/* ==========================================================================
   耀AI-创梦 · 落地页样式表
   设计令牌 → 基础层 → 组件层 → 响应式层
   零构建：纯 CSS，无框架、无预处理器
   ========================================================================== */

/* ==========================================================================
   1. 设计令牌
   ========================================================================== */
:root {
  /* 色板 —— 所有正文色均为实色，保证深色底上的对比度 ≥ 4.5:1 (WCAG AA) */
  --bg: #06060e;
  --bg-card: #161630;
  --bg-card-hover: #1c1c3e;
  --bg-soft: rgba(255, 255, 255, .03);

  --line: rgba(255, 255, 255, .07);
  --line-strong: rgba(255, 255, 255, .14);

  --txt: #ffffff;
  --txt-2: #c9cee8;
  --txt-3: #8b93b5;

  --accent: #6b8cff;
  --accent-2: #9b6cff;
  --accent-soft: #a8bcff;
  --grad: linear-gradient(135deg, #6b8cff, #8b6cff);
  --grad-soft: linear-gradient(135deg, rgba(107, 140, 255, .18), rgba(139, 108, 255, .12));

  /* 排版 —— 桌面系统字体栈，零外部字体请求 */
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
    'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', Roboto, Helvetica, Arial, sans-serif;

  --fs-h1: clamp(2.25rem, 1.05rem + 5.4vw, 4.4rem);
  --fs-h2: clamp(1.5rem, 1.15rem + 1.6vw, 2.15rem);
  --fs-h3: clamp(1rem, .95rem + .3vw, 1.15rem);
  --fs-body: clamp(.95rem, .92rem + .15vw, 1.02rem);
  --fs-sm: .85rem;
  --fs-xs: .75rem;

  /* 布局 */
  --container: 1200px;
  --container-narrow: 880px;
  --gutter: clamp(1rem, .35rem + 3vw, 2.5rem);
  --section-y: clamp(3.5rem, 1.8rem + 7vw, 7rem);
  --radius: 24px;
  --radius-sm: 14px;
  --nav-h: 72px;

  /* 动效 */
  --ease: cubic-bezier(.16, 1, .3, 1);
  --dur: .3s;

  /* 阴影 */
  --shadow: 0 8px 40px rgba(0, 0, 0, .3);
  --shadow-lg: 0 14px 60px rgba(0, 0, 0, .45);
  --glow: 0 4px 30px rgba(107, 140, 255, .25);
}

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

* { margin: 0; }

html {
  scroll-behavior: smooth;
  /* 关键修复：锚点跳转时给固定导航留出高度，避免标题被遮住 */
  scroll-padding-top: calc(var(--nav-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--txt);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  /* 用 clip 而不是 hidden：不会创建滚动容器，避免 sticky 失效 */
  overflow-x: clip;
}

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

/* 关键：基础层的 display:block 会覆盖 UA 的 [hidden]{display:none}，必须显式还原 */
[hidden] { display: none !important; }

h1, h2, h3, h4 { line-height: 1.15; font-weight: 700; letter-spacing: -.02em; text-wrap: balance; }
p { text-wrap: pretty; }

a { color: inherit; text-decoration: none; }
button, input { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }

ul, ol { list-style: none; padding: 0; }

/* 焦点可见性 —— 键盘用户必须有清晰焦点指示 */
:focus-visible {
  outline: 2px solid var(--accent-soft);
  outline-offset: 3px;
  border-radius: 6px;
}

::selection { background: rgba(107, 140, 255, .35); }

/* 滚动条 */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: rgba(255, 255, 255, .02); }
::-webkit-scrollbar-thumb { background: rgba(107, 140, 255, .3); border-radius: 8px; }
::-webkit-scrollbar-thumb:hover { background: rgba(107, 140, 255, .5); }

/* 跳到主要内容（无障碍） */
.skip-link {
  position: absolute;
  left: 50%;
  top: 0;
  z-index: 2000;
  padding: .6rem 1.2rem;
  background: var(--accent);
  color: #fff;
  border-radius: 0 0 12px 12px;
  font-size: var(--fs-sm);
  transform: translate(-50%, -120%);
  transition: transform .2s;
}
.skip-link:focus { transform: translate(-50%, 0); }

/* 渐变大标题文字 */
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ==========================================================================
   3. 背景层
   ========================================================================== */
.backdrop {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(ellipse 120% 80% at 50% 0%, #0d0d20 0%, #06060e 60%);
}

/* 星云光晕层：静态绘制一次，CSS 模糊不参与逐帧重绘 */
.backdrop__glow {
  position: absolute;
  inset: -10%;
  background:
    radial-gradient(circle 42vw at 26% 18%, rgba(107, 140, 255, .10), transparent 70%),
    radial-gradient(circle 38vw at 78% 74%, rgba(155, 108, 255, .09), transparent 70%);
  filter: blur(60px);
  animation: glowPulse 12s ease-in-out infinite alternate;
}

