/* ==================== CSS Variables ==================== */
:root {
  --bg-dark: #0b0f1a;
  --bg-card: #111827;
  --bg-section: #0f1724;
  --blue: #2563eb;
  --blue-light: #3b82f6;
  --blue-dark: #1d4ed8;
  --green: #10b981;
  --green-light: #34d399;
  --purple: #8b5cf6;
  --purple-light: #a78bfa;
  --orange: #f97316;
  --orange-light: #fb923c;
  --white: #ffffff;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-lg: 0 12px 48px rgba(0,0,0,0.5);
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-dark);
  color: var(--gray-200);
  line-height: 1.7;
  overflow-x: hidden;
}

a {
  color: var(--blue-light);
  text-decoration: none;
  transition: var(--transition);
}

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

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

ul {
  list-style: none;
}

/* ==================== Header & Navigation ==================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(11,15,26,0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: var(--transition);
}

.site-header.scrolled {
  box-shadow: 0 2px 20px rgba(0,0,0,0.4);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--white);
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: var(--white);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.main-nav a {
  color: var(--gray-300);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--white);
  background: rgba(37,99,235,0.15);
}

.nav-cta {
  background: linear-gradient(135deg, var(--blue), var(--purple)) !important;
  color: var(--white) !important;
  padding: 8px 20px !important;
  border-radius: 24px !important;
  font-weight: 600 !important;
  margin-left: 12px;
}

.nav-cta:hover {
  box-shadow: 0 4px 20px rgba(37,99,235,0.4);
  transform: translateY(-1px);
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--white);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 4px;
}

/* ==================== Hero Section ==================== */
.hero {
  padding: 140px 24px 100px;
  text-align: center;
  position: relative;
  overflow: hidden;
  background: radial-gradient(ellipse at 50% 0%, rgba(37,99,235,0.15) 0%, transparent 60%),
              radial-gradient(ellipse at 80% 20%, rgba(139,92,246,0.1) 0%, transparent 50%);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><rect width="100" height="100" fill="none" stroke="rgba(255,255,255,0.02)" stroke-width="0.5"/></svg>');
  opacity: 0.5;
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(37,99,235,0.15);
  border: 1px solid rgba(37,99,235,0.3);
  color: var(--blue-light);
  padding: 6px 16px;
  border-radius: 24px;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 24px;
  animation: fadeInUp 0.6s ease-out;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  background: var(--green);
  border-radius: 50%;
  animation: pulse-dot 2s infinite;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 800;
  color: var(--white);
  line-height: 1.25;
  margin-bottom: 20px;
  animation: fadeInUp 0.6s ease-out 0.1s both;
}

.hero h1 .blue { color: var(--blue-light); }
.hero h1 .green { color: var(--green); }
.hero h1 .purple { color: var(--purple-light); }
.hero h1 .orange { color: var(--orange-light); }

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--gray-400);
  max-width: 680px;
  margin: 0 auto 36px;
  animation: fadeInUp 0.6s ease-out 0.2s both;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
  animation: fadeInUp 0.6s ease-out 0.3s both;
}

.hero-tags span {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.875rem;
  color: var(--gray-300);
}

.hero-tags span:nth-child(1) { border-color: rgba(37,99,235,0.3); color: var(--blue-light); }
.hero-tags span:nth-child(2) { border-color: rgba(16,185,129,0.3); color: var(--green-light); }
.hero-tags span:nth-child(3) { border-color: rgba(139,92,246,0.3); color: var(--purple-light); }
.hero-tags span:nth-child(4) { border-color: rgba(249,115,22,0.3); color: var(--orange-light); }

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  animation: fadeInUp 0.6s ease-out 0.4s both;
}

/* ==================== Buttons ==================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 28px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  text-decoration: none;
  color: var(--white);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--blue), var(--blue-dark));
  box-shadow: 0 4px 16px rgba(37,99,235,0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(37,99,235,0.5);
  color: var(--white);
}

.btn-green {
  background: linear-gradient(135deg, var(--green), #059669);
  box-shadow: 0 4px 16px rgba(16,185,129,0.4);
}

.btn-green:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(16,185,129,0.5);
  color: var(--white);
}

.btn-purple {
  background: linear-gradient(135deg, var(--purple), #7c3aed);
  box-shadow: 0 4px 16px rgba(139,92,246,0.4);
}

.btn-purple:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(139,92,246,0.5);
  color: var(--white);
}

.btn-orange {
  background: linear-gradient(135deg, var(--orange), #ea580c);
  box-shadow: 0 4px 16px rgba(249,115,22,0.4);
}

.btn-orange:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(249,115,22,0.5);
  color: var(--white);
}

.btn-outline {
  background: transparent;
  border: 2px solid rgba(255,255,255,0.2);
}

.btn-outline:hover {
  border-color: var(--blue-light);
  background: rgba(37,99,235,0.1);
  color: var(--white);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
  border-radius: 32px;
}

