/* ====================================================================
   猫猫云 (maomaoyun.click) - STYLE 52: STEAMPUNK WORKSHOP
   设计语言：Steampunk / Victorian Machinery / Mechanical Craft / Brass
   视觉人格：复杂、温暖、机械、手工。19 世纪发明家私人实验室
   核心理念：Every UI component feels physically manufactured.
   ==================================================================== */

:root {
  /* 调色系统 COLOR SYSTEM */
  --walnut-deep: #160e06;
  --walnut-dark: #231709;
  --walnut-mid: #2e1e0f;
  --walnut-light: #3b2716;
  
  --brass-dark: #8e6520;
  --brass-base: #c8963e;
  --brass-bright: #dfb15b;
  --brass-highlight: #f5d48e;
  --brass-shadow: #5c3f10;
  
  --copper-dark: #702f14;
  --copper-base: #b85d34;
  --copper-bright: #d47343;
  --copper-glow: #ea8554;
  
  --cream-pure: #fffaf0;
  --cream-base: #f6eedb;
  --cream-parchment: #eee1c5;
  --cream-aged: #dfceaa;
  --cream-text-muted: #bfa980;
  
  --burgundy-dark: #3a0d15;
  --burgundy-base: #5c1824;
  --burgundy-bright: #8a2436;
  
  --oil-black: #110f0d;
  --oil-surface: #1a1714;
  --oil-border: #29241f;
  
  --aged-green: #243b31;
  --aged-green-light: #36594b;
  
  /* 字体栈 TYPOGRAPHY */
  --font-serif: "Georgia", "Baskerville", "Palatino Linotype", "Times New Roman", "Songti SC", "SimSun", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  --font-mono: "SF Mono", "Menlo", "Consolas", "Courier New", monospace;
  
  --max-width: 1240px;
  --transition-mech: all 0.25s cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--cream-parchment);
  background-color: var(--walnut-deep);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

/* 蒸汽车间物理背景纹理与铜管光影 */
body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  position: relative;
  background-color: var(--walnut-deep);
  background-image: 
    radial-gradient(ellipse 90% 50% at 50% 0%, rgba(200, 150, 62, 0.12), transparent 70%),
    radial-gradient(circle at 10% 25%, rgba(184, 93, 52, 0.08), transparent 40%),
    radial-gradient(circle at 90% 70%, rgba(200, 150, 62, 0.06), transparent 50%),
    repeating-linear-gradient(0deg, transparent, transparent 40px, rgba(0, 0, 0, 0.25) 40px, rgba(0, 0, 0, 0.25) 41px),
    linear-gradient(180deg, #1b1108 0%, #120a04 100%);
  background-attachment: fixed;
}

/* 铜管分隔线 PIPES */
.steampunk-pipe-divider {
  width: 100%;
  height: 16px;
  background: linear-gradient(180deg, #d47343 0%, #b85d34 30%, #702f14 70%, #4a1d0b 100%);
  position: relative;
  box-shadow: inset 0 2px 4px rgba(255, 255, 255, 0.35), 0 4px 10px rgba(0, 0, 0, 0.7);
  border-top: 1px solid #e89569;
  border-bottom: 2px solid #230f06;
}

.steampunk-pipe-divider::before, .steampunk-pipe-divider::after {
  content: "";
  position: absolute;
  top: -4px;
  width: 22px;
  height: 24px;
  background: linear-gradient(180deg, #dfb15b, #8e6520);
  border: 1px solid #f5d48e;
  border-radius: 3px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.6);
}

.steampunk-pipe-divider::before { left: 15%; }
.steampunk-pipe-divider::after { right: 15%; }

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

a {
  color: var(--brass-bright);
  text-decoration: none;
  transition: var(--transition-mech);
}

a:hover {
  color: var(--brass-highlight);
  text-shadow: 0 0 8px rgba(223, 177, 91, 0.5);
  text-decoration: none;
}

a:focus-visible, button:focus-visible, summary:focus-visible, input:focus-visible {
  outline: 2px solid var(--brass-bright);
  outline-offset: 3px;
}

