/* ==========================================================================
   SnapIn 官网 · 设计系统
   --------------------------------------------------------------------------
   零依赖:不引任何外部字体 / CSS 框架 / 图标库。
   色板来源(与 App 严格同源,不是"随手调的橙色"):
     --amber / --amber-deep / --soft-yellow / --pale-gold / --cream
        取自 SnapIn/Watermark/WatermarkPreset.swift 的六种水印预设色
     --ink-*  取自 AppIcon1024.png 的像素取样(#262527 / #202022 / #272829)
   字体走系统栈,中文优先 PingFang SC,不加载网络字体(首屏零请求阻塞)。
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. 设计令牌
   -------------------------------------------------------------------------- */
:root {
  /* 炭黑阶 —— 图标底色取样 */
  --ink-1000: #121113;
  --ink-950: #17161A;
  --ink-900: #1B1A1E;
  --ink-850: #201F23;
  --ink-800: #262529;
  --ink-750: #2B2A2F;
  --ink-700: #323136;
  --ink-600: #3E3D44;

  /* 琥珀阶 —— 水印预设色 */
  --amber: #f3a32c;          /* amberClassic */
  --amber-bright: #ffc366;
  --amber-deep: #d98a1f;     /* deepOrange */
  --amber-glow: #f9b458;
  --soft-yellow: #e8c85a;    /* softYellow */
  --pale-gold: #cfae57;      /* paleGold */
  --soft-amber: #e9a64b;     /* softAmber */

  /* 奶油白 —— warmWhite */
  --cream: #f2e7c9;
  --cream-bright: #fcf6ea;
  --cream-90: rgba(242, 231, 201, 0.90);
  --cream-70: rgba(242, 231, 201, 0.70);
  --cream-50: rgba(242, 231, 201, 0.50);
  --cream-34: rgba(242, 231, 201, 0.34);

  /* 描边与浅底 */
  --line: rgba(242, 231, 201, 0.10);
  --line-2: rgba(242, 231, 201, 0.16);
  --line-3: rgba(242, 231, 201, 0.26);
  --amber-line: rgba(243, 163, 44, 0.36);
  --amber-wash: rgba(243, 163, 44, 0.10);
  --amber-wash-2: rgba(243, 163, 44, 0.18);

  /* 圆角 */
  --r-xs: 8px;
  --r-sm: 12px;
  --r-md: 16px;
  --r-lg: 22px;
  --r-xl: 30px;
  --r-pill: 999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 20px 44px -28px rgba(0, 0, 0, 0.95), 0 1px 0 rgba(255, 255, 255, 0.03) inset;
  --shadow-lg: 0 44px 90px -40px rgba(0, 0, 0, 1), 0 1px 0 rgba(255, 255, 255, 0.04) inset;
  --shadow-amber: 0 18px 50px -22px rgba(243, 163, 44, 0.55);

  /* 尺寸 */
  --maxw: 1140px;
  --maxw-wide: 1280px;
  --header-h: 64px;
  --gutter: 24px;

  /* 字体 */
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  /* 动效 */
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
}

body {
  margin: 0;
  background: var(--ink-1000);
  color: var(--cream);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 英文文案的字距/行高需要单独一档:中文靠字距呼吸,英文靠词距 */
html[data-lang="en"] body { letter-spacing: 0; line-height: 1.65; }

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

a { color: var(--amber); text-decoration: none; }
a:hover { color: var(--amber-bright); }

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

h1, h2, h3, h4 {
  margin: 0;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.015em;
}
html[data-lang="zh"] h1,
html[data-lang="zh"] h2 { letter-spacing: 0.005em; }

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

::selection { background: var(--amber); color: var(--ink-1000); }

/* 统一焦点环:键盘可达性 */
:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
  border-radius: 4px;
}

/* 跳转到主内容(键盘/读屏) */
.skip-link {
  position: absolute;
  left: 50%;
  top: -100px;
  transform: translateX(-50%);
  z-index: 200;
  padding: 12px 22px;
  border-radius: 0 0 var(--r-md) var(--r-md);
  background: var(--amber);
  color: var(--ink-1000);
  font-weight: 700;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 0; color: var(--ink-1000); }

/* --------------------------------------------------------------------------
   3. 背景层
   -------------------------------------------------------------------------- */
.bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

/* 顶部琥珀落日辉光 —— 呼应 App 图标里的夕阳 */
.bg__glow {
  position: absolute;
  left: 50%;
  top: -520px;
  width: 1500px;
  height: 1000px;
  transform: translateX(-50%);
  background:
    radial-gradient(closest-side, rgba(243, 163, 44, 0.30), rgba(243, 163, 44, 0) 72%);
  filter: blur(20px);
}
.bg__glow--2 {
  top: auto;
  bottom: -640px;
  left: -260px;
  width: 1100px;
  height: 900px;
  background: radial-gradient(closest-side, rgba(217, 138, 31, 0.16), rgba(217, 138, 31, 0) 70%);
}
.bg__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(242, 231, 201, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(242, 231, 201, 0.035) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 55% at 50% 0%, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 80% 55% at 50% 0%, #000 20%, transparent 78%);
}
/* 极轻噪点,避免大面积深色出现色带 */
.bg__grain {
  position: absolute;
  inset: 0;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* --------------------------------------------------------------------------
   4. 布局与通用组件
   -------------------------------------------------------------------------- */
.page { position: relative; z-index: 1; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.container--wide { max-width: var(--maxw-wide); }

.section { padding: 108px 0; }
.section--tight { padding: 76px 0; }
.section--flush-top { padding-top: 0; }