@keyframes glowPulse {
  from { opacity: .55; transform: scale(1); }
  to   { opacity: 1;   transform: scale(1.06); }
}

/* 星星画布：透明叠加在星云之上，逐帧只画星点 */
#starfield {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* ==========================================================================
   4. 布局工具
   ========================================================================== */
.container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: var(--container-narrow); }

.section {
  position: relative;
  z-index: 1;
  padding-block: var(--section-y);
}
/* 长页面节奏：极淡分隔线 + 局部色偏，避免 7 屏压在同一层星空上 */
.section + .section { border-top: 1px solid rgba(255, 255, 255, .05); }

/* 首屏光环属于装饰，允许视觉溢出，但绝不能撑出横向滚动条 */
main { overflow-x: clip; }
#section-flow,
#section-aq { background: linear-gradient(180deg, rgba(107, 140, 255, .045), rgba(107, 140, 255, 0) 45%); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem 1.5rem;
  margin-bottom: clamp(1.5rem, 1rem + 2vw, 2.75rem);
}
.section-head__side {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .6rem;
}

.section-title {
  display: flex;
  align-items: center;
  gap: .6em;
  font-size: var(--fs-h2);
}
.section-title i { color: var(--accent-soft); font-size: .85em; }

.section-sub { color: var(--txt-3); font-size: var(--fs-sm); }

/* ==========================================================================
   5. 通用组件
   ========================================================================== */

/* --- 卡片 --- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* --- 按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5em;
  padding: .7em 1.6em;
  border-radius: 999px;
  font-size: var(--fs-sm);
  font-weight: 600;
  line-height: 1.2;
  border: 1px solid transparent;
  white-space: nowrap;
  transition: transform var(--dur), box-shadow var(--dur), background var(--dur), border-color var(--dur);
}
.btn--primary {
  background: var(--grad);
  color: #fff;
  border-color: rgba(255, 255, 255, .12);
  box-shadow: var(--glow);
}
.btn--outline {
  color: var(--accent-soft);
  border-color: rgba(107, 140, 255, .3);
  background: rgba(107, 140, 255, .06);
}
.btn--ghost {
  color: var(--txt-2);
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, .03);
}
/* 次级实心按钮：与主按钮同级但材质不同，用于「免费领取」这类必须被看见的次要动作 */
.btn--secondary {
  color: #fff;
  border-color: rgba(255, 255, 255, .24);
  background: rgba(255, 255, 255, .08);
}
.btn--sm { padding: .5em 1.1em; font-size: var(--fs-xs); }
.btn--lg { padding: .85em 2.2em; font-size: clamp(.95rem, .9rem + .3vw, 1.1rem); }
.btn--block { width: 100%; }

@media (hover: hover) {
  .btn--primary:hover { transform: translateY(-2px); box-shadow: 0 8px 40px rgba(107, 140, 255, .4); }
  .btn--outline:hover { background: rgba(107, 140, 255, .14); border-color: rgba(107, 140, 255, .5); }
  .btn--ghost:hover   { background: rgba(255, 255, 255, .07); color: var(--txt); }
  .btn--secondary:hover { background: rgba(255, 255, 255, .16); border-color: rgba(255, 255, 255, .38); }
}
.btn:active { transform: translateY(0) scale(.985); }

/* 载入态：文件读取与后续的接口请求共用 */
.btn.is-loading { pointer-events: none; opacity: .72; }
.btn.is-loading::after {
  content: '';
  width: .9em;
  height: .9em;
  border-radius: 50%;
  border: 2px solid currentColor;
  border-top-color: transparent;
  animation: btnSpin .6s linear infinite;
}
@keyframes btnSpin { to { transform: rotate(1turn); } }

/* --- 标签 --- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: .5em;
  padding: .35em 1.1em;
  border-radius: 999px;
  font-size: var(--fs-sm);
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--accent-soft);
  background: rgba(107, 140, 255, .12);
  border: 1px solid rgba(107, 140, 255, .2);
}

.pill {
  display: inline-block;
  padding: .3em 1em;
  border-radius: 999px;
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--txt-3);
  background: var(--bg-soft);
  border: 1px solid var(--line);
  white-space: nowrap;
}
.pill--accent {
  color: var(--accent-soft);
  background: rgba(107, 140, 255, .1);
  border-color: rgba(107, 140, 255, .22);
  font-weight: 600;
}

.strip {
  margin-top: 1.25rem;
  padding: .7rem 1rem;
  text-align: center;
  border-radius: 999px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--txt-2);
  background: var(--bg-soft);
  border: 1px solid var(--line);
}
.strip i { color: var(--accent-soft); margin-right: .4em; }

.chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .75rem;
  margin-top: clamp(1.25rem, 1rem + 1.5vw, 2rem);
}
.chip {
  padding: .4em 1.1em;
  border-radius: 999px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--txt-2);
  background: var(--bg-soft);
  border: 1px solid var(--line);
}
.chip i { color: var(--accent-soft); margin-right: .4em; }
.chip--accent {
  color: #fff;
  background: var(--grad-soft);
  border-color: rgba(107, 140, 255, .25);
  font-weight: 600;
}

/* --- 入场动画 --- */
/* .js 由 main.js 第一时间加上：JS 不可用时内容默认可见，不会白屏 */
.js .reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .8s var(--ease), transform .8s var(--ease);
}
.js .reveal.is-visible { opacity: 1; transform: none; }
.js .reveal[data-delay="1"] { transition-delay: .06s; }
.js .reveal[data-delay="2"] { transition-delay: .12s; }
.js .reveal[data-delay="3"] { transition-delay: .18s; }
.js .reveal[data-delay="4"] { transition-delay: .24s; }
.js .reveal[data-delay="5"] { transition-delay: .3s; }
.js .reveal[data-delay="6"] { transition-delay: .36s; }

/* ==========================================================================
   6. 导航
   ========================================================================== */
.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 900;
  background: rgba(10, 10, 20, .8);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
  transition: background var(--dur), box-shadow var(--dur);
}
.nav.is-scrolled {
  background: rgba(10, 10, 20, .94);
  box-shadow: 0 8px 40px rgba(0, 0, 0, .45);
}

.nav__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: var(--nav-h);
}

.nav__logo {
  display: inline-flex;
  align-items: center;
  gap: .45em;
  font-size: clamp(1.15rem, 1.05rem + .5vw, 1.5rem);
  font-weight: 700;
  letter-spacing: -.01em;
  flex-shrink: 0;
}
.nav__logo i { color: var(--accent-soft); font-size: .9em; }

.nav__menu {
  display: flex;
  align-items: center;
  gap: .25rem;
  margin-inline: auto;
}
.nav__menu a {
  padding: .45em .85em;
  border-radius: 12px;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--txt-2);
  border: 1px solid transparent;
  transition: color var(--dur), background var(--dur), border-color var(--dur);
}
@media (hover: hover) {
  .nav__menu a:hover { color: var(--txt); background: rgba(255, 255, 255, .07); border-color: var(--line); }
}

.nav__actions { display: flex; align-items: center; gap: .6rem; flex-shrink: 0; }

/* 汉堡按钮：桌面隐藏 */
.nav__toggle {
  display: none;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, .03);
  place-items: center;
  transition: background var(--dur), border-color var(--dur);
}
.nav__toggle-bar,
.nav__toggle-bar::before,
.nav__toggle-bar::after {
  display: block;
  width: 18px;
  height: 2.5px;
  border-radius: 2px;
  background: var(--txt);
  transition: transform .3s var(--ease), opacity .2s;
}
.nav__toggle-bar { position: relative; }
.nav__toggle-bar::before { content: ''; position: absolute; top: -6px; }
.nav__toggle-bar::after  { content: ''; position: absolute; top: 6px; }
.nav__toggle[aria-expanded="true"] { background: rgba(255, 255, 255, .12); border-color: rgba(255, 255, 255, .32); }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar { transform: rotate(45deg); }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar::before { transform: translateY(6px) rotate(-90deg); }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar::after { opacity: 0; }

/* ==========================================================================
   7. 首屏
   ========================================================================== */
.section--hero {
  display: flex;
  align-items: center;
  min-height: 100vh;      /* 兜底 */
  min-height: 100svh;     /* 移动端：不受地址栏收缩影响 */
  padding-block: calc(var(--nav-h) + clamp(2rem, 4vw, 4rem)) clamp(2.5rem, 6vw, 5rem);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) auto;
  align-items: center;
  gap: clamp(1.5rem, 4vw, 4rem);
  width: 100%;
}

.hero__content { max-width: 44rem; }

.hero__content h1 {
  font-size: var(--fs-h1);
  margin-block: .5em .35em;
}

.hero__slogans {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem .8rem;
  margin-bottom: 1.5rem;
}
.hero__slogans span {
  padding: .3em 1.2em;
  border-radius: 999px;
  font-size: clamp(.95rem, .85rem + .7vw, 1.4rem);
  font-weight: 600;
  color: var(--txt-2);
  background: rgba(255, 255, 255, .04);
  border: 1px solid var(--line);
}

