/* ============================================================
   YZMT TECHNOLOGY - Global Style System
   参考 constgroup.com 设计风格
   ============================================================ */

/* --- CSS Variables --- */
:root {
  /* Brand Colors */
  --color-primary: #1a3f8a;
  --color-primary-light: #1e5abf;
  --color-primary-dark: #0f2d66;
  --color-accent: #1565c0;
  --color-accent-light: #e8f0fe;

  /* Neutrals */
  --color-white: #ffffff;
  --color-bg: #f8f9fb;
  --color-bg-gray: #f0f2f5;
  --color-border: #e8eaed;
  --color-divider: #eeeeee;

  /* Text */
  --color-text: #2c2c2c;
  --color-text-secondary: #5f6368;
  --color-text-muted: #999999;
  --color-text-light: #cccccc;

  /* Dark / Footer */
  --color-dark: #1e2229;
  --color-dark-secondary: #282d35;
  --color-dark-text: #b0b5bd;
  --color-dark-text-light: #7d8289;

  /* Status */
  --color-success: #0d904f;
  --color-warning: #f5a623;
  --color-error: #d93025;

  /* Sizing */
  --header-height: 72px;
  --max-width: 1200px;
  --section-padding: 80px;

  /* Typography */
  --font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-family-en: "Inter", "Segoe UI", "Helvetica Neue", Arial, sans-serif;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Hero Gradient */
  --gradient-hero: linear-gradient(135deg, #0f2d66 0%, #1a3f8a 40%, #1e5abf 100%);
  --gradient-hero-light: linear-gradient(135deg, #1a3f8a 0%, #2563c7 50%, #3b82f6 100%);
  --gradient-card: linear-gradient(180deg, rgba(26, 63, 138, 0.03) 0%, rgba(26, 63, 138, 0) 100%);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background: var(--color-white);
  line-height: 1.7;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

ul,
ol {
  list-style: none;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
  font-size: inherit;
}

input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
  width: 100%;
}

input:focus,
textarea:focus,
select:focus {
  border-color: var(--color-primary-light);
  box-shadow: 0 0 0 3px rgba(26, 63, 138, 0.08);
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 600;
  color: var(--color-text);
}

h1 { font-size: 2.75rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

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

.section-title h2 {
  font-size: 2rem;
  color: var(--color-text);
  margin-bottom: 12px;
  letter-spacing: 0.5px;
}

.section-title p {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.section-title h2::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--gradient-hero-light);
  border-radius: 2px;
  margin: 16px auto 0;
}

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

/* --- Header / Navigation --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition-normal);
}

.header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.5px;
}

.logo-icon {
  min-width: 52px;
  height: 36px;
  padding: 0 8px;
  background: var(--gradient-hero-light);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 0.78rem;
  letter-spacing: 0.5px;
}

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

.nav a {
  display: block;
  padding: 8px 20px;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  font-weight: 500;
}

.nav a:hover,
.nav a.active {
  color: var(--color-primary);
  background: var(--color-accent-light);
}

/* Mobile Menu Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
  cursor: pointer;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-normal);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Hero Section --- */
.hero {
  padding: calc(var(--header-height) + 80px) 0 100px;
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
  color: var(--color-white);
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.03);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.03);
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content h1 {
  font-size: 2.75rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 20px;
  line-height: 1.3;
}

.hero-content h1 span {
  color: #6db3f2;
}

.hero-content p {
  font-size: 1.15rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 36px;
  line-height: 1.8;
  max-width: 500px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-image {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-img {
  width: 100%;
  max-width: 520px;
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.hero-image-placeholder {
  width: 100%;
  max-width: 480px;
  aspect-ratio: 4/3;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255, 255, 255, 0.4);
  font-size: 4rem;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: all var(--transition-normal);
  white-space: nowrap;
  letter-spacing: 0.3px;
}