.site-container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.text-container {
  width: 100%;
  max-width: 860px;
  margin-left: auto;
  margin-right: auto;
}

/* ================= 顶栏黄铜控制台导航 ================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(180deg, #2a1a0c 0%, #1a1007 100%);
  border-bottom: 3px solid var(--brass-base);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.8), inset 0 1px 0 rgba(223, 177, 91, 0.4);
}

.site-header::after {
  content: "";
  display: block;
  height: 4px;
  background: repeating-linear-gradient(90deg, #8e6520, #8e6520 8px, #dfb15b 8px, #dfb15b 12px, #3b2716 12px, #3b2716 20px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 74px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--brass-bright);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.8);
}

.brand-icon {
  width: 40px;
  height: 40px;
  filter: drop-shadow(0 2px 5px rgba(0, 0, 0, 0.6));
  transition: transform 0.6s ease;
}

.brand-logo:hover .brand-icon {
  transform: rotate(45deg);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--cream-parchment);
  padding: 6px 12px;
  border: 1px solid transparent;
  border-radius: 2px;
}

.nav-link:hover {
  color: var(--brass-bright);
  border-color: var(--brass-dark);
  background: rgba(46, 30, 15, 0.6);
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.6);
}

.nav-link.active {
  color: var(--brass-bright);
  border-color: var(--brass-base);
  background: linear-gradient(180deg, rgba(200, 150, 62, 0.2) 0%, rgba(35, 23, 9, 0.6) 100%);
  box-shadow: inset 0 0 8px rgba(200, 150, 62, 0.25);
}

.mobile-toggle {
  display: none;
  background: var(--walnut-mid);
  border: 2px solid var(--brass-base);
  color: var(--brass-bright);
  padding: 6px 12px;
  font-family: var(--font-mono);
  cursor: pointer;
  border-radius: 3px;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.5);
}

.mobile-nav-panel {
  display: none;
  background: var(--walnut-dark);
  border-bottom: 2px solid var(--brass-base);
  padding: 16px 20px 24px;
}

.mobile-nav-panel.is-open {
  display: block;
}

.mobile-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 16px;
}

.mobile-nav-list a {
  display: block;
  padding: 8px 10px;
  font-family: var(--font-mono);
  color: var(--cream-parchment);
  border-bottom: 1px solid var(--walnut-light);
}

/* ================= 机械按钮系统 MECHANICAL BUTTONS ================= */
.mech-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 28px;
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-decoration: none;
  cursor: pointer;
  position: relative;
  transition: var(--transition-mech);
  border: none;
  user-select: none;
}

/* 核心黄铜拉杆主按钮 [ START ENGINE ] */
.btn-start-engine {
  background: linear-gradient(180deg, #dfb15b 0%, #c8963e 40%, #8e6520 85%, #5c3f10 100%);
  color: var(--oil-black);
  border: 2px solid #f5d48e;
  border-radius: 4px;
  box-shadow: 
    0 6px 0 #3b2716,
    0 8px 16px rgba(0, 0, 0, 0.7),
    inset 0 1px 0 rgba(255, 255, 255, 0.6),
    inset 0 -2px 0 rgba(0, 0, 0, 0.4);
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.4);
  overflow: hidden;
}

.btn-start-engine .lever-knob {
  width: 14px;
  height: 22px;
  background: linear-gradient(90deg, #702f14, #d47343, #702f14);
  border: 1px solid #f5d48e;
  border-radius: 2px;
  display: inline-block;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.6);
  transition: transform 0.25s cubic-bezier(0.18, 0.89, 0.32, 1.28);
}

.btn-start-engine .mini-gauge {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--cream-parchment);
  border: 2px solid #5c3f10;
  position: relative;
  display: inline-block;
}

.btn-start-engine .mini-gauge::after {
  content: "";
  position: absolute;
  bottom: 3px;
  left: 50%;
  width: 2px;
  height: 7px;
  background: #8a2436;
  transform-origin: bottom center;
  transform: rotate(-35deg);
  transition: transform 0.3s ease;
}