.hero__desc {
  max-width: 40rem;
  margin-bottom: 2rem;
  color: var(--txt-2);
  font-size: clamp(.95rem, .9rem + .25vw, 1.1rem);
  line-height: 1.85;
}
.hero__desc i { color: var(--accent-soft); margin-right: .5em; }

.hero__actions { display: flex; flex-wrap: wrap; gap: .8rem; }

/* 首屏视觉锚点：把「创梦」做成一个会呼吸的光环，而不是一块图标占位 */
.hero__deco {
  position: relative;
  display: grid;
  place-items: center;
  width: clamp(200px, 22vw, 300px);
  aspect-ratio: 1;
  border-radius: 50%;
  font-size: clamp(3.2rem, 6vw, 4.8rem);
  color: #d3ddff;
  background:
    radial-gradient(circle at 50% 45%, rgba(107, 140, 255, .26), rgba(107, 140, 255, 0) 66%),
    rgba(107, 140, 255, .05);
  border: 1px solid rgba(107, 140, 255, .22);
  box-shadow: var(--shadow), 0 0 80px rgba(107, 140, 255, .22);
  animation: floatDeco 7s ease-in-out infinite alternate;
}
.hero__deco > i { filter: drop-shadow(0 0 18px rgba(168, 188, 255, .55)); }
/* 内圈虚线环：缓慢自转 */
.hero__deco::before {
  content: '';
  position: absolute;
  inset: -13%;
  border-radius: 50%;
  border: 1px dashed rgba(168, 188, 255, .3);
  animation: spinSlow 28s linear infinite;
}
/* 外圈扫掠光弧：conic-gradient + 环形遮罩 */
.hero__deco::after {
  content: '';
  position: absolute;
  inset: -30%;
  border-radius: 50%;
  background: conic-gradient(from 0deg, rgba(155, 108, 255, 0) 0 66%, rgba(155, 108, 255, .55) 84%, rgba(155, 108, 255, 0) 100%);
  -webkit-mask: radial-gradient(closest-side, transparent 75%, #000 77%);
  mask: radial-gradient(closest-side, transparent 75%, #000 77%);
  animation: spinSlow 13s linear infinite reverse;
}
@keyframes spinSlow { to { transform: rotate(1turn); } }
@keyframes floatDeco {
  from { transform: translateY(-10px); }
  to   { transform: translateY(10px); }
}

/* ==========================================================================
   8. 功能演示
   ========================================================================== */
.func {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.5fr);
  gap: clamp(1rem, .5rem + 1.8vw, 1.75rem);
  align-items: start;
}

.func__side {
  min-width: 0;
  padding-right: clamp(0px, 1.5vw, 1.5rem);
  border-right: 1px solid var(--line);
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin-bottom: 1rem;
}
.tab {
  padding: .4em .95em;
  border-radius: 999px;
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--txt-3);
  background: rgba(255, 255, 255, .03);
  border: 1px solid var(--line);
  transition: all .2s;
}
@media (hover: hover) {
  .tab:hover { color: var(--txt-2); background: rgba(255, 255, 255, .07); }
}
.tab.is-active {
  color: #fff;
  background: var(--grad-soft);
  border-color: rgba(107, 140, 255, .35);
  font-weight: 600;
}
.tab i { margin-right: .35em; color: var(--accent-soft); }

.func__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(84px, 1fr));
  gap: .5rem;
  max-height: 26rem;
  overflow-y: auto;
  padding-right: .25rem;
}
.func__item {
  padding: .6rem .3rem;
  border-radius: var(--radius-sm);
  text-align: center;
  font-size: var(--fs-xs);
  font-weight: 500;
  line-height: 1.35;
  color: var(--txt-2);
  background: #1a1a38;
  border: 1px solid var(--line);
  transition: all .2s;
}
.func__item i {
  display: block;
  margin-bottom: .3em;
  font-size: 1.15rem;
  color: var(--accent-soft);
}
@media (hover: hover) {
  .func__item:hover { background: #22224a; border-color: rgba(107, 140, 255, .5); color: var(--txt); box-shadow: 0 0 0 1px rgba(107, 140, 255, .18); }
}
.func__item.is-active {
  background: rgba(107, 140, 255, .16);
  border-color: rgba(107, 140, 255, .45);
  color: #fff;
}

.func__tip {
  margin-top: .75rem;
  padding: .5rem;
  border-radius: 12px;
  border: 1px dashed var(--line);
  text-align: center;
  font-size: var(--fs-xs);
  color: var(--txt-3);
}

/* --- 预览面板 --- */
.preview {
  display: flex;
  flex-direction: column;
  padding: clamp(1rem, .7rem + 1.2vw, 1.5rem);
}

