/* ===================================================================
   DeepSeek 多模态 AI 风 - 专用样式表 (Multimodal AI Convergence)
   核心设计语言: 文字、图片、音频、视频四模态卡片汇聚，多维感官交互，全域色彩流转
   =================================================================== */

:root {
  --bg-space: #070a12;
  --bg-surface: #0f1523;
  --bg-raised: #151d30;
  --bg-glass: rgba(15, 21, 35, 0.88);
  
  /* 多模态四大色谱 */
  --modal-text: #38bdf8;    /* 文字模态: 智慧天蓝 */
  --modal-vision: #d946ef;  /* 图像模态: 炫光霓紫 */
  --modal-audio: #10b981;   /* 音频模态: 律动翠绿 */
  --modal-video: #f59e0b;   /* 视频模态: 动力琥珀 */

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(56, 189, 248, 0.25);
  --shadow-multimodal: 0 16px 36px rgba(0, 0, 0, 0.5), 0 0 24px rgba(217, 70, 239, 0.08);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", Consolas, Menlo, monospace;
  --container-max: 1200px;
  --radius-card: 12px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-space);
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(56, 189, 248, 0.05) 0%, transparent 40%),
    radial-gradient(circle at 90% 30%, rgba(217, 70, 239, 0.05) 0%, transparent 40%),
    radial-gradient(circle at 30% 80%, rgba(16, 185, 129, 0.04) 0%, transparent 40%),
    radial-gradient(circle at 75% 85%, rgba(245, 158, 11, 0.04) 0%, transparent 40%);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 20px;
}

a {
  color: inherit;
  text-decoration: none;
}

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

/* 多模态通用标签徽章 (Modal Badge) */
.modal-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.5px;
  padding: 3px 10px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
}

.modal-pill.text-tag {
  color: var(--modal-text);
  border-color: rgba(56, 189, 248, 0.35);
  background: rgba(56, 189, 248, 0.1);
}

.modal-pill.vision-tag {
  color: var(--modal-vision);
  border-color: rgba(217, 70, 239, 0.35);
  background: rgba(217, 70, 239, 0.1);
}

.modal-pill.audio-tag {
  color: var(--modal-audio);
  border-color: rgba(16, 185, 129, 0.35);
  background: rgba(16, 185, 129, 0.1);
}

.modal-pill.video-tag {
  color: var(--modal-video);
  border-color: rgba(245, 158, 11, 0.35);
  background: rgba(245, 158, 11, 0.1);
}

/* 标题通用样式 */
.section-title {
  text-align: center;
  margin-bottom: 48px;
  position: relative;
}

.section-title .fusion-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 4px 14px;
  border-radius: 30px;
  background: linear-gradient(90deg, rgba(56,189,248,0.12), rgba(217,70,239,0.12), rgba(16,185,129,0.12), rgba(245,158,11,0.12));
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #e2e8f0;
  margin-bottom: 12px;
  letter-spacing: 0.5px;
}

.section-title h2 {
  font-size: 32px;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.5px;
}

.section-title p {
  color: var(--text-secondary);
  margin-top: 10px;
  font-size: 15px;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

/* ===================================================================
   1. 顶栏 (Top Navigation)
   Logo 靠左，导航居中，主按钮靠右；移动端只留 Logo 和菜单按钮
   =================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-logo img {
  height: 38px;
  width: auto;
}

.logo-badge {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  font-family: var(--font-mono);
  padding: 2px 8px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
}

.dot-cluster {
  display: flex;
  gap: 3px;
}
.dot-cluster span {
  width: 5px;
  height: 5px;
  border-radius: 50%;
}
.dot-cluster .d-t { background: var(--modal-text); }
.dot-cluster .d-v { background: var(--modal-vision); }
.dot-cluster .d-a { background: var(--modal-audio); }
.dot-cluster .d-m { background: var(--modal-video); }

.header-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.header-nav a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all 0.25s;
  padding: 6px 0;
  position: relative;
}

.header-nav a:hover,
.header-nav a.active {
  color: #fff;
}

.header-nav a.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--modal-text), var(--modal-vision));
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, #38bdf8 0%, #a855f7 50%, #ec4899 100%);
  color: #ffffff;
  font-weight: 600;
  font-size: 14px;
  padding: 10px 22px;
  border-radius: 8px;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 4px 16px rgba(168, 85, 247, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(236, 72, 153, 0.4);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 20px;
  border-radius: 8px;
  transition: all 0.25s;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.25);
}

.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border-subtle);
  color: #fff;
  padding: 8px;
  border-radius: 6px;
  cursor: pointer;
}

