/* ===================================================================
   老头vpn (oldmanvpn.homes) - 重装工业粗野主义与地堡防御设计系统 (Heavy Bunker UI)
   排版创新：重装控制台 Hero + 镀锌装甲工程四相矩阵 + 机械指针仪表盘 + 条码蓝图卷宗
   背景创新：45° 黄黑警示斑马条纹 + 蓝图工程十字网格 (+) + 钢板螺栓角标
   =================================================================== */

:root {
  --bg-primary: #0c0d13;
  --bg-surface: #14161f;
  --bg-card: #1a1d29;
  --hazard-yellow: #fbbf24;
  --hazard-gold: #f59e0b;
  --hazard-orange: #ea580c;
  --industrial-border: #374151;
  --steel-white: #f8fafc;
  --steel-muted: #9ca3af;
  --font-mono: "SF Mono", Monaco, Consolas, "Liberation Mono", monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

body {
  background-color: var(--bg-primary);
  color: var(--steel-white);
  font-family: var(--font-sans);
  line-height: 1.65;
  position: relative;
  overflow-x: hidden;
  /* Blueprint Crosshair Grid Background */
  background-image: 
    linear-gradient(rgba(251, 191, 36, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(251, 191, 36, 0.05) 1px, transparent 1px),
    radial-gradient(circle at 10% 20%, rgba(234, 88, 12, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 90% 80%, rgba(251, 191, 36, 0.08) 0%, transparent 40%);
  background-size: 40px 40px, 40px 40px, 100% 100%, 100% 100%;
}

/* 45deg Hazard Caution Tape Top Stripe */
.hazard-tape-top {
  height: 8px;
  width: 100%;
  background: repeating-linear-gradient(
    -45deg,
    #fbbf24,
    #fbbf24 16px,
    #000000 16px,
    #000000 32px
  );
  position: sticky;
  top: 0;
  z-index: 101;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* Header & Stencil Nav */
header.site-header {
  background: rgba(14, 16, 23, 0.95);
  border-bottom: 2px solid var(--hazard-yellow);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky;
  top: 8px;
  z-index: 100;
}
.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}
.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--steel-white);
  font-weight: 900;
  font-size: 1.35rem;
  letter-spacing: 0.06em;
  font-family: var(--font-sans);
}
.brand-logo svg {
  width: 38px;
  height: 38px;
}
.stencil-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 2px 8px;
  background: var(--hazard-yellow);
  color: #000;
  font-weight: 800;
  letter-spacing: 0.05em;
  border: 1px solid #000;
}

nav.main-nav ul {
  display: flex;
  list-style: none;
  gap: 24px;
  align-items: center;
}
nav.main-nav a {
  color: var(--steel-muted);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  transition: color 0.2s;
}
nav.main-nav a:hover, nav.main-nav a.active {
  color: var(--hazard-yellow);
}

.btn-bunker-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 20px;
  background: var(--hazard-yellow);
  color: #000;
  text-decoration: none;
  font-weight: 800;
  font-size: 0.92rem;
  border: 2px solid #000;
  box-shadow: 3px 3px 0 #ea580c;
  transition: all 0.15s ease;
  font-family: var(--font-mono);
}
.btn-bunker-cta:hover {
  transform: translate(-2px, -2px);
  box-shadow: 5px 5px 0 #ea580c;
}