.preview__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .5rem;
  padding-bottom: .7rem;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--line);
}
.preview__name { font-size: var(--fs-h3); display: flex; align-items: center; gap: .45em; }
.preview__name i { color: var(--accent-soft); }
.preview__more {
  padding: .3em .9em;
  border-radius: 999px;
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--accent-soft);
  border: 1px solid rgba(107, 140, 255, .22);
  transition: background .2s;
}
@media (hover: hover) { .preview__more:hover { background: rgba(107, 140, 255, .12); } }

.preview__thumb {
  display: flex;
  align-items: center;
  gap: .85rem;
  padding: .5rem .75rem;
  margin-bottom: 1rem;
  border-radius: var(--radius-sm);
  background: var(--bg-soft);
  border: 1px solid var(--line);
  font-size: var(--fs-sm);
  color: var(--txt-3);
}
.preview__thumb-box {
  flex-shrink: 0;
  width: 88px;
  height: 56px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  font-size: var(--fs-xs);
  color: var(--txt-3);
  background: rgba(255, 255, 255, .05);
  border: 1px solid var(--line);
}

/* aspect-ratio 预留空间 → 图片加载/切换不会造成布局抖动 (CLS) */
.preview__stage {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 16 / 10;
  max-height: 34rem;
  border-radius: var(--radius-sm);
  border: 1px dashed var(--line-strong);
  background: rgba(255, 255, 255, .02);
  background-image: radial-gradient(circle, rgba(255, 255, 255, .035) 1px, transparent 1px);
  background-size: 20px 20px;
  overflow: hidden;
}
.preview__placeholder {
  padding: 1rem;
  text-align: center;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--txt-3);
}
.preview__placeholder i { display: block; margin-bottom: .4em; font-size: 2.4rem; color: rgba(255, 255, 255, .16); }
.preview__placeholder small { display: block; margin-top: .35em; font-size: var(--fs-xs); font-weight: 400; }

/* 空态用「原图 / 效果」中缝，暗示这块区域将来呈现前后对比 */
.preview__stage::before {
  content: '';
  position: absolute;
  inset: 1rem;
  border-radius: 10px;
  background: linear-gradient(90deg, transparent calc(50% - .5px), rgba(255, 255, 255, .07) 50%, transparent calc(50% + .5px));
  pointer-events: none;
}
.preview__tag {
  position: absolute;
  top: .85rem;
  z-index: 1;
  padding: .15em .7em;
  border-radius: 999px;
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--txt-3);
  background: rgba(6, 6, 14, .6);
  border: 1px solid var(--line);
  transition: opacity var(--dur);
}
.preview__tag--l { left: 1.5rem; }
.preview__tag--r { right: 1.5rem; }
.preview__stage.has-image .preview__tag { opacity: 0; }

.preview__img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 12px;
}

.preview__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .6rem;
  padding-top: 1rem;
  margin-top: 1rem;
  border-top: 1px solid var(--line);
}
.preview__cta { display: flex; gap: .5rem; margin-left: auto; }

.preview__desc {
  display: flex;
  align-items: flex-start;
  gap: .7rem;
  margin-top: 1rem;
  padding: .75rem 1rem;
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  color: var(--txt-2);
  background: var(--bg-soft);
  border: 1px solid var(--line);
}
.preview__desc i { color: var(--accent-soft); margin-top: .2em; }

.preview__banner {
  margin-top: .85rem;
  padding: .6rem 1rem;
  text-align: center;
  border-radius: 999px;
  font-size: var(--fs-sm);
  font-weight: 600;
  background: var(--grad-soft);
  border: 1px solid rgba(107, 140, 255, .22);
}
.preview__banner i { color: var(--accent-soft); margin-right: .4em; }

/* ==========================================================================
   9. 流程 / 安装步骤
   ========================================================================== */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: clamp(.85rem, .5rem + 1.2vw, 1.25rem);
  counter-reset: step;
}
.steps--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

.step {
  padding: clamp(1.25rem, 1rem + 1.2vw, 1.75rem) 1.25rem;
  text-align: center;
  transition: background var(--dur), border-color var(--dur), box-shadow var(--dur);
}
/* 步骤卡：不做通用位移，改用边框点亮 + 序号提亮 */
@media (hover: hover) {
  .step:hover { background: var(--bg-card-hover); border-color: rgba(107, 140, 255, .45); box-shadow: 0 0 0 1px rgba(107, 140, 255, .12); }
  .step:hover .step__num { color: #fff; border-bottom-color: rgba(107, 140, 255, .65); }
}
.step__num {
  display: inline-block;
  padding-bottom: .15em;
  transition: color var(--dur), border-color var(--dur);
  margin-bottom: .4em;
  font-size: clamp(1.8rem, 1.5rem + 1.6vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  color: var(--accent-soft);
  border-bottom: 2px solid var(--line);
}
.step h3 { font-size: var(--fs-h3); font-weight: 600; margin-bottom: .35em; }
.step h3 i { color: var(--accent-soft); margin-right: .3em; }
.step p { font-size: var(--fs-sm); color: var(--txt-3); }