.btn-primary {
  background: var(--color-white);
  color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background: transparent;
  color: var(--color-white);
  border: 2px solid rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
  border-color: var(--color-white);
  background: rgba(255, 255, 255, 0.08);
}

.btn-blue {
  background: var(--color-primary);
  color: var(--color-white);
  box-shadow: var(--shadow-sm);
}

.btn-blue:hover {
  background: var(--color-primary-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* --- Page Banner --- */
.page-banner {
  padding: calc(var(--header-height) + 60px) 0 56px;
  background: var(--gradient-hero);
  text-align: center;
  color: var(--color-white);
}

.page-banner h1 {
  color: var(--color-white);
  font-size: 2.25rem;
  margin-bottom: 10px;
}

.page-banner p {
  color: rgba(255, 255, 255, 0.75);
  font-size: 1.05rem;
}

.breadcrumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-bottom: 16px;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.6);
}

.breadcrumb a {
  color: rgba(255, 255, 255, 0.8);
}

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

/* --- Section --- */
.section {
  padding: var(--section-padding) 0;
}

.section-gray {
  background: var(--color-bg);
}

/* --- Product Cards --- */
.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.product-card {
  background: var(--color-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
  cursor: pointer;
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.product-card-image {
  aspect-ratio: 4/3;
  background: var(--color-bg-gray);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.product-card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.product-card:hover .product-card-image img {
  transform: scale(1.05);
}

.product-card-image::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-hero-light);
  transform: scaleX(0);
  transition: transform var(--transition-normal);
}

.product-card:hover .product-card-image::after {
  transform: scaleX(1);
}

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

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

.product-card-body p {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.product-card-tags {
  display: flex;
  gap: 8px;
  margin-top: 14px;
  flex-wrap: wrap;
}

.tag {
  display: inline-block;
  padding: 4px 12px;
  font-size: 0.8rem;
  background: var(--color-accent-light);
  color: var(--color-primary);
  border-radius: 100px;
  font-weight: 500;
}

/* --- Advantage Cards --- */
.advantage-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.advantage-card {
  text-align: center;
  padding: 36px 24px;
  background: var(--color-white);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
}

.advantage-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.advantage-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  background: var(--color-accent-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  color: var(--color-primary);
}

.advantage-card h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.advantage-card p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* --- About Intro --- */
.about-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-intro-content h2 {
  font-size: 2rem;
  margin-bottom: 20px;
}

.about-intro-content p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  line-height: 1.9;
}

.about-intro-image {
  aspect-ratio: 4/3;
  background: var(--color-bg-gray);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.about-intro-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 36px;
}

.stat-item {
  text-align: center;
  padding: 16px;
}

.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-primary);
}

.stat-label {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-top: 4px;
}

/* --- Homepage About (compact) --- */
.section-about-home {
  padding: 56px 0;
}

.about-intro-compact {
  gap: 36px;
  align-items: center;
}

.about-intro-compact .about-intro-content h2 {
  font-size: 1.75rem;
  margin-bottom: 14px;
}

.about-intro-compact .about-intro-content p {
  margin-bottom: 12px;
  line-height: 1.75;
  font-size: 0.98rem;
}

.about-intro-image-compact {
  aspect-ratio: auto;
  max-height: 280px;
  background: var(--color-bg);
}

.about-intro-image-compact img {
  object-fit: contain;
}

.stats-row-compact {
  margin-top: 20px;
  gap: 12px;
}

.stats-row-compact .stat-item {
  padding: 10px 8px;
}

.stats-row-compact .stat-number {
  font-size: 1.5rem;
}

.stats-row-compact .stat-label {
  font-size: 0.82rem;
}

.about-intro-action {
  margin-top: 16px;
}

/* --- Product Filter Tabs --- */
.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.filter-tab {
  padding: 10px 24px;
  border-radius: 100px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--color-bg-gray);
  transition: all var(--transition-fast);
}

.filter-tab:hover {
  color: var(--color-primary);
  background: var(--color-accent-light);
}

