/* W Robotics — Style Sheet */
/* Apple-inspired clean design */

:root {
  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-dim: #86868b;
  --accent: #0071e3;
  --bg: #ffffff;
  --bg-secondary: #f5f5f7;
  --border: rgba(0,0,0,0.08);
  --radius: 12px;
  --max-w: 980px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  color: var(--text-primary);
  background: var(--bg);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Language toggle */
html[lang="en"] .zh-only { display: none !important; }
html[lang="zh"] .en-only { display: none !important; }

/* ========== HEADER ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
.logo:hover { text-decoration: none; }

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--text-primary);
  color: #fff;
  border-radius: 7px;
  font-size: 15px;
  font-weight: 700;
}

.nav-links {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  font-size: 13px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}
.nav-links a:hover,
.nav-links a.active { color: var(--text-primary); text-decoration: none; }

.btn-nav {
  background: var(--accent) !important;
  color: #fff !important;
  padding: 6px 16px !important;
  border-radius: 18px;
  font-size: 13px !important;
  font-weight: 500;
  transition: background 0.2s;
}
.btn-nav:hover { background: #0077ed !important; }

.lang-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
  font-size: 12px;
  color: var(--text-dim);
  cursor: pointer;
}

.menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 22px;
  cursor: pointer;
  color: var(--text-primary);
}

/* ========== CONTAINER ========== */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

.page-content {
  padding-top: 20px;
  padding-bottom: 60px;
}

/* ========== HERO ========== */
.hero {
  text-align: center;
  padding: 80px 0 60px;
}

.hero-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  color: var(--accent);
  background: rgba(0,113,227,0.06);
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 18px;
}

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

.hero-sub {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto 28px;
  line-height: 1.5;
}

.btn-row {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ========== BUTTONS ========== */
.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
}
.btn:hover { text-decoration: none; }

.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: #0077ed; }

.btn-ghost {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn-ghost:hover { background: rgba(0,113,227,0.06); }

/* ========== STATS ROW ========== */
.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 80px;
}

.stat-item {
  background: var(--bg);
  padding: 28px 20px;
  text-align: center;
}

.stat-num {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.stat-label {
  font-size: 12px;
  color: var(--text-dim);
  margin-top: 4px;
}

/* ========== SECTIONS ========== */
.section {
  padding: 60px 0;
}

.section-centered {
  text-align: center;
}

.section-label {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(24px, 3.5vw, 36px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  margin-bottom: 14px;
}

.section-desc {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 600px;
  line-height: 1.5;
}

.section-centered .section-desc {
  margin: 0 auto;
}

/* ========== FEATURE GRID ========== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 40px;
}

.feature-card {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: left;
}

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

.feature-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ========== SPEC TABLE ========== */
.spec-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 24px;
}

.spec-table tr {
  border-bottom: 1px solid var(--border);
}

.spec-table th,
.spec-table td {
  padding: 14px 16px;
  font-size: 14px;
  text-align: left;
}

.spec-table th {
  font-weight: 500;
  color: var(--text-dim);
  width: 200px;
}

.spec-table td {
  color: var(--text-primary);
}

/* ========== COMPARISON TABLE ========== */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 24px;
}

.comparison-table thead tr {
  border-bottom: 2px solid var(--border);
}

.comparison-table th {
  padding: 12px 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-dim);
  text-align: left;
}

.comparison-table td {
  padding: 14px 16px;
  font-size: 14px;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border);
}

.comparison-table .highlight-col {
  font-weight: 600;
  color: var(--accent);
}

.comparison-table .price-tag {
  font-weight: 600;
}

/* ========== CTA SECTION ========== */
.cta-section {
  padding: 60px 0;
}

.cta-box {
  background: var(--bg-secondary);
  border-radius: 20px;
  padding: 56px 40px;
  text-align: center;
}

.cta-box h2 {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  margin-bottom: 10px;
}

.cta-box > p {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.contact-info {
  margin-top: 24px;
  display: flex;
  gap: 32px;
  justify-content: center;
  font-size: 14px;
}

.contact-label {
  font-size: 12px;
  color: var(--text-dim);
  display: block;
  margin-bottom: 2px;
}

/* ========== BLOG ========== */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin-top: 32px;
}

.blog-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.2s;
}
.blog-card:hover { box-shadow: 0 4px 20px rgba(0,0,0,0.06); }

.blog-card-body {
  padding: 28px 24px;
}

.blog-tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent);
  margin-bottom: 12px;
}

.blog-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.3;
}

.blog-card h3 a {
  color: var(--text-primary);
  text-decoration: none;
}
.blog-card h3 a:hover { color: var(--accent); }

.blog-excerpt {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
}

.blog-meta {
  font-size: 12px;
  color: var(--text-dim);
  display: flex;
  gap: 16px;
}

/* ========== FOOTER ========== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-copy {
  font-size: 12px;
  color: var(--text-dim);
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 20px;
}

.footer-links a {
  font-size: 12px;
  color: var(--text-secondary);
  text-decoration: none;
}
.footer-links a:hover { color: var(--text-primary); }

/* ========== MOBILE ========== */
@media (max-width: 768px) {
  .menu-btn { display: block; }
  
  .nav-links {
    display: none;
    position: absolute;
    top: 52px;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 20px 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }

  .hero { padding: 48px 0 40px; }
  .hero h1 { font-size: 28px; }
  .hero-sub { font-size: 15px; }

  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .stat-num { font-size: 22px; }

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

  .cta-box { padding: 36px 20px; }

  .spec-table th { width: 140px; }

  .footer-inner { flex-direction: column; gap: 12px; text-align: center; }
  .footer-links { justify-content: center; }
  
  .contact-info { flex-direction: column; gap: 16px; }
}

@media (max-width: 480px) {
  .stats-row { grid-template-columns: 1fr 1fr; }
  .btn-row { flex-direction: column; align-items: center; }
  .btn { width: 100%; text-align: center; }
}