/* ============================================
   宜小集官网 - 全局样式
   设计风格：简约白色（Apple/Stripe风格）
   ============================================ */

/* === CSS Variables === */
:root {
  /* Colors */
  --color-primary: #1a1a2e;
  --color-accent: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-accent-light: #dbeafe;
  --color-accent-gradient: linear-gradient(135deg, #3b82f6, #6366f1);
  --color-bg: #ffffff;
  --color-bg-secondary: #f8fafc;
  --color-bg-tertiary: #f1f5f9;
  --color-text: #1e293b;
  --color-text-secondary: #64748b;
  --color-text-tertiary: #94a3b8;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-card-bg: #ffffff;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.06), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.06), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.04), 0 0 0 1px rgba(0, 0, 0, 0.02);
  --shadow-card-hover: 0 10px 40px rgba(0, 0, 0, 0.08), 0 0 0 1px rgba(0, 0, 0, 0.04);

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;

  /* Layout */
  --max-width: 1200px;
  --max-width-narrow: 800px;
  --nav-height: 72px;
}

/* === Reset & Base === */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent-hover);
}

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

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  font-size: inherit;
}

input, textarea {
  font-family: inherit;
  font-size: inherit;
}

h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 700;
  color: var(--color-text);
}

/* === Utility Classes === */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container--narrow {
  max-width: var(--max-width-narrow);
}

.section {
  padding: var(--space-24) 0;
}

.section--sm {
  padding: var(--space-16) 0;
}

.section--bg {
  background-color: var(--color-bg-secondary);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-16);
}

.section-header__label {
  display: inline-block;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-4);
  padding: var(--space-1) var(--space-3);
  background: var(--color-accent-light);
  border-radius: var(--radius-full);
}

.section-header__title {
  font-size: var(--text-4xl);
  font-weight: 800;
  margin-bottom: var(--space-4);
  letter-spacing: -0.02em;
}

.section-header__desc {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 640px;
  margin: 0 auto;
}

.text-center { text-align: center; }
.text-left { text-align: left; }

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  white-space: nowrap;
  line-height: 1.5;
}

.btn--primary {
  background: var(--color-accent-gradient);
  color: #ffffff;
  box-shadow: 0 1px 2px rgba(59, 130, 246, 0.3);
}

.btn--primary:hover {
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.35);
}

.btn--secondary {
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn--secondary:hover {
  color: var(--color-text);
  border-color: var(--color-text-tertiary);
  box-shadow: var(--shadow-sm);
}

.btn--ghost {
  color: var(--color-text-secondary);
  padding: var(--space-2) var(--space-4);
}

.btn--ghost:hover {
  color: var(--color-text);
  background: var(--color-bg-tertiary);
}

.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
  border-radius: var(--radius-xl);
}

.btn--full {
  width: 100%;
  justify-content: center;
}

.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

.btn--icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-md);
}

/* === Navigation === */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition-base);
}

.nav--scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-xs);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.nav__logo:hover {
  color: var(--color-text);
}

.nav__logo-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-gradient);
  color: #fff;
  border-radius: var(--radius-md);
  font-size: var(--text-lg);
  font-weight: 800;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav__link {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav__link:hover {
  color: var(--color-text);
  background: var(--color-bg-tertiary);
}

.nav__link--active {
  color: var(--color-text);
  background: var(--color-bg-tertiary);
}

.nav__cta {
  margin-left: var(--space-4);
}

/* Mobile menu button */
.nav__menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text);
}

.nav__menu-btn:hover {
  background: var(--color-bg-tertiary);
}

.nav__menu-icon {
  width: 20px;
  height: 14px;
  position: relative;
}

.nav__menu-icon span {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
  border-radius: 1px;
  position: absolute;
  left: 0;
  transition: all var(--transition-fast);
}

.nav__menu-icon span:nth-child(1) { top: 0; }
.nav__menu-icon span:nth-child(2) { top: 6px; }
.nav__menu-icon span:nth-child(3) { top: 12px; }

.nav__menu-btn.active .nav__menu-icon span:nth-child(1) {
  transform: rotate(45deg);
  top: 6px;
}
.nav__menu-btn.active .nav__menu-icon span:nth-child(2) {
  opacity: 0;
}
.nav__menu-btn.active .nav__menu-icon span:nth-child(3) {
  transform: rotate(-45deg);
  top: 6px;
}

