/* ==============================================================================
   DEEPSEEK AURORA POLAR OBSERVATORY THEME (极光横带 · 极地观测站系统)
   色限与参数：
   - 雪 (Snow/Frost): #F4F8FB
   - 极光 (Aurora Glow): #7CFFB2
   - 夜蓝 (Polar Night Blue): #0B1D3A
   - 深夜基底 (Deep Deck): #061122
   - 仪器面板蓝 (Instrument Slate): #0F2548
   - 声呐绿 (Sonar Accent): rgba(0, 229, 160, 1)
   ============================================================================== */

:root {
  --c-snow: #F4F8FB;
  --c-aurora: #7CFFB2;
  --c-night: #0B1D3A;
  --c-abyss: #050E1C;
  --c-deck: #0E2445;
  --c-deck-card: #132D54;
  --c-border: #1C3D6E;
  --c-border-glow: rgba(124, 255, 178, 0.4);
  --c-sonar-green: rgba(0, 229, 160, 1);
  --c-sonar-dim: rgba(0, 229, 160, 0.2);
  --c-text-muted: #8EA4C2;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Cascadia Code", Consolas, "Courier New", monospace;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--c-night);
}

body {
  font-family: var(--font-sans);
  background-color: var(--c-night);
  color: var(--c-snow);
  line-height: 1.6;
  position: relative;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.25s ease;
}

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

/* ==============================================================================
   1. 顶栏：左右分栏
   左边只有 Logo，右边是「API 开放平台」和「English」。
   不承担主导航，首页、网页版、Harness 都没放在这里，入口被下放到首屏卡片和页脚。
   ============================================================================== */
.topbar {
  width: 100%;
  background: rgba(11, 29, 58, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.topbar-inner {
  max-width: 1300px;
  margin: 0 auto;
  padding: 0.85rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand-logo-link {
  display: inline-flex;
  align-items: center;
}

.brand-logo-img {
  height: 38px;
  width: auto;
  object-fit: contain;
  filter: drop-shadow(0 0 10px rgba(124, 255, 178, 0.45));
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 2rem;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  font-weight: 600;
}

.topbar-link {
  color: var(--c-snow);
  padding: 0.35rem 0.75rem;
  border: 1px solid rgba(124, 255, 178, 0.3);
  background: rgba(14, 36, 69, 0.6);
  border-radius: 2px;
}
.topbar-link:hover {
  color: var(--c-aurora);
  border-color: var(--c-aurora);
  box-shadow: 0 0 15px rgba(124, 255, 178, 0.35);
}

.topbar-lang {
  color: var(--c-text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}
.topbar-lang:hover {
  color: var(--c-snow);
}

/* ==============================================================================
   2. 首屏：整页重心
   Canvas 画在上层区域偏右：同心圆、十字线、扫描扇形和回波点，颜色是 rgba(0,229,160) 的声呐绿。
   文字叠在画布上，顺序是公告条、超大标题、副题，然后两张同结构卡片。
   主卡链到 web.html，次卡是空链接。
   两张卡都是「图标、标题、说明、箭头」，差别只在主次样式，布局上是一对等宽入口。
   ============================================================================== */
.hero-section {
  position: relative;
  max-width: 1300px;
  margin: 0 auto;
  padding: 3.5rem 2rem 5rem 2rem;
  min-height: 640px;
  display: flex;
  align-items: center;
}

/* 偏右区域的声呐 Canvas 画布容器 */
.sonar-canvas-wrap {
  position: absolute;
  top: 15px;
  right: 20px;
  width: 580px;
  height: 580px;
  pointer-events: none;
  z-index: 1;
  opacity: 0.95;
  border-radius: 50%;
  box-shadow: 0 0 45px rgba(0, 229, 160, 0.12);
}

/* 叠在画布上的文字流 */
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 760px;
}

.hero-bulletin {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(14, 36, 69, 0.75);
  border: 1px solid var(--c-border);
  border-left: 3px solid var(--c-aurora);
  padding: 0.4rem 1.1rem;
  margin-bottom: 1.8rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--c-snow);
  box-shadow: 0 0 20px rgba(11, 29, 58, 0.5);
}

