/* ==========================================================================
   ArithCloud — 企业级算力云平台
   统一主题样式表
   设计原则：KISS（零依赖）、DRY（CSS 变量集中管理）、移动优先响应式
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. 设计令牌（Design Tokens）
   -------------------------------------------------------------------------- */
:root {
  /* 品牌色 */
  --c-cyan: #22d3ee;
  --c-blue: #4f8cff;
  --c-violet: #8b5cf6;
  --c-magenta: #c084fc;
  --c-mint: #34d399;
  --c-amber: #fbbf24;

  /* 渐变 */
  --grad-brand: linear-gradient(135deg, var(--c-cyan) 0%, var(--c-blue) 45%, var(--c-violet) 100%);
  --grad-brand-soft: linear-gradient(135deg, rgba(34, 211, 238, .18), rgba(139, 92, 246, .18));
  --grad-text: linear-gradient(120deg, #a5f3fc 0%, #93c5fd 40%, #c4b5fd 100%);

  /* 背景层次 */
  --bg-base: #05070e;
  --bg-elev-1: #0a0e1a;
  --bg-elev-2: #0f1524;
  --bg-elev-3: #151d31;

  /* 玻璃拟态 */
  --glass-bg: rgba(255, 255, 255, .038);
  --glass-bg-strong: rgba(255, 255, 255, .06);
  --glass-border: rgba(255, 255, 255, .09);
  --glass-border-hi: rgba(255, 255, 255, .18);

  /* 文字 */
  --tx-primary: #e8eefb;
  --tx-secondary: #9fb0cc;
  --tx-muted: #6b7c99;

  /* 阴影与光晕 */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, .35);
  --shadow-md: 0 12px 32px rgba(0, 0, 0, .45);
  --shadow-lg: 0 24px 64px rgba(0, 0, 0, .55);
  --glow-cyan: 0 0 0 1px rgba(34, 211, 238, .35), 0 8px 40px rgba(34, 211, 238, .22);
  --glow-violet: 0 0 0 1px rgba(139, 92, 246, .35), 0 8px 40px rgba(139, 92, 246, .22);

  /* 圆角 */
  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-xl: 28px;
  --r-pill: 999px;

  /* 间距节奏 */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 24px;
  --sp-6: 32px;
  --sp-7: 48px;
  --sp-8: 64px;
  --sp-9: 96px;
  --sp-10: 128px;

  /* 版心与导航 */
  --container: 1200px;
  --header-h: 72px;

  /* 动效 */
  --ease-out: cubic-bezier(.22, 1, .36, 1);
  --dur-fast: .18s;
  --dur-base: .32s;
  --dur-slow: .6s;

  /* 字体栈：不依赖外网字体，保证首屏速度 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC",
    Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
}

/* --------------------------------------------------------------------------
   2. 基础重置
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--tx-primary);
  background: var(--bg-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 全局氛围光：两团固定渐变光斑，营造深空科技感 */
body::before,
body::after {
  content: "";
  position: fixed;
  z-index: 0;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
}

body::before {
  top: -240px;
  left: -160px;
  width: 720px;
  height: 720px;
  background: radial-gradient(circle, rgba(34, 211, 238, .16), transparent 68%);
}

body::after {
  top: 40%;
  right: -220px;
  width: 640px;
  height: 640px;
  background: radial-gradient(circle, rgba(139, 92, 246, .15), transparent 68%);
}

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

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
textarea,
select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

ul,
ol {
  list-style: none;
}

:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection {
  background: rgba(79, 140, 255, .35);
  color: #fff;
}

/* --------------------------------------------------------------------------
   3. 排版
   -------------------------------------------------------------------------- */
h1,
h2,
h3,
h4 {
  line-height: 1.22;
  font-weight: 700;
  letter-spacing: -.02em;
}

h1 {
  font-size: clamp(2.1rem, 5.2vw, 3.75rem);
}

h2 {
  font-size: clamp(1.6rem, 3.4vw, 2.5rem);
}

h3 {
  font-size: clamp(1.1rem, 1.9vw, 1.35rem);
}

p {
  color: var(--tx-secondary);
}

.gradient-text {
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.mono {
  font-family: var(--font-mono);
  font-size: .875em;
}

/* --------------------------------------------------------------------------
   4. 布局容器
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--sp-5);
  position: relative;
  z-index: 1;
}

section {
  position: relative;
  z-index: 1;
  padding-block: clamp(56px, 8vw, 96px);
}

