/* ==========================================================================
   ggremote.com — 远程控制 / 远程桌面
   主题样式表 · 冷灰白 + 深藏青 + 电光蓝
   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
   -------------------------------------------------------------------------- */
:root {
  /* 主色：深藏青（按钮/标题） + 电光蓝（强调） */
  --c-navy: #0b2138;
  --c-navy-2: #14314f;
  --c-blue: #2979ff;
  --c-blue-dk: #1565e0;
  --c-blue-lt: #e6f0ff;

  /* 状态语义色 */
  --c-green: #00c853;
  --c-green-lt: #dcfce9;
  --c-amber: #ffab00;
  --c-amber-lt: #fff5e0;
  --c-red: #ff5252;
  --c-red-lt: #ffe8e8;
  --c-violet: #7c4dff;

  /* 渐变 */
  --grad-brand: linear-gradient(120deg, #2979ff 0%, #7c4dff 100%);
  --grad-navy: linear-gradient(120deg, #14314f 0%, #0b2138 100%);

  /* 底色 */
  --bg: #f6f8fb;
  --bg-alt: #eef2f8;
  --surface: #ffffff;
  --surface-2: #f8fafd;
  --line: #e3e9f2;
  --line-strong: #cbd6e6;

  /* 墨色 */
  --ink: #0b2138;
  --ink-2: #4a5b73;
  --ink-3: #8b9aad;

  /* 阴影 */
  --sh-sm: 0 1px 2px rgba(11, 33, 56, .06);
  --sh-md: 0 8px 24px rgba(11, 33, 56, .09);
  --sh-lg: 0 20px 48px rgba(11, 33, 56, .14);
  --sh-navy: 0 10px 26px rgba(11, 33, 56, .28);

  /* 圆角 */
  --r-sm: 7px;
  --r-md: 11px;
  --r-lg: 16px;
  --r-xl: 22px;
  --r-pill: 999px;

  /* 间距 */
  --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;

  --container: 1180px;
  --header-h: 68px;

  --ease: cubic-bezier(.22, 1, .36, 1);
  --dur-f: .16s;
  --dur: .28s;
  --dur-s: .5s;

  --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: 1.68;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

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

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

ul,
ol {
  list-style: none;
}

:focus-visible {
  outline: 2.5px solid var(--c-blue);
  outline-offset: 3px;
  border-radius: 5px;
}

::selection {
  background: rgba(41, 121, 255, .2);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* --------------------------------------------------------------------------
   3. 排版
   -------------------------------------------------------------------------- */
h1,
h2,
h3,
h4 {
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -.025em;
  color: var(--ink);
}

h1 {
  font-size: clamp(1.95rem, 4.6vw, 3.15rem);
}

h2 {
  font-size: clamp(1.4rem, 2.8vw, 2.1rem);
}

h3 {
  font-size: clamp(.98rem, 1.6vw, 1.16rem);
}

p {
  color: var(--ink-2);
}

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

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

code {
  padding: 2px 7px;
  border-radius: 5px;
  background: var(--bg-alt);
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: .85em;
  color: var(--c-blue-dk);
}

/* --------------------------------------------------------------------------
   4. 布局
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--sp-5);
}

section {
  padding-block: clamp(46px, 6.5vw, 82px);
}

.section-head {
  max-width: 680px;
  margin-bottom: var(--sp-7);
}

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

.section-head h2 {
  margin-bottom: var(--sp-3);
}

.section-head p {
  font-size: 1rem;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 4px 12px;
  margin-bottom: var(--sp-4);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: var(--surface);
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-blue);
}

.eyebrow.green::before {
  background: var(--c-green);
}

.eyebrow.violet::before {
  background: var(--c-violet);
}

/* --------------------------------------------------------------------------
   5. 按钮
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 11px 22px;
  border-radius: var(--r-md);
  font-size: .92rem;
  font-weight: 700;
  white-space: nowrap;
  transition: transform var(--dur-f) var(--ease), box-shadow var(--dur) var(--ease),
    background-color var(--dur-f) var(--ease), border-color var(--dur-f) var(--ease),
    color var(--dur-f) var(--ease);
}

.btn:hover {
  transform: translateY(-1px);
}

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

.btn-primary {
  background: var(--c-navy);
  color: #fff;
  box-shadow: var(--sh-navy);
}

.btn-primary:hover {
  background: var(--c-navy-2);
}

.btn-blue {
  background: var(--grad-brand);
  color: #fff;
  box-shadow: 0 8px 22px rgba(41, 121, 255, .3);
}

