/* ============================================
   USBT Wallet Website - Main Stylesheet
   Theme: Blockchain Next-Gen, Deep Dark + Tech Blue + Gold
   ============================================ */

:root {
  --bg-primary: #0a0f1a;
  --bg-secondary: #111827;
  --bg-card: #1a1f2e;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #2563eb;
  --accent-blue-light: #3b82f6;
  --accent-blue-dark: #1d4ed8;
  --accent-gold: #f59e0b;
  --accent-gold-light: #fbbf24;
  --accent-green: #10b981;
  --accent-purple: #7c3aed;
  --accent-purple-light: #8b5cf6;
  --border-color: #1e293b;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 20px rgba(37,99,235,0.3);
  --shadow-gold: 0 0 20px rgba(245,158,11,0.3);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
  --max-width: 1200px;
  --header-height: 70px;
}

* { 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", "Microsoft YaHei", sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

/* ============================================
   Typography
   ============================================ */
h1 { font-size: 2.8rem; font-weight: 800; letter-spacing: -0.02em; line-height: 1.2; }
h2 { font-size: 2.2rem; font-weight: 700; letter-spacing: -0.01em; line-height: 1.3; }
h3 { font-size: 1.4rem; font-weight: 600; line-height: 1.4; }
p { margin-bottom: 1rem; color: var(--text-secondary); }

.gradient-text {
  background: linear-gradient(135deg, var(--accent-blue-light), var(--accent-purple-light), var(--accent-gold));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-title {
  text-align: center;
  margin-bottom: 0.5rem;
}
.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 3rem;
}

/* ============================================
   Header & Navigation
   ============================================ */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: rgba(10,15,26,0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: var(--transition-base);
}

header .header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.logo .logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: #fff;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 0.25rem;
}

nav ul li a {
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  transition: var(--transition-base);
  font-size: 0.95rem;
  font-weight: 500;
}

nav ul li a:hover,
nav ul li a.active {
  color: var(--text-primary);
  background: rgba(37,99,235,0.12);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 2rem;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition-base);
  border: none;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-blue-dark));
  color: #fff;
  box-shadow: 0 4px 16px rgba(37,99,235,0.4);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37,99,235,0.5);
}

.btn-gold {
  background: linear-gradient(135deg, var(--accent-gold), #d97706);
  color: #1a1a1a;
  box-shadow: 0 4px 16px rgba(245,158,11,0.4);
}
.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(245,158,11,0.5);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--accent-blue);
  color: var(--accent-blue-light);
}
.btn-outline:hover {
  background: rgba(37,99,235,0.1);
  transform: translateY(-2px);
}

.btn-lg { padding: 1rem 2.5rem; font-size: 1.1rem; border-radius: var(--radius-lg); }

.cta-pulse {
  animation: ctaPulse 2s infinite;
}

@keyframes ctaPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(37,99,235,0.5); }
  50% { box-shadow: 0 0 0 16px rgba(37,99,235,0); }
}

/* ============================================
   Main Container
   ============================================ */
main {
  margin-top: var(--header-height);
}

section {
  padding: 5rem 1.5rem;
}

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

/* ============================================
   Hero Section
   ============================================ */
#hero {
  padding: 6rem 1.5rem 5rem;
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--bg-primary) 0%, #0d1525 50%, var(--bg-primary) 100%);
}

#hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -20%;
  width: 140%;
  height: 200%;
  background: radial-gradient(ellipse at 30% 50%, rgba(37,99,235,0.08) 0%, transparent 60%),
              radial-gradient(ellipse at 70% 30%, rgba(124,58,237,0.06) 0%, transparent 60%),
              radial-gradient(ellipse at 50% 80%, rgba(245,158,11,0.04) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

#hero .section-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content h1 {
  margin-bottom: 1.5rem;
}

.hero-content h1 .highlight {
  display: block;
  font-size: 3.2rem;
}

.hero-content .hero-desc {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 540px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 2rem;
}

.hero-tag {
  padding: 0.35rem 0.9rem;
  border-radius: 20px;
  background: rgba(37,99,235,0.12);
  color: var(--accent-blue-light);
  font-size: 0.85rem;
  font-weight: 500;
  border: 1px solid rgba(37,99,235,0.2);
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.hero-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-img {
  max-width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.blockchain-nodes {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  pointer-events: none;
}

.node {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-blue-light);
  animation: nodePulse 2.5s infinite ease-in-out;
  box-shadow: 0 0 12px rgba(37,99,235,0.6);
}
.node:nth-child(1) { top: 10%; left: 5%; animation-delay: 0s; }
.node:nth-child(2) { top: 25%; right: 10%; animation-delay: 0.5s; background: var(--accent-gold); }
.node:nth-child(3) { bottom: 20%; left: 15%; animation-delay: 1s; background: var(--accent-purple-light); }
.node:nth-child(4) { bottom: 10%; right: 5%; animation-delay: 1.5s; }
.node:nth-child(5) { top: 50%; left: 50%; animation-delay: 0.8s; background: var(--accent-green); }
.node:nth-child(6) { top: 70%; right: 25%; animation-delay: 2s; background: var(--accent-gold); }