/* ===================================================================
   HERO: Industrial Brutalism Split + Gigabit Needle Gauge
   =================================================================== */
.hero-bunker {
  padding: 60px 0 80px;
  position: relative;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}
.hero-spec-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  background: rgba(251, 191, 36, 0.12);
  border: 1px solid var(--hazard-yellow);
  color: var(--hazard-yellow);
  padding: 5px 12px;
  margin-bottom: 20px;
  font-weight: 700;
}
.hero-title {
  font-size: 2.85rem;
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  text-transform: uppercase;
}
.hero-title span.strike-gold {
  color: var(--hazard-yellow);
  background: linear-gradient(180deg, transparent 70%, rgba(251, 191, 36, 0.25) 70%);
}
.hero-desc {
  font-size: 1.1rem;
  color: var(--steel-muted);
  line-height: 1.75;
  margin-bottom: 32px;
}
.hero-buttons {
  display: flex;
  gap: 18px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}
.btn-heavy-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  background: var(--hazard-yellow);
  color: #000;
  text-decoration: none;
  font-weight: 800;
  font-size: 1.05rem;
  border: 3px solid #000;
  box-shadow: 4px 4px 0 #000, 4px 4px 0 2px var(--hazard-orange);
  transition: all 0.15s ease;
}
.btn-heavy-primary:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 #000, 6px 6px 0 2px var(--hazard-orange);
}
.btn-heavy-secondary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 26px;
  background: #14161f;
  color: var(--steel-white);
  text-decoration: none;
  font-weight: 700;
  font-size: 1.02rem;
  border: 2px solid var(--industrial-border);
  box-shadow: 3px 3px 0 #000;
  transition: all 0.15s ease;
}
.btn-heavy-secondary:hover {
  border-color: var(--hazard-yellow);
  color: var(--hazard-yellow);
}

.hero-spec-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  border-top: 2px dashed var(--industrial-border);
  padding-top: 24px;
}
.spec-box h4 {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--hazard-yellow);
}
.spec-box p {
  font-size: 0.8rem;
  color: var(--steel-muted);
}

/* Mechanical Needle Gauge Console */
.gauge-console-card {
  background: #161824;
  border: 3px solid #000;
  box-shadow: 6px 6px 0 #000, 6px 6px 0 2px var(--hazard-yellow);
  border-radius: 4px;
  padding: 28px;
  position: relative;
}
.console-rivet {
  position: absolute;
  width: 8px;
  height: 8px;
  background: #6b7280;
  border-radius: 50%;
  border: 1px solid #000;
}
.rivet-tl { top: 8px; left: 8px; }
.rivet-tr { top: 8px; right: 8px; }
.rivet-bl { bottom: 8px; left: 8px; }
.rivet-br { bottom: 8px; right: 8px; }

.gauge-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 2px solid #2d3345;
  padding-bottom: 12px;
  margin-bottom: 18px;
}
.gauge-title {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--hazard-yellow);
  text-transform: uppercase;
}
.gauge-status-led {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: #10b981;
  font-family: var(--font-mono);
}
.gauge-status-led::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 8px #10b981;
}

/* Semi-circular Mechanical SVG Gauge */
.needle-gauge-svg {
  width: 100%;
  max-width: 280px;
  display: block;
  margin: 0 auto 12px;
}
.gauge-needle {
  transform-origin: 100px 100px;
  transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.gauge-readout-box {
  background: #090a0f;
  border: 1px solid #2d3345;
  padding: 10px 16px;
  text-align: center;
  margin-bottom: 18px;
}
.gauge-value-text {
  font-family: var(--font-mono);
  font-size: 1.85rem;
  font-weight: 900;
  color: var(--hazard-yellow);
  line-height: 1;
}
.gauge-sub-text {
  font-size: 0.72rem;
  color: var(--steel-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.console-slider-label {
  display: block;
  font-size: 0.8rem;
  color: var(--steel-muted);
  margin-bottom: 6px;
  font-family: var(--font-mono);
}
.console-range-input {
  width: 100%;
  accent-color: var(--hazard-yellow);
}

/* ===================================================================
   SECTION 2: Heavy Steel Armor 4-Quadrant Matrix
   =================================================================== */
.section-armor {
  padding: 80px 0;
  position: relative;
}
.section-bunker-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 50px;
}
.bunker-stencil-pill {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 3px 10px;
  background: rgba(251, 191, 36, 0.15);
  border: 1px solid var(--hazard-yellow);
  color: var(--hazard-yellow);
  margin-bottom: 12px;
  font-weight: 700;
}
.section-bunker-header h2 {
  font-size: 2.2rem;
  font-weight: 900;
  letter-spacing: -0.01em;
}

