/* ==========================================================================
   Mitce VPN - Precision Swiss-Engineered Tech & Aerodynamic Obsidian Design System
   Pure Native CSS | Zero External Dependencies | High-Contrast Telemetry
   ========================================================================== */

:root {
  /* Color Palette - Precision Daylight (Default Mode) */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-surface: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.88);
  --bg-glass-card: rgba(255, 255, 255, 0.82);
  --bg-telemetry: #0f172a;
  --bg-oscilloscope: #060911;

  --text-primary: #0a0d14;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --text-inverse: #ffffff;

  /* Precision Accents */
  --accent-cobalt: #2563eb;
  --accent-cobalt-hover: #1d4ed8;
  --accent-cyan: #06b6d4;
  --accent-cyan-glow: rgba(6, 182, 212, 0.35);
  --accent-cobalt-glow: rgba(37, 99, 235, 0.28);
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;

  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #1d4ed8 45%, #06b6d4 100%);
  --accent-gradient-cyan: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);

  /* Technical Hairlines & Borders */
  --border-hairline: rgba(226, 232, 240, 0.9);
  --border-tech: rgba(148, 163, 184, 0.35);
  --border-glow: rgba(37, 99, 235, 0.4);

  /* Elevation & Telemetry Shadows */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.07), 0 2px 4px -2px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, 0.1), 0 8px 10px -6px rgba(15, 23, 42, 0.05);
  --shadow-laser: 0 0 24px rgba(6, 182, 212, 0.2);

  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;

  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --container-max: 1240px;

  --cursor-x: 50%;
  --cursor-y: 50%;
}

/* Dark Mode - Deep Stealth Obsidian Velocity (#0a0d14) */
[data-theme="dark"] {
  --bg-primary: #0a0d14;
  --bg-secondary: #0f1422;
  --bg-tertiary: #141c2e;
  --bg-surface: #111827;
  --bg-glass: rgba(10, 13, 20, 0.88);
  --bg-glass-card: rgba(15, 20, 34, 0.75);
  --bg-telemetry: #05080f;
  --bg-oscilloscope: #040710;

  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --text-inverse: #0a0d14;

  --border-hairline: rgba(30, 41, 59, 0.85);
  --border-tech: rgba(51, 65, 85, 0.7);
  --border-glow: rgba(6, 182, 212, 0.45);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 10px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 12px 24px rgba(0, 0, 0, 0.6);
  --shadow-xl: 0 24px 38px rgba(0, 0, 0, 0.75);
  --shadow-laser: 0 0 32px rgba(6, 182, 212, 0.25);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1), color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

/* Fine Hairline Technical Grid Background */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: 
    linear-gradient(to right, var(--border-hairline) 1px, transparent 1px),
    linear-gradient(to bottom, var(--border-hairline) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(circle at 50% 20%, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(circle at 50% 20%, black 30%, transparent 80%);
  opacity: 0.35;
  z-index: 0;
}

/* Precision Cursor Ambient Light Sheen */
.cursor-light-sheen {
  position: fixed;
  top: 0;
  left: 0;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  pointer-events: none;
  background: radial-gradient(circle, var(--accent-cyan-glow) 0%, transparent 70%);
  transform: translate(calc(var(--cursor-x) - 250px), calc(var(--cursor-y) - 250px));
  transition: opacity 0.3s ease;
  z-index: 1;
  opacity: 0.45;
  filter: blur(50px);
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.15s ease, opacity 0.15s ease;
}

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

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

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

/* ==========================================================================
   Precision Mechanical Press Feedback Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.94rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-align: center;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.1s ease, background-color 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
  position: relative;
  user-select: none;
}

/* 2px Diagonal Mechanical Press Feedback on Click */
.btn:active {
  transform: translate(2px, 2px) !important;
  box-shadow: none !important;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 4px 14px var(--accent-cobalt-glow), inset 0 1px 0 rgba(255, 255, 255, 0.25);
}

.btn-primary:hover {
  box-shadow: 0 6px 20px var(--accent-cobalt-glow), 0 0 15px var(--accent-cyan-glow);
  filter: brightness(1.05);
}

.btn-secondary {
  background: var(--bg-surface);
  color: var(--text-primary);
  border: 1px solid var(--border-tech);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cobalt);
  box-shadow: 0 2px 10px rgba(6, 182, 212, 0.15);
}

.btn-lg {
  padding: 15px 32px;
  font-size: 1.05rem;
  border-radius: var(--radius-md);
}

