:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --text: #111111;
  --text-secondary: #5f6368;
  --text-tertiary: #8b9099;
  --border: rgba(17, 17, 17, 0.08);
  --shadow: 0 24px 80px rgba(17, 24, 39, 0.08);
  --shadow-soft: 0 12px 40px rgba(17, 24, 39, 0.06);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --max-width: 1120px;
  --nav-height: 72px;
  --gradient-hero: radial-gradient(ellipse 80% 60% at 50% -10%, rgba(147, 197, 253, 0.35), transparent 70%),
    radial-gradient(ellipse 60% 50% at 80% 20%, rgba(196, 181, 253, 0.22), transparent 65%),
    linear-gradient(180deg, #f7f8fb 0%, #ffffff 100%);
  --gradient-section: linear-gradient(180deg, #ffffff 0%, #f3f6ff 100%);
  --gradient-cta: linear-gradient(135deg, #eef4ff 0%, #f5f0ff 100%);
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Helvetica Neue", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

.container {
  width: min(var(--max-width), calc(100% - 48px));
  margin: 0 auto;
}

/* Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  backdrop-filter: blur(16px);
  background: rgba(247, 248, 251, 0.82);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 15px;
  letter-spacing: -0.02em;
}

.brand img {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 14px;
  color: var(--text-secondary);
}

.nav-links a:hover {
  color: var(--text);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: #111;
  color: #fff;
  box-shadow: 0 8px 24px rgba(17, 17, 17, 0.18);
}

.btn-primary:hover {
  background: #222;
}

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

.btn-large {
  padding: 14px 28px;
  font-size: 15px;
}

/* Hero */
.hero {
  padding: 72px 0 48px;
  background: var(--gradient-hero);
  text-align: center;
  overflow: hidden;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.75);
  border: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.hero-badge span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #22c55e;
  box-shadow: 0 0 0 4px rgba(34, 197, 94, 0.15);
}

.hero h1 {
  margin: 0 0 16px;
  font-size: clamp(40px, 6vw, 64px);
  line-height: 1.08;
  letter-spacing: -0.04em;
  font-weight: 700;
}

.hero p.lead {
  margin: 0 auto 32px;
  max-width: 640px;
  font-size: clamp(17px, 2.2vw, 20px);
  line-height: 1.65;
  color: var(--text-secondary);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 56px;
}

.hero-note {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-top: 12px;
}

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  gap: 24px;
  padding: 0 24px 24px;
  flex-wrap: wrap;
}

.mock-card {
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.mock-card.small {
  width: min(280px, 100%);
  padding: 20px;
}

.mock-card.large {
  width: min(420px, 100%);
  padding: 0;
}

.mock-titlebar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.6);
}

.mock-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #e5e7eb;
}

.mock-dot:nth-child(1) { background: #fca5a5; }
.mock-dot:nth-child(2) { background: #fde047; }
.mock-dot:nth-child(3) { background: #86efac; }

.mock-body {
  padding: 20px;
}

.mock-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  margin-bottom: 8px;
}

.mock-text {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  min-height: 72px;
}

.mock-wave {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  height: 48px;
  margin-top: 16px;
}

.mock-wave span {
  width: 4px;
  border-radius: 999px;
  background: linear-gradient(180deg, #60a5fa, #818cf8);
  animation: wave 1.2s ease-in-out infinite;
}

.mock-wave span:nth-child(1) { height: 14px; animation-delay: 0s; }
.mock-wave span:nth-child(2) { height: 28px; animation-delay: 0.1s; }
.mock-wave span:nth-child(3) { height: 38px; animation-delay: 0.2s; }
.mock-wave span:nth-child(4) { height: 24px; animation-delay: 0.3s; }
.mock-wave span:nth-child(5) { height: 32px; animation-delay: 0.4s; }
.mock-wave span:nth-child(6) { height: 18px; animation-delay: 0.5s; }

@keyframes wave {
  0%, 100% { transform: scaleY(0.6); opacity: 0.55; }
  50% { transform: scaleY(1); opacity: 1; }
}

.mock-mic {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: linear-gradient(135deg, #111 0%, #333 100%);
  color: white;
  font-size: 22px;
  box-shadow: 0 12px 32px rgba(17, 17, 17, 0.2);
}

.mock-status {
  text-align: center;
  font-size: 13px;
  color: var(--text-secondary);
}

/* Section common */
section {
  padding: 96px 0;
}

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.section-head h2 {
  margin: 0 0 12px;
  font-size: clamp(32px, 4vw, 44px);
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.section-head p {
  margin: 0;
  font-size: 18px;
  color: var(--text-secondary);
  line-height: 1.65;
}