/* Mobile sidebar */
.nav__mobile-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.3);
  z-index: 998;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.nav__mobile-overlay.active {
  opacity: 1;
}

.nav__mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  right: 0;
  width: 280px;
  height: 100%;
  background: var(--color-bg);
  z-index: 999;
  padding: var(--space-8) var(--space-6);
  transform: translateX(100%);
  transition: transform var(--transition-slow);
  box-shadow: var(--shadow-xl);
  overflow-y: auto;
}

.nav__mobile-menu.active {
  transform: translateX(0);
}

.nav__mobile-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: var(--text-xl);
}

.nav__mobile-close:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text);
}

.nav__mobile-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  margin-top: var(--space-8);
}

.nav__mobile-link {
  display: block;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav__mobile-link:hover,
.nav__mobile-link--active {
  color: var(--color-text);
  background: var(--color-bg-tertiary);
}

.nav__mobile-cta {
  margin-top: var(--space-6);
}

/* === Hero Section === */
.hero {
  padding-top: calc(var(--nav-height) + var(--space-20));
  padding-bottom: var(--space-24);
  position: relative;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(59, 130, 246, 0.06) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(99, 102, 241, 0.05) 0%, transparent 50%),
    radial-gradient(ellipse at 60% 80%, rgba(59, 130, 246, 0.03) 0%, transparent 50%);
  pointer-events: none;
}

.hero__inner {
  display: flex;
  align-items: center;
  gap: var(--space-16);
  position: relative;
  z-index: 1;
}

.hero__content {
  flex: 1;
  max-width: 600px;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-6);
}

.hero__badge-dot {
  width: 6px;
  height: 6px;
  background: var(--color-success);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero__title {
  font-size: var(--text-6xl);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-6);
}

.hero__title-accent {
  background: var(--color-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__desc {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-8);
}

.hero__actions {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.hero__visual {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.hero__graphic {
  width: 100%;
  max-width: 480px;
  aspect-ratio: 1;
  position: relative;
}

.hero__graphic-circle {
  position: absolute;
  border-radius: 50%;
  border: 1px solid var(--color-border);
}

.hero__graphic-circle--1 {
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  border-color: var(--color-border-light);
  animation: rotate 60s linear infinite;
}

.hero__graphic-circle--2 {
  width: 75%;
  height: 75%;
  top: 12.5%;
  left: 12.5%;
  border-color: var(--color-accent-light);
  opacity: 0.5;
  animation: rotate 45s linear infinite reverse;
}

.hero__graphic-circle--3 {
  width: 50%;
  height: 50%;
  top: 25%;
  left: 25%;
  background: var(--color-accent-gradient);
  opacity: 0.08;
  border: none;
}

.hero__graphic-dot {
  position: absolute;
  width: 10px;
  height: 10px;
  background: var(--color-accent);
  border-radius: 50%;
  box-shadow: 0 0 20px rgba(59, 130, 246, 0.3);
}

.hero__graphic-dot--1 { top: 15%; left: 50%; }
.hero__graphic-dot--2 { top: 50%; right: 10%; }
.hero__graphic-dot--3 { bottom: 20%; left: 20%; }

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

/* === Page Hero (Sub-pages) === */
.page-hero {
  padding-top: calc(var(--nav-height) + var(--space-16));
  padding-bottom: var(--space-16);
  background: var(--color-bg-secondary);
  text-align: center;
}

.page-hero__title {
  font-size: var(--text-5xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-4);
}

.page-hero__desc {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto;
}

/* === Product Cards === */
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: var(--space-8);
}

.product-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: all var(--transition-slow);
  position: relative;
  overflow: hidden;
}

.product-card:hover {
  border-color: var(--color-accent-light);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-4px);
}

.product-card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-light);
  color: var(--color-accent);
  border-radius: var(--radius-lg);
  font-size: var(--text-2xl);
  margin-bottom: var(--space-6);
}

.product-card__title {
  font-size: var(--text-xl);
  font-weight: 700;
  margin-bottom: var(--space-3);
}

.product-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-6);
}

.product-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.product-card__tag {
  padding: var(--space-1) var(--space-3);
  background: var(--color-bg-secondary);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  font-weight: 500;
}

.product-card__link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-accent);
}

.product-card__link:hover {
  gap: var(--space-3);
}

/* === Feature Cards === */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-6);
}

