/* ─────────────────────────────────────────────
   讯汇光影 官网 CSS
   深色科技风 · 蓝色主题 · 响应式
───────────────────────────────────────────── */

/* ── 变量 ── */
:root {
  --bg:          #080c14;
  --bg-2:        #0d1321;
  --bg-3:        #111827;
  --surface:     #141e2e;
  --surface-2:   #1a2640;
  --border:      rgba(10, 132, 255, 0.12);
  --border-2:    rgba(10, 132, 255, 0.22);
  --blue:        #0a84ff;
  --blue-dim:    rgba(10, 132, 255, 0.15);
  --blue-glow:   rgba(10, 132, 255, 0.35);
  --text-1:      #f0f4fc;
  --text-2:      #9ba8be;
  --text-3:      #5a6a85;
  --radius:      12px;
  --radius-lg:   20px;
  --transition:  0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── 基础重置 ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  background: var(--bg);
  color: var(--text-1);
  font-family: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
}

img, video { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
ul { list-style: none; }

/* ── 滚动条 ── */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--blue); border-radius: 2px; }

/* ── 容器 ── */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ── 通用按钮 ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  transition: var(--transition);
}

.btn-primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 0 24px var(--blue-glow);
}
.btn-primary:hover {
  background: #2e9bff;
  box-shadow: 0 0 40px var(--blue-glow);
  transform: translateY(-2px);
}

.btn-ghost {
  color: var(--blue);
  border: 1px solid var(--border-2);
}
.btn-ghost:hover {
  background: var(--blue-dim);
  border-color: var(--blue);
}

.btn-outline {
  color: var(--text-2);
  border: 1px solid var(--border-2);
}
.btn-outline:hover {
  color: var(--blue);
  border-color: var(--blue);
  background: var(--blue-dim);
}

.btn-full { width: 100%; justify-content: center; }

/* ── Section 通用 ── */
.section { padding: 120px 0; position: relative; }

.section-header { text-align: center; margin-bottom: 72px; }

.section-label {
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 12px;
  display: block;
  font-weight: 500;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--text-1);
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.section-sub {
  margin-top: 16px;
  color: var(--text-2);
  font-size: 1rem;
}

/* ── Reveal 动画 ── */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}
.reveal.visible {
  opacity: 1;
  transform: none;
}

/* ─────────────────────────────────────────────
   NAV
───────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 0;
  transition: background 0.4s, backdrop-filter 0.4s, border-color 0.4s;
  border-bottom: 1px solid transparent;
}

.nav.scrolled {
  background: rgba(8, 12, 20, 0.88);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom-color: var(--border);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-1);
}

.logo-mark {
  width: 34px; height: 34px;
  background: var(--blue);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: 800;
  color: #fff;
  box-shadow: 0 0 14px var(--blue-glow);
}

.logo-text { color: var(--text-1); }

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

.nav-links a {
  font-size: 0.9rem;
  color: var(--text-2);
  transition: color 0.25s;
  font-weight: 400;
}
.nav-links a:hover { color: var(--text-1); }

.nav-cta {
  background: var(--blue) !important;
  color: #fff !important;
  padding: 8px 20px;
  border-radius: 8px;
  font-weight: 500 !important;
  transition: var(--transition) !important;
}
.nav-cta:hover {
  background: #2e9bff !important;
  box-shadow: 0 0 20px var(--blue-glow);
}

.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 24px; height: 2px;
  background: var(--text-2);
  border-radius: 1px;
  transition: var(--transition);
}

/* ─────────────────────────────────────────────
   HERO
───────────────────────────────────────────── */
.hero {
  position: relative;
  height: 100vh;
  min-height: 700px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero-canvas {
  position: absolute;
  inset: 0;
  z-index: 1;
}

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

.hero-video {
  width: 100%; height: 100%;
  object-fit: cover;
  opacity: 0.35;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(8, 12, 20, 0.3) 0%,
    rgba(8, 12, 20, 0.15) 40%,
    rgba(8, 12, 20, 0.6) 80%,
    rgba(8, 12, 20, 1) 100%
  );
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
  padding: 0 24px;
}

.hero-eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--blue);
  font-weight: 500;
  margin-bottom: 24px;
  display: block;
}

.hero-headline {
  font-size: clamp(3.2rem, 8vw, 6.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--text-1);
  margin-bottom: 20px;
}

