/* =============================================
   Velo Tract — Global Styles
   ============================================= */

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

:root {
  --clr-bg: #060B18;
  --clr-bg-2: #0A1128;
  --clr-surface: rgba(255,255,255,0.04);
  --clr-surface-hover: rgba(255,255,255,0.07);
  --clr-border: rgba(255,255,255,0.08);
  --clr-border-strong: rgba(255,255,255,0.14);

  --clr-blue-400: #60A5FA;
  --clr-blue-500: #3B82F6;
  --clr-blue-600: #2563EB;
  --clr-blue-700: #1D4ED8;
  --clr-blue-900: #1E3A8A;
  --clr-navy: #0F172A;

  --clr-text: #F1F5F9;
  --clr-text-muted: #94A3B8;
  --clr-text-subtle: #475569;

  --font-main: 'Inter', 'DM Sans', sans-serif;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  --transition: 0.25s ease;
  --transition-slow: 0.45s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* =============================================
   Typography
   ============================================= */

h1, h2, h3, h4 {
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

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

ul { list-style: none; }

/* =============================================
   Navigation
   ============================================= */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 0 24px;
  transition: background var(--transition), backdrop-filter var(--transition), border-color var(--transition);
  border-bottom: 1px solid transparent;
}

.navbar.scrolled {
  background: rgba(6, 11, 24, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom-color: var(--clr-border);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 16px;
}

/* Logo: white pill, image sets its own natural size */
.nav-logo-wrap {
  display: inline-flex;
  align-items: center;
  background: #ffffff;
  border-radius: 8px;
  padding: 5px 12px;
  line-height: 0;
}

.nav-logo-img {
  height: 32px;
  width: auto;
  display: block;
  object-fit: contain;
  object-position: left center;
}

/* Nav right side: links + actions */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* Language toggle button */
.lang-toggle {
  display: inline-flex;
  align-items: center;
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.14);
  border-radius: 100px;
  padding: 5px 14px;
  cursor: pointer;
  font-family: var(--font-main);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--clr-text-muted);
  transition: background var(--transition), border-color var(--transition), color var(--transition);
  white-space: nowrap;
}

.lang-toggle:hover {
  background: rgba(59,130,246,0.12);
  border-color: rgba(59,130,246,0.3);
  color: var(--clr-blue-400);
}

.lang-toggle .lang-en,
.lang-toggle .lang-zh {
  display: none;
}

.lang-toggle .lang-en.active,
.lang-toggle .lang-zh.active {
  display: inline;
}

.nav-links {
  display: flex;
  gap: 36px;
  align-items: center;
}

.nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--clr-text-muted);
  transition: color var(--transition);
  letter-spacing: 0.01em;
}

.nav-link:hover {
  color: var(--clr-text);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--clr-text-muted);
  border-radius: 2px;
  transition: var(--transition);
}

/* Address bilingual display */
.addr-zh {
  font-size: 0.88rem !important;
  color: var(--clr-text-subtle) !important;
  margin-top: -4px;
}

/* Footer logo */
.footer-logo-wrap {
  display: inline-flex;
  align-items: center;
  background: #ffffff;
  border-radius: 8px;
  padding: 5px 12px;
  line-height: 0;
  margin-bottom: 16px;
}

.footer-logo-img {
  height: 28px;
  width: auto;
  display: block;
  object-fit: contain;
}

/* =============================================
   Hero Section
   ============================================= */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 100px 24px 60px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.25;
  animation: float 8s ease-in-out infinite;
}

.hero-orb-1 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, #2563EB, #1E40AF);
  top: -150px;
  left: -100px;
  animation-delay: 0s;
}

.hero-orb-2 {
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, #3B82F6, #1D4ED8);
  bottom: -80px;
  right: -80px;
  animation-delay: -3s;
}

.hero-orb-3 {
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, #60A5FA, #2563EB);
  top: 40%;
  left: 55%;
  animation-delay: -5s;
  opacity: 0.15;
}

@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-30px) scale(1.05); }
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(59, 130, 246, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59, 130, 246, 0.05) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 20%, transparent 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 720px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.25);
  color: var(--clr-blue-400);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 28px;
  animation: fadeInUp 0.6s ease both;
}

.hero-badge-dot {
  width: 7px;
  height: 7px;
  background: var(--clr-blue-400);
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.hero-title {
  font-size: clamp(3rem, 7vw, 5.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 24px;
  color: var(--clr-text);
  animation: fadeInUp 0.6s 0.1s ease both;
}