.section-head {
  max-width: 720px;
  margin-bottom: var(--sp-8);
}

.section-head.center {
  margin-inline: auto;
  text-align: center;
}

.section-head h2 {
  margin-bottom: var(--sp-4);
}

.section-head p {
  font-size: 1.05rem;
}

/* 小标签 */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 6px 14px;
  margin-bottom: var(--sp-5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-pill);
  background: var(--glass-bg);
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: 0 0 10px var(--c-cyan);
}

/* --------------------------------------------------------------------------
   5. 按钮
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 13px 26px;
  border-radius: var(--r-pill);
  font-size: .95rem;
  font-weight: 600;
  white-space: nowrap;
  transition: transform var(--dur-fast) var(--ease-out),
    box-shadow var(--dur-base) var(--ease-out),
    background-color var(--dur-fast) var(--ease-out),
    border-color var(--dur-fast) var(--ease-out);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: var(--grad-brand);
  color: #04070f;
  box-shadow: 0 8px 28px rgba(79, 140, 255, .3);
}

.btn-primary:hover {
  box-shadow: 0 14px 40px rgba(79, 140, 255, .45);
}

.btn-ghost {
  border: 1px solid var(--glass-border-hi);
  background: var(--glass-bg);
  color: var(--tx-primary);
  backdrop-filter: blur(12px);
}

.btn-ghost:hover {
  border-color: rgba(34, 211, 238, .5);
  background: var(--glass-bg-strong);
}

.btn-sm {
  padding: 9px 18px;
  font-size: .875rem;
}

.btn-block {
  width: 100%;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
}

/* --------------------------------------------------------------------------
   6. 顶部导航
   -------------------------------------------------------------------------- */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  transition: background-color var(--dur-base) var(--ease-out),
    border-color var(--dur-base) var(--ease-out),
    backdrop-filter var(--dur-base) var(--ease-out);
  border-bottom: 1px solid transparent;
}

.site-header.is-stuck {
  background: rgba(5, 7, 14, .78);
  backdrop-filter: blur(18px) saturate(160%);
  border-bottom-color: var(--glass-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-5);
}

/* 品牌标识 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -.02em;
}

.brand .logo-mark {
  width: 34px;
  height: 34px;
  flex: 0 0 34px;
}

.brand span b {
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* 主导航 */
.nav {
  display: flex;
  align-items: center;
  gap: var(--sp-6);
}

.nav a {
  position: relative;
  font-size: .93rem;
  font-weight: 500;
  color: var(--tx-secondary);
  transition: color var(--dur-fast) var(--ease-out);
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--grad-brand);
  transition: width var(--dur-base) var(--ease-out);
}

.nav a:hover,
.nav a[aria-current="page"] {
  color: var(--tx-primary);
}

.nav a:hover::after,
.nav a[aria-current="page"]::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--glass-border);
  border-radius: var(--r-sm);
  background: var(--glass-bg);
  align-items: center;
  justify-content: center;
}

.nav-toggle span {
  position: relative;
  width: 18px;
  height: 2px;
  background: var(--tx-primary);
  border-radius: 2px;
  transition: background-color var(--dur-fast) var(--ease-out);
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--tx-primary);
  border-radius: 2px;
  transition: transform var(--dur-base) var(--ease-out);
}

.nav-toggle span::before {
  top: -6px;
}

.nav-toggle span::after {
  top: 6px;
}

.nav-toggle[aria-expanded="true"] span {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] span::before {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span::after {
  transform: translateY(-6px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   7. Hero 区
   -------------------------------------------------------------------------- */
.hero {
  padding-top: calc(var(--header-h) + clamp(48px, 8vw, 96px));
  padding-bottom: clamp(56px, 8vw, 104px);
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(32px, 5vw, 72px);
  align-items: center;
}

.hero h1 {
  margin-bottom: var(--sp-5);
}

.hero-lead {
  font-size: clamp(1rem, 1.35vw, 1.14rem);
  max-width: 56ch;
  margin-bottom: var(--sp-7);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-6);
  max-width: 560px;
  margin-top: var(--sp-8);
  padding-top: var(--sp-7);
  border-top: 1px solid var(--glass-border);
}

.hero-stats .num {
  font-size: clamp(1.4rem, 2.6vw, 1.9rem);
  font-weight: 800;
  letter-spacing: -.03em;
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-stats .lbl {
  font-size: .82rem;
  color: var(--tx-muted);
}

/* 终端演示卡 */
.terminal {
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, rgba(15, 21, 36, .92), rgba(8, 11, 20, .92));
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  backdrop-filter: blur(14px);
}