.feature-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  transition: all var(--transition-slow);
}

.feature-card:hover {
  border-color: var(--color-accent-light);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-2px);
}

.feature-card__icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-secondary);
  border-radius: var(--radius-lg);
  font-size: var(--text-xl);
  margin-bottom: var(--space-4);
}

.feature-card__title {
  font-size: var(--text-base);
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.feature-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* === Stats === */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-8);
  text-align: center;
  padding: var(--space-12) 0;
}

.stat__number {
  font-size: var(--text-4xl);
  font-weight: 800;
  color: var(--color-accent);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-2);
}

.stat__label {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

/* === Scenario Cards === */
.scenarios-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-6);
}

.scenario-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: all var(--transition-slow);
  position: relative;
}

.scenario-card:hover {
  border-color: var(--color-accent-light);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-2px);
}

.scenario-card__number {
  font-size: var(--text-6xl);
  font-weight: 800;
  color: var(--color-bg-tertiary);
  line-height: 1;
  margin-bottom: var(--space-4);
}

.scenario-card__title {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-3);
}

.scenario-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* === Download Cards === */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: var(--space-8);
}

.download-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: all var(--transition-slow);
  display: flex;
  flex-direction: column;
}

.download-card:hover {
  box-shadow: var(--shadow-card-hover);
}

.download-card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-light);
  color: var(--color-accent);
  border-radius: var(--radius-lg);
  font-size: var(--text-2xl);
  margin-bottom: var(--space-6);
}

.download-card__title {
  font-size: var(--text-xl);
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.download-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-6);
}

.download-card__checklist {
  list-style: none;
  margin-bottom: var(--space-6);
}

.download-card__checklist li {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.download-card__checklist li::before {
  content: '\2713';
  color: var(--color-success);
  font-weight: 700;
  flex-shrink: 0;
}

.download-card .btn {
  margin-top: auto;
}

.download-card__note {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  margin-top: var(--space-4);
}

/* === Update Notice === */
.update-notice {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-5);
  margin-bottom: var(--space-6);
  display: none;
}

.update-notice--visible {
  display: block;
}

.update-notice__title {
  font-size: var(--text-sm);
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--color-accent);
}

.update-notice__content {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
  white-space: pre-wrap;
}

/* === Content Blocks === */
.content-block {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  margin-bottom: var(--space-6);
}

.content-block__title {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.content-block__body {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.content-block__body ul {
  list-style: disc;
  padding-left: var(--space-5);
}

.content-block__body li {
  margin-bottom: var(--space-2);
}

/* === Contact Form === */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: start;
}

.contact-form {
  max-width: 100%;
}

.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  color: var(--color-text);
  transition: all var(--transition-fast);
  outline: none;
}

.form-input:focus,
.form-textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-tertiary);
}

/* === Contact Info === */
.contact-info {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

.contact-info-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  transition: all var(--transition-slow);
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
}

.contact-info-card:hover {
  border-color: var(--color-accent-light);
  box-shadow: var(--shadow-md);
}

.contact-info-card__icon {
  font-size: var(--text-2xl);
  flex-shrink: 0;
}

.contact-info-card__label {
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-1);
}

.contact-info-card__value {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* === FAQ === */
.faq-list {
  max-width: 720px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-6) 0;
}

.faq-item:first-child {
  padding-top: 0;
}

.faq-item__question {
  font-size: var(--text-base);
  font-weight: 700;
  margin-bottom: 0;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
}

.faq-item__question::after {
  content: '+';
  font-size: var(--text-xl);
  color: var(--color-text-tertiary);
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.faq-item.active .faq-item__question::after {
  transform: rotate(45deg);
}

.faq-item__answer {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.8;
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow), margin var(--transition-slow);
}

.faq-item.active .faq-item__answer {
  max-height: 500px;
  margin-top: var(--space-3);
}

/* === Partners === */
.partners {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-12);
  align-items: center;
  opacity: 0.4;
}

.partners__item {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text-secondary);
  letter-spacing: -0.01em;
}

/* === Values Grid === */
.values-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-6);
}

.value-card {
  text-align: center;
  padding: var(--space-8) var(--space-6);
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  transition: all var(--transition-slow);
}

.value-card:hover {
  border-color: var(--color-accent-light);
  box-shadow: var(--shadow-md);
}