/* Hover 机械反馈 */
.btn-start-engine:hover {
  background: linear-gradient(180deg, #f5d48e 0%, #dfb15b 40%, #a37322 85%, #704c13 100%);
  color: #000000;
  box-shadow: 
    0 4px 0 #3b2716,
    0 0 20px rgba(223, 177, 91, 0.7),
    0 10px 20px rgba(0, 0, 0, 0.8),
    inset 0 1px 0 rgba(255, 255, 255, 0.8);
  transform: translateY(2px);
}

.btn-start-engine:hover .lever-knob {
  transform: translateY(4px);
}

.btn-start-engine:hover .mini-gauge::after {
  transform: rotate(45deg);
}

.btn-start-engine:active {
  transform: translateY(6px);
  box-shadow: 
    0 0 0 #3b2716,
    0 2px 6px rgba(0, 0, 0, 0.9),
    inset 0 3px 6px rgba(0, 0, 0, 0.5);
}

/* 次级机械按钮 */
.btn-mech-secondary {
  background: linear-gradient(180deg, #2b1b0d 0%, #1a1007 100%);
  color: var(--cream-parchment);
  border: 2px solid var(--brass-dark);
  border-radius: 4px;
  box-shadow: 0 4px 0 #120a04, inset 0 1px 0 rgba(200, 150, 62, 0.2);
}

.btn-mech-secondary:hover {
  border-color: var(--brass-bright);
  color: var(--brass-bright);
  background: linear-gradient(180deg, #3b2716 0%, #231709 100%);
  box-shadow: 0 2px 0 #120a04, 0 0 12px rgba(200, 150, 62, 0.3);
  transform: translateY(2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.15rem;
}

.btn-block {
  width: 100%;
}

/* 通用按钮样式兼容 (Inner Pages & Articles) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 28px;
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-decoration: none;
  cursor: pointer;
  border-radius: 4px;
  transition: var(--transition-mech);
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(180deg, #dfb15b 0%, #c8963e 40%, #8e6520 85%, #5c3f10 100%);
  color: var(--oil-black);
  border: 2px solid #f5d48e;
  box-shadow: 0 4px 0 #3b2716, 0 6px 14px rgba(0, 0, 0, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.6);
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(180deg, #f5d48e 0%, #dfb15b 40%, #a37322 85%, #704c13 100%);
  color: #000000;
  box-shadow: 0 2px 0 #3b2716, 0 0 16px rgba(223, 177, 91, 0.6);
  transform: translateY(2px);
  text-decoration: none;
}

.btn-secondary {
  background: linear-gradient(180deg, #2b1b0d 0%, #1a1007 100%);
  color: var(--cream-parchment);
  border: 2px solid var(--brass-dark);
  box-shadow: 0 3px 0 #120a04;
}

.btn-secondary:hover {
  border-color: var(--brass-bright);
  color: var(--brass-bright);
  background: linear-gradient(180deg, #3b2716 0%, #231709 100%);
  box-shadow: 0 1px 0 #120a04, 0 0 10px rgba(200, 150, 62, 0.3);
  transform: translateY(2px);
  text-decoration: none;
}

/* ================= 启动流程滚动指示器 SCROLL MILESTONES ================= */
.scroll-process-bar {
  background: #120a04;
  border-bottom: 1px solid var(--brass-dark);
  padding: 10px 0;
  box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.8);
}

.process-steps-grid {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

.process-step {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cream-text-muted);
}

.step-num {
  font-weight: 700;
  color: var(--brass-bright);
  background: var(--walnut-light);
  padding: 2px 6px;
  border: 1px solid var(--brass-dark);
  border-radius: 2px;
}

.step-arrow {
  color: var(--copper-bright);
}

/* ================= HERO 机械工坊 ================= */
.hero-workshop {
  padding: 72px 0 64px;
  position: relative;
  background: 
    radial-gradient(ellipse 70% 60% at 50% 40%, rgba(200, 150, 62, 0.15), transparent 75%),
    linear-gradient(180deg, rgba(22, 14, 6, 0.9) 0%, rgba(14, 9, 4, 0.98) 100%);
  border-bottom: 2px solid var(--brass-dark);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

