/* ==========================================================================
   AI本相 (AI Explainer) - Design System & Modern Cybernetic Aesthetics
   ========================================================================== */

:root {
  /* Color Tokens */
  --bg-deep: #06070b;
  --bg-surface: #0b0e17;
  --bg-card: rgba(14, 18, 28, 0.75);
  --bg-card-hover: rgba(20, 26, 40, 0.85);
  --bg-glass: rgba(16, 22, 36, 0.6);

  --border-subtle: rgba(255, 255, 255, 0.07);
  --border-highlight: rgba(0, 240, 255, 0.35);
  --border-amber: rgba(255, 183, 0, 0.35);
  --border-emerald: rgba(0, 255, 157, 0.35);

  --text-main: #f0f4fc;
  --text-muted: #8e9bb4;
  --text-dim: #5c6882;

  --cyan-primary: #00f0ff;
  --cyan-glow: rgba(0, 240, 255, 0.25);
  --emerald-accent: #00ff9d;
  --amber-accent: #ffb700;
  --purple-accent: #7928ca;
  --red-accent: #ff4757;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Layout */
  --max-width: 1200px;
  --header-height: 72px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-pill: 9999px;

  /* Shadows & Glows */
  --glow-cyan: 0 0 35px rgba(0, 240, 255, 0.2);
  --glow-amber: 0 0 35px rgba(255, 183, 0, 0.2);
  --shadow-card: 0 12px 36px -10px rgba(0, 0, 0, 0.6);
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 24px);
}

body {
  background-color: var(--bg-deep);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Ambient Background Lights */
.ambient-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(140px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.45;
  animation: floatLight 20s infinite alternate ease-in-out;
}

.glow-1 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0, 240, 255, 0.2) 0%, rgba(121, 40, 202, 0.05) 70%, transparent 100%);
  top: -150px;
  left: 20%;
}

.glow-2 {
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(255, 183, 0, 0.15) 0%, rgba(0, 255, 157, 0.05) 70%, transparent 100%);
  top: 40%;
  right: -200px;
  animation-duration: 25s;
}

.ambient-grid {
  position: fixed;
  inset: 0;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
  mask-image: radial-gradient(ellipse at center, black 40%, transparent 80%);
}

@keyframes floatLight {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(40px, 60px) scale(1.1); }
  100% { transform: translate(-30px, 30px) scale(0.95); }
}

/* Layout Container */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* Typography Helpers */
h1, h2, h3, h4 {
  color: var(--text-main);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.gradient-text {
  background: linear-gradient(135deg, #00f0ff 0%, #00ff9d 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-text-alt {
  background: linear-gradient(135deg, #ffb700 0%, #ff5e3a 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-header {
  margin-bottom: 40px;
}

.section-header.text-center {
  text-align: center;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--cyan-primary);
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
}

.section-subtext {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 680px;
  margin: 12px auto 0;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-pill);
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  font-family: var(--font-sans);
}

.btn-primary {
  background: linear-gradient(135deg, #00f0ff, #00a8ff);
  color: #040810;
  box-shadow: 0 4px 18px rgba(0, 240, 255, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 240, 255, 0.45);
}

.btn-youtube {
  background: rgba(255, 0, 0, 0.12);
  color: #ff4d4d;
  border-color: rgba(255, 0, 0, 0.25);
}

.btn-youtube:hover {
  background: rgba(255, 0, 0, 0.22);
  border-color: rgba(255, 0, 0, 0.45);
  transform: translateY(-2px);
}

.btn-glow {
  background: linear-gradient(135deg, #00f0ff 0%, #00ff9d 100%);
  color: #040810;
  font-weight: 700;
  box-shadow: 0 4px 20px rgba(0, 240, 255, 0.35);
}

.btn-glow:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 240, 255, 0.55);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-main);
  border-color: var(--border-subtle);
  backdrop-filter: blur(8px);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--cyan-primary);
  color: var(--cyan-primary);
  transform: translateY(-2px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
}

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

.btn-large {
  padding: 14px 28px;
  font-size: 1.05rem;
}

.btn-sm {
  padding: 6px 14px;
  font-size: 0.85rem;
}

/* Badges */
.badge {
  display: inline-block;
  padding: 4px 10px;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
}

.badge-amber {
  background: rgba(255, 183, 0, 0.15);
  color: var(--amber-accent);
  border: 1px solid var(--border-amber);
}

.badge-outline {
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-muted);
  border: 1px solid var(--border-subtle);
}

