/* ==========================================================================
   长春市洵宇元数字科技有限公司 · 官方网站样式
   Design Token 体系 + 组件化架构
   ========================================================================== */

/* ============ 1. DESIGN TOKENS ============ */
:root {
  /* Colors - Primary Palette (科技蓝主色) */
  --color-primary: #003DA5;
  --color-primary-dark: #002A75;
  --color-primary-light: #2E6FD4;
  --color-accent: #00D4FF;
  --color-accent-2: #722ED1;

  /* Colors - Neutral */
  --color-bg: #FFFFFF;
  --color-bg-alt: #F5F7FA;
  --color-bg-dark: #0A1628;
  --color-bg-dark-2: #0D1F3C;

  --color-text: #1A2B4A;
  --color-text-secondary: #5A6B8A;
  --color-text-muted: #8B9AB8;
  --color-text-inverse: #FFFFFF;

  --color-border: #E4E9F2;
  --color-border-light: #EEF1F8;

  /* Colors - Functional */
  --color-success: #52C41A;
  --color-warning: #FAAD14;
  --color-error: #F5222D;

  /* Typography */
  --font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-md: 18px;
  --font-size-lg: 20px;
  --font-size-xl: 24px;
  --font-size-2xl: 32px;
  --font-size-3xl: 40px;
  --font-size-4xl: 48px;
  --font-size-5xl: 60px;

  --font-weight-light: 300;
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 700;
  --font-weight-black: 900;

  --line-height-tight: 1.2;
  --line-height-normal: 1.6;
  --line-height-relaxed: 1.8;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  --spacing-4xl: 80px;
  --spacing-5xl: 120px;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 61, 165, 0.06);
  --shadow-sm: 0 2px 8px rgba(0, 61, 165, 0.08);
  --shadow-md: 0 8px 24px rgba(0, 61, 165, 0.12);
  --shadow-lg: 0 16px 48px rgba(0, 61, 165, 0.16);
  --shadow-xl: 0 24px 64px rgba(0, 61, 165, 0.2);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Container */
  --container-max: 1200px;
  --container-pad: 24px;

  /* Z-index */
  --z-header: 1000;
  --z-overlay: 900;
  --z-tooltip: 1100;
}

/* ============ 2. RESET & BASE ============ */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

img, svg {
  display: block;
  max-width: 100%;
}

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

a:hover {
  color: var(--color-primary-light);
}

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

ul {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }

/* ============ 3. LAYOUT ============ */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}

/* ============ 4. HEADER / NAV ============ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-header);
  padding: 16px 0;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition-base);
}

.site-header.scrolled {
  padding: 10px 0;
  box-shadow: var(--shadow-sm);
  border-bottom-color: var(--color-border-light);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-lg);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--color-text);
}

.brand:hover {
  color: var(--color-text);
}

.brand-logo svg {
  width: 40px;
  height: 40px;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  color: var(--color-primary);
  letter-spacing: 0.5px;
}

.brand-sub {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  font-weight: var(--font-weight-medium);
  letter-spacing: 1px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.nav-link {
  position: relative;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text);
  padding: 8px 4px;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Nav toggle (mobile) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  border-radius: var(--radius-md);
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============ 5. BUTTONS ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  cursor: pointer;
  text-align: center;
  white-space: nowrap;
}

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

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

.btn-outline {
  background: transparent;
  color: var(--color-text-inverse);
  border: 1.5px solid rgba(255, 255, 255, 0.6);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.15);
  color: var(--color-text-inverse);
  border-color: var(--color-text-inverse);
}

.btn-block {
  width: 100%;
  padding: 14px 28px;
  font-size: var(--font-size-base);
}

/* ============ 6. SECTION COMMON ============ */
section {
  padding: var(--spacing-5xl) 0;
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto var(--spacing-3xl);
}

.section-tag {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  letter-spacing: 3px;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
  padding: 4px 12px;
  background: rgba(0, 61, 165, 0.08);
  border-radius: var(--radius-full);
}

.section-title {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: var(--spacing-md);
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--color-primary);
  margin: var(--spacing-md) auto 0;
  border-radius: 2px;
}

.section-desc {
  font-size: var(--font-size-md);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* ============ 7. HERO ============ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  background: var(--color-bg-dark);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 80% 20%, rgba(0, 212, 255, 0.18) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 20% 80%, rgba(114, 46, 209, 0.15) 0%, transparent 60%),
    radial-gradient(ellipse 100% 80% at 50% 50%, rgba(0, 61, 165, 0.4) 0%, transparent 70%);
  z-index: 0;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black 0%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black 0%, transparent 80%);
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  color: var(--color-text-inverse);
  max-width: 820px;
}