.btn-outline {
  border: 1.5px solid var(--line-strong);
  background: var(--surface);
  color: var(--ink);
}

.btn-outline:hover {
  border-color: var(--c-blue);
  color: var(--c-blue-dk);
}

.btn-soft {
  background: var(--bg-alt);
  color: var(--ink);
}

.btn-soft:hover {
  background: var(--line);
}

.btn-sm {
  padding: 7px 14px;
  font-size: .83rem;
}

.btn-lg {
  padding: 14px 30px;
  font-size: 1rem;
}

.btn-block {
  width: 100%;
}

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

/* --------------------------------------------------------------------------
   6. 顶部导航
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(246, 248, 251, .9);
  backdrop-filter: blur(14px) saturate(180%);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.site-header.is-stuck {
  border-bottom-color: var(--line);
  box-shadow: 0 2px 14px rgba(11, 33, 56, .05);
}

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

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 1.16rem;
  font-weight: 900;
  letter-spacing: -.03em;
}

.brand .logo-mark {
  width: 32px;
  height: 32px;
  flex: 0 0 32px;
}

.brand b {
  color: var(--c-blue);
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--sp-5);
}

.nav a {
  position: relative;
  font-size: .9rem;
  font-weight: 600;
  color: var(--ink-2);
  padding-block: 4px;
  transition: color var(--dur-f) var(--ease);
}

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

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

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

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

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--r-sm);
  background: var(--surface);
  align-items: center;
  justify-content: center;
}

.nav-toggle span {
  position: relative;
  width: 17px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: background-color var(--dur-f) var(--ease);
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 17px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform var(--dur) var(--ease);
}

.nav-toggle span::before {
  top: -5.5px;
}

.nav-toggle span::after {
  top: 5.5px;
}

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

.nav-toggle[aria-expanded="true"] span::before {
  transform: translateY(5.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span::after {
  transform: translateY(-5.5px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   7. Hero
   -------------------------------------------------------------------------- */
.hero {
  padding-top: clamp(32px, 5vw, 58px);
  padding-bottom: clamp(40px, 5.5vw, 74px);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 880px;
  height: 500px;
  background: radial-gradient(ellipse, rgba(41, 121, 255, .1), transparent 65%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: .92fr 1.08fr;
  gap: clamp(32px, 4.5vw, 58px);
  align-items: center;
}

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

.hero-lead {
  font-size: clamp(1rem, 1.3vw, 1.08rem);
  max-width: 46ch;
  margin-bottom: var(--sp-6);
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-6);
  margin-top: var(--sp-7);
  padding-top: var(--sp-6);
  border-top: 1px solid var(--line);
}

.hero-stats .num {
  font-size: clamp(1.25rem, 2.3vw, 1.65rem);
  font-weight: 900;
  letter-spacing: -.03em;
  font-family: var(--font-mono);
  color: var(--ink);
}

.hero-stats .lbl {
  font-size: .79rem;
  color: var(--ink-3);
}

/* 下载徽标行 */
.os-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  margin-top: var(--sp-5);
}

.os-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: var(--surface);
  font-size: .78rem;
  font-weight: 600;
  color: var(--ink-2);
}

.os-chip svg {
  width: 14px;
  height: 14px;
}

/* --------------------------------------------------------------------------
   8. 远程会话窗口（核心视觉符号）
   -------------------------------------------------------------------------- */
.session {
  border-radius: var(--r-lg);
  background: var(--c-navy);
  box-shadow: var(--sh-lg);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, .08);
}

.session-bar {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: 10px 14px;
  background: rgba(255, 255, 255, .04);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}

.session-bar .dots {
  display: flex;
  gap: 6px;
}

.session-bar .dots i {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: block;
}

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

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

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

.session-bar .peer {
  display: flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-mono);
  font-size: .76rem;
  color: #c7d6e8;
  min-width: 0;
}

.session-bar .peer .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-green);
  box-shadow: 0 0 8px rgba(0, 200, 83, .8);
  flex: 0 0 7px;
}

.session-bar .peer span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* 延迟徽标 */
.latency {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  border-radius: var(--r-pill);
  background: rgba(0, 200, 83, .16);
  color: #6ef0a4;
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 700;
  white-space: nowrap;
}

.latency.mid {
  background: rgba(255, 171, 0, .16);
  color: #ffcc66;
}

.latency.bad {
  background: rgba(255, 82, 82, .16);
  color: #ff9b9b;
}

.latency svg {
  width: 12px;
  height: 12px;
}

/* 会话画面 */
.session-screen {
  position: relative;
  aspect-ratio: 16 / 10;
  background: linear-gradient(160deg, #14314f 0%, #0b2138 100%);
  overflow: hidden;
}