.bulletin-badge {
  background-color: var(--c-aurora);
  color: var(--c-night);
  padding: 0.15rem 0.5rem;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  border-radius: 2px;
}

/* 超大标题 */
.hero-title {
  font-size: 3.75rem;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--c-snow);
}

.hero-title em {
  font-style: normal;
  display: block;
  font-size: 2.85rem;
  color: var(--c-aurora);
  text-shadow: 0 0 25px rgba(124, 255, 178, 0.45);
  margin-top: 0.35rem;
}

.hero-subtitle {
  font-size: 1.18rem;
  line-height: 1.7;
  color: #BED0E6;
  margin-bottom: 2.25rem;
  max-width: 680px;
}

.hero-subtitle strong {
  color: var(--c-aurora);
  font-weight: 700;
}

/* 两张同结构卡片：等宽入口 */
.hero-cards-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.75rem;
  max-width: 680px;
}

.hero-entry-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.6rem 1.4rem;
  border-radius: 4px;
  position: relative;
  transition: all 0.25s ease;
}

/* 主卡：链到 web.html (极光荧光高亮) */
.hero-entry-card.primary {
  background: linear-gradient(135deg, rgba(14, 36, 69, 0.95), rgba(19, 45, 84, 0.95));
  border: 1px solid var(--c-aurora);
  box-shadow: 0 0 25px rgba(124, 255, 178, 0.2), inset 0 0 15px rgba(124, 255, 178, 0.08);
}
.hero-entry-card.primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 0 35px rgba(124, 255, 178, 0.4), inset 0 0 20px rgba(124, 255, 178, 0.15);
}

/* 次卡：空链接 (深色夜蓝微光) */
.hero-entry-card.secondary {
  background: rgba(14, 36, 69, 0.6);
  border: 1px solid var(--c-border);
  box-shadow: 0 4px 15px rgba(5, 14, 28, 0.5);
  cursor: default;
}
.hero-entry-card.secondary:hover {
  border-color: rgba(124, 255, 178, 0.4);
}

.card-icon-line {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: bold;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}
.hero-entry-card.primary .card-icon-line {
  color: var(--c-aurora);
}
.hero-entry-card.secondary .card-icon-line {
  color: var(--c-text-muted);
}

.card-title {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: var(--c-snow);
}

.card-subtitle {
  font-size: 0.88rem;
  color: var(--c-text-muted);
  line-height: 1.5;
  margin-bottom: 1.25rem;
}

.card-arrow-wrap {
  display: flex;
  justify-content: flex-end;
}
.card-arrow {
  font-size: 1.4rem;
  font-weight: 900;
  font-family: var(--font-mono);
  line-height: 1;
}
.hero-entry-card.primary .card-arrow {
  color: var(--c-aurora);
  text-shadow: 0 0 10px rgba(124, 255, 178, 0.6);
}
.hero-entry-card.secondary .card-arrow {
  color: var(--c-text-muted);
}

/* ==============================================================================
   3. 极光横带 · 极地观测站专属核心区
   布局：顶部 30% 为一条极光，下面是深色操作区。
   设计：极地观测站，横带是唯一色彩。
   骨架：现象带，观测日志，三个仪器。
   配色：雪 #F4F8FB、极光 #7CFFB2、夜蓝 #0B1D3A。
   提示词：DeepSeek AI 观测站。极光带上写「探索未至之境」。日志区是网页版对话。三个仪器命名为 API、Harness、官网。入口按钮在日志末行。色限 #F4F8FB #7CFFB2 #0B1D3A。
   ============================================================================== */
.aurora-observatory-section {
  max-width: 1300px;
  margin: 3.5rem auto 5rem auto;
  padding: 0 2rem;
}

.observatory-deck-container {
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--c-border);
  box-shadow: 0 10px 40px rgba(5, 14, 28, 0.8);
  position: relative;
  background: var(--c-night);
}