.armor-quad-matrix {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}
.armor-steel-plate {
  background: var(--bg-card);
  border: 2px solid var(--industrial-border);
  border-left: 6px solid var(--hazard-yellow);
  padding: 32px;
  position: relative;
  transition: all 0.2s ease;
}
.armor-steel-plate:hover {
  border-color: var(--hazard-yellow);
  transform: translateY(-2px);
  box-shadow: 4px 4px 0 #000;
}
.plate-index {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 900;
  color: rgba(251, 191, 36, 0.35);
  position: absolute;
  top: 20px;
  right: 24px;
}
.armor-steel-plate h3 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--steel-white);
  margin-bottom: 12px;
}
.armor-steel-plate p {
  color: var(--steel-muted);
  font-size: 0.94rem;
  line-height: 1.7;
  margin-bottom: 18px;
}
.armor-specs-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: #cbd5e1;
}
.armor-specs-list li {
  background: rgba(0, 0, 0, 0.3);
  padding: 6px 10px;
  border-left: 2px solid var(--hazard-orange);
}

/* ===================================================================
   SECTION 3: Peak-Hour Stress & Buffer-Buster Tool
   =================================================================== */
.section-stress {
  padding: 60px 0 80px;
}
.stress-bunker-box {
  background: #12141c;
  border: 3px solid #000;
  box-shadow: 6px 6px 0 #000, 6px 6px 0 2px var(--hazard-orange);
  padding: 44px;
}
.stress-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}
.select-industrial {
  width: 100%;
  padding: 12px 14px;
  background: #090a0f;
  border: 2px solid #2d3345;
  color: var(--steel-white);
  font-family: var(--font-mono);
  font-size: 0.92rem;
  margin-bottom: 18px;
  outline: none;
}
.select-industrial:focus {
  border-color: var(--hazard-yellow);
}

.stress-result-display {
  background: #07080c;
  border: 2px solid #1f2433;
  padding: 28px;
  text-align: center;
}
.stress-metric-big {
  font-family: var(--font-mono);
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--hazard-yellow);
  line-height: 1.1;
  margin-bottom: 8px;
}

/* ===================================================================
   SECTION 4: Industrial Tech Spec Sheet Ledger (蓝图卷宗)
   =================================================================== */
.section-ledger {
  padding: 80px 0;
}
.ledger-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.ledger-dossier-card {
  background: #141620;
  border: 2px solid var(--industrial-border);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  color: inherit;
  position: relative;
  transition: all 0.2s ease;
}
.ledger-dossier-card:hover {
  border-color: var(--hazard-yellow);
  transform: translateY(-3px);
  box-shadow: 4px 4px 0 #000, 4px 4px 0 2px var(--hazard-yellow);
}
.card-barcode {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: #64748b;
  letter-spacing: 0.15em;
  margin-bottom: 12px;
  display: flex;
  justify-content: space-between;
  border-bottom: 1px solid #2d3345;
  padding-bottom: 8px;
}
.card-barcode span.stamp-tag {
  color: var(--hazard-yellow);
  font-weight: 700;
}
.ledger-dossier-card h3 {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--steel-white);
  line-height: 1.45;
  margin-bottom: 12px;
}
.ledger-dossier-card p {
  font-size: 0.86rem;
  color: var(--steel-muted);
  line-height: 1.65;
  margin-bottom: 20px;
}
.card-bottom-action {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--hazard-yellow);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ===================================================================
   SECTION 5: Heavy Stamped Industrial FAQ
   =================================================================== */
.section-faq {
  padding: 80px 0 100px;
}
.faq-box-container {
  max-width: 860px;
  margin: 0 auto;
}
.faq-item-bunker {
  background: var(--bg-card);
  border: 2px solid var(--industrial-border);
  margin-bottom: 14px;
  transition: border-color 0.2s;
}
.faq-item-bunker:hover {
  border-color: var(--hazard-yellow);
}
.faq-btn-bunker {
  width: 100%;
  padding: 18px 22px;
  background: none;
  border: none;
  color: var(--steel-white);
  font-size: 1.05rem;
  font-weight: 700;
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-sans);
}
.faq-bolt-icon {
  font-family: var(--font-mono);
  font-weight: 800;
  color: var(--hazard-yellow);
  font-size: 1.1rem;
}
.faq-ans-bunker {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  padding: 0 22px;
  color: var(--steel-muted);
  font-size: 0.94rem;
  line-height: 1.75;
}
.faq-item-bunker.active .faq-ans-bunker {
  padding-bottom: 20px;
}