/* 模拟桌面壁纸网格 */
.session-screen::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(41, 121, 255, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(41, 121, 255, .07) 1px, transparent 1px);
  background-size: 28px 28px;
}

/* 桌面图标 */
.desktop-icons {
  position: absolute;
  top: 16px;
  left: 16px;
  display: grid;
  gap: 14px;
}

.desktop-icons .ico {
  display: grid;
  gap: 5px;
  justify-items: center;
  font-size: .62rem;
  color: #9fb6ce;
  font-family: var(--font-mono);
}

.desktop-icons .ico i {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  background: rgba(255, 255, 255, .1);
  border: 1px solid rgba(255, 255, 255, .12);
  display: block;
}

/* 模拟应用窗口 */
.app-window {
  position: absolute;
  top: 22%;
  left: 26%;
  right: 8%;
  bottom: 20%;
  border-radius: 9px;
  background: rgba(255, 255, 255, .05);
  border: 1px solid rgba(255, 255, 255, .13);
  backdrop-filter: blur(3px);
  padding: 12px;
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 10px;
}

.app-window .aw-bar {
  display: flex;
  align-items: center;
  gap: 6px;
}

.app-window .aw-bar i {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, .22);
  display: block;
}

.app-window .aw-body {
  display: grid;
  gap: 7px;
  align-content: start;
}

.app-window .aw-body i {
  display: block;
  height: 7px;
  border-radius: 4px;
  background: rgba(255, 255, 255, .13);
}

.app-window .aw-body i:nth-child(1) {
  width: 62%;
}

.app-window .aw-body i:nth-child(2) {
  width: 88%;
}

.app-window .aw-body i:nth-child(3) {
  width: 45%;
}

.app-window .aw-body i:nth-child(4) {
  width: 74%;
}

/* 远端光标 */
.remote-cursor {
  position: absolute;
  top: 54%;
  left: 58%;
  z-index: 3;
  filter: drop-shadow(0 2px 5px rgba(0, 0, 0, .5));
  animation: cursorMove 5.5s var(--ease) infinite;
}

.remote-cursor svg {
  width: 20px;
  height: 20px;
}

@keyframes cursorMove {

  0%,
  100% {
    transform: translate(0, 0);
  }

  25% {
    transform: translate(34px, -18px);
  }

  50% {
    transform: translate(-22px, 22px);
  }

  75% {
    transform: translate(14px, 12px);
  }
}

/* 底部任务栏 */
.session-taskbar {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 30px;
  background: rgba(11, 33, 56, .85);
  border-top: 1px solid rgba(255, 255, 255, .09);
  display: flex;
  align-items: center;
  gap: 8px;
  padding-inline: 12px;
}

.session-taskbar i {
  width: 16px;
  height: 16px;
  border-radius: 4px;
  background: rgba(255, 255, 255, .14);
  display: block;
}

.session-taskbar .tb-right {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: .62rem;
  color: #9fb6ce;
}

/* 会话工具栏 */
.session-tools {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  padding: 11px 14px;
  background: rgba(255, 255, 255, .04);
  border-top: 1px solid rgba(255, 255, 255, .08);
}

.tool {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 11px;
  border-radius: var(--r-sm);
  border: 1px solid rgba(255, 255, 255, .12);
  background: rgba(255, 255, 255, .05);
  color: #c7d6e8;
  font-size: .74rem;
  font-weight: 600;
}

.tool.on {
  border-color: rgba(41, 121, 255, .6);
  background: rgba(41, 121, 255, .18);
  color: #a8c9ff;
}

.tool svg {
  width: 13px;
  height: 13px;
}

/* 会话底部指标 */
.session-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: rgba(255, 255, 255, .08);
}

.session-metrics div {
  padding: 10px 14px;
  background: var(--c-navy);
  text-align: center;
}

.session-metrics b {
  display: block;
  font-family: var(--font-mono);
  font-size: .95rem;
  font-weight: 800;
  color: #fff;
}

.session-metrics span {
  font-size: .68rem;
  color: #8fa7c0;
}

/* --------------------------------------------------------------------------
   9. 卡片 / 能力
   -------------------------------------------------------------------------- */
.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));
}

.grid-auto {
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
}

.card {
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.card:hover {
  transform: translateY(-3px);
  border-color: var(--line-strong);
  box-shadow: var(--sh-md);
}