.filter-tab.active {
  color: var(--color-white);
  background: var(--color-primary);
}

/* --- Product Modal --- */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  padding: 24px;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  max-width: 700px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  transform: translateY(20px);
  transition: transform var(--transition-normal);
}

.modal-overlay.active .modal {
  transform: translateY(0);
}

.modal-header {
  padding: 24px 28px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  background: var(--color-white);
  z-index: 1;
}

.modal-header h3 {
  font-size: 1.3rem;
}

.modal-close {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.modal-close:hover {
  background: var(--color-bg-gray);
  color: var(--color-text);
}

.modal-body {
  padding: 28px;
}

.modal-body h4 {
  margin-bottom: 8px;
  font-size: 1.05rem;
}

.modal-body p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  line-height: 1.8;
}

.modal-specs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 20px 0;
}

.spec-item {
  display: flex;
  justify-content: space-between;
  padding: 10px 14px;
  background: var(--color-bg);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
}

.spec-label {
  color: var(--color-text-secondary);
}

.spec-value {
  font-weight: 600;
}

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

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-border);
  transform: translateX(-50%);
}

.timeline-item {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
  position: relative;
}

.timeline-item:nth-child(even) {
  direction: rtl;
}

.timeline-item:nth-child(even) .timeline-content {
  direction: ltr;
}

.timeline-dot {
  position: absolute;
  left: 50%;
  top: 20px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 3px solid var(--color-white);
  box-shadow: 0 0 0 3px var(--color-primary);
  transform: translateX(-50%);
  z-index: 1;
}

.timeline-year {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  text-align: right;
}

.timeline-item:nth-child(even) .timeline-year {
  text-align: left;
  direction: ltr;
}

.timeline-content {
  background: var(--color-white);
  padding: 24px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
}

.timeline-content h3 {
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.timeline-content p {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
}

/* --- Certificates --- */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.cert-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 20px;
  text-align: center;
  transition: all var(--transition-normal);
}

.cert-card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.cert-icon {
  font-size: 2.5rem;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.cert-card h4 {
  font-size: 1rem;
  margin-bottom: 4px;
}

.cert-card p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* --- Culture / Vision --- */
.culture-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.culture-card {
  padding: 36px 28px;
  background: var(--color-white);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  text-align: center;
  transition: all var(--transition-normal);
}

.culture-card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.culture-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  background: var(--gradient-hero);
  color: var(--color-white);
}

.culture-card h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.culture-card p {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* --- Contact Layout --- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
}

.contact-info-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-info-card {
  display: flex;
  gap: 16px;
  padding: 24px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
}

.contact-info-card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.contact-info-icon {
  width: 48px;
  height: 48px;
  min-width: 48px;
  border-radius: 50%;
  background: var(--color-accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  font-size: 1.2rem;
}

.contact-info-card h4 {
  font-size: 1rem;
  margin-bottom: 4px;
}

.contact-info-card p {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
}

.contact-form-wrapper {
  background: var(--color-white);
  padding: 36px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
}

.contact-form-wrapper h3 {
  margin-bottom: 24px;
  font-size: 1.25rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 6px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--color-text);
}

.form-group label .required {
  color: var(--color-error);
}

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

.form-error {
  font-size: 0.82rem;
  color: var(--color-error);
  margin-top: 4px;
  display: none;
}

.form-group.error .form-error {
  display: block;
}

.form-group.error input,
.form-group.error textarea {
  border-color: var(--color-error);
}

.form-success {
  display: none;
  padding: 16px;
  background: #e6f4ea;
  border-radius: var(--radius-sm);
  color: var(--color-success);
  font-weight: 500;
  margin-bottom: 20px;
}

.form-success.show {
  display: block;
}

/* --- Map Placeholder --- */
.map-placeholder {
  width: 100%;
  height: 320px;
  background: var(--color-bg-gray);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 1rem;
  margin-top: 48px;
}