.btn-block {
  width: 100%;
}

.btn-telemetry {
  background: rgba(6, 182, 212, 0.08);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.35);
  font-family: var(--font-mono);
  font-size: 0.88rem;
}

.btn-telemetry:hover {
  background: rgba(6, 182, 212, 0.16);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 12px var(--accent-cyan-glow);
}

/* ==========================================================================
   Top Frosted Glass Navbar - Precision Swiss-Engineered Layout
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-hairline);
  transition: background-color 0.3s ease, border-color 0.3s ease;
  width: 100%;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 clamp(16px, 2.5vw, 32px);
  gap: 16px;
  box-sizing: border-box;
}

.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
  text-decoration: none;
  flex-shrink: 0;
  white-space: nowrap;
}

.brand-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--accent-gradient);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  box-shadow: 0 2px 10px var(--accent-cobalt-glow);
  border: 1px solid rgba(255, 255, 255, 0.2);
  flex-shrink: 0;
}

.brand-name {
  color: var(--text-primary);
  font-weight: 800;
  white-space: nowrap;
  display: inline-block;
  line-height: 1;
}

.brand-tagline {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.1);
  padding: 3px 8px;
  border-radius: var(--radius-xs);
  border: 1px solid rgba(6, 182, 212, 0.28);
  letter-spacing: 0.04em;
  white-space: nowrap;
  display: inline-block;
  line-height: 1.2;
  flex-shrink: 0;
}

.nav-menu {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(8px, 1.1vw, 20px);
  margin: 0 auto;
  padding: 0;
  list-style: none;
  flex: 1 1 auto;
  white-space: nowrap;
}

.nav-link {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
  position: relative;
  padding: 6px 3px;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  line-height: 1.4;
  flex-shrink: 0;
  transition: color 0.15s ease;
}

.nav-link:hover {
  color: var(--accent-cobalt);
}

[data-theme="dark"] .nav-link:hover {
  color: var(--accent-cyan);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--accent-cyan);
  transition: width 0.2s ease;
  box-shadow: 0 0 6px var(--accent-cyan);
}

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

/* Badge for "推荐资讯" entry */
.nav-badge-new {
  font-size: 0.65rem;
  background: var(--accent-gradient);
  color: #fff;
  padding: 1px 5px;
  border-radius: var(--radius-xs);
  margin-left: 5px;
  font-weight: 700;
  vertical-align: middle;
  line-height: 1.2;
  display: inline-block;
  box-shadow: 0 0 6px var(--accent-cyan-glow);
  white-space: nowrap;
}

.nav-actions {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
  white-space: nowrap;
}

.theme-toggle-btn {
  position: relative;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-tech);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
  flex-shrink: 0;
}

.theme-toggle-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  box-shadow: 0 0 10px var(--accent-cyan-glow);
  transform: translateY(-1px);
}

.theme-toggle-btn:active {
  transform: translate(2px, 2px);
}

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
}

.theme-icon-sun { display: block; }
.theme-icon-moon { display: none; }
[data-theme="dark"] .theme-icon-sun { display: none; }
[data-theme="dark"] .theme-icon-moon { display: block; }

.mobile-toggle-btn {
  display: none;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-tech);
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
}

/* ==========================================================================
   Hero Section & Interactive Precision Oscilloscope
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 70px 0 60px;
  overflow: hidden;
}

.hero-glow-trace {
  position: absolute;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 450px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.15) 0%, rgba(6, 182, 212, 0.12) 40%, transparent 70%);
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
}

[data-theme="dark"] .hero-glow-trace {
  background: radial-gradient(circle, rgba(37, 99, 235, 0.25) 0%, rgba(6, 182, 212, 0.18) 45%, transparent 75%);
}

.hero-content {
  text-align: center;
  max-width: 920px;
  margin: 0 auto;
}

.hero-telemetry-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: rgba(6, 182, 212, 0.08);
  border: 1px solid rgba(6, 182, 212, 0.3);
  color: var(--accent-cyan);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.telemetry-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 8px #10b981;
  animation: pulseBeacon 1.8s infinite;
}

@keyframes pulseBeacon {
  0% { transform: scale(0.9); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.9); opacity: 0.8; }
}

.hero-title {
  font-size: clamp(2.3rem, 5vw, 3.8rem);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.035em;
  color: var(--text-primary);
  margin-bottom: 18px;
}

.hero-title .brand-highlight {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-title .laser-text {
  color: var(--accent-cyan);
  text-shadow: 0 0 20px var(--accent-cyan-glow);
}

.hero-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 760px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