.terminal-bar {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 12px 16px;
  border-bottom: 1px solid var(--glass-border);
  background: rgba(255, 255, 255, .025);
}

.terminal-bar i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  display: block;
}

.terminal-bar i:nth-child(1) {
  background: #ff5f57;
}

.terminal-bar i:nth-child(2) {
  background: #febc2e;
}

.terminal-bar i:nth-child(3) {
  background: #28c840;
}

.terminal-bar .title {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: .76rem;
  color: var(--tx-muted);
}

.terminal-body {
  padding: var(--sp-5);
  font-family: var(--font-mono);
  font-size: .82rem;
  line-height: 2;
  overflow-x: auto;
}

.terminal-body .c-cmd {
  color: var(--c-cyan);
}

.terminal-body .c-key {
  color: var(--c-magenta);
}

.terminal-body .c-str {
  color: var(--c-mint);
}

.terminal-body .c-cmt {
  color: var(--tx-muted);
}

.terminal-body .c-out {
  color: var(--tx-secondary);
}

/* 打字光标 */
.caret::after {
  content: "▋";
  color: var(--c-cyan);
  animation: blink 1.1s steps(1) infinite;
}

@keyframes blink {
  50% {
    opacity: 0;
  }
}

/* --------------------------------------------------------------------------
   8. 信任背书（Logo 墙）
   -------------------------------------------------------------------------- */
.trust {
  padding-block: var(--sp-8);
  border-block: 1px solid var(--glass-border);
  background: rgba(255, 255, 255, .012);
}

.trust p {
  text-align: center;
  font-size: .8rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--tx-muted);
  margin-bottom: var(--sp-6);
}

.trust-logos {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: clamp(24px, 5vw, 64px);
}

.trust-logos span {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--tx-muted);
  opacity: .75;
  transition: color var(--dur-base) var(--ease-out), opacity var(--dur-base) var(--ease-out);
}

.trust-logos span:hover {
  color: var(--tx-primary);
  opacity: 1;
}

/* --------------------------------------------------------------------------
   9. 卡片网格
   -------------------------------------------------------------------------- */
.grid {
  display: grid;
  gap: var(--sp-5);
}

.grid-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  position: relative;
  padding: var(--sp-6);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  transition: transform var(--dur-base) var(--ease-out),
    border-color var(--dur-base) var(--ease-out),
    box-shadow var(--dur-base) var(--ease-out),
    background-color var(--dur-base) var(--ease-out);
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(34, 211, 238, .5), transparent);
  opacity: 0;
  transition: opacity var(--dur-base) var(--ease-out);
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--glass-border-hi);
  background: var(--glass-bg-strong);
  box-shadow: var(--shadow-md);
}

.card:hover::before {
  opacity: 1;
}

.card h3 {
  margin-bottom: var(--sp-3);
}

.card p {
  font-size: .93rem;
}

/* 图标容器 */
.icon-box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  margin-bottom: var(--sp-5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  background: var(--grad-brand-soft);
  color: var(--c-cyan);
}

.icon-box svg {
  width: 22px;
  height: 22px;
}

/* 功能要点列表 */
.feature-list {
  margin-top: var(--sp-5);
  display: grid;
  gap: var(--sp-3);
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-3);
  font-size: .9rem;
  color: var(--tx-secondary);
}

.feature-list svg {
  width: 18px;
  height: 18px;
  flex: 0 0 18px;
  margin-top: 3px;
  color: var(--c-mint);
}

/* --------------------------------------------------------------------------
   10. 产品能力矩阵（大卡 + 规格）
   -------------------------------------------------------------------------- */
.product-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(24px, 4vw, 56px);
  align-items: center;
  padding: clamp(32px, 4vw, 56px);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-xl);
  background: linear-gradient(135deg, rgba(255, 255, 255, .045), rgba(255, 255, 255, .015));
  backdrop-filter: blur(12px);
  margin-bottom: var(--sp-6);
}

.product-card:nth-child(even) .product-visual {
  order: -1;
}

.product-card h3 {
  font-size: clamp(1.3rem, 2.4vw, 1.85rem);
  margin-bottom: var(--sp-4);
}

.spec-list {
  display: grid;
  gap: var(--sp-4);
  margin-top: var(--sp-5);
}

.spec-list > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--sp-4);
  padding-bottom: var(--sp-3);
  border-bottom: 1px dashed var(--glass-border);
  font-size: .88rem;
}

.spec-list dt {
  color: var(--tx-muted);
}

.spec-list dd {
  font-weight: 600;
  color: var(--tx-primary);
  font-family: var(--font-mono);
}