.hero-headline em {
  font-style: normal;
  color: var(--blue);
  text-shadow: 0 0 40px var(--blue-glow);
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--text-2);
  margin-bottom: 40px;
  letter-spacing: 0.06em;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-scroll-hint {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  color: var(--text-3);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.scroll-line {
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--blue), transparent);
  animation: scrollPulse 1.8s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(0.6) translateY(-8px); }
  50% { opacity: 1; transform: scaleY(1) translateY(0); }
}

/* Hero reveal stagger */
.hero-content .reveal { transition-delay: calc(var(--i, 0) * 0.15s); }
.hero-content .reveal:nth-child(1) { --i: 0; }
.hero-content .reveal:nth-child(2) { --i: 1; }
.hero-content .reveal:nth-child(3) { --i: 2; }
.hero-content .reveal:nth-child(4) { --i: 3; }

/* ─────────────────────────────────────────────
   BUSINESS
───────────────────────────────────────────── */
.business { background: var(--bg); }

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

.biz-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px 36px;
  position: relative;
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.biz-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--blue-dim) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.4s;
}

.biz-card:hover {
  border-color: var(--blue);
  transform: translateY(-6px);
  box-shadow: 0 20px 60px rgba(10, 132, 255, 0.15);
}

.biz-card:hover::before { opacity: 1; }

.biz-card-icon {
  width: 56px; height: 56px;
  color: var(--text-2);
}

.biz-card-tag {
  position: absolute;
  top: 28px; right: 28px;
  font-size: 3.5rem;
  font-weight: 800;
  color: rgba(10, 132, 255, 0.06);
  line-height: 1;
  letter-spacing: -0.04em;
  pointer-events: none;
}

.biz-card-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-1);
  position: relative;
}

.biz-card-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  position: relative;
}

.biz-card-list li {
  font-size: 0.85rem;
  color: var(--text-2);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  padding: 5px 12px;
  border-radius: 20px;
}

.biz-card-highlight {
  display: flex;
  gap: 8px;
  position: relative;
  margin-top: auto;
}

.biz-card-highlight span {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--blue);
  background: var(--blue-dim);
  border: 1px solid rgba(10, 132, 255, 0.25);
  padding: 4px 12px;
  border-radius: 20px;
}

/* ─────────────────────────────────────────────
   CASES
───────────────────────────────────────────── */
.cases { background: var(--bg-2); }

.case-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 48px;
  align-items: flex-start;
}

.filter-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.filter-label {
  font-size: 0.8rem;
  color: var(--text-3);
  white-space: nowrap;
}

.filter-btn {
  font-size: 0.82rem;
  color: var(--text-2);
  border: 1px solid var(--border);
  padding: 6px 16px;
  border-radius: 20px;
  transition: var(--transition);
  background: transparent;
}

.filter-btn:hover {
  color: var(--blue);
  border-color: var(--blue);
  background: var(--blue-dim);
}

.filter-btn.active {
  color: #fff;
  background: var(--blue);
  border-color: var(--blue);
  box-shadow: 0 0 14px var(--blue-glow);
}

/* 瀑布流 */
.cases-masonry {
  columns: 3;
  column-gap: 20px;
}

.case-card {
  break-inside: avoid;
  margin-bottom: 20px;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--border);
  transition: var(--transition);
  cursor: pointer;
  position: relative;
}

.case-card:hover {
  border-color: var(--blue);
  box-shadow: 0 12px 40px rgba(10, 132, 255, 0.15);
  transform: scale(1.02);
}

.case-card-media {
  aspect-ratio: 16/10;
  overflow: hidden;
}

.case-card.tall .case-card-media {
  aspect-ratio: 3/4;
}

.case-card-media img, .case-card-media video {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.case-card:hover .case-card-media img,
.case-card:hover .case-card-media video {
  transform: scale(1.06);
}

.case-placeholder {
  width: 100%; height: 100%;
  background: var(--ph-color, #0a84ff22);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  border-bottom: 1px solid var(--border);
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.case-card:hover .case-placeholder { transform: scale(1.06); }

.ph-icon { opacity: 0.5; }

.case-card-info {
  padding: 18px 20px;
}

.case-card-info h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-1);
  margin-bottom: 10px;
  line-height: 1.4;
}

.case-tags { display: flex; flex-wrap: wrap; gap: 6px; }

.tag {
  font-size: 0.75rem;
  color: var(--blue);
  background: var(--blue-dim);
  border: 1px solid rgba(10, 132, 255, 0.2);
  padding: 3px 10px;
  border-radius: 12px;
}

.case-card.hidden { display: none; }

.cases-more {
  text-align: center;
  margin-top: 56px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.cases-note {
  font-size: 0.82rem;
  color: var(--text-3);
}

