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

:root {
  --primary: #059669;
  --primary-dark: #047857;
  --primary-light: #34D399;
  --primary-bg: #ECFDF5;
  --accent: #0D9488;
  --secondary: #111827;
  --text: #374151;
  --text-light: #6B7280;
  --background: #FFFFFF;
  --background-alt: #F9FAFB;
  --border: #E5E7EB;
  --gradient: linear-gradient(135deg, #059669 0%, #0D9488 100%);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--text);
  line-height: 1.6;
  background: var(--background);
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3 {
  color: var(--secondary);
  font-weight: 700;
  line-height: 1.2;
}

h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.75rem, 3.5vw, 2.25rem); letter-spacing: -0.02em; }
h3 { font-size: 1.1rem; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(5,150,105,0.25);
}

.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--primary);
  background: var(--primary-bg);
}

.btn-large {
  padding: 15px 36px;
  font-size: 1.05rem;
}

/* ==================== HEADER ==================== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.logo-img { width: 32px; height: 32px; }

.logo-text {
  font-weight: 700;
  font-size: 1rem;
  color: var(--secondary);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-right a {
  color: var(--text-light);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.875rem;
  padding: 6px 12px;
  border-radius: 6px;
  transition: all 0.2s;
}

.nav-right a:hover {
  color: var(--primary);
  background: var(--primary-bg);
}

.nav-right .btn {
  margin-left: 8px;
  padding: 8px 20px;
  font-size: 0.875rem;
  background: var(--secondary);
  color: white;
}

.nav-right .btn:hover {
  background: #1F2937;
}

/* ==================== HERO - 纯文字左对齐极简 ==================== */
.hero {
  padding: 140px 0 80px;
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  max-width: 680px;
}

.hero-tag {
  display: inline-block;
  padding: 4px 12px;
  background: var(--primary-bg);
  color: var(--primary);
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: 6px;
  margin-bottom: 20px;
}

.hero h1 {
  margin-bottom: 20px;
}

.hero h1 em {
  font-style: normal;
  color: var(--primary);
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-light);
  line-height: 1.75;
  margin-bottom: 32px;
  max-width: 560px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  margin-bottom: 48px;
}

/* 横向 inline 统计条 */
.hero-proof {
  display: flex;
  gap: 36px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}

.proof-item {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.proof-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--secondary);
}

.proof-label {
  font-size: 0.8rem;
  color: var(--text-light);
}

/* ==================== FEATURES - Bento 混合网格 ==================== */
.features {
  padding: 100px 0;
  background: var(--background-alt);
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary);
  margin-bottom: 8px;
}

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

.section-header p {
  color: var(--text-light);
  font-size: 1rem;
  margin-top: 8px;
  max-width: 480px;
}

/* Bento grid: 2 大 + 4 小 */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: auto auto;
  gap: 16px;
}

.bento-card {
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px 24px;
  transition: box-shadow 0.25s ease;
}

.bento-card:hover {
  box-shadow: 0 8px 24px rgba(0,0,0,0.06);
}

/* 前两个大卡片各占 2 列 */
.bento-card:nth-child(1),
.bento-card:nth-child(2) {
  grid-column: span 2;
}

/* 后四个各占 1 列 */
.bento-card:nth-child(n+3) {
  grid-column: span 1;
}

.bento-emoji {
  font-size: 2rem;
  margin-bottom: 14px;
  display: block;
}

.bento-card h3 {
  margin-bottom: 6px;
}

.bento-card p {
  color: var(--text-light);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ==================== HOW IT WORKS - 横向数字卡 ==================== */
.how-it-works {
  padding: 100px 0;
}

.steps-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.step-card {
  background: var(--primary-bg);
  border-radius: 14px;
  padding: 32px 24px;
  position: relative;
  overflow: hidden;
}

.step-big-number {
  font-size: 5rem;
  font-weight: 800;
  color: var(--primary);
  opacity: 0.1;
  position: absolute;
  top: -10px;
  right: 12px;
  line-height: 1;
}

.step-card h3 {
  margin-bottom: 8px;
  position: relative;
}

.step-card p {
  color: var(--text-light);
  font-size: 0.9rem;
  line-height: 1.65;
  position: relative;
}

/* ==================== EXPORT OPTIONS - 左图标右文字大卡 ==================== */
.export-options {
  padding: 100px 0;
  background: var(--background-alt);
}

.export-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.export-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
  transition: box-shadow 0.25s ease;
}

.export-item:hover {
  box-shadow: 0 8px 24px rgba(0,0,0,0.06);
}

.export-item-icon {
  width: 48px;
  height: 48px;
  min-width: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.export-item-icon svg {
  width: 24px;
  height: 24px;
}

.export-item-icon.doc { background: #DBEAFE; }
.export-item-icon.pdf { background: #FEE2E2; }
.export-item-icon.sheet { background: #D1FAE5; }
.export-item-icon.slide { background: #FEF3C7; }

.export-item-text h3 {
  margin-bottom: 4px;
  font-size: 1rem;
}

.export-item-text p {
  color: var(--text-light);
  font-size: 0.85rem;
  line-height: 1.55;
}

/* ==================== SELECTION - 横条展示 ==================== */
.selection {
  padding: 80px 0;
}

.selection-strip {
  display: flex;
  gap: 0;
  background: var(--background-alt);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
}

.selection-item {
  flex: 1;
  padding: 32px 24px;
  text-align: center;
  border-right: 1px solid var(--border);
  transition: background 0.2s;
}

.selection-item:last-child {
  border-right: none;
}

.selection-item:hover {
  background: var(--primary-bg);
}

.selection-item-emoji {
  font-size: 2rem;
  margin-bottom: 12px;
  display: block;
}

.selection-item h3 {
  margin-bottom: 4px;
  font-size: 1rem;
}

.selection-item p {
  color: var(--text-light);
  font-size: 0.825rem;
  line-height: 1.5;
}

/* ==================== CTA - 浅色背景 ==================== */
.cta {
  padding: 80px 0;
  background: var(--primary-bg);
  text-align: center;
}

.cta h2 {
  margin-bottom: 12px;
}

.cta p {
  color: var(--text-light);
  margin-bottom: 28px;
  font-size: 1.05rem;
}

/* ==================== FOOTER - 两行式 ==================== */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
}

.footer-row-1 {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--secondary);
}

.footer-logo { width: 24px; height: 24px; }

.footer-nav {
  display: flex;
  gap: 24px;
}

.footer-nav a {
  color: var(--text-light);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color 0.2s;
}

.footer-nav a:hover {
  color: var(--primary);
}

.footer-row-2 {
  text-align: center;
  color: var(--text-light);
  font-size: 0.8rem;
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 1024px) {
  .bento-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .bento-card:nth-child(1),
  .bento-card:nth-child(2) {
    grid-column: span 1;
  }
}

@media (max-width: 768px) {
  .nav-right a:not(.btn) {
    display: none;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .hero-actions {
    flex-direction: column;
  }

  .hero-proof {
    flex-direction: column;
    gap: 16px;
  }

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

  .bento-card:nth-child(1),
  .bento-card:nth-child(2) {
    grid-column: span 1;
  }

  .steps-row {
    grid-template-columns: 1fr;
  }

  .export-list {
    grid-template-columns: 1fr;
  }

  .selection-strip {
    flex-direction: column;
  }

  .selection-item {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .selection-item:last-child {
    border-bottom: none;
  }

  .footer-row-1 {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }

  .footer-nav {
    flex-wrap: wrap;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .btn-large {
    width: 100%;
    justify-content: center;
  }
}