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

.card p {
  font-size: .9rem;
}

.icon-box {
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  margin-bottom: var(--sp-4);
  border-radius: var(--r-md);
  background: var(--c-blue-lt);
  color: var(--c-blue-dk);
}

.icon-box svg {
  width: 20px;
  height: 20px;
}

.icon-box.green {
  background: var(--c-green-lt);
  color: #01803a;
}

.icon-box.violet {
  background: #ede7ff;
  color: #5b21b6;
}

.icon-box.amber {
  background: var(--c-amber-lt);
  color: #b57500;
}

.tick-list {
  display: grid;
  gap: var(--sp-3);
  margin-top: var(--sp-5);
}

.tick-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-3);
  font-size: .87rem;
  color: var(--ink-2);
}

.tick-list svg {
  width: 17px;
  height: 17px;
  flex: 0 0 17px;
  margin-top: 3px;
  color: var(--c-green);
}

/* 带编号的能力块 */
.cap {
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.cap:hover {
  transform: translateY(-3px);
  border-color: var(--c-blue);
}

.cap .num {
  display: inline-block;
  margin-bottom: var(--sp-4);
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 800;
  color: var(--c-blue);
  letter-spacing: .06em;
}

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

.cap p {
  font-size: .89rem;
}

/* --------------------------------------------------------------------------
   10. 网络质量模拟器
   -------------------------------------------------------------------------- */
.sim {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
  padding: clamp(26px, 3.5vw, 44px);
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  background: var(--surface);
  box-shadow: var(--sh-md);
}

.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: .87rem;
  font-weight: 700;
}

.field label output {
  font-family: var(--font-mono);
  color: var(--c-blue-dk);
  font-weight: 800;
}

/* 模式切换 */
.mode-switch {
  display: inline-flex;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--bg-alt);
}

.mode-switch button {
  padding: 7px 16px;
  border-radius: var(--r-sm);
  font-size: .83rem;
  font-weight: 700;
  color: var(--ink-2);
  transition: all var(--dur-f) var(--ease);
}

.mode-switch button[aria-pressed="true"] {
  background: var(--surface);
  color: var(--c-blue-dk);
  box-shadow: var(--sh-sm);
}

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

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--c-blue);
  border: 3px solid #fff;
  box-shadow: 0 1px 6px rgba(11, 33, 56, .3);
  cursor: pointer;
}

input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--c-blue);
  border: 3px solid #fff;
  cursor: pointer;
}

/* 模拟结果面板 */
.sim-result {
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--c-navy);
  color: #fff;
}

.sim-result .sr-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  padding-bottom: var(--sp-5);
  margin-bottom: var(--sp-5);
  border-bottom: 1px solid rgba(255, 255, 255, .1);
}

.sim-result .sr-head h3 {
  color: #fff;
  font-size: .95rem;
}

.sim-result .sr-grade {
  padding: 3px 12px;
  border-radius: var(--r-pill);
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 800;
}

.sr-grade.a {
  background: rgba(0, 200, 83, .18);
  color: #6ef0a4;
}

.sr-grade.b {
  background: rgba(255, 171, 0, .18);
  color: #ffcc66;
}

.sr-grade.c {
  background: rgba(255, 82, 82, .18);
  color: #ff9b9b;
}

.sim-stats {
  display: grid;
  gap: var(--sp-4);
}

.sim-stat {
  display: grid;
  gap: 6px;
}

.sim-stat .ss-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: .82rem;
  color: #c7d6e8;
}

.sim-stat .ss-top b {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: #fff;
}

.sim-bar {
  height: 7px;
  border-radius: var(--r-pill);
  background: rgba(255, 255, 255, .1);
  overflow: hidden;
}

.sim-bar i {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--c-green);
  width: 0;
  transition: width .35s var(--ease), background-color .35s var(--ease);
}

.sim-bar i.mid {
  background: var(--c-amber);
}

.sim-bar i.bad {
  background: var(--c-red);
}

.sim-note {
  margin-top: var(--sp-6);
  padding-top: var(--sp-5);
  border-top: 1px solid rgba(255, 255, 255, .1);
  font-size: .82rem;
  color: #9fb6ce;
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   11. 数据指标
   -------------------------------------------------------------------------- */
.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(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
}

.metric .val {
  font-size: clamp(1.45rem, 3vw, 2.05rem);
  font-weight: 900;
  letter-spacing: -.03em;
  font-family: var(--font-mono);
  color: var(--ink);
}

.metric .cap {
  font-size: .82rem;
  color: var(--ink-3);
  margin-top: var(--sp-2);
}