/* ==========================================================================
   Navigation Bar
   ========================================================================== */
.navbar {
  position: sticky;
  top: 0;
  width: 100%;
  height: var(--header-height);
  background: rgba(6, 7, 11, 0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  z-index: 100;
  transition: var(--transition);
}

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

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-chip {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, rgba(0, 240, 255, 0.15), rgba(0, 255, 157, 0.05));
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cyan-primary);
  box-shadow: 0 0 16px rgba(0, 240, 255, 0.2);
}

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

.brand-name {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--text-main);
}

.brand-tag {
  font-size: 0.65rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--cyan-primary);
  letter-spacing: 0.1em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
}

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

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

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  padding: 80px 0 60px;
  text-align: center;
}

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

.badge-wrapper {
  margin-bottom: 24px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 18px;
  background: rgba(0, 240, 255, 0.08);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-pill);
  color: var(--cyan-primary);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
}

.badge-pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan-primary);
  box-shadow: 0 0 10px var(--cyan-primary);
  animation: pulse 2s infinite ease-in-out;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

.hero-title {
  font-size: 3.6rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  max-width: 900px;
}

.hero-subtext {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 780px;
  margin-bottom: 40px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 72px;
  flex-wrap: wrap;
  justify-content: center;
}

/* Metrics Grid */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  width: 100%;
}

.metric-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  text-align: left;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.metric-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--cyan-primary), transparent);
  opacity: 0;
  transition: var(--transition);
}

.metric-card:hover {
  transform: translateY(-3px);
  border-color: rgba(0, 240, 255, 0.2);
  background: var(--bg-card-hover);
}

.metric-card:hover::after {
  opacity: 1;
}

.metric-num {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--cyan-primary);
  margin-bottom: 6px;
  letter-spacing: -0.03em;
}

.metric-label {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 4px;
}

.metric-desc {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ==========================================================================
   Featured Section (EP04 Spotlight)
   ========================================================================== */
.featured-section {
  padding: 60px 0;
}

.featured-card {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 36px;
  background: linear-gradient(145deg, rgba(20, 26, 42, 0.7), rgba(10, 14, 24, 0.9));
  border: 1px solid rgba(255, 183, 0, 0.25);
  border-radius: var(--radius-lg);
  padding: 32px;
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-card), 0 0 40px rgba(255, 183, 0, 0.06);
  position: relative;
  overflow: hidden;
}

.featured-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #ffb700, #ff5e3a);
}

.media-thumb-wrap {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
  aspect-ratio: 16 / 9;
  background: #000;
}

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

.media-thumb-wrap:hover .featured-img {
  transform: scale(1.03);
}

.media-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.7) 0%, transparent 60%);
  display: flex;
  align-items: center;
  justify-content: center;
}

.play-btn-circle {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  background: rgba(255, 0, 0, 0.9);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 24px rgba(255, 0, 0, 0.6);
  transition: var(--transition);
  text-decoration: none;
}

.play-btn-circle:hover {
  transform: scale(1.12);
  background: #ff0000;
  box-shadow: 0 0 35px rgba(255, 0, 0, 0.85);
}

.video-duration {
  position: absolute;
  bottom: 12px;
  right: 12px;
  background: rgba(0, 0, 0, 0.85);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 3px 8px;
  border-radius: 4px;
}

.featured-content {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.featured-badges {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.featured-heading {
  font-size: 1.55rem;
  line-height: 1.35;
  margin-bottom: 14px;
  color: #fff;
}

.featured-summary {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

.takeaways-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 24px;
}

.takeaway-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.03);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border-left: 2px solid var(--amber-accent);
}

.takeaway-icon {
  font-size: 1rem;
}

.featured-foot-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* ==========================================================================
   Episodes Grid Section
   ========================================================================== */
.episodes-section {
  padding: 80px 0;
}

.section-head-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 40px;
  flex-wrap: wrap;
  gap: 20px;
}

.filter-group {
  display: flex;
  gap: 6px;
  background: rgba(255, 255, 255, 0.03);
  padding: 4px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-subtle);
}

.filter-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: var(--transition);
}

.filter-btn.active {
  background: var(--cyan-primary);
  color: #040810;
  box-shadow: 0 2px 10px rgba(0, 240, 255, 0.35);
}

.episodes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 24px;
}

.episode-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  box-shadow: var(--shadow-card);
}

.episode-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 240, 255, 0.3);
  box-shadow: 0 16px 36px -10px rgba(0, 0, 0, 0.7), 0 0 25px rgba(0, 240, 255, 0.1);
}

.card-thumb-wrap {
  position: relative;
  aspect-ratio: 16 / 9;
  background: #000;
  overflow: hidden;
}