/* 图标版步骤卡（课程体系 / 合作方向复用 step 的版式） */
.step__icon {
  display: block;
  margin-bottom: .45em;
  font-size: 2.1rem;
  line-height: 1;
  color: var(--accent-soft);
}

/* 五步流程：默认一行铺满，窄屏逐级降列 */
.steps--flow { grid-template-columns: repeat(5, 1fr); }

.partner-flow-title {
  display: flex;
  align-items: center;
  gap: .45em;
  margin: clamp(1.5rem, 1.2rem + 1.5vw, 2.25rem) 0 .85rem;
  font-size: clamp(1.1rem, 1.05rem + .4vw, 1.35rem);
}
.partner-flow-title i { color: var(--accent-soft); }

/* --- 安装教程合并区 --- */
.tutorial {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem 1.5rem;
  margin-top: clamp(1rem, .6rem + 1.2vw, 1.5rem);
  padding: clamp(1.25rem, 1rem + 1.2vw, 1.75rem);
  transition: background var(--dur), border-color var(--dur);
}
@media (hover: hover) { .tutorial:hover { background: var(--bg-card-hover); border-color: var(--line-strong); } }
.tutorial__text { flex: 1 1 20rem; min-width: 0; }
.tutorial__text h3 { font-size: var(--fs-h3); display: flex; align-items: center; gap: .45em; margin-bottom: .4em; }
.tutorial__text h3 i { color: var(--accent-soft); }
.tutorial__text p { font-size: var(--fs-sm); color: var(--txt-2); line-height: 1.7; }
.tutorial__text p i { color: var(--accent-soft); margin-right: .35em; }
.tutorial__actions { flex-shrink: 0; }

/* ==========================================================================
   10. 定价
   ========================================================================== */
.plans {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: clamp(1rem, .6rem + 1.5vw, 1.5rem);
  max-width: 46rem;
  margin-inline: auto;
}

.plan {
  position: relative;
  padding: clamp(1.5rem, 1.2rem + 1.2vw, 2rem);
  text-align: center;
  transition: box-shadow var(--dur), background var(--dur), border-color var(--dur);
}
/* 定价卡：hover 用顶部内发光条替代位移，保持价格区的稳重感
   注意排除推荐卡：它是黑白反转配色，普通 hover 换背景会把反转文字打到对比度崩掉 */
@media (hover: hover) {
  .plan:hover:not(.plan--featured) {
    background: var(--bg-card-hover);
    border-color: rgba(107, 140, 255, .42);
    box-shadow: inset 0 2px 0 rgba(107, 140, 255, .6), var(--shadow);
  }
}
.plan h3 { font-size: var(--fs-h3); margin-bottom: .6em; }
.plan__price { font-size: clamp(2.2rem, 1.8rem + 2vw, 3rem); font-weight: 700; line-height: 1.1; }
.plan__meta {
  padding-bottom: .7rem;
  margin-bottom: .7rem;
  font-size: var(--fs-sm);
  color: var(--txt-3);
  border-bottom: 1px solid var(--line);
}
.plan__list { margin-bottom: 1.25rem; text-align: left; }
.plan__list li {
  display: flex;
  align-items: center;
  gap: .55em;
  padding: .35em 0;
  font-size: var(--fs-sm);
  color: var(--txt-2);
  border-bottom: 1px solid rgba(255, 255, 255, .035);
}
.plan__list i { color: var(--accent-soft); font-size: .85em; flex-shrink: 0; }
.plan__note { margin-top: .8rem; font-size: var(--fs-xs); color: var(--txt-3); }
.plan__note i { color: var(--accent-soft); margin-right: .35em; }

.plan--featured {
  border-color: rgba(107, 140, 255, .35);
  background: #181840;
  box-shadow: 0 10px 50px rgba(107, 140, 255, .12);
}
@media (hover: hover) {
  .plan--featured:hover {
    box-shadow: inset 0 2px 0 rgba(107, 140, 255, .65), 0 10px 50px rgba(107, 140, 255, .18);
  }
}
.plan--featured::before {
  content: "推荐";
  position: absolute;
  top: 0;
  right: 1.25rem;
  transform: translateY(-50%);
  padding: .25em 1.1em;
  border-radius: 999px;
  font-size: var(--fs-xs);
  font-weight: 600;
  /* 深色字压品牌渐变：最亮端仍有 5.47:1，白字原本只有 3.08:1 */
  color: #05060e;
  background: var(--grad);
  box-shadow: var(--glow);
}