.hero-title-gradient {
  background: linear-gradient(135deg, #60A5FA, #3B82F6, #818CF8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  color: var(--clr-text-muted);
  max-width: 520px;
  margin: 0 auto 40px;
  font-weight: 400;
  animation: fadeInUp 0.6s 0.2s ease both;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 64px;
  animation: fadeInUp 0.6s 0.3s ease both;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--clr-blue-500), var(--clr-blue-700));
  color: white;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 14px 32px;
  border-radius: 100px;
  transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
  box-shadow: 0 4px 24px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(37, 99, 235, 0.5);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--clr-surface);
  color: var(--clr-text);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 14px 32px;
  border-radius: 100px;
  border: 1px solid var(--clr-border-strong);
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
}

.btn-secondary:hover {
  background: var(--clr-surface-hover);
  border-color: rgba(255,255,255,0.22);
  transform: translateY(-2px);
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  animation: fadeInUp 0.6s 0.4s ease both;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.stat-number {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--clr-text);
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--clr-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.stat-divider {
  width: 1px;
  height: 36px;
  background: var(--clr-border-strong);
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
}

.scroll-indicator {
  width: 24px;
  height: 38px;
  border: 2px solid var(--clr-border-strong);
  border-radius: 12px;
  display: flex;
  justify-content: center;
  padding-top: 6px;
}

.scroll-indicator span {
  display: block;
  width: 4px;
  height: 8px;
  background: var(--clr-blue-400);
  border-radius: 2px;
  animation: scroll-bob 1.8s ease-in-out infinite;
}

@keyframes scroll-bob {
  0%, 100% { transform: translateY(0); opacity: 1; }
  80% { transform: translateY(10px); opacity: 0; }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

/* =============================================
   Section Commons
   ============================================= */

.section-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 100px 24px;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--clr-blue-400);
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.2);
  padding: 5px 14px;
  border-radius: 100px;
  margin-bottom: 20px;
}

.section-title {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--clr-text);
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--clr-text-muted);
  max-width: 480px;
  margin: 0 auto;
}

/* =============================================
   About Section
   ============================================= */

.about {
  background: var(--clr-bg-2);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto;
  gap: 20px;
}

.about-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
}

.about-card:hover {
  background: var(--clr-surface-hover);
  border-color: var(--clr-border-strong);
  transform: translateY(-3px);
}

.about-card-main {
  grid-column: 1 / 2;
  grid-row: 1 / 3;
}

.about-card-icon {
  width: 60px;
  height: 60px;
  margin-bottom: 24px;
}

.about-card-icon.about-card-icon-sm {
  width: 44px;
  height: 44px;
}

.about-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--clr-text);
}

.about-card p {
  font-size: 0.97rem;
  color: var(--clr-text-muted);
  line-height: 1.7;
}

/* =============================================
   Products Section
   ============================================= */

.products {
  background: var(--clr-bg);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.product-card {
  border-radius: var(--radius-xl);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  overflow: hidden;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
  cursor: default;
}

.product-card:hover {
  transform: translateY(-6px);
  border-color: rgba(59, 130, 246, 0.35);
  box-shadow: 0 20px 60px rgba(37, 99, 235, 0.15);
}

.product-card-inner {
  padding: 36px 32px;
}

.product-platform-badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--clr-blue-400);
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.18);
  padding: 4px 12px;
  border-radius: 100px;
  margin-bottom: 20px;
}

.product-icon {
  width: 64px;
  height: 64px;
  margin-bottom: 20px;
}

.product-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--clr-text);
}

.product-card p {
  font-size: 0.93rem;
  color: var(--clr-text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
}

.product-features {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.product-features li {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--clr-text-subtle);
  display: flex;
  align-items: center;
  gap: 10px;
}

.product-features li::before {
  content: '';
  display: block;
  width: 6px;
  height: 6px;
  background: var(--clr-blue-500);
  border-radius: 50%;
  flex-shrink: 0;
}

/* =============================================
   Values Section
   ============================================= */

.values {
  background: var(--clr-bg-2);
}

.values-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.values-text {
  max-width: 500px;
}

.values-text > p {
  font-size: 1rem;
  color: var(--clr-text-muted);
  margin-bottom: 40px;
  line-height: 1.7;
}

.values-list {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.value-item {
  display: flex;
  gap: 18px;
  align-items: flex-start;
}

.value-icon {
  font-size: 1rem;
  color: var(--clr-blue-400);
  margin-top: 2px;
  flex-shrink: 0;
}

.value-item strong {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  color: var(--clr-text);
  margin-bottom: 4px;
}

.value-item p {
  font-size: 0.9rem;
  color: var(--clr-text-muted);
  line-height: 1.65;
  margin: 0;
}