.section-label {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #6366f1;
}

/* Apps strip */
.apps {
  padding: 64px 0;
  background: #fff;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.apps p {
  text-align: center;
  margin: 0 0 28px;
  font-size: 15px;
  color: var(--text-secondary);
}

.app-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
}

.app-pill {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--bg);
  border: 1px solid var(--border);
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
}

.app-icon {
  width: 28px;
  height: 28px;
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  color: #fff;
}

/* Feature rows */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  margin-bottom: 96px;
}

.feature-row:last-child {
  margin-bottom: 0;
}

.feature-row.reverse .feature-copy {
  order: 2;
}

.feature-row.reverse .feature-visual {
  order: 1;
}

.feature-copy h3 {
  margin: 0 0 12px;
  font-size: 32px;
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.feature-copy p {
  margin: 0 0 20px;
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 10px;
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 15px;
  color: var(--text);
}

.feature-list li::before {
  content: "✓";
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #ecfdf5;
  color: #059669;
  font-size: 11px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
}

.feature-visual {
  position: relative;
}

.visual-panel {
  background: var(--gradient-section);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-soft);
  min-height: 280px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.visual-panel.offline {
  background: linear-gradient(145deg, #f0fdf4 0%, #eff6ff 100%);
}

.visual-panel.privacy {
  background: linear-gradient(145deg, #faf5ff 0%, #eff6ff 100%);
}

.visual-panel.ocr {
  background: linear-gradient(145deg, #fff7ed 0%, #fef3c7 100%);
}

.visual-panel.translate {
  background: linear-gradient(145deg, #eef2ff 0%, #fce7f3 100%);
}

.visual-icon {
  font-size: 40px;
  margin-bottom: 16px;
}

.visual-panel h4 {
  margin: 0 0 8px;
  font-size: 20px;
}

.visual-panel p {
  margin: 0;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Grid features */
.grid-section {
  background: #fff;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.grid-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-soft);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.grid-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.grid-card .icon {
  font-size: 28px;
  margin-bottom: 14px;
}

.grid-card h4 {
  margin: 0 0 8px;
  font-size: 18px;
}

.grid-card p {
  margin: 0;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* Compare */
.compare {
  background: var(--gradient-cta);
}

.compare-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

.compare-table th,
.compare-table td {
  padding: 18px 24px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 15px;
}

.compare-table th {
  background: rgba(255, 255, 255, 0.9);
  font-weight: 600;
}

.compare-table tr:last-child td {
  border-bottom: none;
}

.compare-table td:first-child {
  color: var(--text-secondary);
  width: 40%;
}

.check-yes {
  color: #059669;
  font-weight: 600;
}

.check-no {
  color: var(--text-tertiary);
}

/* Principles */
.principles {
  text-align: center;
}

.principle-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 48px;
}

.principle-card {
  padding: 24px 16px;
}

.principle-card .num {
  font-size: 13px;
  font-weight: 700;
  color: #6366f1;
  margin-bottom: 12px;
}

.principle-card h4 {
  margin: 0 0 8px;
  font-size: 17px;
}

.principle-card p {
  margin: 0;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* CTA */
.cta {
  padding: 96px 0 112px;
  text-align: center;
  background: var(--gradient-hero);
}

.cta h2 {
  margin: 0 0 12px;
  font-size: clamp(32px, 4vw, 48px);
  letter-spacing: -0.03em;
}

.cta p {
  margin: 0 auto 28px;
  max-width: 520px;
  font-size: 18px;
  color: var(--text-secondary);
}

.cta-meta {
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-tertiary);
}

/* Footer */
.footer {
  padding: 48px 0 56px;
  background: #fff;
  border-top: 1px solid var(--border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: 40px;
}

.footer-brand p {
  margin: 12px 0 0;
  font-size: 14px;
  color: var(--text-secondary);
  max-width: 280px;
  line-height: 1.65;
}

.footer-col h5 {
  margin: 0 0 14px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-tertiary);
}

.footer-col a {
  display: block;
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.footer-col a:hover {
  color: var(--text);
}

.footer-bottom {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--text-tertiary);
}

/* Responsive */
@media (max-width: 960px) {
  .nav-links {
    display: none;
  }

  .feature-row,
  .feature-row.reverse {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .feature-row.reverse .feature-copy,
  .feature-row.reverse .feature-visual {
    order: unset;
  }

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

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

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

@media (max-width: 640px) {
  section {
    padding: 72px 0;
  }

  .hero {
    padding-top: 48px;
  }

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

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

  .compare-table {
    display: block;
    overflow-x: auto;
  }
}