/* ==========================================================================
   Interactive Widget: Precision Latency Oscilloscope (专线延迟示波器)
   ========================================================================== */
.oscilloscope-card {
  background: var(--bg-oscilloscope);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl), var(--shadow-laser);
  overflow: hidden;
  position: relative;
  text-align: left;
  margin: 0 auto;
  color: #e2e8f0;
}

.oscilloscope-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: rgba(255, 255, 255, 0.03);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.oscilloscope-title-group {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.86rem;
  color: var(--accent-cyan);
}

.oscilloscope-title-group svg {
  width: 16px;
  height: 16px;
}

.oscilloscope-node-tabs {
  display: flex;
  gap: 6px;
}

.node-tab-btn {
  padding: 6px 14px;
  border-radius: var(--radius-xs);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: #94a3b8;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid transparent;
  transition: all 0.15s ease;
}

.node-tab-btn:hover {
  color: #f8fafc;
  border-color: rgba(6, 182, 212, 0.4);
}

.node-tab-btn.active {
  background: rgba(6, 182, 212, 0.15);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  box-shadow: 0 0 10px var(--accent-cyan-glow);
}

/* Oscilloscope Canvas & Wave Display */
.oscilloscope-body {
  position: relative;
  height: 170px;
  background: 
    linear-gradient(rgba(6, 182, 212, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(6, 182, 212, 0.05) 1px, transparent 1px);
  background-size: 20px 20px;
}

#oscilloscopeCanvas {
  width: 100%;
  height: 100%;
  display: block;
}

.oscilloscope-metrics-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 14px 20px;
  background: rgba(255, 255, 255, 0.02);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-family: var(--font-mono);
}

.scope-metric-item {
  display: flex;
  flex-direction: column;
}

.scope-metric-label {
  font-size: 0.74rem;
  color: #64748b;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.scope-metric-value {
  font-size: 1.15rem;
  font-weight: 700;
  color: #38bdf8;
  margin-top: 2px;
}

.scope-metric-value.green {
  color: #34d399;
}

/* ==========================================================================
   Section Headers (Technical Precision)
   ========================================================================== */
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 52px;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.08);
  padding: 4px 12px;
  border-radius: var(--radius-xs);
  border: 1px solid rgba(6, 182, 212, 0.25);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.85rem, 3.5vw, 2.5rem);
  font-weight: 900;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin-bottom: 14px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ==========================================================================
   Engineering Core Grid (4 Precision Glass Cards)
   ========================================================================== */
.section-engineering {
  padding: 90px 0;
}

.engineering-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}

.engine-card {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  padding: 30px 24px;
  position: relative;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.engine-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-lg), 0 0 20px var(--accent-cyan-glow);
}

.engine-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.engine-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  background: rgba(37, 99, 235, 0.08);
  border: 1px solid rgba(37, 99, 235, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cobalt);
}

[data-theme="dark"] .engine-icon {
  background: rgba(6, 182, 212, 0.1);
  border-color: rgba(6, 182, 212, 0.3);
  color: var(--accent-cyan);
}

.engine-icon svg {
  width: 24px;
  height: 24px;
}

.engine-index {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 700;
}

.engine-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.engine-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.engine-spec-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px dashed var(--border-hairline);
  font-size: 0.84rem;
  color: var(--text-secondary);
}

.engine-spec-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.engine-spec-item svg {
  width: 14px;
  height: 14px;
  color: var(--accent-emerald);
  flex-shrink: 0;
}

/* ==========================================================================
   Real-Time Node Status Board (实时专线节点矩阵大盘)
   ========================================================================== */
.section-telemetry {
  padding: 80px 0;
  background-color: var(--bg-tertiary);
  transition: background-color 0.3s ease;
}

.telemetry-board {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.telemetry-board-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-hairline);
  flex-wrap: wrap;
  gap: 12px;
}

.board-status-live {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--accent-emerald);
}

.board-status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-emerald);
  box-shadow: 0 0 8px var(--accent-emerald);
  animation: pulseBeacon 2s infinite;
}

.telemetry-table-wrapper {
  overflow-x: auto;
}

.telemetry-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  text-align: left;
}

.telemetry-table th {
  padding: 14px 20px;
  background: var(--bg-tertiary);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  border-bottom: 1px solid var(--border-hairline);
}

.telemetry-table td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-hairline);
  color: var(--text-primary);
}

.telemetry-table tr:hover td {
  background-color: rgba(6, 182, 212, 0.03);
}

.cluster-name {
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.flag-tag {
  display: inline-block;
  font-size: 0.76rem;
  font-family: var(--font-mono);
  padding: 2px 6px;
  border-radius: var(--radius-xs);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-tech);
  color: var(--text-secondary);
}