/* 规格可视面板 */
.product-visual {
  padding: var(--sp-6);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  background: rgba(5, 7, 14, .6);
  display: grid;
  gap: var(--sp-4);
}

.meter {
  display: grid;
  gap: var(--sp-2);
}

.meter-head {
  display: flex;
  justify-content: space-between;
  font-size: .78rem;
  color: var(--tx-muted);
  font-family: var(--font-mono);
}

.meter-track {
  height: 8px;
  border-radius: var(--r-pill);
  background: rgba(255, 255, 255, .07);
  overflow: hidden;
}

.meter-fill {
  height: 100%;
  border-radius: inherit;
  background: var(--grad-brand);
  width: 0;
  transition: width 1.4s var(--ease-out);
}

/* --------------------------------------------------------------------------
   11. 数据/指标带
   -------------------------------------------------------------------------- */
.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--sp-5);
}

.metric {
  text-align: center;
  padding: var(--sp-6) var(--sp-4);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  background: var(--glass-bg);
}

.metric .val {
  font-size: clamp(1.6rem, 3.4vw, 2.4rem);
  font-weight: 800;
  letter-spacing: -.03em;
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.metric .cap {
  font-size: .85rem;
  color: var(--tx-muted);
  margin-top: var(--sp-2);
}

/* --------------------------------------------------------------------------
   12. 价格方案
   -------------------------------------------------------------------------- */
.billing-toggle {
  display: inline-flex;
  gap: var(--sp-1);
  padding: var(--sp-1);
  margin-bottom: var(--sp-8);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-pill);
  background: var(--glass-bg);
}

.billing-toggle button {
  padding: 9px 22px;
  border-radius: var(--r-pill);
  font-size: .88rem;
  font-weight: 600;
  color: var(--tx-secondary);
  transition: color var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}

.billing-toggle button[aria-pressed="true"] {
  background: var(--grad-brand);
  color: #04070f;
}

.billing-toggle .save {
  font-size: .72rem;
  opacity: .85;
}

.price-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-5);
  align-items: start;
}

.plan {
  display: flex;
  flex-direction: column;
  padding: var(--sp-7) var(--sp-6);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-xl);
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  transition: transform var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out);
}

.plan:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.plan.featured {
  border-color: rgba(34, 211, 238, .45);
  background: linear-gradient(180deg, rgba(34, 211, 238, .07), rgba(139, 92, 246, .05));
  box-shadow: var(--glow-cyan);
  position: relative;
}

.plan.featured::after {
  content: "最受欢迎";
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  padding: 4px 14px;
  border-radius: var(--r-pill);
  background: var(--grad-brand);
  color: #04070f;
  font-size: .72rem;
  font-weight: 700;
  white-space: nowrap;
}

.plan h3 {
  margin-bottom: var(--sp-2);
}

.plan .desc {
  font-size: .87rem;
  min-height: 44px;
  margin-bottom: var(--sp-5);
}

.plan .price {
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding-bottom: var(--sp-5);
  margin-bottom: var(--sp-5);
  border-bottom: 1px solid var(--glass-border);
}

.plan .price .cur {
  font-size: 1.1rem;
  color: var(--tx-secondary);
}

.plan .price .amt {
  font-size: clamp(2rem, 4vw, 2.7rem);
  font-weight: 800;
  letter-spacing: -.04em;
}

.plan .price .per {
  font-size: .85rem;
  color: var(--tx-muted);
}

.plan .feature-list {
  flex: 1;
  margin-top: 0;
  margin-bottom: var(--sp-6);
}

/* --------------------------------------------------------------------------
   13. 价格计算器
   -------------------------------------------------------------------------- */
.calc {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
  padding: clamp(28px, 3.5vw, 48px);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-xl);
  background: linear-gradient(135deg, rgba(255, 255, 255, .045), rgba(255, 255, 255, .012));
  backdrop-filter: blur(12px);
}

.field {
  margin-bottom: var(--sp-5);
}

.field label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--sp-3);
  margin-bottom: var(--sp-2);
  font-size: .88rem;
  font-weight: 600;
  color: var(--tx-primary);
}

.field label output {
  font-family: var(--font-mono);
  color: var(--c-cyan);
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: var(--r-pill);
  background: rgba(255, 255, 255, .1);
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--grad-brand);
  border: 2px solid #05070e;
  box-shadow: 0 0 0 3px rgba(34, 211, 238, .22);
  cursor: pointer;
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--c-cyan);
  border: 2px solid #05070e;
  cursor: pointer;
}