/* ===================================================================
   2. 首屏 (Hero)
   左文右图，约 560px + 584px；文案在上，界面在下
   =================================================================== */
.hero-section {
  padding: 64px 0 80px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 560px 584px;
  gap: 36px;
  align-items: center;
  justify-content: space-between;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.hero-pills {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.hero-title {
  font-size: 42px;
  line-height: 1.25;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.5px;
}

.gradient-multimodal {
  background: linear-gradient(135deg, #38bdf8 0%, #c084fc 35%, #f472b6 70%, #fbbf24 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-top: 6px;
}

/* 首屏右侧：多模态卡片汇聚工作台 (Four Modality Cards Converging) */
.hero-convergence-frame {
  position: relative;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 20px;
  box-shadow: var(--shadow-multimodal);
  overflow: hidden;
}

.convergence-backdrop-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

/* 四张代表性模态聚合卡 */
.modal-stream-card {
  background: var(--bg-raised);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  position: relative;
  transition: all 0.3s;
}

.modal-stream-card:hover {
  transform: translateY(-3px);
  border-color: rgba(255, 255, 255, 0.3);
}

.modal-stream-card.text-box {
  border-top: 3px solid var(--modal-text);
}
.modal-stream-card.vision-box {
  border-top: 3px solid var(--modal-vision);
}
.modal-stream-card.audio-box {
  border-top: 3px solid var(--modal-audio);
}
.modal-stream-card.video-box {
  border-top: 3px solid var(--modal-video);
}

.card-header-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.stream-preview {
  height: 90px;
  border-radius: 6px;
  background: #080c14;
  overflow: hidden;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.stream-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.text-code-preview {
  font-family: var(--font-mono);
  font-size: 11px;
  color: #7dd3fc;
  padding: 8px;
  line-height: 1.4;
  width: 100%;
  height: 100%;
  background: rgba(56, 189, 248, 0.05);
}

.audio-wave-preview {
  display: flex;
  align-items: center;
  gap: 3px;
  height: 40px;
  padding: 0 10px;
}

.audio-wave-preview span {
  width: 4px;
  background: var(--modal-audio);
  border-radius: 2px;
  animation: wave-anim 1.4s ease-in-out infinite alternate;
}

.audio-wave-preview span:nth-child(2) { animation-delay: 0.2s; height: 32px; }
.audio-wave-preview span:nth-child(3) { animation-delay: 0.4s; height: 18px; }
.audio-wave-preview span:nth-child(4) { animation-delay: 0.1s; height: 28px; }
.audio-wave-preview span:nth-child(5) { animation-delay: 0.5s; height: 36px; }
.audio-wave-preview span:nth-child(6) { animation-delay: 0.3s; height: 22px; }

@keyframes wave-anim {
  0% { transform: scaleY(0.4); opacity: 0.6; }
  100% { transform: scaleY(1.2); opacity: 1; }
}

.video-play-preview {
  width: 100%;
  height: 100%;
  position: relative;
}
.play-badge-center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 28px;
  height: 28px;
  background: rgba(0,0,0,0.6);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--modal-video);
  font-size: 12px;
  border: 1px solid var(--modal-video);
}

/* 汇聚中心 Hub */
.convergence-hub-footer {
  margin-top: 14px;
  background: #080c14;
  border: 1px dashed rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
}

.hub-status {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
}

.hub-status .pulse-circle {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 8px #10b981;
}

/* ===================================================================
   3. 能力 (Capabilities)
   居中标题 + 四列实心卡片；768px 以下两列，480px 以下一列
   =================================================================== */
.cap-section {
  padding: 80px 0;
}

.cap-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.cap-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.cap-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 255, 255, 0.25);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.4);
}

.cap-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  opacity: 0.8;
}

.cap-card.text-type::before { background: var(--modal-text); }
.cap-card.vision-type::before { background: var(--modal-vision); }
.cap-card.audio-type::before { background: var(--modal-audio); }
.cap-card.video-type::before { background: var(--modal-video); }

.cap-icon-box {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
}

.cap-card.text-type .cap-icon-box { color: var(--modal-text); border-color: rgba(56,189,248,0.3); }
.cap-card.vision-type .cap-icon-box { color: var(--modal-vision); border-color: rgba(217,70,239,0.3); }
.cap-card.audio-type .cap-icon-box { color: var(--modal-audio); border-color: rgba(16,185,129,0.3); }
.cap-card.video-type .cap-icon-box { color: var(--modal-video); border-color: rgba(245,158,11,0.3); }

.cap-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
}

.cap-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
}

.cap-card-footer {
  margin-top: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-secondary);
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
}

/* ===================================================================
   4. 场景 (Scenarios)
   居中标题 + 五列卡片，背景抬起；移动端一列
   =================================================================== */
.scene-section {
  padding: 80px 0;
  background: var(--bg-raised);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