/* Values Card Stack */
.values-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.values-card-stack {
  position: relative;
  width: 300px;
  height: 380px;
}

.vcard {
  position: absolute;
  width: 280px;
  height: 360px;
  border-radius: var(--radius-xl);
  border: 1px solid var(--clr-border);
}

.vcard-back {
  background: rgba(15, 23, 42, 0.6);
  top: 20px;
  left: 20px;
  transform: rotate(6deg);
}

.vcard-mid {
  background: rgba(30, 58, 138, 0.3);
  top: 10px;
  left: 10px;
  transform: rotate(3deg);
}

.vcard-front {
  background: linear-gradient(145deg, #0F1E3D, #0A1128);
  border-color: rgba(59, 130, 246, 0.3);
  top: 0;
  left: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 24px;
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(37, 99, 235, 0.2);
}

.vcard-glow {
  position: absolute;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.2), transparent);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation: glow-pulse 3s ease-in-out infinite;
}

@keyframes glow-pulse {
  0%, 100% { opacity: 0.5; transform: translate(-50%, -50%) scale(1); }
  50% { opacity: 1; transform: translate(-50%, -50%) scale(1.2); }
}

.vcard-logo {
  font-size: 3.5rem;
  font-weight: 900;
  letter-spacing: -0.06em;
  background: linear-gradient(135deg, #60A5FA, #3B82F6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  position: relative;
  z-index: 1;
}

.vcard-text {
  display: flex;
  flex-direction: column;
  gap: 8px;
  text-align: center;
  position: relative;
  z-index: 1;
}

.vcard-text span {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--clr-text-muted);
  transition: color var(--transition);
}

.vcard-front:hover .vcard-text span {
  color: var(--clr-blue-400);
}

/* =============================================
   Contact Section
   ============================================= */

.contact {
  background: var(--clr-bg);
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 16px;
  transition: background var(--transition), border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.contact-card:hover {
  background: var(--clr-surface-hover);
  border-color: rgba(59, 130, 246, 0.3);
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(37, 99, 235, 0.12);
}

.contact-icon {
  width: 52px;
  height: 52px;
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-blue-400);
  flex-shrink: 0;
}

.contact-icon svg {
  width: 22px;
  height: 22px;
}

.contact-card h3 {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--clr-text-subtle);
}

.contact-card p {
  font-size: 0.97rem;
  color: var(--clr-text-muted);
  line-height: 1.65;
}

.contact-cn {
  font-size: 0.9rem !important;
  color: var(--clr-text-subtle) !important;
  margin-top: -8px;
}

.contact-link {
  font-size: 1rem;
  font-weight: 600;
  color: var(--clr-blue-400);
  transition: color var(--transition);
}

.contact-link:hover {
  color: var(--clr-blue-500);
}

/* =============================================
   Footer
   ============================================= */

.footer {
  background: var(--clr-navy);
  border-top: 1px solid var(--clr-border);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 64px 24px 32px;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 60px;
  margin-bottom: 48px;
}

.footer-brand {
  max-width: 300px;
}

.footer-logo {
  height: 28px;
  width: auto;
  margin-bottom: 16px;
  background: white;
  border-radius: 6px;
  padding: 3px 8px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--clr-text-subtle);
  line-height: 1.65;
}

.footer-links-col h4 {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--clr-text-subtle);
  margin-bottom: 20px;
}

.footer-links-col ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links-col a {
  font-size: 0.93rem;
  color: var(--clr-text-muted);
  transition: color var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid var(--clr-border);
  padding-top: 28px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-bottom p {
  font-size: 0.85rem;
  color: var(--clr-text-subtle);
}

/* =============================================
   Scroll Animation
   ============================================= */

.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* =============================================
   Responsive
   ============================================= */

@media (max-width: 1024px) {
  .products-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .values-inner {
    grid-template-columns: 1fr;
    gap: 60px;
  }

  .values-visual {
    order: -1;
  }

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

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: rgba(6, 11, 24, 0.97);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 20px 24px;
    gap: 20px;
    border-bottom: 1px solid var(--clr-border);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .lang-toggle {
    font-size: 0.78rem;
    padding: 4px 12px;
  }

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

  .about-card-main {
    grid-column: 1 / 2;
    grid-row: auto;
  }

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

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

  .hero-stats {
    gap: 24px;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .values-card-stack {
    width: 260px;
    height: 320px;
  }

  .vcard {
    width: 240px;
    height: 300px;
  }
}

@media (max-width: 480px) {
  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .section-container {
    padding: 72px 20px;
  }
}