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

.workshop-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 14px;
  background: linear-gradient(90deg, var(--burgundy-dark), var(--walnut-dark));
  border: 1px solid var(--brass-base);
  border-left: 4px solid var(--copper-bright);
  color: var(--brass-bright);
  font-family: var(--font-mono);
  font-size: 0.825rem;
  letter-spacing: 0.08em;
  width: fit-content;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
}

.hero-headline {
  font-family: var(--font-serif);
  font-size: 3rem;
  line-height: 1.2;
  font-weight: 800;
  color: var(--cream-pure);
  letter-spacing: 0.02em;
  text-shadow: 0 3px 8px rgba(0, 0, 0, 0.9), 0 0 25px rgba(223, 177, 91, 0.2);
}

.hero-headline .sub-en-stamp {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--brass-bright);
  margin-bottom: 8px;
  text-transform: uppercase;
}

.hero-desc {
  font-size: 1.15rem;
  line-height: 1.75;
  color: var(--cream-parchment);
  border-left: 2px solid var(--brass-dark);
  padding-left: 16px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.hero-specs-row {
  display: flex;
  gap: 24px;
  padding-top: 24px;
  border-top: 1px dashed var(--brass-dark);
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--cream-text-muted);
}

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

.spec-gear-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--copper-bright);
  border: 2px solid var(--brass-bright);
  box-shadow: 0 0 6px var(--copper-glow);
}

/* Hero 右侧机械物理仪表板 */
.hero-instrument-panel {
  background: linear-gradient(135deg, #2b1b0d 0%, #160e06 100%);
  border: 4px solid var(--brass-base);
  border-radius: 8px;
  padding: 24px;
  box-shadow: 
    0 12px 30px rgba(0, 0, 0, 0.85),
    inset 0 0 20px rgba(0, 0, 0, 0.9),
    inset 0 2px 2px rgba(245, 212, 142, 0.4);
  position: relative;
}

/* 金属角螺栓 RIVETS & BOLTS */
.hero-instrument-panel::before, .hero-instrument-panel::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
  background: radial-gradient(circle, #f5d48e, #8e6520);
  border-radius: 50%;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.8);
}
.hero-instrument-panel::before { top: 8px; left: 8px; }
.hero-instrument-panel::after { bottom: 8px; right: 8px; }

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--walnut-light);
  margin-bottom: 20px;
}

.panel-brass-plate {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--brass-bright);
  letter-spacing: 0.05em;
  background: #1b1108;
  padding: 4px 10px;
  border: 1px solid var(--brass-dark);
}

.steam-status-beacon {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #4ade80;
  text-transform: uppercase;
}

.beacon-lamp {
  width: 8px;
  height: 8px;
  background-color: #22c55e;
  border-radius: 50%;
  box-shadow: 0 0 8px #22c55e;
  animation: pulse-lamp 2s infinite ease-in-out;
}

@keyframes pulse-lamp {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* 压力仪表盘 GAUGES & METERS */
.gauges-cluster {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 20px;
}

.circular-gauge-box {
  background: radial-gradient(circle, #f6eedb 0%, #dfceaa 75%, #a37322 100%);
  border: 5px solid var(--brass-dark);
  border-radius: 50%;
  width: 140px;
  height: 140px;
  margin: 0 auto;
  position: relative;
  box-shadow: 
    0 4px 12px rgba(0, 0, 0, 0.7),
    inset 0 3px 6px rgba(0, 0, 0, 0.4);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: #231709;
}

.gauge-dial-marks {
  position: absolute;
  top: 6px;
  left: 6px;
  right: 6px;
  bottom: 6px;
  border: 1px dashed rgba(60, 40, 15, 0.5);
  border-radius: 50%;
}

.gauge-needle {
  position: absolute;
  width: 3px;
  height: 52px;
  background: #8a2436;
  bottom: 70px;
  left: calc(50% - 1.5px);
  transform-origin: bottom center;
  transform: rotate(25deg);
  transition: transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 1px 0 3px rgba(0,0,0,0.4);
}