.card-thumb {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.35s ease;
}

.episode-card:hover .card-thumb {
  transform: scale(1.04);
}

.card-badge-row {
  position: absolute;
  bottom: 8px;
  left: 8px;
  right: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.card-tag {
  font-size: 0.7rem;
  font-family: var(--font-mono);
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 4px;
  backdrop-filter: blur(8px);
}

.tag-main {
  background: rgba(0, 240, 255, 0.2);
  color: var(--cyan-primary);
  border: 1px solid rgba(0, 240, 255, 0.4);
}

.tag-extra {
  background: rgba(0, 255, 157, 0.2);
  color: var(--emerald-accent);
  border: 1px solid rgba(0, 255, 157, 0.4);
}

.card-duration {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background: rgba(0, 0, 0, 0.85);
  color: #fff;
  padding: 2px 6px;
  border-radius: 4px;
}

.card-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.card-title {
  font-size: 1.15rem;
  line-height: 1.35;
  margin-bottom: 10px;
  color: var(--text-main);
}

.card-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 16px;
  flex-grow: 1;
}

.card-meta {
  display: flex;
  gap: 12px;
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
  margin-bottom: 16px;
}

.card-actions {
  display: flex;
  gap: 10px;
}

/* Upcoming Card */
.card-upcoming {
  border: 1px dashed rgba(255, 255, 255, 0.15);
  background: rgba(14, 18, 28, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 380px;
}

.upcoming-inner {
  padding: 32px 24px;
  text-align: center;
}

.upcoming-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--amber-accent);
  background: rgba(255, 183, 0, 0.1);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  margin-bottom: 16px;
  border: 1px solid rgba(255, 183, 0, 0.25);
}

.upcoming-title {
  font-size: 1.3rem;
  margin-bottom: 12px;
  color: #fff;
}

.upcoming-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  max-width: 280px;
  margin: 0 auto 20px;
}

.upcoming-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cyan-primary);
}

/* ==========================================================================
   Interactive Lab Section
   ========================================================================== */
.lab-section {
  padding: 80px 0;
  background: linear-gradient(180deg, transparent 0%, rgba(0, 240, 255, 0.02) 50%, transparent 100%);
}

.lab-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-top: 48px;
}

.lab-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
}

.lab-card-header {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 24px;
}

.lab-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: rgba(0, 240, 255, 0.12);
  color: var(--cyan-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  border: 1px solid rgba(0, 240, 255, 0.25);
}

.lab-card-title {
  font-size: 1.25rem;
  color: #fff;
  margin-bottom: 4px;
}

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

.chip-preset-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-subtle);
}

.preset-label {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

.chip-btn, .rack-btn {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  font-size: 0.8rem;
  font-family: var(--font-mono);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.chip-btn:hover, .rack-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
}

.chip-btn.active, .rack-btn.active {
  background: rgba(0, 240, 255, 0.18);
  border-color: var(--cyan-primary);
  color: var(--cyan-primary);
}

.lab-controls {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 24px;
}

.control-row {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.control-value {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--cyan-primary);
}

/* Custom Range Slider */
input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--cyan-primary);
  box-shadow: 0 0 12px var(--cyan-primary);
  cursor: pointer;
  transition: transform 0.15s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.25);
}

/* Result Box */
.lab-result-box {
  background: rgba(6, 9, 16, 0.8);
  border: 1px solid rgba(0, 240, 255, 0.2);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-top: auto;
}

.result-metric {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 12px;
}

.result-title {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 600;
}

.result-number {
  font-family: var(--font-mono);
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--cyan-primary);
}

.result-number small {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.result-diagnosis {
  font-size: 0.85rem;
  line-height: 1.6;
  color: #c9d4e8;
  padding-top: 12px;
  border-top: 1px dashed var(--border-subtle);
}

/* Power Metrics Grid */
.power-metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 16px;
}

.power-sub-card {
  background: rgba(6, 9, 16, 0.7);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 14px;
}

.power-sub-title {
  display: block;
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-bottom: 4px;
}

.power-sub-value {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--amber-accent);
}

.power-sub-value small {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Manifesto Section
   ========================================================================== */
.manifesto-section {
  padding: 80px 0;
}

.manifesto-card {
  background: linear-gradient(160deg, rgba(16, 20, 32, 0.85) 0%, rgba(8, 10, 16, 0.95) 100%);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 56px 48px;
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
}