/* 单选组 */
.radio-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
}

.radio-row label {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 9px 16px;
  border: 1px solid var(--glass-border);
  border-radius: var(--r-pill);
  background: var(--glass-bg);
  font-size: .85rem;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}

.radio-row label:hover {
  border-color: var(--glass-border-hi);
}

.radio-row input {
  accent-color: var(--c-cyan);
  width: 15px;
  height: 15px;
}

.radio-row label:has(input:checked) {
  border-color: rgba(34, 211, 238, .55);
  background: rgba(34, 211, 238, .09);
  color: var(--tx-primary);
}

/* 计算结果面板 */
.calc-result {
  padding: var(--sp-6);
  border: 1px solid rgba(34, 211, 238, .28);
  border-radius: var(--r-lg);
  background: radial-gradient(120% 120% at 100% 0%, rgba(34, 211, 238, .12), rgba(139, 92, 246, .07));
  text-align: center;
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.calc-result .total {
  font-size: clamp(2.2rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: -.04em;
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.15;
}

.calc-result .total small {
  font-size: .95rem;
  font-weight: 600;
  letter-spacing: 0;
}

.calc-breakdown {
  margin-block: var(--sp-5);
  padding-block: var(--sp-5);
  border-block: 1px solid var(--glass-border);
  display: grid;
  gap: var(--sp-3);
  text-align: left;
}

.calc-breakdown > div {
  display: flex;
  justify-content: space-between;
  font-size: .86rem;
}

.calc-breakdown dt {
  color: var(--tx-muted);
}

.calc-breakdown dd {
  font-family: var(--font-mono);
  color: var(--tx-primary);
}

/* --------------------------------------------------------------------------
   14. 客户案例 / 引言
   -------------------------------------------------------------------------- */
.quote-card {
  padding: var(--sp-7) var(--sp-6);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  background: var(--glass-bg);
  display: flex;
  flex-direction: column;
  gap: var(--sp-5);
  transition: transform var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out);
}

.quote-card:hover {
  transform: translateY(-4px);
  border-color: var(--glass-border-hi);
}

.quote-card blockquote {
  font-size: .98rem;
  line-height: 1.75;
  color: var(--tx-primary);
  flex: 1;
}

.quote-card blockquote::before {
  content: "\201C";
  display: block;
  font-size: 2.6rem;
  line-height: .8;
  color: var(--c-violet);
  opacity: .6;
  margin-bottom: var(--sp-2);
}

.quote-meta {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--glass-border);
}

.avatar {
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: .95rem;
  color: #04070f;
  background: var(--grad-brand);
}

.quote-meta .who {
  font-size: .88rem;
  font-weight: 600;
  color: var(--tx-primary);
}

.quote-meta .role {
  font-size: .79rem;
  color: var(--tx-muted);
}

/* 案例数据条 */
.case-stats {
  display: flex;
  gap: var(--sp-6);
  flex-wrap: wrap;
}

.case-stats div {
  font-size: .8rem;
  color: var(--tx-muted);
}

.case-stats b {
  display: block;
  font-size: 1.25rem;
  color: var(--c-cyan);
  font-family: var(--font-mono);
}

/* --------------------------------------------------------------------------
   15. FAQ 手风琴
   -------------------------------------------------------------------------- */
.faq {
  display: grid;
  gap: var(--sp-3);
  max-width: 860px;
  margin-inline: auto;
}

.faq-item {
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  background: var(--glass-bg);
  overflow: hidden;
  transition: border-color var(--dur-fast) var(--ease-out);
}

.faq-item:hover {
  border-color: var(--glass-border-hi);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  padding: var(--sp-5);
  font-weight: 600;
  font-size: .98rem;
  cursor: pointer;
  list-style: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "";
  width: 9px;
  height: 9px;
  flex: 0 0 9px;
  border-right: 2px solid var(--c-cyan);
  border-bottom: 2px solid var(--c-cyan);
  transform: rotate(45deg);
  transition: transform var(--dur-base) var(--ease-out);
}

.faq-item[open] summary::after {
  transform: rotate(-135deg);
}

.faq-item .answer {
  padding: 0 var(--sp-5) var(--sp-5);
  font-size: .92rem;
  color: var(--tx-secondary);
}