/* 顶部 30% 极光现象带 (Aurora Phenomenon Ribbon) - 横带是唯一色彩 */
.aurora-ribbon-band {
  width: 100%;
  height: 260px;
  position: relative;
  background: radial-gradient(ellipse at 50% 120%, rgba(124, 255, 178, 0.95) 0%, rgba(124, 255, 178, 0.65) 30%, rgba(0, 163, 224, 0.25) 60%, rgba(11, 29, 58, 0.98) 100%),
              linear-gradient(90deg, #050E1C 0%, rgba(124, 255, 178, 0.2) 25%, rgba(124, 255, 178, 0.7) 50%, rgba(124, 255, 178, 0.2) 75%, #050E1C 100%);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 2rem;
  border-bottom: 2px solid var(--c-aurora);
  box-shadow: 0 0 50px rgba(124, 255, 178, 0.4);
  overflow: hidden;
}

/* 极光横流动效微粒子 */
.aurora-ribbon-band::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -20%;
  right: -20%;
  bottom: -20%;
  background: radial-gradient(circle at 60% 40%, rgba(124, 255, 178, 0.5) 0%, transparent 50%),
              radial-gradient(circle at 30% 70%, rgba(0, 229, 160, 0.4) 0%, transparent 60%);
  filter: blur(40px);
  opacity: 0.8;
  pointer-events: none;
}

.aurora-telemetry-tag {
  position: relative;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--c-night);
  background: rgba(244, 248, 251, 0.9);
  padding: 0.25rem 0.9rem;
  border-radius: 20px;
  margin-bottom: 1rem;
}

/* 极光带上写「探索未至之境」 */
.aurora-slogan-inscription {
  position: relative;
  z-index: 2;
  font-size: 3rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  color: var(--c-snow);
  text-shadow: 0 0 25px rgba(11, 29, 58, 0.9), 0 0 45px rgba(124, 255, 178, 0.8);
}

.aurora-coord-info {
  position: relative;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--c-night);
  font-weight: 600;
  margin-top: 0.75rem;
}

/* 下面是深色操作区 (Dark Operating Deck) */
.dark-operating-deck {
  background: var(--c-abyss);
  padding: 2.5rem;
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 2.25rem;
}

/* 观测日志区 (日志区是网页版对话，入口按钮在日志末行) */
.observatory-log-panel {
  background: var(--c-deck);
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
}

.log-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 1rem;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--c-border);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--c-text-muted);
}

.log-stream-messages {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 1.75rem;
}

.log-msg-item {
  background: rgba(5, 14, 28, 0.6);
  border: 1px solid var(--c-border);
  padding: 1.1rem 1.25rem;
  border-radius: 3px;
}

.log-msg-user {
  border-left: 3px solid var(--c-snow);
}

.log-msg-ai {
  border-left: 3px solid var(--c-aurora);
  background: rgba(11, 29, 58, 0.8);
}

.msg-meta-line {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  display: flex;
  justify-content: space-between;
}
.log-msg-user .msg-meta-line { color: var(--c-snow); }
.log-msg-ai .msg-meta-line { color: var(--c-aurora); }

.msg-content-text {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--c-snow);
}

/* 入口按钮在日志末行 */
.log-entry-footer-line {
  margin-top: auto;
  padding-top: 1.25rem;
  border-top: 1px dashed var(--c-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.log-entry-btn {
  background: var(--c-aurora);
  color: var(--c-night);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 800;
  padding: 0.75rem 1.75rem;
  border-radius: 3px;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 0 20px rgba(124, 255, 178, 0.35);
}
.log-entry-btn:hover {
  background: #9BFFC6;
  box-shadow: 0 0 30px rgba(124, 255, 178, 0.6);
  transform: translateY(-2px);
}

/* 三个仪器 (API、Harness、官网) */
.three-instruments-panel {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.instrument-card {
  background: var(--c-deck);
  border: 1px solid var(--c-border);
  padding: 1.25rem 1.4rem;
  border-radius: 4px;
  transition: all 0.25s ease;
}
.instrument-card:hover {
  border-color: var(--c-aurora);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(5, 14, 28, 0.6);
}

.instrument-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--c-aurora);
  font-weight: 700;
  letter-spacing: 0.1em;
  margin-bottom: 0.25rem;
}

.instrument-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--c-snow);
  margin-bottom: 0.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.instrument-desc {
  font-size: 0.85rem;
  color: var(--c-text-muted);
  line-height: 1.5;
}