.manifesto-header {
  max-width: 680px;
  margin-bottom: 48px;
}

.manifesto-title {
  font-size: 2.2rem;
  margin-bottom: 12px;
}

.manifesto-sub {
  color: var(--text-muted);
  font-size: 1.05rem;
}

.commitments-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.commit-item {
  position: relative;
}

.commit-num {
  font-family: var(--font-mono);
  font-size: 2.4rem;
  font-weight: 800;
  color: rgba(0, 240, 255, 0.25);
  margin-bottom: 8px;
}

.commit-title {
  font-size: 1.2rem;
  margin-bottom: 12px;
  color: #fff;
}

.commit-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ==========================================================================
   About Section
   ========================================================================== */
.about-section {
  padding: 80px 0;
  border-top: 1px solid var(--border-subtle);
}

.about-container {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 48px;
  align-items: center;
}

.about-avatar-wrap {
  position: relative;
  width: 160px;
  height: 160px;
  margin: 0 auto;
}

.avatar-glow {
  position: absolute;
  inset: -10px;
  background: radial-gradient(circle, rgba(0, 240, 255, 0.4), transparent 70%);
  border-radius: 50%;
  filter: blur(12px);
}

.avatar-box {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: linear-gradient(135deg, #101826, #07090f);
  border: 2px solid var(--border-highlight);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 1;
  box-shadow: 0 0 30px rgba(0, 240, 255, 0.25);
}

.avatar-initials {
  font-family: var(--font-mono);
  font-size: 2.6rem;
  font-weight: 800;
  background: linear-gradient(135deg, #00f0ff, #00ff9d);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.about-content {
  display: flex;
  flex-direction: column;
}

.about-name {
  font-size: 2.4rem;
  margin-bottom: 4px;
}

.about-role {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--cyan-primary);
  margin-bottom: 18px;
}

.about-bio {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.7;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.about-links {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.85rem;
}

.link-divider {
  color: var(--text-dim);
}

.about-location {
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* ==========================================================================
   Subscribe Section
   ========================================================================== */
.subscribe-section {
  padding: 60px 0 100px;
}

.subscribe-card {
  background: radial-gradient(ellipse at bottom, rgba(0, 240, 255, 0.1) 0%, rgba(14, 18, 28, 0.8) 70%);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-lg);
  padding: 64px 32px;
  text-align: center;
  box-shadow: var(--glow-cyan);
}

.subscribe-content {
  max-width: 600px;
  margin: 0 auto;
}

.subscribe-title {
  font-size: 2.2rem;
  margin-bottom: 14px;
}

.subscribe-desc {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 32px;
}

.subscribe-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.input-wrap {
  display: flex;
  gap: 10px;
  background: rgba(6, 7, 11, 0.7);
  padding: 6px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-subtle);
  transition: var(--transition);
}

.input-wrap:focus-within {
  border-color: var(--cyan-primary);
  box-shadow: 0 0 18px rgba(0, 240, 255, 0.25);
}

.input-wrap input {
  flex-grow: 1;
  background: transparent;
  border: none;
  padding: 0 18px;
  color: #fff;
  font-size: 0.95rem;
  font-family: var(--font-sans);
  outline: none;
}

.input-wrap input::placeholder {
  color: var(--text-dim);
}

.form-feedback {
  font-size: 0.85rem;
  font-family: var(--font-mono);
  min-height: 24px;
}

.form-feedback.success {
  color: var(--emerald-accent);
}

.form-feedback.error {
  color: var(--red-accent);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
  border-top: 1px solid var(--border-subtle);
  padding: 40px 0;
  background: var(--bg-deep);
}

.footer-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-brand .brand-name {
  font-size: 1.1rem;
  font-weight: 800;
}

.footer-brand .brand-sub {
  display: block;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.85rem;
  transition: var(--transition);
}

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

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* ==========================================================================
   Modal Reader (沉浸阅读弹窗)
   ========================================================================== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(3, 4, 8, 0.85);
  backdrop-filter: blur(12px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.modal-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-container {
  background: var(--bg-surface);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 860px;
  max-height: 88vh;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.8), var(--glow-cyan);
  transform: translateY(20px);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-backdrop.open .modal-container {
  transform: translateY(0);
}

.modal-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  z-index: 10;
}

.modal-close:hover {
  background: rgba(255, 0, 0, 0.2);
  color: #ff4757;
  border-color: rgba(255, 71, 87, 0.4);
}

.modal-content {
  padding: 40px;
  overflow-y: auto;
  line-height: 1.75;
}

/* Modal Typography & Elements */
.modal-header-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cyan-primary);
  margin-bottom: 8px;
}

.modal-title {
  font-size: 2rem;
  margin-bottom: 16px;
  color: #fff;
  line-height: 1.3;
}