/* --------------------------------------------------------------------------
   16. CTA 区块
   -------------------------------------------------------------------------- */
.cta {
  text-align: center;
  padding: clamp(48px, 7vw, 88px) var(--sp-6);
  border: 1px solid rgba(34, 211, 238, .3);
  border-radius: var(--r-xl);
  background: radial-gradient(120% 140% at 50% 0%, rgba(34, 211, 238, .14), rgba(139, 92, 246, .1) 55%, transparent);
  box-shadow: var(--shadow-lg);
}

.cta h2 {
  margin-bottom: var(--sp-4);
}

.cta p {
  max-width: 60ch;
  margin: 0 auto var(--sp-7);
  font-size: 1.02rem;
}

.cta .btn-row {
  justify-content: center;
}

.cta-note {
  margin-top: var(--sp-5);
  font-size: .82rem;
  color: var(--tx-muted);
}

/* --------------------------------------------------------------------------
   17. 页面头部（子页）
   -------------------------------------------------------------------------- */
.page-hero {
  padding-top: calc(var(--header-h) + clamp(40px, 6vw, 80px));
  padding-bottom: clamp(32px, 4vw, 56px);
  text-align: center;
}

.page-hero h1 {
  font-size: clamp(1.9rem, 4.2vw, 3rem);
  margin-bottom: var(--sp-4);
}

.page-hero p {
  max-width: 62ch;
  margin-inline: auto;
  font-size: 1.03rem;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  margin-bottom: var(--sp-5);
  font-size: .8rem;
  color: var(--tx-muted);
}

.breadcrumb a:hover {
  color: var(--c-cyan);
}

/* --------------------------------------------------------------------------
   18. 文档页
   -------------------------------------------------------------------------- */
.docs-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
}

.docs-nav {
  position: sticky;
  top: calc(var(--header-h) + 24px);
  display: grid;
  gap: var(--sp-2);
  padding: var(--sp-5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  background: var(--glass-bg);
}

.docs-nav p {
  font-size: .74rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--tx-muted);
  margin-bottom: var(--sp-2);
}

.docs-nav a {
  padding: 6px 10px;
  border-radius: var(--r-sm);
  font-size: .87rem;
  color: var(--tx-secondary);
  transition: background var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}

.docs-nav a:hover {
  background: var(--glass-bg-strong);
  color: var(--tx-primary);
}

.docs-body h2 {
  font-size: 1.5rem;
  margin-top: var(--sp-8);
  margin-bottom: var(--sp-4);
  padding-top: var(--sp-4);
}

.docs-body h2:first-child {
  margin-top: 0;
}

.docs-body h3 {
  font-size: 1.1rem;
  margin-top: var(--sp-6);
  margin-bottom: var(--sp-3);
}

.docs-body p {
  margin-bottom: var(--sp-4);
  font-size: .95rem;
}

.docs-body ul {
  margin-bottom: var(--sp-5);
  display: grid;
  gap: var(--sp-2);
}

.docs-body ul li {
  position: relative;
  padding-left: 20px;
  font-size: .93rem;
  color: var(--tx-secondary);
}

.docs-body ul li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: .68em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--c-cyan);
}

/* 代码块 */
.code-block {
  position: relative;
  margin-bottom: var(--sp-5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  background: rgba(3, 5, 10, .8);
  overflow: hidden;
}

.code-block header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  border-bottom: 1px solid var(--glass-border);
  background: rgba(255, 255, 255, .025);
  font-family: var(--font-mono);
  font-size: .76rem;
  color: var(--tx-muted);
}

.copy-btn {
  padding: 4px 12px;
  border: 1px solid var(--glass-border);
  border-radius: var(--r-pill);
  font-size: .74rem;
  color: var(--tx-secondary);
  transition: color var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out);
}

.copy-btn:hover {
  color: var(--c-cyan);
  border-color: rgba(34, 211, 238, .5);
}

.code-block pre {
  padding: var(--sp-5);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: .82rem;
  line-height: 1.8;
  color: var(--tx-secondary);
}

/* 表格 */
.table-wrap {
  overflow-x: auto;
  margin-bottom: var(--sp-5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: .87rem;
}

th,
td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--glass-border);
}

th {
  background: rgba(255, 255, 255, .03);
  font-weight: 600;
  font-size: .8rem;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--tx-muted);
  white-space: nowrap;
}

td {
  color: var(--tx-secondary);
}

tbody tr:last-child td {
  border-bottom: none;
}

tbody tr:hover {
  background: rgba(255, 255, 255, .02);
}

/* API 方法徽章 */
.method {
  display: inline-block;
  padding: 2px 9px;
  border-radius: var(--r-sm);
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 700;
}