/* ==========================================================================
   11. A&Q
   ========================================================================== */
.faq { display: flex; flex-direction: column; gap: .7rem; }

.faq__item {
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: background var(--dur), border-color var(--dur);
}
@media (hover: hover) { .faq__item:hover { background: var(--bg-card-hover); border-color: var(--line-strong); } }

.faq__item summary {
  display: flex;
  align-items: center;
  gap: .6em;
  padding: 1rem 1.15rem;
  font-size: var(--fs-body);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  transition: color var(--dur);
}
.faq__item summary::-webkit-details-marker { display: none; }
.faq__item summary i { color: var(--accent-soft); transition: transform .3s var(--ease); flex-shrink: 0; }
.faq__item[open] summary i { transform: rotate(45deg); }
.faq__item summary::after {
  content: '';
  margin-left: auto;
  width: .5em;
  height: .5em;
  border-right: 2px solid var(--txt-3);
  border-bottom: 2px solid var(--txt-3);
  transform: rotate(45deg) translateY(-2px);
  transition: transform .3s var(--ease);
  flex-shrink: 0;
}
.faq__item[open] summary::after { transform: rotate(-135deg) translateY(-2px); }

.faq__answer {
  padding: 0 1.15rem 1.15rem 2rem;
  margin-left: .35rem;
  border-left: 2px solid rgba(107, 140, 255, .25);
  font-size: var(--fs-sm);
  line-height: 1.8;
  color: var(--txt-2);
}

/* ==========================================================================
   12. 加入 / 二维码
   ========================================================================== */
.qr-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: clamp(1rem, .6rem + 1.4vw, 1.5rem);
  max-width: 60rem;
  margin-inline: auto;
}

.qr {
  padding: clamp(1.25rem, 1rem + 1vw, 1.75rem) clamp(1rem, .8rem + 1vw, 1.5rem);
  text-align: center;
  transition: box-shadow var(--dur), background var(--dur), border-color var(--dur);
}
@media (hover: hover) {
  .qr:hover { background: var(--bg-card-hover); border-color: rgba(107, 140, 255, .45); box-shadow: 0 0 0 1px rgba(107, 140, 255, .14); }
}

.qr__box {
  position: relative;
  display: grid;
  place-items: center;
  width: min(100%, 170px);
  aspect-ratio: 1;
  margin: 0 auto .9rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, .03);
  overflow: hidden;
  transition: border-color var(--dur), box-shadow var(--dur);
}
@media (hover: hover) { .qr__box:hover { border-color: rgba(107, 140, 255, .5); box-shadow: 0 4px 32px rgba(107, 140, 255, .12); } }
.qr__box > i { font-size: 2.6rem; color: rgba(255, 255, 255, .14); }
.qr__box img { width: 100%; height: 100%; object-fit: contain; }

.qr__title {
  padding-bottom: .35em;
  margin-bottom: .5em;
  font-size: clamp(1.05rem, 1rem + .5vw, 1.4rem);
  border-bottom: 1px solid var(--line);
}
.qr__title i { margin-right: .3em; color: var(--accent-soft); }

.qr__desc { font-size: clamp(.85rem, .83rem + .15vw, 1rem); color: var(--txt-2); line-height: 1.9; }
.qr__desc p i { margin-right: .4em; color: var(--accent-soft); }
.qr__accent {
  display: inline-block;
  margin-top: .5em;
  padding: .15em .8em;
  border-radius: 8px;
  font-size: .92em;
  font-weight: 500;
  color: var(--accent-soft);
  background: rgba(107, 140, 255, .1);
}
.qr__field-value[data-value] { color: var(--accent-soft); font-weight: 600; }
.qr__field-value.is-missing { color: var(--txt-3); font-weight: 400; font-style: italic; }
.qr__field.is-copyable { cursor: pointer; }
@media (hover: hover) { .qr__field.is-copyable:hover .qr__field-value { text-decoration: underline; } }

/* ==========================================================================
   13. 底部
   ========================================================================== */
.section--last { padding-bottom: clamp(2.5rem, 5vw, 4rem); }

.footer {
  position: relative;
  z-index: 1;
  padding-block: 2rem;
  border-top: 1px solid var(--line);
  background: rgba(6, 6, 14, .55);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.footer__inner { text-align: center; }
.footer__inner > p { font-size: var(--fs-sm); color: var(--txt-3); }
.footer__inner > p i { color: var(--accent); margin-right: .4em; }
.footer__legal {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .5rem;
  margin-top: .6rem;
  font-size: var(--fs-xs);
  color: var(--txt-3);
}
.footer__sep { opacity: .4; }