.hero-eyebrow {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  letter-spacing: 4px;
  color: var(--color-accent);
  margin-bottom: var(--spacing-lg);
}

.hero-title {
  font-size: clamp(var(--font-size-3xl), 6vw, var(--font-size-5xl));
  font-weight: var(--font-weight-black);
  line-height: var(--line-height-tight);
  margin-bottom: var(--spacing-xl);
  color: var(--color-text-inverse);
}

.hero-title .highlight {
  color: var(--color-accent);
  position: relative;
}

.hero-sub {
  font-size: var(--font-size-lg);
  color: rgba(255, 255, 255, 0.75);
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--spacing-2xl);
  max-width: 640px;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-3xl);
}

/* Stats */
.hero-stats {
  display: flex;
  gap: var(--spacing-xl);
  padding-top: var(--spacing-2xl);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-num {
  font-size: clamp(var(--font-size-xl), 3vw, var(--font-size-3xl));
  font-weight: var(--font-weight-black);
  color: var(--color-accent);
  line-height: 1;
}

.stat-suffix {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-bold);
  color: var(--color-accent);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
  font-weight: var(--font-weight-medium);
}

/* Scroll hint */
.scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255, 255, 255, 0.5);
  font-size: var(--font-size-xs);
  letter-spacing: 2px;
  z-index: 1;
}

.scroll-arrow {
  width: 1px;
  height: 32px;
  background: rgba(255, 255, 255, 0.5);
  position: relative;
  overflow: hidden;
}

.scroll-arrow::after {
  content: '';
  position: absolute;
  top: -32px;
  left: 0;
  width: 100%;
  height: 32px;
  background: var(--color-accent);
  animation: scrollPulse 2s infinite ease-in-out;
}

@keyframes scrollPulse {
  0% { top: -32px; }
  100% { top: 32px; }
}

/* ============ 8. ABOUT ============ */
.about {
  background: var(--color-bg);
}

.about-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: var(--spacing-4xl);
  align-items: center;
}

.about-text p {
  font-size: var(--font-size-md);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--spacing-lg);
}

.about-highlights {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-2xl);
}

.highlight-item {
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-start;
}

.highlight-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  background: rgba(0, 61, 165, 0.06);
  display: flex;
  align-items: center;
  justify-content: center;
}

.highlight-item strong {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: 2px;
}

.highlight-item span {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

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

.about-card {
  background: var(--color-bg);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-2xl);
  position: relative;
}

.about-card-main {
  width: 280px;
  height: 280px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.about-card-main svg {
  width: 200px;
  height: 200px;
  margin-bottom: var(--spacing-md);
}

.about-card-label {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-primary);
  letter-spacing: 1px;
}

.about-card-sub {
  position: absolute;
  bottom: -20px;
  left: 20px;
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.about-card-sub strong {
  font-size: var(--font-size-sm);
  color: var(--color-text-inverse);
}

.about-card-sub span {
  font-size: var(--font-size-xs);
  opacity: 0.8;
}

/* ============ 9. SERVICES ============ */
.services {
  background: var(--color-bg-alt);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-xl);
}

.service-card {
  background: var(--color-bg);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  border: 1px solid var(--color-border-light);
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.service-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

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

.service-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-lg);
  background: rgba(0, 61, 165, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  margin-bottom: var(--spacing-lg);
  transition: all var(--transition-base);
}

.service-card:hover .service-icon {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.service-title {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.service-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: var(--line-height-relaxed);
}

.service-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.service-list li {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  padding-left: 16px;
  position: relative;
}

.service-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-primary);
  opacity: 0.5;
}

/* ============ 10. PRODUCTS ============ */
.products {
  background: var(--color-bg);
}

.products-tabs {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-2xl);
  flex-wrap: wrap;
}

.tab-btn {
  padding: 10px 24px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  background: var(--color-bg-alt);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
}

.tab-btn:hover {
  color: var(--color-primary);
}

.tab-btn.active {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-sm);
}

.tab-panel {
  display: none;
  animation: fadeIn 0.4s ease;
}

.tab-panel.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-xl);
}

.product-card {
  background: var(--color-bg);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
}

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

.product-img {
  height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.product-body {
  padding: var(--spacing-xl);
}

.product-body h3 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.product-body > p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--spacing-md);
}

.feature-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: var(--spacing-md);
}

.feature-list li {
  font-size: var(--font-size-xs);
  padding: 4px 12px;
  background: rgba(0, 61, 165, 0.06);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  font-weight: var(--font-weight-medium);
}

.product-link {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-primary);
  display: inline-block;
  transition: all var(--transition-fast);
}