/* CTA Pulse */
.btn-pulse {
  animation: cta-pulse 2s infinite;
}

@keyframes cta-pulse {
  0%, 100% { box-shadow: 0 4px 16px rgba(37,99,235,0.4); }
  50% { box-shadow: 0 4px 40px rgba(37,99,235,0.7), 0 0 0 8px rgba(37,99,235,0.1); }
}

/* ==================== Section Common ==================== */
.section {
  padding: 80px 24px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-label {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--blue-light);
  margin-bottom: 12px;
}

.section-header h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  font-weight: 700;
  color: var(--white);
  margin-bottom: 12px;
}

.section-header p {
  color: var(--gray-400);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ==================== Device Showcase ==================== */
.device-showcase {
  background: var(--bg-section);
  padding: 80px 24px;
}

.device-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.device-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
  cursor: default;
}

.device-card:hover {
  transform: translateY(-6px);
  border-color: rgba(37,99,235,0.3);
  box-shadow: 0 12px 40px rgba(0,0,0,0.4);
}

.device-card img {
  width: 80px;
  height: 80px;
  border-radius: 16px;
  margin: 0 auto 16px;
  object-fit: cover;
}

.device-card h3 {
  color: var(--white);
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.device-card p {
  color: var(--gray-400);
  font-size: 0.875rem;
  margin-bottom: 16px;
}

.device-card .btn {
  padding: 8px 18px;
  font-size: 0.875rem;
}

/* ==================== Steps Preview ==================== */
.steps-section {
  padding: 80px 24px;
}

.steps-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
  counter-reset: step;
}

.step-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 28px 18px;
  text-align: center;
  position: relative;
  transition: var(--transition);
  opacity: 0;
  transform: translateY(30px);
}

.step-card.revealed {
  opacity: 1;
  transform: translateY(0);
}

.step-card:hover {
  border-color: rgba(37,99,235,0.3);
  transform: translateY(-4px);
}

.step-card.revealed:hover {
  transform: translateY(-4px);
}

.step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  margin: 0 auto 14px;
}

.step-card img {
  width: 100%;
  height: 140px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}

.step-card h4 {
  color: var(--white);
  font-size: 0.95rem;
  margin-bottom: 6px;
}

.step-card p {
  color: var(--gray-400);
  font-size: 0.8rem;
  line-height: 1.5;
}

/* ==================== Advantages ==================== */
.advantages {
  background: var(--bg-section);
  padding: 80px 24px;
}

.adv-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.adv-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: var(--transition);
}

.adv-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.adv-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 16px;
}

.adv-icon.blue { background: rgba(37,99,235,0.15); color: var(--blue-light); }
.adv-icon.green { background: rgba(16,185,129,0.15); color: var(--green-light); }
.adv-icon.purple { background: rgba(139,92,246,0.15); color: var(--purple-light); }
.adv-icon.orange { background: rgba(249,115,22,0.15); color: var(--orange-light); }

.adv-card h3 {
  color: var(--white);
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.adv-card p {
  color: var(--gray-400);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ==================== Stats Section ==================== */
.stats-section {
  padding: 80px 24px;
}

.stats-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-card {
  padding: 32px 16px;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--blue-light), var(--purple-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
}

.stat-label {
  color: var(--gray-400);
  font-size: 0.95rem;
}

/* ==================== Page Hero (Sub Pages) ==================== */
.page-hero {
  padding: 120px 24px 60px;
  text-align: center;
  background: radial-gradient(ellipse at 50% 0%, rgba(37,99,235,0.12) 0%, transparent 60%);
}

.page-hero h1 {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  color: var(--white);
  margin-bottom: 14px;
}

.page-hero p {
  color: var(--gray-400);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ==================== About Page ==================== */
.about-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px 80px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.about-text h2 {
  color: var(--white);
  font-size: 1.6rem;
  margin-bottom: 16px;
}

.about-text p {
  color: var(--gray-300);
  margin-bottom: 16px;
  line-height: 1.8;
}

.about-image img {
  border-radius: var(--radius);
  width: 100%;
}

.about-features {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 80px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.about-feature {
  text-align: center;
  padding: 28px 16px;
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
}

.about-feature .feature-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.about-feature h3 {
  color: var(--white);
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.about-feature p {
  color: var(--gray-400);
  font-size: 0.875rem;
}

/* Timeline */
.timeline {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.timeline h2 {
  text-align: center;
  color: var(--white);
  font-size: 1.8rem;
  margin-bottom: 40px;
}

.timeline-item {
  display: flex;
  gap: 20px;
  margin-bottom: 32px;
  padding-left: 20px;
  border-left: 2px solid rgba(37,99,235,0.3);
  position: relative;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -7px;
  top: 0;
  width: 12px;
  height: 12px;
  background: var(--blue);
  border-radius: 50%;
}

.timeline-year {
  font-weight: 700;
  color: var(--blue-light);
  min-width: 70px;
  font-size: 0.95rem;
}

.timeline-desc {
  color: var(--gray-300);
}

/* ==================== Services Page ==================== */
.services-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.service-platforms {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 60px;
}

.platform-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}

.platform-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(37,99,235,0.3);
}