/* ==========================================================================
   14. 轻提示
   ========================================================================== */
.toast-wrap {
  position: fixed;
  left: 50%;
  bottom: max(1.25rem, env(safe-area-inset-bottom));
  z-index: 1500;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .5rem;
  width: min(92vw, 26rem);
  transform: translateX(-50%);
  pointer-events: none;
}
.toast {
  display: flex;
  align-items: center;
  gap: .55em;
  padding: .7em 1.2em;
  border-radius: 999px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--txt);
  background: rgba(28, 28, 62, .97);
  border: 1px solid var(--line-strong);
  box-shadow: var(--shadow-lg);
  animation: toastIn .35s var(--ease);
}
.toast i { color: var(--accent-soft); flex-shrink: 0; }
.toast.is-out { animation: toastOut .3s var(--ease) forwards; }
@keyframes toastIn  { from { opacity: 0; transform: translateY(14px) scale(.96); } }
@keyframes toastOut { to   { opacity: 0; transform: translateY(10px) scale(.96); } }

/* ==========================================================================
   15. 响应式
   ========================================================================== */

/* --- 平板 / 小笔记本 --- */
@media (max-width: 1080px) {
  .func { grid-template-columns: 1fr; }
  .func__side { padding-right: 0; padding-bottom: 1.25rem; border-right: 0; border-bottom: 1px solid var(--line); }
  .func__grid { max-height: none; grid-template-columns: repeat(auto-fill, minmax(88px, 1fr)); }
  .hero { grid-template-columns: 1fr; }
  .hero__deco { display: none; }
}

/* --- 移动端导航切换 --- */
@media (max-width: 900px) {
  :root { --nav-h: 64px; }

  .nav__toggle { display: grid; }

  .nav__menu {
    position: absolute;
    top: var(--nav-h);
    left: 0;
    right: 0;
    display: grid;
    gap: .25rem;
    max-height: 0;
    padding: 0 var(--gutter);
    overflow: hidden;
    margin-inline: 0;
    /* 完全不透明：抽屉下方内容不能透出干扰阅读 */
    background: #0a0a14;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-bottom: 1px solid transparent;
    transition: max-height .35s var(--ease), padding .35s var(--ease), border-color .35s;
  }
  .nav__menu.is-open {
    /* 用视口高度兜底：以后入口变多也不会被裁掉 */
    max-height: calc(100vh - var(--nav-h) - 1rem);
    overflow-y: auto;
    overscroll-behavior: contain;
    padding-block: .85rem 1.1rem;
    border-bottom-color: var(--line);
    box-shadow: 0 20px 50px rgba(0, 0, 0, .5);
  }
  .nav__menu a {
    padding: .7em 1em;
    font-size: var(--fs-body);
    background: rgba(255, 255, 255, .03);
  }
}

/* --- 手机 --- */
@media (max-width: 640px) {
  :root { --radius: 20px; }

  .section-head { flex-direction: column; align-items: flex-start; }
  .section-head__side { width: 100%; }

  .section-title { gap: .45em; }

  .preview__cta { margin-left: 0; width: 100%; }
  .preview__cta .btn { flex: 1; }
  .preview__actions .pill { flex-basis: 100%; text-align: center; }

  .tutorial__actions { width: 100%; }
  .tutorial__actions .btn { width: 100%; }

  .faq__answer { padding-left: 1.25rem; }

  .qr-grid { grid-template-columns: 1fr; }
  .steps, .steps--3 { grid-template-columns: 1fr; }
  .steps--flow { grid-template-columns: 1fr; }
  .plans { grid-template-columns: 1fr; }
  .plan--featured::before { right: 50%; transform: translate(50%, -50%); }
}

/* --- 小屏手机 --- */
@media (max-width: 420px) {
  .func__grid { grid-template-columns: repeat(auto-fill, minmax(76px, 1fr)); }
  .hero__actions .btn { width: 100%; }
  /* 保留转化入口：CTA 收成图标按钮，而不是整块隐藏 */
  .nav__actions { gap: .4rem; }
  .nav__actions .btn { padding: .55em .8em; }
  .nav__actions .btn__label { display: none; }
}

/* --- 大屏 --- */
@media (min-width: 1600px) {
  :root { --container: 1320px; }
}

/* ==========================================================================
   16. 无障碍 / 偏好
   ========================================================================== */

/* 尊重「减少动态效果」系统偏好 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
  .js .reveal { opacity: 1; transform: none; }
}

/* 强制高对比度模式 */
@media (forced-colors: active) {
  .card, .btn, .tab { border: 1px solid CanvasText; }
}

/* 打印：去掉背景与动效，保留内容 */
@media print {
  .backdrop, .nav, .toast-wrap, .preview__actions, .footer__legal { display: none !important; }
  body { background: #fff; color: #000; }
  .card { border: 1px solid #ccc; box-shadow: none; }
  .js .reveal { opacity: 1; transform: none; }
}