.method.get {
  background: rgba(52, 211, 153, .15);
  color: var(--c-mint);
}

.method.post {
  background: rgba(79, 140, 255, .15);
  color: var(--c-blue);
}

.method.del {
  background: rgba(248, 113, 113, .15);
  color: #f87171;
}

/* 提示条 */
.note {
  display: flex;
  gap: var(--sp-4);
  padding: var(--sp-5);
  margin-bottom: var(--sp-5);
  border: 1px solid rgba(79, 140, 255, .28);
  border-left: 3px solid var(--c-blue);
  border-radius: var(--r-md);
  background: rgba(79, 140, 255, .07);
  font-size: .89rem;
}

.note svg {
  width: 20px;
  height: 20px;
  flex: 0 0 20px;
  color: var(--c-blue);
  margin-top: 2px;
}

.note strong {
  color: var(--tx-primary);
}

/* --------------------------------------------------------------------------
   19. 关于我们
   -------------------------------------------------------------------------- */
.timeline {
  display: grid;
  gap: var(--sp-5);
  max-width: 780px;
}

.timeline-item {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: var(--sp-5);
  padding-bottom: var(--sp-5);
  border-bottom: 1px solid var(--glass-border);
}

.timeline-item .year {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--c-cyan);
}

.timeline-item h3 {
  font-size: 1.02rem;
  margin-bottom: var(--sp-2);
}

.timeline-item p {
  font-size: .9rem;
}

/* 团队成员 */
.member {
  text-align: center;
  padding: var(--sp-6) var(--sp-5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  background: var(--glass-bg);
  transition: transform var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out);
}

.member:hover {
  transform: translateY(-4px);
  border-color: var(--glass-border-hi);
}

.member .avatar {
  width: 68px;
  height: 68px;
  flex: none;
  margin: 0 auto var(--sp-4);
  font-size: 1.35rem;
}

.member .name {
  font-weight: 700;
  margin-bottom: 2px;
}

.member .title {
  font-size: .82rem;
  color: var(--c-cyan);
  margin-bottom: var(--sp-3);
}

.member .bio {
  font-size: .85rem;
  color: var(--tx-muted);
}

/* 价值观 */
.value-card {
  padding: var(--sp-6);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  background: var(--glass-bg);
}

.value-card .idx {
  font-family: var(--font-mono);
  font-size: .8rem;
  color: var(--c-violet);
  margin-bottom: var(--sp-3);
}

.value-card h3 {
  font-size: 1.05rem;
  margin-bottom: var(--sp-3);
}

.value-card p {
  font-size: .89rem;
}

/* --------------------------------------------------------------------------
   20. 联系我们
   -------------------------------------------------------------------------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
}

.contact-info {
  display: grid;
  gap: var(--sp-4);
}

.info-item {
  display: flex;
  gap: var(--sp-4);
  padding: var(--sp-5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  background: var(--glass-bg);
  transition: border-color var(--dur-fast) var(--ease-out);
}

.info-item:hover {
  border-color: var(--glass-border-hi);
}

.info-item .icon-box {
  margin-bottom: 0;
  width: 40px;
  height: 40px;
  flex: 0 0 40px;
}

.info-item h3 {
  font-size: .95rem;
  margin-bottom: 2px;
}

.info-item p {
  font-size: .86rem;
}

.info-item a:hover {
  color: var(--c-cyan);
}

/* 表单 */
.form {
  padding: clamp(24px, 3vw, 40px);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-xl);
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-4);
}

.form-field {
  margin-bottom: var(--sp-5);
}

.form-field label {
  display: block;
  margin-bottom: var(--sp-2);
  font-size: .86rem;
  font-weight: 600;
}

.form-field label .req {
  color: #f87171;
}

.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--glass-border);
  border-radius: var(--r-sm);
  background: rgba(3, 5, 10, .5);
  font-size: .92rem;
  transition: border-color var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast) var(--ease-out);
}

.form-field textarea {
  min-height: 130px;
  resize: vertical;
  line-height: 1.65;
}

.form-field select {
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--tx-secondary) 50%),
    linear-gradient(135deg, var(--tx-secondary) 50%, transparent 50%);
  background-position: calc(100% - 20px) 50%, calc(100% - 15px) 50%;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
}

.form-field input::placeholder,
.form-field textarea::placeholder {
  color: var(--tx-muted);
}

.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  outline: none;
  border-color: rgba(34, 211, 238, .6);
  box-shadow: 0 0 0 3px rgba(34, 211, 238, .12);
}

.form-field .err {
  display: none;
  margin-top: 6px;
  font-size: .78rem;
  color: #f87171;
}