@keyframes nodePulse {
  0%, 100% { transform: scale(1); opacity: 0.6; }
  50% { transform: scale(2.5); opacity: 1; }
}

.node-line {
  position: absolute;
  background: linear-gradient(90deg, transparent, rgba(37,99,235,0.2), transparent);
  height: 1px;
  animation: lineFlow 3s infinite ease-in-out;
}
.node-line:nth-child(7) { top: 15%; left: 8%; width: 40%; transform: rotate(15deg); animation-delay: 0s; }
.node-line:nth-child(8) { top: 40%; left: 20%; width: 50%; transform: rotate(-10deg); animation-delay: 1s; }
.node-line:nth-child(9) { bottom: 20%; left: 12%; width: 35%; transform: rotate(5deg); animation-delay: 2s; }

@keyframes lineFlow {
  0%, 100% { opacity: 0.1; }
  50% { opacity: 0.5; }
}

/* ============================================
   Stats Section
   ============================================ */
#stats {
  padding: 3rem 1.5rem;
  background: var(--bg-secondary);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  text-align: center;
}

.stat-item {
  padding: 1.5rem;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.stat-number {
  font-size: 2.2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent-blue-light), var(--accent-purple-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 0.3rem;
}

/* ============================================
   Features Section
   ============================================ */
#features {
  background: var(--bg-primary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition-base);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-purple), var(--accent-gold));
  transform: scaleX(0);
  transition: transform 0.4s ease;
}

.feature-card:hover::before {
  transform: scaleX(1);
}

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

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.2rem;
}

.feature-icon.blue { background: rgba(37,99,235,0.15); color: var(--accent-blue-light); }
.feature-icon.green { background: rgba(16,185,129,0.15); color: var(--accent-green); }
.feature-icon.gold { background: rgba(245,158,11,0.15); color: var(--accent-gold); }
.feature-icon.purple { background: rgba(124,58,237,0.15); color: var(--accent-purple-light); }

.feature-card h3 {
  margin-bottom: 0.6rem;
  font-size: 1.2rem;
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* ============================================
   Ecosystem Section
   ============================================ */
#ecosystem {
  background: var(--bg-secondary);
}

.eco-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  text-align: center;
}

.eco-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  transition: var(--transition-base);
}

.eco-item:hover {
  transform: translateY(-4px);
  border-color: rgba(245,158,11,0.3);
  box-shadow: var(--shadow-gold);
}

.eco-item img {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-md);
  margin-bottom: 1rem;
  object-fit: cover;
}

.eco-item h3 {
  font-size: 1.05rem;
  margin-bottom: 0.4rem;
}

.eco-item p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* ============================================
   CTA Section
   ============================================ */
#cta {
  background: linear-gradient(135deg, #0d1525, #12182b, #0d1525);
  text-align: center;
  position: relative;
  overflow: hidden;
}

#cta::before {
  content: '';
  position: absolute;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(37,99,235,0.1) 0%, transparent 70%);
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
}

#cta .section-inner { position: relative; z-index: 1; }

#cta h2 {
  margin-bottom: 1rem;
}

#cta p {
  max-width: 600px;
  margin: 0 auto 2rem;
  font-size: 1.1rem;
}

/* ============================================
   About Page
   ============================================ */
.page-hero {
  padding: 6rem 1.5rem 3rem;
  text-align: center;
  background: linear-gradient(180deg, #0d1525, var(--bg-primary));
}

.page-hero h1 {
  margin-bottom: 1rem;
}

.page-hero p {
  max-width: 700px;
  margin: 0 auto;
  font-size: 1.1rem;
}

/* Timeline */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-blue), var(--accent-purple), var(--accent-gold));
  transform: translateX(-50%);
}

.timeline-item {
  display: flex;
  align-items: flex-start;
  margin-bottom: 2.5rem;
  position: relative;
}

.timeline-item:nth-child(odd) {
  flex-direction: row;
  text-align: right;
  padding-right: calc(50% + 2rem);
}

.timeline-item:nth-child(even) {
  flex-direction: row-reverse;
  text-align: left;
  padding-left: calc(50% + 2rem);
}

.timeline-dot {
  position: absolute;
  left: 50%;
  top: 5px;
  width: 16px;
  height: 16px;
  background: var(--accent-blue);
  border-radius: 50%;
  transform: translateX(-50%);
  box-shadow: 0 0 12px rgba(37,99,235,0.5);
  z-index: 1;
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  width: 100%;
}

.timeline-content h3 {
  color: var(--accent-blue-light);
  margin-bottom: 0.4rem;
}

.timeline-content p {
  font-size: 0.95rem;
  margin-bottom: 0;
}

/* Team Grid */
.team-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.team-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  text-align: center;
  transition: var(--transition-base);
}

.team-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.team-card img {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 1rem;
}