.product-link:hover {
  color: var(--color-primary-dark);
  letter-spacing: 0.5px;
}

/* ============ 11. CASES ============ */
.cases {
  background: var(--color-bg-alt);
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-xl);
}

.case-card {
  background: var(--color-bg);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

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

.case-cover {
  height: 240px;
  position: relative;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  padding: var(--spacing-xl);
  color: var(--color-text-inverse);
}

.case-tag {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  letter-spacing: 2px;
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-full);
}

.case-num {
  font-size: 60px;
  font-weight: var(--font-weight-black);
  opacity: 0.15;
  line-height: 1;
}

.case-body {
  padding: var(--spacing-xl);
}

.case-body h3 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.case-body > p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--spacing-md);
}

.case-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--font-size-sm);
}

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

.case-meta a {
  color: var(--color-primary);
  font-weight: var(--font-weight-medium);
}

/* ============ 12. CONTACT ============ */
.contact {
  background: var(--color-bg);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: var(--spacing-4xl);
  align-items: start;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.info-item {
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-start;
}

.info-icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: rgba(0, 61, 165, 0.08);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.info-item strong {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  margin-bottom: 2px;
}

.info-item span {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* Form */
.contact-form {
  background: var(--color-bg-alt);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-sm);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

.form-group label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text);
  margin-bottom: var(--spacing-xs);
}

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

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: var(--font-size-sm);
  font-family: inherit;
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  outline: none;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--color-text-muted);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 61, 165, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

.form-note {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  text-align: center;
  margin-top: var(--spacing-md);
}

/* ============ 13. FOOTER ============ */
.site-footer {
  background: var(--color-bg-dark);
  color: rgba(255, 255, 255, 0.7);
  padding-top: var(--spacing-4xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.4fr;
  gap: var(--spacing-3xl);
  padding-bottom: var(--spacing-3xl);
}

.footer-brand .brand {
  margin-bottom: var(--spacing-md);
}

.footer-desc {
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  max-width: 320px;
}

.footer-links h4,
.footer-contact h4 {
  color: var(--color-text-inverse);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-md);
  letter-spacing: 1px;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-links a {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-contact p {
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-xs);
}

.footer-social {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.social-link {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-base);
}

.social-link:hover {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  transform: translateY(-2px);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: var(--spacing-lg) 0;
  text-align: center;
}

.footer-bottom p {
  font-size: var(--font-size-xs);
  color: rgba(255, 255, 255, 0.4);
}

/* ============ 14. BACK TO TOP ============ */
.back-to-top {
  position: fixed;
  right: 32px;
  bottom: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base);
  z-index: var(--z-tooltip);
}

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

.back-to-top:hover {
  background: var(--color-primary-dark);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

/* ============ 15. ANIMATIONS ============ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

.fade-up {
  opacity: 0;
  transform: translateY(24px);
  animation: fadeUp 0.8s ease forwards;
}

.fade-up.delay-1 { animation-delay: 0.2s; }
.fade-up.delay-2 { animation-delay: 0.4s; }
.fade-up.delay-3 { animation-delay: 0.6s; }
.fade-up.delay-4 { animation-delay: 0.8s; }

@keyframes fadeUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============ 15.5. THEME GRADIENTS (semantic classes) ============ */
.product-img--ai { background: linear-gradient(135deg, #003DA5, #00D4FF); }
.product-img--vision { background: linear-gradient(135deg, #0052D9, #36CFC9); }
.product-img--engine { background: linear-gradient(135deg, #1890FF, #722ED1); }
.product-img--platform { background: linear-gradient(135deg, #13C2C2, #08979C); }
.product-img--bi { background: linear-gradient(135deg, #2F54EB, #597EF7); }
.product-img--realtime { background: linear-gradient(135deg, #F759AB, #EB2F96); }
.product-img--park { background: linear-gradient(135deg, #52C41A, #73D13D); }
.product-img--vehicle { background: linear-gradient(135deg, #FA8C16, #FFC53D); }
.product-img--drone { background: linear-gradient(135deg, #2F54EB, #13C2C2); }

.case-cover--gov { background: linear-gradient(135deg, #003DA5, #00D4FF); }
.case-cover--factory { background: linear-gradient(135deg, #1890FF, #722ED1); }
.case-cover--park { background: linear-gradient(135deg, #52C41A, #13C2C2); }
.case-cover--retail { background: linear-gradient(135deg, #FA8C16, #F759AB); }

/* ============ 15.6. MAP ============ */
.contact-map {
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
  height: 320px;
  position: relative;
}