.ping-tag {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent-emerald);
}

.sla-tag {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--accent-cyan);
}

.status-pill-active {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: rgba(16, 185, 129, 0.1);
  color: #10b981;
  border: 1px solid rgba(16, 185, 129, 0.3);
  font-weight: 600;
}

/* ==========================================================================
   Specialized Media & AI Showcase Cards
   ========================================================================== */
.section-showcase {
  padding: 90px 0;
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.showcase-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  padding: 36px;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  transition: all 0.25s ease;
  box-shadow: var(--shadow-sm);
}

.showcase-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--accent-cyan);
}

.showcase-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
}

.showcase-streaming::before {
  background: linear-gradient(90deg, #ea580c, #ec4899);
}

.showcase-ai::before {
  background: linear-gradient(90deg, #3b82f6, #06b6d4);
}

.showcase-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
  width: fit-content;
}

.showcase-streaming .showcase-badge {
  background: rgba(234, 88, 12, 0.1);
  color: #ea580c;
  border: 1px solid rgba(234, 88, 12, 0.3);
}

.showcase-ai .showcase-badge {
  background: rgba(6, 182, 212, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.3);
}

.showcase-title {
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.showcase-desc {
  font-size: 0.96rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 24px;
}

.showcase-tags-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 26px;
}

.app-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: var(--radius-xs);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-hairline);
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: transform 0.15s ease;
}

.app-pill:hover {
  transform: translateY(-2px);
  border-color: var(--accent-cyan);
}

.app-pill svg {
  width: 18px;
  height: 18px;
}

.showcase-features-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 28px;
  flex-grow: 1;
}

.showcase-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.showcase-feature-item svg {
  width: 17px;
  height: 17px;
  color: var(--accent-emerald);
  margin-top: 3px;
  flex-shrink: 0;
}

/* ==========================================================================
   Aerospace-Grade Pricing Cards (真实参考资费)
   ========================================================================== */
.section-pricing {
  padding: 90px 0;
  background-color: var(--bg-tertiary);
  transition: background-color 0.3s ease;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  padding: 38px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.25s ease;
  box-shadow: var(--shadow-sm);
}

.pricing-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--accent-cobalt);
}

.pricing-card.featured {
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-xl), 0 0 25px var(--accent-cyan-glow);
  transform: scale(1.02);
  z-index: 2;
}

.pricing-card.featured:hover {
  transform: scale(1.04) translateY(-4px);
}

.pricing-ribbon {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-gradient);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  letter-spacing: 0.05em;
  box-shadow: 0 4px 12px var(--accent-cobalt-glow);
  white-space: nowrap;
}

.pricing-name {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.pricing-tagline {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 22px;
}

.pricing-price-box {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-hairline);
  font-family: var(--font-mono);
}

.currency-sym {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent-cobalt);
}

[data-theme="dark"] .currency-sym {
  color: var(--accent-cyan);
}

.price-val {
  font-size: 2.8rem;
  font-weight: 900;
  color: var(--text-primary);
  line-height: 1;
}

.price-period {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.pricing-features-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-feature {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.pricing-feature svg {
  width: 16px;
  height: 16px;
  color: var(--accent-emerald);
  flex-shrink: 0;
}

.pricing-guarantee {
  margin-top: 14px;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* ==========================================================================
   User Testimonials / Reviews
   ========================================================================== */
.section-reviews {
  padding: 90px 0;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.review-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  padding: 30px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: all 0.2s ease;
}

.review-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-md);
}

.review-stars {
  display: flex;
  gap: 4px;
  color: #f59e0b;
  margin-bottom: 16px;
}

.review-stars svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.review-comment {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 22px;
  flex-grow: 1;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px solid var(--border-hairline);
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-weight: 700;
  font-size: 0.95rem;
}

.user-meta-name {
  font-weight: 700;
  font-size: 0.94rem;
  color: var(--text-primary);
}

.user-meta-role {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Interactive FAQ Section
   ========================================================================== */
.section-faq {
  padding: 90px 0;
  background-color: var(--bg-tertiary);
  transition: background-color 0.3s ease;
}

.faq-container {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item:hover {
  border-color: var(--accent-cyan);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  text-align: left;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--text-primary);
  background: none;
  cursor: pointer;
  user-select: none;
}

.faq-icon {
  width: 18px;
  height: 18px;
  color: var(--text-muted);
  transition: transform 0.25s ease;
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
  color: var(--accent-cyan);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out, padding 0.3s ease-out;
  padding: 0 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 320px;
  padding: 0 24px 20px 24px;
}