.gauge-center-cap {
  width: 16px;
  height: 16px;
  background: radial-gradient(circle, #dfb15b, #5c3f10);
  border-radius: 50%;
  position: absolute;
  top: calc(50% - 8px);
  left: calc(50% - 8px);
  box-shadow: 0 1px 3px rgba(0,0,0,0.6);
}

.gauge-val-display {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 800;
  margin-top: 45px;
  color: #3b0d16;
}

.gauge-caption {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  color: #5c3f10;
  font-weight: 700;
}

/* 控制台旋钮标签 */
.panel-selector-tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
  margin-bottom: 16px;
}

.mech-tab-btn {
  background: var(--walnut-dark);
  border: 1px solid var(--brass-dark);
  padding: 8px 4px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--cream-parchment);
  border-radius: 2px;
  cursor: pointer;
  text-align: center;
  transition: var(--transition-mech);
}

.mech-tab-btn.is-active, .mech-tab-btn:hover {
  background: var(--brass-base);
  color: var(--oil-black);
  border-color: var(--brass-bright);
  box-shadow: 0 0 8px rgba(223, 177, 91, 0.5);
}

.panel-readout-screen {
  background: #0f0c09;
  border: 2px solid var(--walnut-light);
  border-radius: 4px;
  padding: 14px 18px;
  font-family: var(--font-mono);
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.95);
}

.readout-title {
  color: var(--brass-bright);
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.readout-route {
  color: var(--cream-text-muted);
  font-size: 0.8rem;
  margin-bottom: 6px;
}

.readout-efficiency {
  color: var(--copper-bright);
  font-size: 0.8rem;
}

/* ================= 机械面板卡片 MECHANICAL PANELS ================= */
.section-padding {
  padding: 80px 0;
  position: relative;
}

.section-head {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 52px;
}

.section-brass-badge {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.15em;
  color: var(--brass-bright);
  text-transform: uppercase;
  margin-bottom: 8px;
  display: block;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 2.35rem;
  font-weight: 800;
  color: var(--cream-pure);
  letter-spacing: 0.03em;
  margin-bottom: 14px;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.8);
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--cream-aged);
  line-height: 1.65;
}

/* 4 张特性金属板 CARDS */
.features-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.metal-panel-card {
  background: linear-gradient(145deg, #26170a 0%, #191007 100%);
  border: 2px solid var(--brass-dark);
  border-radius: 4px;
  padding: 30px 22px;
  position: relative;
  box-shadow: 
    0 8px 20px rgba(0, 0, 0, 0.7),
    inset 0 1px 0 rgba(223, 177, 91, 0.2),
    inset 0 -1px 0 rgba(0, 0, 0, 0.5);
  display: flex;
  flex-direction: column;
  transition: var(--transition-mech);
}

/* 铆钉装饰角 */
.metal-panel-card::before, .metal-panel-card::after {
  content: "";
  position: absolute;
  width: 6px;
  height: 6px;
  background: #c8963e;
  border-radius: 50%;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.8);
}
.metal-panel-card::before { top: 6px; left: 6px; }
.metal-panel-card::after { top: 6px; right: 6px; }

.metal-panel-card:hover {
  transform: translateY(-5px);
  border-color: var(--brass-bright);
  box-shadow: 
    0 14px 28px rgba(0, 0, 0, 0.8),
    0 0 15px rgba(200, 150, 62, 0.25);
}

.panel-num-tag {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--copper-bright);
  border-bottom: 1px dashed var(--brass-dark);
  padding-bottom: 6px;
  margin-bottom: 14px;
}

.panel-card-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--cream-pure);
  margin-bottom: 10px;
}

.panel-card-desc {
  font-size: 0.95rem;
  color: var(--cream-aged);
  line-height: 1.65;
  flex-grow: 1;
}

/* ================= 4K 流媒体与 AI 双重做功模块 ================= */
.media-ai-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.workshop-chamber {
  background: linear-gradient(180deg, #221408 0%, #150d05 100%);
  border: 3px solid var(--copper-dark);
  border-top: 4px solid var(--brass-base);
  border-radius: 6px;
  padding: 36px 30px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.7);
  position: relative;
}

.chamber-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.chamber-title {
  font-family: var(--font-serif);
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--cream-pure);
}