/* --------------------------------------------------------------------------
   12. 步骤
   -------------------------------------------------------------------------- */
.steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--sp-5);
  counter-reset: step;
}

.step {
  position: relative;
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
}

.step::before {
  counter-increment: step;
  content: counter(step);
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  margin-bottom: var(--sp-4);
  border-radius: var(--r-sm);
  background: var(--c-navy);
  color: #fff;
  font-weight: 900;
  font-size: .88rem;
  font-family: var(--font-mono);
}

.step h3 {
  font-size: .97rem;
  margin-bottom: var(--sp-2);
}

.step p {
  font-size: .86rem;
}

/* --------------------------------------------------------------------------
   13. 价格 / 算价器
   -------------------------------------------------------------------------- */
.billing-toggle {
  display: inline-flex;
  gap: var(--sp-1);
  padding: var(--sp-1);
  margin-bottom: var(--sp-7);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: var(--surface);
}

.billing-toggle button {
  padding: 8px 20px;
  border-radius: var(--r-pill);
  font-size: .86rem;
  font-weight: 700;
  color: var(--ink-2);
  transition: all var(--dur-f) var(--ease);
}

.billing-toggle button[aria-pressed="true"] {
  background: var(--c-navy);
  color: #fff;
}

.billing-toggle .save {
  font-size: .71rem;
  opacity: .85;
}

.plan-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(--line);
  border-radius: var(--r-xl);
  background: var(--surface);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.plan:hover {
  transform: translateY(-3px);
  box-shadow: var(--sh-md);
}

.plan.featured {
  position: relative;
  border-color: var(--c-blue);
  box-shadow: 0 10px 30px rgba(41, 121, 255, .16);
}

.plan.featured::after {
  content: "最受欢迎";
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  padding: 3px 13px;
  border-radius: var(--r-pill);
  background: var(--grad-brand);
  color: #fff;
  font-size: .71rem;
  font-weight: 800;
  white-space: nowrap;
}

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

.plan .desc {
  font-size: .86rem;
  min-height: 42px;
  margin-bottom: var(--sp-5);
}

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

.plan .price .cur {
  font-size: 1rem;
  color: var(--ink-2);
}

.plan .price .amt {
  font-size: clamp(1.85rem, 3.6vw, 2.4rem);
  font-weight: 900;
  letter-spacing: -.04em;
  font-family: var(--font-mono);
}

.plan .price .per {
  font-size: .82rem;
  color: var(--ink-3);
}

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

.plan .plan-note {
  font-size: .76rem;
  color: var(--ink-3);
  margin-bottom: var(--sp-4);
}

.calc {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
  padding: clamp(26px, 3.5vw, 44px);
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  background: var(--surface);
  box-shadow: var(--sh-md);
}

.calc-result {
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--bg-alt);
  text-align: center;
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.calc-result .total {
  font-size: clamp(2.1rem, 4.6vw, 2.9rem);
  font-weight: 900;
  letter-spacing: -.04em;
  font-family: var(--font-mono);
  line-height: 1.1;
  color: var(--ink);
}

.calc-result .total small {
  font-size: .92rem;
  font-weight: 600;
  letter-spacing: 0;
}

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

.calc-breakdown > div {
  display: flex;
  justify-content: space-between;
  font-size: .84rem;
}

.calc-breakdown dt {
  color: var(--ink-3);
}

.calc-breakdown dd {
  font-family: var(--font-mono);
  color: var(--ink);
  font-weight: 700;
}

.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: 8px 15px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--r-md);
  background: var(--surface);
  font-size: .84rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--dur-f) var(--ease);
}

.radio-row label:hover {
  border-color: var(--c-blue);
}

.radio-row input {
  accent-color: var(--c-blue);
  width: 14px;
  height: 14px;
}

.radio-row label:has(input:checked) {
  border-color: var(--c-blue);
  background: var(--c-blue-lt);
}

/* --------------------------------------------------------------------------
   14. 下载卡
   -------------------------------------------------------------------------- */
.dl-card {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.dl-card:hover {
  transform: translateY(-3px);
  border-color: var(--c-blue);
  box-shadow: var(--sh-md);
}

.dl-card .dl-top {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
}

.dl-card .dl-logo {
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  border-radius: var(--r-md);
  display: grid;
  place-items: center;
  background: var(--c-navy);
  color: #fff;
}

.dl-card .dl-logo svg {
  width: 22px;
  height: 22px;
}

.dl-card h3 {
  font-size: .98rem;
}

.dl-card .dl-ver {
  font-size: .74rem;
  color: var(--ink-3);
  font-family: var(--font-mono);
}