.team-card h3 {
  margin-bottom: 0.2rem;
}

.team-card .role {
  display: block;
  color: var(--accent-blue-light);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.team-card p {
  font-size: 0.85rem;
  margin-bottom: 0;
}

/* ============================================
   Services Page
   ============================================ */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
}

.service-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition-base);
}

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

.service-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: var(--radius-md);
  margin-bottom: 1.2rem;
}

.service-card h3 {
  margin-bottom: 0.5rem;
}

.service-card p {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.service-table-wrap {
  overflow-x: auto;
}

.service-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 2rem;
}

.service-table th,
.service-table td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.service-table th {
  background: var(--bg-card);
  color: var(--accent-blue-light);
  font-weight: 600;
  font-size: 0.95rem;
}

.service-table tr:hover td {
  background: rgba(37,99,235,0.04);
}

/* ============================================
   FAQ Page
   ============================================ */
.faq-search {
  max-width: 600px;
  margin: 0 auto 2rem;
}

.faq-search input {
  width: 100%;
  padding: 0.9rem 1.2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 1rem;
  outline: none;
  transition: var(--transition-base);
}

.faq-search input:focus {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

.faq-category {
  margin-bottom: 2rem;
}

.faq-category h3 {
  color: var(--accent-blue-light);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid rgba(37,99,235,0.2);
}

.faq-list details {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 0.75rem;
  transition: var(--transition-base);
}

.faq-list details:hover {
  border-color: rgba(37,99,235,0.3);
}

.faq-list summary {
  padding: 1rem 1.2rem;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-list summary::after {
  content: '+';
  font-size: 1.3rem;
  color: var(--accent-blue-light);
  transition: transform 0.3s;
}

.faq-list details[open] summary::after {
  content: '−';
  transform: rotate(180deg);
}

.faq-list .faq-answer {
  padding: 0 1.2rem 1.2rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ============================================
   Contact Page
   ============================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 3rem;
  align-items: start;
}

.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
}

.form-group {
  margin-bottom: 1.2rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.4rem;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.8rem 1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: var(--transition-base);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.08);
}

.form-group textarea {
  min-height: 140px;
  resize: vertical;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: var(--transition-base);
}

.contact-card:hover {
  border-color: rgba(37,99,235,0.3);
}

.contact-card h3 {
  color: var(--accent-blue-light);
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}

.contact-card p {
  font-size: 0.9rem;
  margin-bottom: 0;
}

.social-links {
  display: flex;
  gap: 1rem;
  margin-top: 0.5rem;
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  text-decoration: none;
  transition: var(--transition-base);
  font-size: 1rem;
}

.social-link:hover {
  background: var(--accent-blue);
  color: #fff;
  border-color: var(--accent-blue);
}

/* ============================================
   Footer
   ============================================ */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 2rem 1.5rem;
  text-align: center;
}

footer p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 0;
}

/* ============================================
   Animations — Scroll Reveal
   ============================================ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* Fade In Up */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(40px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in-up {
  animation: fadeInUp 0.8s ease forwards;
}

/* Data flow animation */
@keyframes dataFlow {
  0% { background-position: 0% 50%; }
  100% { background-position: 200% 50%; }
}

.data-flow-bg {
  background: linear-gradient(90deg, transparent, rgba(37,99,235,0.06), transparent);
  background-size: 200% 100%;
  animation: dataFlow 3s linear infinite;
}

/* ============================================
   Breadcrumb
   ============================================ */
.breadcrumb {
  display: flex;
  list-style: none;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
  font-size: 0.9rem;
}

.breadcrumb a {
  color: var(--accent-blue-light);
  text-decoration: none;
}

.breadcrumb span {
  color: var(--text-muted);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
  h1 { font-size: 2.2rem; }
  h2 { font-size: 1.8rem; }
  .hero-content h1 .highlight { font-size: 2.4rem; }

  .features-grid,
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .eco-grid { grid-template-columns: repeat(2, 1fr); }
  .team-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }

  .timeline::before { left: 20px; }
  .timeline-item:nth-child(odd),
  .timeline-item:nth-child(even) {
    padding: 0 0 0 50px;
    text-align: left;
    flex-direction: row;
  }
  .timeline-dot { left: 20px; }
}

@media (max-width: 768px) {
  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.5rem; }
  .hero-content h1 .highlight { font-size: 2rem; }

  section { padding: 3rem 1rem; }

  #hero .section-inner {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }

  .hero-content .hero-desc { max-width: 100%; }
  .hero-tags { justify-content: center; }
  .hero-buttons { justify-content: center; }

  .features-grid,
  .services-grid,
  .stats-grid,
  .eco-grid,
  .team-grid { grid-template-columns: 1fr; }

  nav ul {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background: var(--bg-secondary);
    flex-direction: column;
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
  }

  nav ul.open {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }

  .service-table-wrap { font-size: 0.85rem; }
}

@media (max-width: 480px) {
  .hero-buttons { flex-direction: column; width: 100%; }
  .hero-buttons .btn { width: 100%; }
  .btn { padding: 0.7rem 1.5rem; }
}