.platform-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.platform-card-body {
  padding: 24px;
}

.platform-card-body h3 {
  color: var(--white);
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.platform-card-body p {
  color: var(--gray-400);
  font-size: 0.875rem;
  margin-bottom: 16px;
}

.service-sync {
  margin-bottom: 60px;
}

.service-sync h2 {
  color: var(--white);
  font-size: 1.8rem;
  text-align: center;
  margin-bottom: 40px;
}

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

.sync-feature {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
}

.sync-feature .sf-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.sync-feature h3 {
  color: var(--white);
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.sync-feature p {
  color: var(--gray-400);
  font-size: 0.875rem;
}

.tutorial-section {
  max-width: var(--max-width);
  margin: 0 auto;
  text-align: center;
}

.tutorial-section h2 {
  color: var(--white);
  font-size: 1.8rem;
  margin-bottom: 40px;
}

.tutorial-steps {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.tutorial-step {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px;
}

.tutorial-step .ts-num {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--orange), var(--orange-light));
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  margin: 0 auto 12px;
}

.tutorial-step h4 {
  color: var(--white);
  font-size: 0.9rem;
  margin-bottom: 6px;
}

.tutorial-step p {
  color: var(--gray-400);
  font-size: 0.8rem;
}

/* ==================== FAQ Page ==================== */
.faq-content {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.faq-category {
  margin-bottom: 48px;
}

.faq-category h2 {
  color: var(--white);
  font-size: 1.4rem;
  margin-bottom: 20px;
  padding-bottom: 8px;
  border-bottom: 2px solid rgba(37,99,235,0.2);
}

.faq-item {
  margin-bottom: 8px;
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  border-color: rgba(37,99,235,0.2);
}

.faq-item summary {
  padding: 18px 20px;
  cursor: pointer;
  font-weight: 600;
  color: var(--white);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.3rem;
  color: var(--blue-light);
  font-weight: 300;
  transition: var(--transition);
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-answer {
  padding: 0 20px 20px;
  color: var(--gray-300);
  font-size: 0.9rem;
  line-height: 1.75;
}

/* ==================== Contact Page ==================== */
.contact-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px 80px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.contact-form-section h2 {
  color: var(--white);
  font-size: 1.4rem;
  margin-bottom: 24px;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  color: var(--gray-300);
  font-size: 0.875rem;
  font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  color: var(--white);
  font-size: 0.95rem;
  font-family: inherit;
  transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.15);
}

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

.contact-info-section h2 {
  color: var(--white);
  font-size: 1.4rem;
  margin-bottom: 24px;
}

.contact-info-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
}

.contact-info-card h3 {
  color: var(--white);
  font-size: 1rem;
  margin-bottom: 8px;
}

.contact-info-card p {
  color: var(--gray-400);
  font-size: 0.9rem;
}

/* ==================== Footer ==================== */
.site-footer {
  background: var(--bg-card);
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: 40px 24px 28px;
  text-align: center;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 24px;
  margin-bottom: 20px;
}

.footer-nav a {
  color: var(--gray-400);
  font-size: 0.9rem;
}

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

.footer-copy {
  color: var(--gray-500);
  font-size: 0.85rem;
}

/* ==================== Animations ==================== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

@keyframes device-switch {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.8; transform: scale(0.97); }
}

.animate-in {
  animation: fadeInUp 0.6s ease-out both;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }

/* Reveal on scroll */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* ==================== Responsive ==================== */
@media (max-width: 1024px) {
  .device-grid { grid-template-columns: repeat(2, 1fr); }
  .steps-grid { grid-template-columns: repeat(3, 1fr); }
  .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .about-content { grid-template-columns: 1fr; }
  .about-features { grid-template-columns: repeat(2, 1fr); }
  .service-platforms { grid-template-columns: repeat(2, 1fr); }
  .sync-features { grid-template-columns: repeat(2, 1fr); }
  .tutorial-steps { grid-template-columns: repeat(3, 1fr); }
  .contact-content { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .main-nav { display: none; }
  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: rgba(11,15,26,0.98);
    backdrop-filter: blur(16px);
    padding: 16px;
    gap: 8px;
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .main-nav.open a { padding: 12px 16px; border-radius: var(--radius-sm); }
  .nav-cta { margin-left: 0; margin-top: 8px; }

  .mobile-toggle { display: block; }

  .device-grid { grid-template-columns: 1fr 1fr; }
  .steps-grid { grid-template-columns: 1fr 1fr; }
  .adv-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .hero { padding: 120px 16px 60px; }
  .hero h1 { font-size: 1.8rem; }
  .hero-cta-group { flex-direction: column; align-items: center; }
  .about-features { grid-template-columns: 1fr; }
  .service-platforms { grid-template-columns: 1fr; }
  .sync-features { grid-template-columns: 1fr; }
  .tutorial-steps { grid-template-columns: 1fr 1fr; }
  .section { padding: 60px 16px; }
}

@media (max-width: 480px) {
  .device-grid { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr; }
  .tutorial-steps { grid-template-columns: 1fr; }
}