.dl-card p {
  font-size: .86rem;
  flex: 1;
}

.dl-card .dl-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  padding-top: var(--sp-4);
  border-top: 1px solid var(--line);
  font-size: .76rem;
  color: var(--ink-3);
}

/* 徽标 */
.st {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 2px 8px;
  border-radius: var(--r-pill);
  font-size: .7rem;
  font-weight: 800;
}

.st::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: currentColor;
}

.st.on {
  background: var(--c-green-lt);
  color: #01803a;
}

.st.beta {
  background: var(--c-amber-lt);
  color: #b57500;
}

.st.soon {
  background: var(--bg-alt);
  color: var(--ink-3);
}

/* --------------------------------------------------------------------------
   15. 安全条目
   -------------------------------------------------------------------------- */
.sec-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--sp-5);
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.sec-item:hover {
  border-color: var(--c-blue);
  transform: translateX(3px);
}

.sec-item .sec-idx {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: var(--r-md);
  background: var(--c-navy);
  color: #fff;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: .85rem;
}

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

.sec-item p {
  font-size: .88rem;
}

/* --------------------------------------------------------------------------
   16. 评价
   -------------------------------------------------------------------------- */
.quote {
  display: flex;
  flex-direction: column;
  gap: var(--sp-5);
  padding: var(--sp-6);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.quote:hover {
  transform: translateY(-3px);
  border-color: var(--c-blue);
}

.quote blockquote {
  flex: 1;
  font-size: .93rem;
  line-height: 1.75;
  color: var(--ink);
}

.quote blockquote::before {
  content: "\201C";
  display: block;
  font-size: 2.4rem;
  line-height: .8;
  color: var(--c-blue);
  opacity: .35;
  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(--line);
}

.avatar {
  width: 42px;
  height: 42px;
  flex: 0 0 42px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 800;
  color: #fff;
  background: var(--c-navy);
}

.quote-meta .who {
  font-size: .87rem;
  font-weight: 700;
}

.quote-meta .role {
  font-size: .77rem;
  color: var(--ink-3);
}

/* --------------------------------------------------------------------------
   17. FAQ
   -------------------------------------------------------------------------- */
.faq {
  display: grid;
  gap: var(--sp-3);
  max-width: 840px;
  margin-inline: auto;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--surface);
  overflow: hidden;
  transition: border-color var(--dur-f) var(--ease);
}

.faq-item:hover {
  border-color: var(--line-strong);
}

.faq-item[open] {
  border-color: var(--c-blue);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  padding: var(--sp-5);
  font-weight: 700;
  font-size: .94rem;
  cursor: pointer;
  list-style: none;
}

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

.faq-item summary::after {
  content: "+";
  font-size: 1.35rem;
  font-weight: 400;
  line-height: 1;
  color: var(--c-blue);
  transition: transform var(--dur) var(--ease);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item .answer {
  padding: 0 var(--sp-5) var(--sp-5);
  font-size: .89rem;
  color: var(--ink-2);
}

/* --------------------------------------------------------------------------
   18. 页面头部 / 筛选
   -------------------------------------------------------------------------- */
.page-hero {
  padding-top: clamp(30px, 4.5vw, 52px);
  padding-bottom: clamp(22px, 3vw, 38px);
  text-align: center;
}

.page-hero h1 {
  font-size: clamp(1.7rem, 3.7vw, 2.6rem);
  margin-bottom: var(--sp-4);
}

.page-hero p {
  max-width: 62ch;
  margin-inline: auto;
  font-size: 1rem;
}

.crumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  margin-bottom: var(--sp-4);
  font-size: .79rem;
  color: var(--ink-3);
}

.crumb a:hover {
  color: var(--c-blue-dk);
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-5);
  margin-bottom: var(--sp-5);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
}

.filter-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-2);
}

.filter-group > span {
  font-size: .8rem;
  font-weight: 800;
  color: var(--ink-3);
  margin-right: var(--sp-2);
}

.chip {
  padding: 7px 15px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--r-md);
  background: var(--surface);
  font-size: .83rem;
  font-weight: 600;
  color: var(--ink-2);
  transition: all var(--dur-f) var(--ease);
}

.chip:hover {
  border-color: var(--c-blue);
}

.chip[aria-pressed="true"] {
  background: var(--c-navy);
  border-color: var(--c-navy);
  color: #fff;
}

.filter-count {
  margin-left: auto;
  font-size: .83rem;
  color: var(--ink-3);
}