/* ==========================================================================
   Final CTA Banner
   ========================================================================== */
.section-final-cta {
  padding: 70px 0 90px;
}

.cta-banner {
  background: var(--bg-oscilloscope);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  padding: 60px 40px;
  text-align: center;
  color: #ffffff;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-xl), var(--shadow-laser);
}

.cta-banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(to right, rgba(6, 182, 212, 0.08) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(6, 182, 212, 0.08) 1px, transparent 1px);
  background-size: 30px 30px;
  pointer-events: none;
}

.cta-banner-title {
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  font-weight: 900;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.cta-banner-desc {
  font-size: 1.08rem;
  color: #94a3b8;
  max-width: 650px;
  margin: 0 auto 32px;
  line-height: 1.6;
}

/* ==========================================================================
   Site Footer (Strictly 4 links per requirement)
   ========================================================================== */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-hairline);
  padding: 50px 0 35px;
  transition: background-color 0.3s ease;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 38px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-link {
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text-secondary);
  position: relative;
  padding: 4px 0;
  transition: color 0.15s ease;
}

.footer-link:hover {
  color: var(--accent-cyan);
}

.footer-bottom {
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-hairline);
  padding-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-domain {
  font-weight: 600;
  color: var(--text-secondary);
  font-family: var(--font-mono);
}

/* ==========================================================================
   Inner Page Styling (Articles, About, Terms, Privacy, Sitemap)
   ========================================================================== */
.inner-page-header {
  padding: 55px 0 35px;
  text-align: center;
  border-bottom: 1px solid var(--border-hairline);
  background: var(--bg-secondary);
}

.inner-page-title {
  font-size: 2.2rem;
  font-weight: 900;
  margin-bottom: 12px;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.inner-page-sub {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto;
}

.inner-page-content {
  padding: 60px 0 80px;
  max-width: 880px;
  margin: 0 auto;
}

.content-block {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  padding: 36px 40px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
}

.content-block h2 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.content-block p {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 14px;
}

.content-block ul {
  margin-left: 20px;
  margin-bottom: 16px;
}

.content-block li {
  list-style-type: disc;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 8px;
}

/* Insights / Articles Grid */
.insights-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 26px;
}

.insight-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tech);
  border-radius: var(--radius-md);
  padding: 30px;
  display: flex;
  flex-direction: column;
  transition: all 0.25s ease;
  box-shadow: var(--shadow-sm);
}

.insight-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-lg), 0 0 15px var(--accent-cyan-glow);
}

.insight-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.insight-tag {
  background: rgba(6, 182, 212, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.3);
  padding: 2px 8px;
  border-radius: var(--radius-xs);
  font-weight: 700;
}

.insight-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 12px;
  line-height: 1.4;
}

.insight-summary {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.insight-readmore {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--accent-cobalt);
}

[data-theme="dark"] .insight-readmore {
  color: var(--accent-cyan);
}

/* ==========================================================================
   Responsive Breakpoints & Mobile Adaptations
   ========================================================================== */
@media (max-width: 1024px) {
  .engineering-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
  }
  .pricing-card.featured {
    transform: none;
  }
  .pricing-card.featured:hover {
    transform: translateY(-4px);
  }
/* Breakpoint for dense navbar with 9 items */
@media (max-width: 1140px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    width: 100%;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-hairline);
    flex-direction: column;
    align-items: stretch;
    padding: 16px 24px 24px;
    gap: 6px;
    box-shadow: var(--shadow-xl);
    z-index: 999;
    box-sizing: border-box;
  }

  .nav-menu.open {
    display: flex;
    animation: navSlideDown 0.22s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  }

  @keyframes navSlideDown {
    from {
      opacity: 0;
      transform: translateY(-8px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .nav-link {
    font-size: 0.96rem;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-sizing: border-box;
  }

  .nav-link:hover {
    background: var(--bg-tertiary);
  }

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

  .mobile-toggle-btn {
    display: inline-flex;
    flex-shrink: 0;
  }
}

@media (max-width: 768px) {
  .hero-section {
    padding: 45px 0 35px;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .oscilloscope-topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .oscilloscope-node-tabs {
    flex-wrap: wrap;
    width: 100%;
  }

  .oscilloscope-metrics-bar {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .engineering-grid,
  .showcase-grid,
  .reviews-grid,
  .insights-grid {
    grid-template-columns: 1fr;
  }

  .content-block {
    padding: 24px 20px;
  }

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