.scene-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 18px;
}

.scene-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 24px 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: all 0.25s;
  position: relative;
}

.scene-card:hover {
  transform: translateY(-3px);
  border-color: rgba(255, 255, 255, 0.3);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.35);
}

.scene-card .scene-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--modal-text);
}

.scene-card h3 {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
}

.scene-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* ===================================================================
   5. 产品 (Products)
   居中标题 + 四列描边卡片；同能力区（768px 两列，480px 一列）
   =================================================================== */
.prod-section {
  padding: 80px 0;
}

.prod-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.prod-card {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-card);
  padding: 28px 22px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: all 0.3s;
  position: relative;
}

.prod-card:hover {
  background: rgba(255, 255, 255, 0.02);
  border-color: rgba(255, 255, 255, 0.4);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.3);
}

.prod-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.prod-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
}

.prod-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
}

.prod-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 13px;
  color: #cbd5e1;
}

.prod-features li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.prod-features li::before {
  content: "✦";
  font-size: 11px;
  color: var(--modal-vision);
}

/* ===================================================================
   6. 接入 (Integration)
   左文右图，背景抬起；移动端文案在上，示意图在下
   =================================================================== */
.integrate-section {
  padding: 80px 0;
  background: var(--bg-raised);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

.integrate-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.integrate-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.integrate-content h2 {
  font-size: 30px;
  font-weight: 800;
  color: #fff;
}

.integrate-content p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.integrate-steps {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 8px;
}

.step-card {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 14px 18px;
}

.step-badge {
  font-family: var(--font-mono);
  font-size: 12px;
  color: #fff;
  background: linear-gradient(135deg, var(--modal-text), var(--modal-vision));
  padding: 4px 10px;
  border-radius: 4px;
}

.step-info h4 {
  font-size: 15px;
  font-weight: 600;
  color: #fff;
}

.step-info p {
  font-size: 13px;
  color: var(--text-secondary);
}

.integrate-preview {
  position: relative;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 12px;
  box-shadow: var(--shadow-multimodal);
}

.integrate-preview img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  border-radius: 8px;
}

/* ===================================================================
   7. 下载 (Download)
   左图右文；移动端图在上，文案在下
   =================================================================== */
.download-section {
  padding: 80px 0;
}

.download-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.download-preview {
  position: relative;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 10px;
  background: var(--bg-surface);
  box-shadow: var(--shadow-multimodal);
}

.download-preview img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  border-radius: 8px;
}

.download-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.download-content h2 {
  font-size: 30px;
  font-weight: 800;
  color: #fff;
}

.download-content p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.download-clients {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 8px;
}

.client-item {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  padding: 12px 16px;
  border-radius: 8px;
  transition: all 0.25s;
}

.client-item:hover {
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.05);
}

.client-icon {
  font-size: 20px;
  color: var(--modal-text);
}

.client-details h4 {
  font-size: 14px;
  color: #fff;
}

.client-details span {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-secondary);
}

/* ===================================================================
   8. 数据 (Metrics)
   四格数字 + 下面一条通栏按钮；移动端数字先两列再一列，按钮区上下排
   =================================================================== */
.metrics-section {
  padding: 80px 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-bottom: 36px;
}

.metric-item {
  background: var(--bg-space);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 24px 20px;
  text-align: center;
  transition: all 0.25s;
}

.metric-item:hover {
  border-color: rgba(255, 255, 255, 0.3);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.metric-num {
  font-family: var(--font-mono);
  font-size: 38px;
  font-weight: 800;
  line-height: 1.1;
  background: linear-gradient(135deg, #38bdf8, #c084fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.metric-unit {
  font-size: 18px;
  color: #cbd5e1;
}

.metric-title {
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  margin-top: 8px;
}

.metric-sub {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
}

.metrics-banner {
  background: linear-gradient(90deg, rgba(56, 189, 248, 0.1), rgba(217, 70, 239, 0.1), rgba(245, 158, 11, 0.1));
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-card);
  padding: 20px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.banner-desc h4 {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
}

.banner-desc p {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ===================================================================
   9. 问答 (FAQ)
   居中标题，内容收窄到约 840px，问题竖排；保持单列，工具条改为上下排
   =================================================================== */
.faq-section {
  padding: 80px 0;
}

.faq-container {
  max-width: 840px;
  margin: 0 auto;
}

.faq-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
  padding: 12px 18px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
}

.faq-filters {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-pill {
  font-size: 12px;
  padding: 4px 14px;
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  border-radius: 20px;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-pill.active,
.filter-pill:hover {
  border-color: var(--modal-text);
  color: #fff;
  background: rgba(56, 189, 248, 0.12);
}