.filter-count b {
  color: var(--ink);
  font-family: var(--font-mono);
}

.empty {
  padding: var(--sp-9) var(--sp-5);
  text-align: center;
  border: 1.5px dashed var(--line-strong);
  border-radius: var(--r-lg);
  background: var(--surface);
  color: var(--ink-3);
}

.empty strong {
  display: block;
  font-size: 1.08rem;
  color: var(--ink);
  margin-bottom: var(--sp-2);
}

.note {
  padding: var(--sp-5);
  border: 1px dashed var(--line-strong);
  border-radius: var(--r-md);
  background: var(--surface);
}

/* 文档布局 */
.docs-layout {
  display: grid;
  grid-template-columns: 210px 1fr;
  gap: clamp(24px, 4vw, 52px);
  align-items: start;
}

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

.docs-nav p {
  font-size: .72rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: var(--sp-2);
}

.docs-nav a {
  padding: 6px 10px;
  border-radius: var(--r-sm);
  font-size: .85rem;
  color: var(--ink-2);
  transition: background-color var(--dur-f) var(--ease), color var(--dur-f) var(--ease);
}

.docs-nav a:hover {
  background: var(--bg-alt);
  color: var(--ink);
}

.docs-body h2 {
  font-size: 1.4rem;
  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: 1.05rem;
  margin-top: var(--sp-6);
  margin-bottom: var(--sp-3);
}

.docs-body p {
  margin-bottom: var(--sp-4);
  font-size: .93rem;
}

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

.docs-body ul li {
  position: relative;
  padding-left: 19px;
  font-size: .91rem;
  color: var(--ink-2);
}

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

.code-block {
  position: relative;
  margin-bottom: var(--sp-5);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: #0b2138;
  overflow: hidden;
}

.code-block header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 15px;
  border-bottom: 1px solid rgba(255, 255, 255, .09);
  font-family: var(--font-mono);
  font-size: .74rem;
  color: #8fa7c0;
}

.copy-btn {
  padding: 3px 11px;
  border: 1px solid rgba(255, 255, 255, .18);
  border-radius: var(--r-sm);
  font-size: .72rem;
  color: #c7d6e8;
  transition: color var(--dur-f) var(--ease), border-color var(--dur-f) var(--ease);
}

.copy-btn:hover {
  color: #fff;
  border-color: rgba(255, 255, 255, .4);
}

.code-block pre {
  padding: var(--sp-5);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: .8rem;
  line-height: 1.8;
  color: #c7d6e8;
}

.method {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 5px;
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 700;
}

.method.get {
  background: var(--c-green-lt);
  color: #01803a;
}

.method.post {
  background: var(--c-blue-lt);
  color: var(--c-blue-dk);
}

.method.del {
  background: var(--c-red-lt);
  color: #c62828;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--surface);
  margin-bottom: var(--sp-5);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: .86rem;
}

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

th {
  background: var(--surface-2);
  font-weight: 700;
  font-size: .77rem;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--ink-3);
}

td {
  color: var(--ink-2);
}

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

tbody tr:hover {
  background: var(--surface-2);
}

.compare-table td.yes {
  color: #01803a;
  font-weight: 700;
}

.compare-table td.no {
  color: var(--ink-3);
}

.compare-table th:first-child,
.compare-table td:first-child {
  font-weight: 700;
  color: var(--ink);
}

/* --------------------------------------------------------------------------
   19. CTA
   -------------------------------------------------------------------------- */
.cta {
  position: relative;
  text-align: center;
  padding: clamp(42px, 5.5vw, 72px) var(--sp-6);
  border-radius: var(--r-xl);
  background: var(--grad-navy);
  color: #fff;
  overflow: hidden;
  box-shadow: var(--sh-lg);
}

.cta::before {
  content: "";
  position: absolute;
  top: -120px;
  right: -80px;
  width: 380px;
  height: 380px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(41, 121, 255, .35), transparent 68%);
}

.cta > * {
  position: relative;
}

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

.cta p {
  color: rgba(255, 255, 255, .82);
  max-width: 56ch;
  margin: 0 auto var(--sp-7);
  font-size: .99rem;
}

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

.cta .btn-primary {
  background: #fff;
  color: var(--c-navy);
  box-shadow: 0 10px 26px rgba(0, 0, 0, .22);
}

.cta .btn-outline {
  border-color: rgba(255, 255, 255, .35);
  background: transparent;
  color: #fff;
}

.cta .btn-outline:hover {
  background: #fff;
  color: var(--c-navy);
}

.cta-note {
  margin-top: var(--sp-5);
  font-size: .79rem;
  color: rgba(255, 255, 255, .72);
}