.modal-lead {
  font-size: 1.1rem;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.03);
  padding: 16px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--cyan-primary);
  margin-bottom: 24px;
}

.modal-h3 {
  font-size: 1.25rem;
  color: var(--cyan-primary);
  margin: 28px 0 12px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border-subtle);
}

.modal-chapters {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 24px;
}

.modal-chapter-item {
  display: flex;
  gap: 12px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.modal-chapter-time {
  font-family: var(--font-mono);
  color: var(--amber-accent);
  font-weight: 600;
  min-width: 50px;
}

.modal-code-block {
  background: #040508;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--emerald-accent);
  overflow-x: auto;
  margin: 12px 0 20px;
}

.modal-ref-list {
  padding-left: 20px;
  color: var(--text-muted);
  font-size: 0.88rem;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.modal-actions {
  display: flex;
  gap: 12px;
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border-subtle);
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 2.8rem;
  }
  .metrics-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .featured-card {
    grid-template-columns: 1fr;
  }
  .lab-grid {
    grid-template-columns: 1fr;
  }
  .commitments-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  .hero-title {
    font-size: 2.2rem;
  }
  .hero-subtext {
    font-size: 1.05rem;
  }
  .desktop-only {
    display: none;
  }
  .about-container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .about-links {
    justify-content: center;
  }
  .input-wrap {
    flex-direction: column;
    border-radius: var(--radius-md);
  }
  .input-wrap input {
    padding: 12px;
  }
  .modal-content {
    padding: 24px;
  }
}

/* ==========================================================================
   Dedicated Article Page Styles (专栏独立长文排版与广告位预留)
   ========================================================================== */
.article-page {
  padding: 40px 0 100px;
}

.article-header {
  margin-bottom: 32px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--cyan-primary);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  margin-bottom: 24px;
  transition: var(--transition);
}

.back-link:hover {
  transform: translateX(-4px);
  color: #fff;
}

.article-headline {
  font-size: 2.6rem;
  line-height: 1.25;
  margin-bottom: 16px;
  color: #fff;
}

.article-meta-row {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
  flex-wrap: wrap;
}

.article-video-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.7), 0 0 30px rgba(0, 240, 255, 0.15);
  margin-bottom: 40px;
  border: 1px solid var(--border-subtle);
  background: #000;
}

.article-video-wrap iframe {
  width: 100%;
  height: 100%;
  border: none;
}

.article-lead {
  font-size: 1.15rem;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.03);
  padding: 24px;
  border-radius: var(--radius-md);
  border-left: 4px solid var(--cyan-primary);
  margin-bottom: 40px;
  line-height: 1.8;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #d1dced;
}

.article-body h2 {
  font-size: 1.7rem;
  color: #fff;
  margin: 48px 0 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-subtle);
}

.article-body h3 {
  font-size: 1.3rem;
  color: var(--cyan-primary);
  margin: 32px 0 16px;
}

.article-body p {
  margin-bottom: 20px;
}

.article-body ul, .article-body ol {
  margin: 16px 0 24px 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.article-body blockquote {
  background: rgba(0, 240, 255, 0.04);
  border-left: 3px solid var(--cyan-primary);
  padding: 18px 24px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 28px 0;
  color: #e4edf8;
  font-style: normal;
}

.article-body pre {
  background: #040508;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 20px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--emerald-accent);
  margin: 24px 0;
}

/* Future Google AdSense Slot Placeholder */
.ad-slot-placeholder {
  margin: 40px 0;
  padding: 24px;
  border: 1px dashed rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.015);
  text-align: center;
  color: var(--text-dim);
  font-size: 0.8rem;
  font-family: var(--font-mono);
  letter-spacing: 0.05em;
  min-height: 100px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.ad-slot-placeholder::before {
  content: 'ADVERTISEMENT · 广告位预留';
  font-size: 0.7rem;
  color: rgba(255, 255, 255, 0.25);
}

.article-pagination {
  display: flex;
  justify-content: space-between;
  margin-top: 60px;
  padding-top: 32px;
  border-top: 1px solid var(--border-subtle);
  gap: 16px;
  flex-wrap: wrap;
}

.pag-card {
  display: flex;
  flex-direction: column;
  background: var(--bg-card);
  padding: 16px 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  text-decoration: none;
  transition: var(--transition);
  max-width: 48%;
  flex-grow: 1;
}

.pag-card:hover {
  border-color: var(--cyan-primary);
  transform: translateY(-2px);
}

.pag-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
  margin-bottom: 4px;
}

.pag-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}