/* ─────────────────────────────────────────────
   TECH
───────────────────────────────────────────── */
.tech {
  background: var(--bg);
  overflow: hidden;
}

.tech-bg-lines {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(10, 132, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(10, 132, 255, 0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.tech-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 44px 40px;
  position: relative;
  overflow: hidden;
  transition: var(--transition);
}

.tech-item:hover {
  border-color: var(--border-2);
  background: var(--surface-2);
  box-shadow: 0 0 40px rgba(10, 132, 255, 0.08);
}

.tech-num {
  position: absolute;
  top: 28px; right: 32px;
  font-size: 4.5rem;
  font-weight: 800;
  color: rgba(10, 132, 255, 0.05);
  line-height: 1;
  letter-spacing: -0.05em;
}

.tech-icon {
  width: 44px; height: 44px;
  color: var(--text-2);
  margin-bottom: 20px;
}

.tech-item h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-1);
  margin-bottom: 16px;
  position: relative;
}

.tech-item h3::after {
  content: '';
  display: block;
  width: 32px; height: 2px;
  background: var(--blue);
  margin-top: 10px;
  border-radius: 1px;
  box-shadow: 0 0 8px var(--blue-glow);
}

.tech-item p {
  color: var(--text-2);
  font-size: 0.92rem;
  line-height: 1.75;
  position: relative;
}

/* ─────────────────────────────────────────────
   WHY
───────────────────────────────────────────── */
.why { background: var(--bg-2); }

.why-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 860px;
  margin: 0 auto;
}

.why-item {
  display: flex;
  gap: 0;
  padding: 40px 0;
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
  position: relative;
}

.why-item:first-child { border-top: 1px solid var(--border); }

.why-accent {
  width: 3px;
  border-radius: 2px;
  background: var(--border);
  flex-shrink: 0;
  margin-right: 36px;
  transition: background 0.4s, box-shadow 0.4s;
}

.why-item:hover .why-accent {
  background: var(--blue);
  box-shadow: 0 0 12px var(--blue-glow);
}

.why-body { flex: 1; }

.why-num {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--blue);
  margin-bottom: 10px;
}

.why-item h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-1);
  margin-bottom: 12px;
}

.why-item p {
  color: var(--text-2);
  font-size: 0.95rem;
  line-height: 1.75;
  max-width: 580px;
}

/* ─────────────────────────────────────────────
   ABOUT
───────────────────────────────────────────── */
.about {
  background: var(--bg);
  overflow: hidden;
}

.about-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 80% 50%, rgba(10, 132, 255, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

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

.about-text .section-label { text-align: left; }

.about-headline {
  font-size: clamp(2.2rem, 4.5vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--text-1);
  margin: 12px 0 28px;
}

.about-body {
  color: var(--text-2);
  line-height: 2;
  font-size: 1rem;
  margin-bottom: 48px;
}

.about-stats {
  display: flex;
  gap: 48px;
}

.stat { display: flex; flex-direction: column; }

.stat-num {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--text-1);
  line-height: 1;
  letter-spacing: -0.03em;
}

.stat-unit {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--blue);
  line-height: 1;
}

.stat-num + .stat-unit {
  display: inline;
  font-size: 1.6rem;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-3);
  margin-top: 4px;
  letter-spacing: 0.06em;
}

/* 团队角色可视化 */
.about-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.team-grid {
  width: 320px; height: 320px;
  position: relative;
}

.team-role {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  font-size: 0.82rem;
  color: var(--text-2);
  font-weight: 500;
}

.team-role:nth-child(1) { top: 12%; left: 50%; transform: translateX(-50%); }
.team-role:nth-child(2) { top: 50%; right: 5%; transform: translateY(-50%); }
.team-role:nth-child(3) { bottom: 12%; left: 50%; transform: translateX(-50%); }
.team-role:nth-child(4) { top: 50%; left: 5%; transform: translateY(-50%); }
.team-role:nth-child(5).center-role { top: 50%; left: 50%; transform: translate(-50%, -50%); }

.role-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--blue);
  box-shadow: 0 0 12px var(--blue-glow);
  position: relative;
}

.role-dot::after {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 1px solid rgba(10, 132, 255, 0.3);
  animation: ping 2s cubic-bezier(0, 0, 0.2, 1) infinite;
}

.role-dot.core {
  width: 16px; height: 16px;
  background: var(--blue);
  box-shadow: 0 0 24px var(--blue-glow);
}