.chamber-desc {
  font-size: 0.975rem;
  color: var(--cream-aged);
  line-height: 1.7;
  margin-bottom: 22px;
}

.brass-tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.brass-tag {
  background: var(--walnut-deep);
  border: 1px solid var(--brass-dark);
  color: var(--brass-bright);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 5px 12px;
  border-radius: 2px;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.6);
}

/* ================= 机械技术架构保障 BENEFITS ================= */
.benefits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.benefit-mechanism-box {
  background: linear-gradient(145deg, #1f1308 0%, #130b04 100%);
  border-left: 4px solid var(--copper-bright);
  border-top: 1px solid var(--brass-dark);
  border-right: 1px solid var(--walnut-light);
  border-bottom: 2px solid var(--walnut-light);
  padding: 28px 24px;
}

.benefit-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--brass-bright);
  margin-bottom: 10px;
}

.benefit-text {
  font-size: 0.95rem;
  color: var(--cream-aged);
  line-height: 1.65;
}

/* ================= 使用场景卡 SCENARIOS ================= */
.scenarios-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.scenario-panel {
  background: #1a1007;
  border: 1px solid var(--brass-dark);
  border-radius: 4px;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
}

.scenario-stage-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--brass-bright);
  background: var(--burgundy-dark);
  border: 1px solid var(--burgundy-bright);
  padding: 2px 8px;
  width: fit-content;
  margin-bottom: 12px;
  border-radius: 2px;
}

.scenario-title {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--cream-pure);
  margin-bottom: 6px;
}

.scenario-device {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cream-text-muted);
  margin-bottom: 12px;
}

.scenario-desc {
  font-size: 0.9rem;
  color: var(--cream-aged);
  line-height: 1.65;
}

/* ================= 动力引擎定价 PRICING (ENGINE / ADVANCED ENGINE / MASTER ENGINE) ================= */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  align-items: stretch;
}

.engine-pricing-card {
  background: linear-gradient(160deg, #241609 0%, #140d05 100%);
  border: 2px solid var(--brass-dark);
  border-radius: 6px;
  padding: 36px 26px;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.8);
}

.engine-pricing-card.featured {
  border: 3px solid var(--brass-bright);
  background: linear-gradient(160deg, #2e1a0b 0%, #1a0f06 100%);
  box-shadow: 
    0 12px 36px rgba(0, 0, 0, 0.9),
    0 0 24px rgba(223, 177, 91, 0.35);
  transform: translateY(-8px);
}

.featured-brass-plate {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(180deg, #dfb15b, #a37322);
  color: var(--oil-black);
  padding: 4px 18px;
  border: 1px solid #f5d48e;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border-radius: 2px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.6);
}

.engine-name {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--brass-bright);
  margin-bottom: 4px;
}

.engine-subtext {
  font-size: 0.85rem;
  color: var(--cream-text-muted);
  margin-bottom: 18px;
}

.engine-price-cluster {
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--walnut-light);
}

.currency-mark {
  font-size: 1.4rem;
  color: var(--brass-bright);
  font-weight: 700;
}

.price-num {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 800;
  color: var(--cream-pure);
  line-height: 1;
}

.cycle-mark {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--cream-text-muted);
}

/* 引擎机械动力参数矩阵 POWER / OUTPUT / EFFICIENCY / CAPACITY */
.engine-specs-matrix {
  background: #0f0a05;
  border: 1px solid var(--brass-dark);
  padding: 12px 14px;
  border-radius: 4px;
  margin-bottom: 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.775rem;
}

.spec-cell-label {
  color: var(--cream-text-muted);
  display: block;
}

.spec-cell-value {
  color: var(--brass-bright);
  font-weight: 700;
}

.engine-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
  flex-grow: 1;
}

.engine-feature-item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 0.925rem;
  color: var(--cream-aged);
}

.gear-bullet {
  color: var(--copper-bright);
  font-weight: 700;
}

/* ================= 蒸汽机械手风琴 FAQ ================= */
.faq-mechanical-container {
  max-width: 840px;
  margin: 0 auto;
}