/* ===================================================================
   FOOTER & COMPLIANCE
   =================================================================== */
footer.site-footer {
  background: #08090d;
  border-top: 2px solid var(--hazard-yellow);
  padding: 60px 0 36px;
  font-size: 0.88rem;
  color: var(--steel-muted);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}
.footer-col h4 {
  color: var(--steel-white);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 800;
  margin-bottom: 18px;
  text-transform: uppercase;
}
.footer-col ul {
  list-style: none;
}
.footer-col li {
  margin-bottom: 10px;
}
.footer-col a {
  color: var(--steel-muted);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-col a:hover {
  color: var(--hazard-yellow);
}
.footer-affiliate-note {
  border-top: 1px solid #1f2433;
  padding-top: 24px;
  font-size: 0.78rem;
  line-height: 1.65;
  color: #64748b;
}

/* ===================================================================
   ARTICLE DETAIL STYLES
   =================================================================== */
.article-header {
  padding: 50px 0 36px;
  border-bottom: 2px solid var(--industrial-border);
  margin-bottom: 40px;
}
.article-meta-row {
  display: flex;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  color: var(--hazard-yellow);
  margin-bottom: 12px;
}
.article-title-detail {
  font-size: 2.3rem;
  font-weight: 900;
  line-height: 1.3;
  margin-bottom: 18px;
}
.article-body {
  max-width: 860px;
  margin: 0 auto 60px;
  font-size: 1.02rem;
  line-height: 1.85;
  color: #d1d5db;
}
.article-body h2 {
  font-size: 1.55rem;
  font-weight: 800;
  color: var(--steel-white);
  margin: 44px 0 18px;
  border-left: 4px solid var(--hazard-yellow);
  padding-left: 14px;
}
.article-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #f3f4f6;
  margin: 28px 0 14px;
}
.article-body p {
  margin-bottom: 20px;
}
.article-body ul, .article-body ol {
  margin-bottom: 24px;
  padding-left: 28px;
}
.article-body li {
  margin-bottom: 10px;
}
.article-body pre {
  background: #090a0f;
  border: 2px solid var(--industrial-border);
  padding: 18px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  margin-bottom: 24px;
  color: #e5e7eb;
}
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 28px;
  background: #141620;
  border: 1px solid var(--industrial-border);
}
.article-body th, .article-body td {
  padding: 14px 18px;
  border: 1px solid #2d3345;
  text-align: left;
  font-size: 0.92rem;
}
.article-body th {
  background: #1f2333;
  color: var(--hazard-yellow);
  font-weight: 700;
  font-family: var(--font-mono);
}
.callout-box-heavy {
  background: rgba(251, 191, 36, 0.08);
  border: 2px solid var(--hazard-yellow);
  padding: 20px 24px;
  margin-bottom: 24px;
}
.callout-box-heavy h4 {
  color: var(--hazard-yellow);
  font-size: 1.05rem;
  font-family: var(--font-mono);
  margin-bottom: 8px;
}

@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; }
  .armor-quad-matrix { grid-template-columns: 1fr; }
  .stress-grid { grid-template-columns: 1fr; }
  .ledger-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}