.value-card__icon {
  font-size: var(--text-4xl);
  margin-bottom: var(--space-4);
}

.value-card__title {
  font-size: var(--text-base);
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.value-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* === Timeline === */
.timeline {
  max-width: 640px;
  margin: 0 auto;
  position: relative;
  padding-left: var(--space-8);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}

.timeline__item {
  position: relative;
  padding-bottom: var(--space-8);
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__dot {
  position: absolute;
  left: calc(-1 * var(--space-8) + 2px);
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-accent-light);
}

.timeline__year {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: var(--space-1);
}

.timeline__title {
  font-size: var(--text-base);
  font-weight: 700;
  margin-bottom: var(--space-1);
}

.timeline__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* === Footer === */
.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-16) 0 var(--space-8);
}

.footer__inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer__brand {
  max-width: 280px;
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.footer__logo-icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-gradient);
  color: #fff;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 800;
}

.footer__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.footer__wechat {
  margin-top: var(--space-5);
}

.footer__wechat-img {
  width: 160px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: transform var(--transition-base);
}

.footer__wechat-img:hover {
  transform: scale(1.03);
}

.footer__wechat-label {
  display: block;
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.footer__col-title {
  font-size: var(--text-sm);
  font-weight: 700;
  margin-bottom: var(--space-5);
  color: var(--color-text);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer__link {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-text);
}

.footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.footer__bottom-links {
  display: flex;
  gap: var(--space-6);
}

.footer__bottom-link {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.footer__bottom-link:hover {
  color: var(--color-text-secondary);
}

/* === Back to Top === */
.back-to-top {
  position: fixed;
  bottom: var(--space-8);
  right: var(--space-8);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  color: var(--color-text-secondary);
  font-size: var(--text-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition-base);
  z-index: 100;
}

.back-to-top--visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  color: var(--color-text);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* === 404 Page === */
.error-page {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  text-align: center;
  padding: var(--space-8);
}

.error-page__code {
  font-size: 120px;
  font-weight: 800;
  background: var(--color-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: var(--space-4);
}

.error-page__title {
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-bottom: var(--space-4);
}

.error-page__desc {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-8);
}

/* === Responsive === */
@media (max-width: 1024px) {
  .hero__inner {
    flex-direction: column;
    text-align: center;
  }

  .hero__content {
    max-width: 100%;
  }

  .hero__actions {
    justify-content: center;
  }

  .hero__visual {
    max-width: 400px;
    margin: 0 auto;
  }

  .stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer__inner {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }

  .contact-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
  }

  .section {
    padding: var(--space-16) 0;
  }

  .section-header__title {
    font-size: var(--text-3xl);
  }

  .nav__links {
    display: none;
  }

  .nav__cta {
    display: none;
  }

  .nav__menu-btn {
    display: flex;
  }

  .nav__mobile-overlay {
    display: block;
  }

  .nav__mobile-menu {
    display: block;
  }

  .hero {
    padding-top: calc(var(--nav-height) + var(--space-12));
    padding-bottom: var(--space-16);
  }

  .hero__title {
    font-size: var(--text-4xl);
  }

  .hero__desc {
    font-size: var(--text-base);
  }

  .hero__visual {
    max-width: 300px;
  }

  .page-hero__title {
    font-size: var(--text-3xl);
  }

  .products-grid {
    grid-template-columns: 1fr;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .scenarios-grid {
    grid-template-columns: 1fr;
  }

  .download-grid {
    grid-template-columns: 1fr;
  }

  .stats {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-6);
  }

  .stat__number {
    font-size: var(--text-3xl);
  }

  .footer__inner {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .footer__bottom {
    flex-direction: column;
    gap: var(--space-4);
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero__title {
    font-size: var(--text-3xl);
  }

  .hero__actions {
    flex-direction: column;
    width: 100%;
  }

  .hero__actions .btn {
    width: 100%;
    justify-content: center;
  }

  .contact-info {
    grid-template-columns: 1fr;
  }

  .values-grid {
    grid-template-columns: 1fr;
  }
}

/* === Print Styles === */
@media print {
  .nav,
  .back-to-top,
  .hero__visual {
    display: none !important;
  }

  .hero {
    padding-top: var(--space-8);
  }

  body {
    color: #000;
    background: #fff;
  }

  a {
    color: #000;
    text-decoration: underline;
  }
}