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

.mech-faq-item {
  background: #1c1107;
  border: 2px solid var(--brass-dark);
  border-radius: 4px;
  overflow: hidden;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.6);
}

.faq-btn {
  width: 100%;
  padding: 20px 24px;
  background: linear-gradient(180deg, #241609 0%, #180f06 100%);
  border: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--cream-pure);
  cursor: pointer;
  text-align: left;
}

.faq-btn:hover {
  color: var(--brass-bright);
}

.faq-indicator-dial {
  width: 24px;
  height: 24px;
  border: 2px solid var(--brass-bright);
  border-radius: 50%;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--brass-bright);
  transition: transform 0.3s ease;
}

.mech-faq-item.is-open .faq-indicator-dial {
  transform: rotate(45deg);
  background: var(--burgundy-base);
  border-color: #f5d48e;
}

.faq-content {
  display: none;
  padding: 18px 24px 22px;
  font-size: 0.975rem;
  line-height: 1.8;
  color: var(--cream-aged);
  border-top: 1px dashed var(--brass-dark);
  background: #140d05;
}

.mech-faq-item.is-open .faq-content {
  display: block;
}

/* ================= 蒸汽爆发 FINAL CTA ================= */
.final-steampunk-cta {
  padding: 88px 0;
  background: 
    radial-gradient(ellipse 80% 60% at 50% 50%, rgba(200, 150, 62, 0.2), transparent 80%),
    linear-gradient(180deg, #180f06 0%, #0e0803 100%);
  border-top: 3px solid var(--brass-base);
  border-bottom: 3px solid var(--brass-base);
  text-align: center;
  position: relative;
}

.final-cta-box {
  max-width: 760px;
  margin: 0 auto;
}

.final-cta-title {
  font-family: var(--font-serif);
  font-size: 2.6rem;
  font-weight: 800;
  color: var(--cream-pure);
  margin-bottom: 16px;
  text-shadow: 0 3px 10px rgba(0, 0, 0, 0.9);
}

.final-cta-desc {
  font-size: 1.15rem;
  color: var(--cream-aged);
  margin-bottom: 32px;
  line-height: 1.7;
}

/* ================= 页脚 FOOTER ================= */
.site-footer {
  background: #120a04;
  border-top: 1px solid var(--brass-dark);
  padding: 60px 0 36px;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 44px;
}

.footer-brand-title {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--brass-bright);
  margin-bottom: 14px;
}

.footer-brand-desc {
  font-size: 0.9rem;
  color: var(--cream-text-muted);
  line-height: 1.7;
  max-width: 360px;
}

.footer-col-title {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--brass-bright);
  text-transform: uppercase;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--walnut-light);
  padding-bottom: 6px;
}

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

.footer-links-list a {
  font-size: 0.9rem;
  color: var(--cream-aged);
}

.footer-links-list a:hover {
  color: var(--brass-bright);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--walnut-light);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cream-text-muted);
}

/* ================= 移动端吸底 CTA ================= */
.mobile-sticky-cta {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 99;
  background: rgba(22, 14, 6, 0.98);
  border-top: 2px solid var(--brass-base);
  padding: 10px 16px;
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.8);
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.sticky-cta-text {
  display: flex;
  flex-direction: column;
}

.sticky-cta-main {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--brass-bright);
}

.sticky-cta-sub {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cream-text-muted);
}

/* ================= 教程与内容文章页 ARTICLE STYLING ================= */
.page-header {
  padding: 56px 0 40px;
  background: linear-gradient(180deg, #241609 0%, #160e06 100%);
  border-bottom: 2px solid var(--brass-dark);
  margin-bottom: 44px;
}

.page-title {
  font-family: var(--font-serif);
  font-size: 2.45rem;
  font-weight: 800;
  color: var(--cream-pure);
  letter-spacing: 0.02em;
  margin-bottom: 14px;
}

.page-meta {
  display: flex;
  align-items: center;
  gap: 18px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--brass-bright);
  flex-wrap: wrap;
}

.article-content {
  background: #1c1107;
  border: 2px solid var(--brass-dark);
  border-radius: 6px;
  padding: 44px;
  margin-bottom: 56px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.75);
}