/* --------------------------------------------------------------------------
   20. 表单
   -------------------------------------------------------------------------- */
.form {
  padding: clamp(24px, 3vw, 38px);
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  background: var(--surface);
}

.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: .85rem;
  font-weight: 700;
}

.form-field .req {
  color: var(--c-red);
}

.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  padding: 11px 15px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--r-sm);
  background: var(--surface-2);
  font-size: .91rem;
  transition: border-color var(--dur-f) var(--ease), box-shadow var(--dur-f) var(--ease),
    background-color var(--dur-f) var(--ease);
}

.form-field textarea {
  min-height: 118px;
  resize: vertical;
  line-height: 1.65;
}

.form-field select {
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--ink-3) 50%),
    linear-gradient(135deg, var(--ink-3) 50%, transparent 50%);
  background-position: calc(100% - 19px) 50%, calc(100% - 14px) 50%;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
}

.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  outline: none;
  background: var(--surface);
  border-color: var(--c-blue);
  box-shadow: 0 0 0 3px rgba(41, 121, 255, .13);
}

.form-field input::placeholder,
.form-field textarea::placeholder {
  color: var(--ink-3);
}

.form-field .err {
  display: none;
  margin-top: 5px;
  font-size: .77rem;
  font-weight: 600;
  color: var(--c-red);
}

.form-field.has-error input,
.form-field.has-error select,
.form-field.has-error textarea {
  border-color: var(--c-red);
}

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

.form-status {
  display: none;
  margin-top: var(--sp-4);
  padding: var(--sp-4) var(--sp-5);
  border-radius: var(--r-md);
  background: var(--c-green-lt);
  border: 1px solid rgba(0, 200, 83, .35);
  font-size: .88rem;
  font-weight: 600;
  color: #01803a;
}

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

/* --------------------------------------------------------------------------
   21. 页脚
   -------------------------------------------------------------------------- */
.site-footer {
  margin-top: var(--sp-9);
  padding-top: var(--sp-8);
  border-top: 1px solid var(--line);
  background: var(--surface);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr repeat(3, 1fr);
  gap: clamp(24px, 4vw, 52px);
  padding-bottom: var(--sp-8);
}

.footer-brand p {
  margin-top: var(--sp-4);
  font-size: .87rem;
  max-width: 34ch;
}

.footer-col h4 {
  font-size: .76rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: var(--sp-4);
}

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

.footer-col a {
  font-size: .87rem;
  color: var(--ink-2);
  transition: color var(--dur-f) var(--ease);
}

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

.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(--line);
  font-size: .81rem;
  color: var(--ink-3);
}

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

.socials a {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border: 1px solid var(--line-strong);
  border-radius: var(--r-sm);
  background: var(--surface);
  color: var(--ink-2);
  transition: all var(--dur-f) var(--ease);
}

.socials a:hover {
  color: #fff;
  border-color: var(--c-navy);
  background: var(--c-navy);
}

.socials svg {
  width: 15px;
  height: 15px;
}

/* --------------------------------------------------------------------------
   22. 滚动入场
   -------------------------------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}

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

@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;
  }

  .remote-cursor {
    animation: none;
  }
}

/* --------------------------------------------------------------------------
   23. 响应式
   -------------------------------------------------------------------------- */
@media (max-width: 1060px) {
  .hero-inner {
    grid-template-columns: 1fr;
  }

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

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

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

  .calc-result {
    position: static;
  }

  .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;
  }

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

@media (max-width: 900px) {
  :root {
    --header-h: 62px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--sp-3) var(--sp-5) var(--sp-5);
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--sh-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease),
      visibility var(--dur);
  }

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

  .nav a {
    padding: var(--sp-4) 0;
    border-bottom: 1px solid var(--line);
    font-size: .98rem;
  }

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

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

  .grid-auto {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  }

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

  .plan.featured {
    order: -1;
  }

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

@media (max-width: 620px) {
  .container {
    padding-inline: var(--sp-4);
  }

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

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

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

  .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%;
  }

  .filter-count {
    margin-left: 0;
  }

  .hero-stats {
    gap: var(--sp-5);
  }

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

  .sec-item {
    grid-template-columns: 1fr;
  }
}

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

  .site-header,
  .nav-toggle,
  .site-footer,
  .cta,
  .calc-result {
    display: none !important;
  }

  body {
    background: #fff;
  }

  .card,
  .plan,
  .session,
  .dl-card,
  .sec-item {
    box-shadow: none;
    border-color: #ccc;
  }
}