.form-field.has-error input,
.form-field.has-error textarea,
.form-field.has-error select {
  border-color: #f87171;
}

.form-field.has-error .err {
  display: block;
}

.form-status {
  display: none;
  margin-top: var(--sp-4);
  padding: var(--sp-4) var(--sp-5);
  border: 1px solid rgba(52, 211, 153, .35);
  border-radius: var(--r-md);
  background: rgba(52, 211, 153, .08);
  font-size: .88rem;
  color: var(--c-mint);
}

.form-status.show {
  display: block;
}

/* --------------------------------------------------------------------------
   21. 页脚
   -------------------------------------------------------------------------- */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: var(--sp-9);
  padding-top: var(--sp-8);
  border-top: 1px solid var(--glass-border);
  background: rgba(3, 5, 10, .5);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr repeat(3, 1fr);
  gap: clamp(24px, 4vw, 56px);
  padding-bottom: var(--sp-8);
}

.footer-brand p {
  margin-top: var(--sp-4);
  font-size: .88rem;
  max-width: 34ch;
}

.footer-col h4 {
  font-size: .8rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--tx-muted);
  margin-bottom: var(--sp-4);
}

.footer-col ul {
  display: grid;
  gap: var(--sp-3);
}

.footer-col a {
  font-size: .88rem;
  color: var(--tx-secondary);
  transition: color var(--dur-fast) var(--ease-out);
}

.footer-col a:hover {
  color: var(--c-cyan);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--sp-4);
  padding-block: var(--sp-5);
  border-top: 1px solid var(--glass-border);
  font-size: .82rem;
  color: var(--tx-muted);
}

.footer-bottom .socials {
  display: flex;
  gap: var(--sp-3);
}

.footer-bottom .socials a {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 1px solid var(--glass-border);
  border-radius: var(--r-sm);
  color: var(--tx-secondary);
  transition: color var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out);
}

.footer-bottom .socials a:hover {
  color: var(--c-cyan);
  border-color: rgba(34, 211, 238, .45);
}

.footer-bottom .socials svg {
  width: 16px;
  height: 16px;
}

/* --------------------------------------------------------------------------
   22. 滚动入场动效
   -------------------------------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* 尊重系统「减少动效」偏好 */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

/* --------------------------------------------------------------------------
   23. 响应式断点
   -------------------------------------------------------------------------- */
@media (max-width: 1040px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .docs-layout {
    grid-template-columns: 1fr;
  }

  .docs-nav {
    position: static;
    grid-auto-flow: column;
    grid-auto-columns: max-content;
    align-items: center;
    overflow-x: auto;
  }

  .docs-nav p {
    display: none;
  }
}

@media (max-width: 900px) {
  :root {
    --header-h: 64px;
  }

  /* 移动端导航抽屉 */
  .nav-toggle {
    display: flex;
  }

  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--sp-4) var(--sp-5) var(--sp-6);
    background: rgba(5, 7, 14, .97);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--dur-base) var(--ease-out),
      transform var(--dur-base) var(--ease-out),
      visibility var(--dur-base);
  }

  .nav.is-open {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav a {
    padding: var(--sp-4) 0;
    border-bottom: 1px solid var(--glass-border);
    font-size: 1rem;
  }

  .nav a::after {
    display: none;
  }

  .header-actions .btn-ghost {
    display: none;
  }

  .grid-3,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .price-grid {
    grid-template-columns: 1fr;
  }

  .plan.featured {
    order: -1;
  }

  .product-card {
    grid-template-columns: 1fr;
  }

  .product-card:nth-child(even) .product-visual {
    order: 0;
  }

  .calc {
    grid-template-columns: 1fr;
  }

  .calc-result {
    position: static;
  }

  .contact-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .container {
    padding-inline: var(--sp-4);
  }

  section {
    padding-block: var(--sp-7);
  }

  .grid-4,
  .metrics {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    grid-template-columns: 1fr;
    gap: var(--sp-5);
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .btn-row .btn {
    width: 100%;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: var(--sp-2);
  }

  .spec-list > div {
    flex-direction: column;
    gap: 2px;
  }
}

/* --------------------------------------------------------------------------
   24. 打印样式
   -------------------------------------------------------------------------- */
@media print {

  body::before,
  body::after,
  .site-header,
  .nav-toggle,
  .cta {
    display: none !important;
  }

  body {
    background: #fff;
    color: #111;
  }

  .card,
  .plan,
  .terminal {
    border-color: #ccc;
    background: #fff;
    box-shadow: none;
  }
}