.article-content h1 {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--cream-pure);
  margin-bottom: 24px;
  border-bottom: 2px solid var(--brass-dark);
  padding-bottom: 12px;
}

.article-content h2 {
  font-family: var(--font-serif);
  font-size: 1.55rem;
  font-weight: 700;
  color: var(--brass-bright);
  margin-top: 40px;
  margin-bottom: 18px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--walnut-light);
}

.article-content h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--cream-pure);
  margin-top: 26px;
  margin-bottom: 12px;
}

.article-content p {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--cream-parchment);
  margin-bottom: 20px;
}

.article-content ul, .article-content ol {
  margin-left: 26px;
  margin-bottom: 24px;
  color: var(--cream-aged);
  line-height: 1.8;
}

.article-content li {
  margin-bottom: 8px;
}

.article-content blockquote {
  border-left: 4px solid var(--brass-bright);
  background: #140d05;
  padding: 16px 22px;
  border-radius: 0 4px 4px 0;
  margin-bottom: 24px;
  font-size: 1rem;
  color: var(--cream-parchment);
}

.article-faq-box {
  background: #130b04;
  border: 1px solid var(--brass-dark);
  border-left: 4px solid var(--copper-bright);
  border-radius: 4px;
  padding: 26px;
  margin: 36px 0;
}

.article-faq-title {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--brass-bright);
  margin-bottom: 14px;
}

.article-cta-box {
  background: linear-gradient(145deg, #241609 0%, #180f06 100%);
  border: 2px solid var(--brass-base);
  border-radius: 6px;
  padding: 32px 24px;
  margin: 40px 0 24px;
  text-align: center;
  box-shadow: inset 0 0 16px rgba(0, 0, 0, 0.6);
}

.article-cta-title {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--cream-pure);
  margin-bottom: 10px;
}

.article-cta-desc {
  font-size: 1rem;
  color: var(--cream-aged);
  margin-bottom: 20px;
}

.internal-links-box {
  border-top: 1px dashed var(--brass-dark);
  padding-top: 26px;
  margin-top: 40px;
}

.internal-links-title {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  color: var(--brass-bright);
  margin-bottom: 14px;
}

.internal-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.internal-links-list a {
  font-size: 0.95rem;
  color: var(--cream-parchment);
}

.internal-links-list a:hover {
  color: var(--brass-bright);
}

/* 指南汇总列表卡片 */
.guides-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 26px;
  margin-bottom: 52px;
}

.guide-card {
  background: #1c1107;
  border: 2px solid var(--brass-dark);
  border-radius: 4px;
  padding: 30px;
  display: flex;
  flex-direction: column;
  transition: var(--transition-mech);
}

.guide-card:hover {
  transform: translateY(-4px);
  border-color: var(--brass-bright);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.8), 0 0 12px rgba(223, 177, 91, 0.2);
}

.guide-card-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--copper-bright);
  margin-bottom: 10px;
}

.guide-card-title {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--cream-pure);
  margin-bottom: 12px;
}

.guide-card-title a {
  color: var(--cream-pure);
}

.guide-card-title a:hover {
  color: var(--brass-bright);
}

.guide-card-desc {
  font-size: 0.95rem;
  color: var(--cream-aged);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.guide-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--cream-text-muted);
  border-top: 1px dashed var(--brass-dark);
  padding-top: 14px;
}

/* ================= 响应式适配 RESPONSIVE ================= */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .features-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .scenarios-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 500px;
    margin: 0 auto;
  }
  
  .engine-pricing-card.featured {
    transform: none;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .main-nav, .header-cta-group {
    display: none;
  }
  
  .mobile-toggle {
    display: block;
  }
  
  .hero-headline {
    font-size: 2.2rem;
  }
  
  .features-grid-4, .media-ai-grid, .benefits-grid, .scenarios-grid, .guides-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
  
  .article-content {
    padding: 26px 18px;
  }
  
  .page-title {
    font-size: 1.85rem;
  }
  
  .process-steps-grid {
    font-size: 0.75rem;
  }
}