.faq-search {
  display: flex;
  align-items: center;
  background: var(--bg-space);
  border: 1px solid var(--border-subtle);
  padding: 6px 14px;
  border-radius: 6px;
  font-size: 13px;
  color: var(--text-secondary);
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 20px 24px;
  transition: all 0.25s;
}

.faq-item:hover {
  border-color: rgba(255, 255, 255, 0.25);
}

.faq-q {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
}

.faq-a {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-top: 10px;
  padding-left: 20px;
  border-left: 2px solid rgba(56, 189, 248, 0.3);
}

/* ===================================================================
   10. 资讯 (News)
   六张横卡竖排，左图约 320px，右文占剩余；图缩小，再往下改成图在上、文在下
   =================================================================== */
.news-section {
  padding: 80px 0;
  background: var(--bg-raised);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

.news-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.news-card {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 28px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  overflow: hidden;
  transition: all 0.3s;
}

.news-card:hover {
  border-color: rgba(255, 255, 255, 0.3);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.35);
}

.news-media {
  position: relative;
  overflow: hidden;
  height: 200px;
}

.news-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s;
}

.news-card:hover .news-media img {
  transform: scale(1.05);
}

.news-content {
  padding: 20px 24px 20px 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 10px;
}

.news-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-secondary);
}

.news-content h3 {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  transition: color 0.2s;
}

.news-card:hover .news-content h3 {
  color: var(--modal-text);
}

.news-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.news-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--modal-text);
  font-weight: 600;
  margin-top: 4px;
}

/* ===================================================================
   11. 页脚 (Footer)
   品牌简介约 1.6 份，后面三列链接各 1 份；先两列，再一列
   =================================================================== */
.site-footer {
  background: #04070e;
  border-top: 1px solid var(--border-subtle);
  padding: 64px 0 32px;
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 36px;
  margin-bottom: 48px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.footer-brand img {
  height: 36px;
  width: auto;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.7;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 16px;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col ul a {
  color: var(--text-secondary);
  transition: all 0.2s;
}

.footer-col ul a:hover {
  color: #fff;
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid var(--border-subtle);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: #64748b;
  font-size: 12px;
  font-family: var(--font-mono);
}

/* ===================================================================
   响应式断点系统 (Strict Responsive Design)
   =================================================================== */

@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .integrate-grid,
  .download-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  .scene-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* 768px 平板竖屏 */
@media (max-width: 768px) {
  /* 顶栏: 只留 Logo 和菜单按钮 */
  .header-nav,
  .header-actions .btn-primary {
    display: none;
  }
  .menu-toggle {
    display: block;
  }

  /* 首屏: 文案在上，界面在下 */
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .hero-title {
    font-size: 32px;
  }

  /* 能力: 768px 以下两列 */
  .cap-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 场景: 背景抬起，移动端一列 */
  .scene-grid {
    grid-template-columns: 1fr;
  }

  /* 产品: 同能力区 (768px 两列) */
  .prod-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 接入: 文案在上，示意图在下 */
  .integrate-grid {
    grid-template-columns: 1fr;
  }

  /* 下载: 图在上，文案在下 */
  .download-grid {
    grid-template-columns: 1fr;
  }
  .download-preview {
    order: -1;
  }

  /* 数据: 数字先两列，按钮区上下排 */
  .metrics-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .metrics-banner {
    flex-direction: column;
    align-items: flex-start;
  }

  /* 问答: 工具条改为上下排 */
  .faq-toolbar {
    flex-direction: column;
    align-items: stretch;
  }

  /* 资讯: 图缩小 (约 220px) */
  .news-card {
    grid-template-columns: 220px 1fr;
  }

  /* 页脚: 先两列 */
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}

/* 480px 移动端小屏 */
@media (max-width: 480px) {
  .hero-title {
    font-size: 26px;
  }
  .hero-actions {
    flex-direction: column;
  }

  /* 能力: 480px 以下一列 */
  .cap-grid {
    grid-template-columns: 1fr;
  }

  /* 产品: 同能力区 (480px 一列) */
  .prod-grid {
    grid-template-columns: 1fr;
  }

  /* 数据: 数字再一列 */
  .metrics-grid {
    grid-template-columns: 1fr;
  }

  /* 资讯: 再往下改成图在上、文在下 */
  .news-card {
    grid-template-columns: 1fr;
  }
  .news-content {
    padding: 0 20px 20px 20px;
  }
  .news-media {
    height: 180px;
  }

  /* 页脚: 再一列 */
  .footer-grid {
    grid-template-columns: 1fr;
  }
}