/* ==============================================================================
   4. 能力区：把首屏的声呐从背景变成内容
   四张卡横排，每张仍是图标、标题、一段说明，对应：
   深海扫描、探测未知、知识显影、Harness。
   下面的指标条把四组数字等分排开，用来打断卡片墙，给页面一个横向节奏。
   ============================================================================== */
.capability-section {
  max-width: 1300px;
  margin: 0 auto 5rem auto;
  padding: 0 2rem;
}

.section-lead-title {
  font-size: 2.1rem;
  font-weight: 900;
  color: var(--c-snow);
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-lead-desc {
  font-size: 1.05rem;
  color: var(--c-text-muted);
  margin-bottom: 2.5rem;
}

.capability-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.cap-card {
  background: var(--c-deck);
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: 1.75rem 1.4rem;
  position: relative;
  transition: all 0.25s ease;
}
.cap-card:hover {
  border-color: var(--c-aurora);
  box-shadow: 0 0 25px rgba(124, 255, 178, 0.15);
  transform: translateY(-2px);
}

.cap-icon-box {
  width: 44px;
  height: 44px;
  border: 1px solid var(--c-border);
  background: var(--c-night);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 900;
  margin-bottom: 1.25rem;
  color: var(--c-aurora);
}

.cap-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--c-snow);
  margin-bottom: 0.65rem;
}

.cap-text {
  font-size: 0.9rem;
  color: var(--c-text-muted);
  line-height: 1.6;
}

/* 指标条：四组数字等分排开，打断卡片墙，给页面一个横向节奏 */
.metric-strip-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  background: var(--c-deck);
  border: 1px solid var(--c-border);
  border-radius: 4px;
  box-shadow: 0 4px 20px rgba(5, 14, 28, 0.4);
}

.metric-item {
  padding: 1.75rem 1.5rem;
  border-right: 1px solid var(--c-border);
  text-align: center;
}
.metric-item:last-child {
  border-right: none;
}

.metric-number {
  font-family: var(--font-mono);
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--c-snow);
  line-height: 1.1;
  margin-bottom: 0.35rem;
}

.metric-number.highlight-aurora {
  color: var(--c-aurora);
  text-shadow: 0 0 20px rgba(124, 255, 178, 0.4);
}

.metric-label {
  font-size: 0.85rem;
  color: var(--c-text-muted);
  font-weight: 600;
}

/* ==============================================================================
   5. 步骤区：唯一写了内联布局的区块
   外层灰底拉通全宽，内层再收成 1200px 居中。
   四步竖向排列，左侧数字、右侧标题加说明，和上面的四列网格形成横竖对比。
   ============================================================================== */
.step-section-outer {
  width: 100%;
  background-color: #0E2445;
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
  padding: 4.75rem 0;
}

.step-section-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.step-section-title {
  font-size: 2rem;
  font-weight: 900;
  color: var(--c-snow);
  margin-bottom: 0.35rem;
}

.step-section-desc {
  font-size: 1.05rem;
  color: var(--c-text-muted);
  margin-bottom: 2.75rem;
}

.steps-vertical-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.step-row-item {
  display: flex;
  align-items: flex-start;
  gap: 2rem;
  background: var(--c-night);
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: 1.5rem 2rem;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.step-row-item:hover {
  transform: translateX(4px);
  border-color: var(--c-aurora);
}

.step-left-num {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--c-aurora);
  line-height: 1;
  min-width: 55px;
  text-shadow: 0 0 15px rgba(124, 255, 178, 0.4);
}

.step-right-body {
  flex: 1;
}

.step-right-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--c-snow);
  margin-bottom: 0.35rem;
}

.step-right-desc {
  font-size: 0.95rem;
  color: var(--c-text-muted);
  line-height: 1.55;
}

/* ==============================================================================
   6. API 区：退成单列代码块
   注释、关键字、字符串靠颜色区分，没有左右分栏，也没有请求和响应对照。
   ============================================================================== */
.api-single-col-section {
  max-width: 1100px;
  margin: 5rem auto;
  padding: 0 2rem;
}

.api-terminal-card {
  background: var(--c-abyss);
  border: 1px solid var(--c-border);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(5, 14, 28, 0.6);
}

.api-terminal-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1.25rem;
  background: var(--c-deck);
  border-bottom: 1px solid var(--c-border);
}

.api-term-dots {
  display: flex;
  gap: 0.45rem;
}
.api-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  display: inline-block;
}

