-width: 800px; margin: 0 auto;
}

.audience-card {
  padding: 28px 24px; background: var(--bg-card);
  border-radius: var(--radius-lg); border: 1px solid var(--border-subtle);
  transition: all var(--duration) var(--ease-out);
}

.audience-card:hover {
  border-color: var(--border-default); transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.audience-who {
  font-family: var(--font-serif); font-size: 16px; font-weight: 400;
  color: var(--accent-primary); margin-bottom: 10px; letter-spacing: -0.01em;
}

.audience-text { font-size: 14px; color: var(--text-secondary); line-height: 1.8; }

@media (max-width: 640px) {
  .audience-grid { grid-template-columns: 1fr; max-width: 400px; }
}

/* ============================================
   Principles — 底线
   ============================================ */
.principles { background: var(--bg-surface); }

.principle-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px;
  max-width: 720px; margin: 0 auto;
}

.principle-card {
  display: flex; align-items: center; gap: 8px;
  padding: 14px 16px; background: var(--bg-card);
  border-radius: var(--radius-md); border: 1px solid var(--border-subtle);
}

.principle-x { color: var(--accent-primary); font-size: 14px; font-weight: 600; opacity: 0.7; flex-shrink: 0; }
.principle-text { font-size: 13px; color: var(--text-muted); }

@media (max-width: 640px) {
  .principle-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ============================================
   Download — 下载
   ============================================ */
.download { background: var(--bg-deep); }

.download-card {
  text-align: center; padding: 60px 40px; background: var(--bg-surface);
  border-radius: var(--radius-xl); border: 1px solid var(--border-subtle);
  position: relative; overflow: hidden;
}

.download-card::before {
  content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
  background: radial-gradient(circle at center, rgba(212, 160, 83, 0.03), transparent 50%);
  pointer-events: none;
}

.download-icon { margin-bottom: 24px; position: relative; }

.download-title {
  font-family: var(--font-serif); font-size: clamp(22px, 3vw, 28px);
  font-weight: 400; margin-bottom: 12px; position: relative; color: var(--text-primary);
}

.download-desc { font-size: 15px; color: var(--text-muted); margin-bottom: 32px; position: relative; }

.download-buttons {
  display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; position: relative;
}

.btn-download { padding: 14px 32px; font-size: 15px; gap: 10px; }

.download-coming-soon { display: flex; align-items: center; gap: 12px; }

@media (max-width: 480px) {
  .download-card { padding: 40px 24px; }
  .download-buttons { flex-direction: column; align-items: center; }
}

/* ============================================
   Principles — 我们不做什么
   ============================================ */
.principles { background: var(--bg-surface); }

.principle-grid {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 12px;
  max-width: 720px; margin: 0 auto;
}

.principle-card {
  display: flex; align-items: center; gap: 8px;
  padding: 10px 18px; background: var(--bg-card);
  border-radius: var(--radius-md); border: 1px solid var(--border-subtle);
}

.principle-x { color: var(--color-cinnabar); font-size: 14px; font-weight: 600; flex-shrink: 0; }
.principle-text { font-size: 13px; color: var(--text-muted); }

/* ============================================
   Footer
   ============================================ */
.footer { padding: 40px 0; border-top: 1px solid var(--border-subtle); }

.footer-content {
  display: flex; justify-content: space-between; align-items: center; margin-bottom: 24px;
}

.footer-brand { }
.footer-logo { font-family: var(--font-serif); font-size: 16px; color: var(--text-primary); }
.footer-sub { font-size: 11px; color: var(--accent-primary); font-weight: 500; letter-spacing: 0.15em; }
.footer-brand p { font-size: 13px; color: var(--text-muted); margin-top: 4px; }

.footer-links { display: flex; gap: 24px; }
.footer-links a { font-size: 13px; color: var(--text-muted) !important; }
.footer-links a:hover { color: var(--accent-primary) !important; }

.footer-bottom { text-align: center; }
.footer-bottom p { font-size: 12px; color: var(--text-muted); }

@media (max-width: 768px) {
  .footer-content { flex-direction: column; gap: 20px; text-align: center; }
}

/* ============================================
   Animations
   ============================================ */
.fade-in {
  opacity: 0; transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}

.fade-in.visible { opacity: 1; transform: translateY(0); }