/* --- Footer --- */
.footer {
  background: var(--color-dark);
  color: var(--color-dark-text);
  padding: 64px 0 0;
}

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

.footer-brand h3 {
  color: var(--color-white);
  font-size: 1.3rem;
  margin-bottom: 14px;
}

.footer-brand p {
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--color-dark-text);
  max-width: 300px;
}

.footer-col h4 {
  color: var(--color-white);
  font-size: 1rem;
  margin-bottom: 18px;
  font-weight: 600;
}

.footer-col a {
  display: block;
  padding: 6px 0;
  font-size: 0.9rem;
  color: var(--color-dark-text);
  transition: all var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-white);
  padding-left: 4px;
}

.footer-bottom {
  margin-top: 48px;
  padding: 24px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--color-dark-text-light);
}

/* --- Back to Top --- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition-normal);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-primary-light);
  transform: translateY(-4px);
}

/* --- Utility --- */
.text-center { text-align: center; }
.mt-20 { margin-top: 20px; }
.mt-40 { margin-top: 40px; }
.mb-20 { margin-bottom: 20px; }

/* ============================================================
   RESPONSIVE
   ============================================================ */

/* Tablet (768px - 1024px) */
@media (max-width: 1024px) {
  :root {
    --section-padding: 60px;
  }

  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content p {
    max-width: 100%;
    margin-left: auto;
    margin-right: auto;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-image {
    display: none;
  }

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

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

  .about-intro {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

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

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

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

  .timeline::before {
    left: 24px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .timeline-item:nth-child(even) {
    direction: ltr;
  }

  .timeline-dot {
    left: 24px;
  }

  .timeline-year {
    text-align: left;
    padding-left: 52px;
  }

  .timeline-item:nth-child(even) .timeline-year {
    text-align: left;
  }

  .timeline-content {
    margin-left: 52px;
  }
}

/* Mobile (< 768px) */
@media (max-width: 768px) {
  :root {
    --header-height: 60px;
    --section-padding: 48px;
  }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.65rem; }

  .section-title h2 { font-size: 1.6rem; }

  .nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--color-white);
    flex-direction: column;
    padding: 80px 24px 24px;
    box-shadow: var(--shadow-xl);
    transition: right var(--transition-normal);
    gap: 2px;
  }

  .nav.active {
    right: 0;
  }

  .nav a {
    padding: 12px 16px;
    width: 100%;
    font-size: 1rem;
  }

  .nav-toggle {
    display: flex;
  }

  /* Mobile overlay */
  .nav-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
  }

  .nav-overlay.active {
    opacity: 1;
    visibility: visible;
  }

  .hero {
    padding: calc(var(--header-height) + 40px) 0 60px;
  }

  .hero-content h1 {
    font-size: 1.8rem;
  }

  .hero-content p {
    font-size: 1rem;
  }

  .product-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin: 0 auto;
  }

  .advantage-grid {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }

  .stats-row {
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
  }

  .stat-number {
    font-size: 1.5rem;
  }

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

  .culture-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin: 0 auto;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
  }

  .btn {
    padding: 12px 24px;
    font-size: 0.95rem;
  }

  .modal {
    margin: 16px;
    max-height: 90vh;
  }

  .modal-specs {
    grid-template-columns: 1fr;
  }

  .filter-tabs {
    gap: 6px;
  }

  .filter-tab {
    padding: 8px 16px;
    font-size: 0.85rem;
  }

  .page-banner {
    padding: calc(var(--header-height) + 36px) 0 40px;
  }

  .page-banner h1 {
    font-size: 1.65rem;
  }

  .contact-form-wrapper {
    padding: 24px;
  }
}

/* Small Mobile (< 480px) */
@media (max-width: 480px) {
  .advantage-grid {
    grid-template-columns: 1fr;
    max-width: 300px;
    margin: 0 auto;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }
}