.api-term-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--c-text-muted);
}

.api-code-block {
  padding: 1.75rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--c-snow);
}

.code-comment { color: #5D7A9E; font-style: italic; }
.code-keyword { color: var(--c-aurora); font-weight: bold; }
.code-string  { color: #00E5A0; }

/* ==============================================================================
   7. 影像区：四张横图，只做展示，没有图注和点击
   ============================================================================== */
.gallery-section {
  max-width: 1300px;
  margin: 0 auto 5rem auto;
  padding: 0 2rem;
}

.gallery-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.gallery-img-card {
  height: 220px;
  border: 1px solid var(--c-border);
  border-radius: 4px;
  background: var(--c-deck);
  overflow: hidden;
  box-shadow: 0 4px 15px rgba(5, 14, 28, 0.4);
}

.gallery-img-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
  filter: contrast(1.05) brightness(0.95);
}

/* ==============================================================================
   常见问题 FAQ
   ============================================================================== */
.faq-section {
  max-width: 1300px;
  margin: 0 auto 5rem auto;
  padding: 0 2rem;
}

.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.faq-card {
  background: var(--c-deck);
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: 1.5rem 1.75rem;
}

.faq-q {
  font-size: 1.12rem;
  font-weight: 800;
  color: var(--c-snow);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.faq-q::before {
  content: "Q:";
  font-family: var(--font-mono);
  color: var(--c-aurora);
}

.faq-a {
  font-size: 0.92rem;
  color: var(--c-text-muted);
  line-height: 1.6;
}

/* ==============================================================================
   8. 页脚：多列布局
   品牌说明占更宽的一列，后面四列是研究、产品、法务、招聘。
   最底下一整条版权和第三方声明。
   ============================================================================== */
.site-footer {
  width: 100%;
  background-color: var(--c-abyss);
  border-top: 1px solid var(--c-border);
  padding: 4.5rem 0 2rem 0;
}

.footer-inner {
  max-width: 1300px;
  margin: 0 auto;
  padding: 0 2rem;
}

.footer-grid-5 {
  display: grid;
  grid-template-columns: 2.2fr 1fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3.5rem;
}

.footer-brand-col {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-logo {
  height: 38px;
  width: auto;
  object-fit: contain;
  margin-bottom: 0.25rem;
  filter: drop-shadow(0 0 10px rgba(124, 255, 178, 0.3));
}

.footer-brand-p {
  font-size: 0.92rem;
  color: var(--c-text-muted);
  line-height: 1.65;
}

.footer-col h4 {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--c-snow);
  margin-bottom: 1.1rem;
  position: relative;
  display: inline-block;
}
.footer-col h4::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 24px;
  height: 2px;
  background: var(--c-aurora);
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-col a {
  font-size: 0.88rem;
  color: var(--c-text-muted);
}
.footer-col a:hover {
  color: var(--c-aurora);
}

.footer-bottom-line {
  border-top: 1px solid var(--c-border);
  padding-top: 2rem;
  font-size: 0.85rem;
  color: #617A9B;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

/* ==============================================================================
   响应式适配
   ============================================================================== */
@media (max-width: 1024px) {
  .hero-section {
    flex-direction: column;
    padding-top: 2.5rem;
  }
  .sonar-canvas-wrap {
    position: relative;
    top: 0;
    right: 0;
    margin: 0 auto 2rem auto;
    width: 440px;
    height: 440px;
  }
  .dark-operating-deck {
    grid-template-columns: 1fr;
  }
  .capability-grid-4, .metric-strip-4, .gallery-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid-5 {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2.6rem;
  }
  .hero-title em {
    font-size: 2rem;
  }
  .hero-cards-grid {
    grid-template-columns: 1fr;
  }
  .aurora-slogan-inscription {
    font-size: 2.1rem;
  }
  .capability-grid-4, .metric-strip-4, .gallery-grid-4, .faq-grid {
    grid-template-columns: 1fr;
  }
  .metric-item {
    border-right: none;
    border-bottom: 1px solid var(--c-border);
  }
  .sonar-canvas-wrap {
    width: 320px;
    height: 320px;
  }
  .footer-grid-5 {
    grid-template-columns: 1fr;
  }
}