.contact-map iframe {
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
}

/* ============ 15.7. FORM MESSAGE ============ */
.form-message {
  padding: 12px 16px;
  border-radius: var(--radius-md);
  margin-top: var(--spacing-md);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  transition: opacity var(--transition-base);
}

.form-message--success {
  background: rgba(82, 196, 26, 0.1);
  color: #389E0D;
  border: 1px solid rgba(82, 196, 26, 0.3);
}

.form-message--error {
  background: rgba(245, 34, 45, 0.1);
  color: #CF1322;
  border: 1px solid rgba(245, 34, 45, 0.3);
}

/* ============ 15.8. FLOATING CONSULT BUTTON ============ */
.floating-consult {
  position: fixed;
  right: 32px;
  bottom: 92px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: var(--color-accent);
  color: var(--color-bg-dark);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-bold);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
  z-index: var(--z-tooltip);
  cursor: pointer;
  border: none;
  font-family: inherit;
}

.floating-consult:hover {
  background: #00B8E6;
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.floating-consult svg {
  flex-shrink: 0;
}

/* ============ 16. RESPONSIVE ============ */

/* 1199px and below */
@media (max-width: 1199px) {
  :root {
    --font-size-5xl: 48px;
    --font-size-4xl: 40px;
    --font-size-3xl: 32px;
    --font-size-2xl: 28px;
    --spacing-5xl: 80px;
    --spacing-4xl: 60px;
  }

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

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

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-2xl);
  }

  .hero-stats {
    gap: var(--spacing-lg);
  }
}

/* 991px and below */
@media (max-width: 991px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
  }

  .about-visual {
    order: -1;
    padding: var(--spacing-xl) 0;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
  }
}

/* 767px and below (tablet/mobile) */
@media (max-width: 767px) {
  :root {
    --font-size-5xl: 36px;
    --font-size-4xl: 32px;
    --font-size-3xl: 26px;
    --font-size-2xl: 22px;
    --font-size-xl: 18px;
    --container-pad: 16px;
    --spacing-5xl: 64px;
    --spacing-4xl: 48px;
    --spacing-3xl: 40px;
    --spacing-2xl: 32px;
    --spacing-xl: 24px;
  }

  section {
    padding: var(--spacing-4xl) 0;
  }

  /* Nav */
  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-md);
    border-top: 1px solid var(--color-border-light);
    transform: translateY(-10px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
  }

  .main-nav.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-list li {
    border-bottom: 1px solid var(--color-border-light);
  }

  .nav-list li:last-child {
    border-bottom: none;
  }

  .nav-link {
    display: block;
    padding: 14px 8px;
    font-size: var(--font-size-base);
  }

  .nav-link::after {
    display: none;
  }

  /* Hero */
  .hero {
    padding: 100px 0 60px;
    min-height: auto;
  }

  .hero-cta {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-stats {
    flex-wrap: wrap;
    gap: var(--spacing-lg);
  }

  .stat-item {
    flex: 0 0 calc(50% - var(--spacing-lg) / 2);
  }

  .scroll-hint {
    display: none;
  }

  /* Services */
  .services-grid {
    grid-template-columns: 1fr;
  }

  .service-card {
    padding: var(--spacing-xl);
  }

  /* Products */
  .product-grid {
    grid-template-columns: 1fr;
  }

  .products-tabs {
    gap: var(--spacing-xs);
  }

  .tab-btn {
    padding: 8px 16px;
    font-size: var(--font-size-sm);
  }

  /* Cases */
  .cases-grid {
    grid-template-columns: 1fr;
  }

  /* About highlights */
  .about-highlights {
    grid-template-columns: 1fr;
  }

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

  .contact-form {
    padding: var(--spacing-xl);
  }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    text-align: center;
  }

  .footer-desc {
    max-width: none;
  }

  .footer-social {
    justify-content: center;
  }

  /* Back to top */
  .back-to-top {
    right: 16px;
    bottom: 16px;
    width: 42px;
    height: 42px;
  }

  .floating-consult {
    right: 16px;
    bottom: 70px;
    padding: 10px 16px;
    font-size: var(--font-size-xs);
  }

  .contact-map {
    height: 240px;
  }

  .about-card-main {
    width: 240px;
    height: 240px;
  }

  .about-card-main svg {
    width: 160px;
    height: 160px;
  }
}

/* 480px and below (small mobile) */
@media (max-width: 480px) {
  :root {
    --font-size-5xl: 30px;
    --font-size-4xl: 26px;
  }

  .section-title {
    font-size: var(--font-size-2xl);
  }

  .about-card-sub {
    left: 10px;
    padding: var(--spacing-sm) var(--spacing-md);
  }
}

/* ============ 17. ACCESSIBILITY ============ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}