.role-dot.core::after {
  inset: -6px;
  border-width: 2px;
  border-color: rgba(10, 132, 255, 0.5);
}

.center-role span {
  font-size: 1rem;
  font-weight: 700;
  color: var(--blue);
}

/* 连线 SVG */
.team-grid::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 50% 50%, rgba(10, 132, 255, 0.08) 0%, transparent 60%);
  border-radius: 50%;
  border: 1px solid var(--border);
}

@keyframes ping {
  0%   { transform: scale(1); opacity: 0.8; }
  80%, 100% { transform: scale(2.4); opacity: 0; }
}

/* ─────────────────────────────────────────────
   CONTACT
───────────────────────────────────────────── */
.contact { background: var(--bg-2); }

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 64px;
  align-items: start;
}

.contact-info { display: flex; flex-direction: column; gap: 32px; }

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
}

.contact-icon {
  width: 44px; height: 44px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--blue);
}

.contact-icon svg { width: 20px; height: 20px; }

.contact-label {
  display: block;
  font-size: 0.78rem;
  color: var(--text-3);
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}

.contact-value {
  display: block;
  font-size: 0.95rem;
  color: var(--text-1);
}

/* 表单 */
.contact-form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 44px 40px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

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

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 0.82rem;
  color: var(--text-3);
  font-weight: 500;
  letter-spacing: 0.04em;
}

.form-group input,
.form-group select,
.form-group textarea {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  color: var(--text-1);
  font-family: inherit;
  font-size: 0.92rem;
  transition: border-color 0.25s, box-shadow 0.25s;
  outline: none;
  width: 100%;
}

.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--text-3); }

.form-group select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%235a6a85' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 40px;
}

.form-group select option { background: var(--bg-3); }

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px var(--blue-dim);
}

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

.form-tip {
  text-align: center;
  font-size: 0.78rem;
  color: var(--text-3);
  margin-top: -8px;
}

/* 发送成功提示 */
.form-success {
  text-align: center;
  padding: 32px;
  color: var(--blue);
  font-size: 1rem;
  font-weight: 500;
}

/* ─────────────────────────────────────────────
   FOOTER
───────────────────────────────────────────── */
.footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 60px 0 32px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 48px;
  gap: 40px;
}

.footer-logo { margin-bottom: 16px; }

.footer-slogan {
  color: var(--text-3);
  font-size: 0.9rem;
  line-height: 1.85;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: flex-end;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--text-3);
  transition: color 0.25s;
}
.footer-links a:hover { color: var(--blue); }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--text-3);
}

.footer-divider { opacity: 0.3; }

/* ─────────────────────────────────────────────
   RESPONSIVE
───────────────────────────────────────────── */
@media (max-width: 960px) {
  .biz-grid { grid-template-columns: 1fr; max-width: 520px; margin: 0 auto; }
  .tech-grid { grid-template-columns: 1fr; }
  .about-inner { grid-template-columns: 1fr; gap: 48px; }
  .about-visual { display: none; }
  .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .cases-masonry { columns: 2; }
}

/* ── 手机端案例优化：卡片更大更清晰，方便浏览 ── */
@media (max-width: 768px) {
  .cases-masonry { columns: 2; column-gap: 12px; }
  .case-card { margin-bottom: 12px; border-radius: 10px; }
  .case-card-info { padding: 12px 14px; }
  .case-card-info h4 { font-size: 0.85rem; }
  /* 视频 hover 自动播放（移动端静音预览） */
  .case-card:hover video { opacity: 1; }
}

@media (max-width: 768px) {
  .section { padding: 80px 0; }
  .container { padding: 0 20px; }

  .nav-links { display: none; }
  .nav-hamburger { display: flex; }

  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    inset: 68px 0 0 0;
    background: rgba(8, 12, 20, 0.96);
    backdrop-filter: blur(20px);
    padding: 40px 32px;
    gap: 24px;
    z-index: 999;
  }

  .nav-links.open a {
    font-size: 1.1rem;
    color: var(--text-1);
  }

  .hero-headline { font-size: clamp(2.8rem, 10vw, 4rem); }

  .about-stats { gap: 28px; }
  .stat-num { font-size: 2.2rem; }

  .contact-form { padding: 28px 20px; }
  .form-row { grid-template-columns: 1fr; }

  .footer-inner { flex-direction: column; }
  .footer-links { align-items: flex-start; }
}

@media (max-width: 480px) {
  .biz-card { padding: 28px 24px; }
  .tech-item { padding: 32px 24px; }
  .why-accent { margin-right: 20px; }
}