.section__head { max-width: 720px; margin-bottom: 56px; }
.section__head--center { margin-left: auto; margin-right: auto; text-align: center; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  color: var(--amber);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--amber);
  opacity: 0.7;
}
.section__head--center .eyebrow::after {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--amber);
  opacity: 0.7;
}

.h2 {
  font-size: clamp(28px, 3.6vw, 44px);
  color: var(--cream-bright);
  /* 平衡换行:中文可以在任意字之间断行,不干预会出现「手机」被拆成
     「手 / 机」这种孤字行。balance 让各行长度接近,顺带修掉孤字。 */
  text-wrap: balance;
}
.h3 { font-size: 19px; color: var(--cream-bright); }

.lede {
  margin-top: 20px;
  font-size: clamp(15px, 1.5vw, 17px);
  color: var(--cream-70);
  line-height: 1.8;
}

.text-amber { color: var(--amber); }
.text-gradient {
  background: linear-gradient(178deg, var(--cream-bright) 8%, var(--amber-bright) 52%, var(--amber-deep) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 13px 24px;
  border-radius: var(--r-pill);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease),
    background-color 0.18s var(--ease), border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--primary {
  background: linear-gradient(180deg, var(--amber-bright), var(--amber) 55%, var(--amber-deep));
  color: #241703;
  box-shadow: var(--shadow-amber);
}
.btn--primary:hover { color: #241703; box-shadow: 0 22px 60px -20px rgba(243, 163, 44, 0.72); }

.btn--ghost {
  border: 1px solid var(--line-2);
  background: rgba(242, 231, 201, 0.03);
  color: var(--cream);
}
.btn--ghost:hover { border-color: var(--line-3); background: rgba(242, 231, 201, 0.06); color: var(--cream-bright); }

.btn--sm { padding: 9px 18px; font-size: 14px; }
.btn--block { width: 100%; }

/* 尚未开放的下载按钮:明确不可点,不伪装成可用链接 */
.btn.is-soon {
  background: rgba(242, 231, 201, 0.05);
  border: 1px dashed var(--line-3);
  color: var(--cream-50);
  box-shadow: none;
  cursor: not-allowed;
}
.btn.is-soon:hover { transform: none; color: var(--cream-50); }
.btn.is-soon .btn__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 0 rgba(243, 163, 44, 0.6);
  animation: pulse 2.4s var(--ease) infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(243, 163, 44, 0.5); }
  70% { box-shadow: 0 0 0 9px rgba(243, 163, 44, 0); }
  100% { box-shadow: 0 0 0 0 rgba(243, 163, 44, 0); }
}

/* 徽标 / 胶囊 */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 7px 15px 7px 11px;
  border: 1px solid var(--amber-line);
  border-radius: var(--r-pill);
  background: var(--amber-wash);
  color: var(--amber);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}
.badge__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
}

/* 卡片 */
.card {
  position: relative;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900));
  box-shadow: var(--shadow-md);
  transition: border-color 0.24s var(--ease), transform 0.24s var(--ease), box-shadow 0.24s var(--ease);
}
.card:hover {
  border-color: var(--amber-line);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg), 0 0 0 1px rgba(243, 163, 44, 0.08);
}

/* 素材工具类 */
/* 内联 SVG 精灵容器:只放 <defs>/<symbol>,不占布局 */
.scene-sprite {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}
/* 所有"照片"画面:铺满容器。symbol 用了 preserveAspectRatio="slice",
   所以画幅区里的 1:1 / 16:9 是真正的中心裁切,而不是拉伸变形。 */
.scene { display: block; width: 100%; height: 100%; }

/* 段落级 CTA / 补充链接 */
.privacy__cta { margin-top: 26px; }
.faq__more { margin-top: 34px; text-align: center; }
.cta__status {
  margin-top: 20px;
  color: var(--cream-34);
  font-size: 13px;
}
.cta__status:empty { display: none; }

/* --------------------------------------------------------------------------
   5. 顶栏
   -------------------------------------------------------------------------- */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid transparent;
  transition: background-color 0.25s var(--ease), border-color 0.25s var(--ease), backdrop-filter 0.25s var(--ease);
}
.header.is-stuck {
  border-bottom-color: var(--line);
  background: rgba(18, 17, 19, 0.78);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  backdrop-filter: saturate(160%) blur(16px);
}
.header__inner {
  display: flex;
  align-items: center;
  gap: 18px;
  width: 100%;
}

.brand { display: inline-flex; align-items: center; gap: 11px; color: var(--cream-bright); }
.brand:hover { color: var(--cream-bright); }
.brand__icon {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  box-shadow: 0 4px 14px -4px rgba(0, 0, 0, 0.9), 0 0 0 1px rgba(242, 231, 201, 0.10);
}
.brand__name { font-size: 17px; font-weight: 800; letter-spacing: 0.01em; }

.nav { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav__link {
  padding: 8px 13px;
  border-radius: var(--r-sm);
  color: var(--cream-70);
  font-size: 14.5px;
  font-weight: 600;
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.nav__link:hover { color: var(--cream-bright); background: rgba(242, 231, 201, 0.06); }

.header__actions { display: flex; align-items: center; gap: 10px; }

/* 语言切换:分段控件 */
.lang {
  display: inline-flex;
  padding: 3px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-pill);
  background: rgba(242, 231, 201, 0.03);
}
.lang__btn {
  padding: 5px 12px;
  border-radius: var(--r-pill);
  color: var(--cream-50);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.03em;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
}
.lang__btn:hover { color: var(--cream); }
.lang__btn.is-active {
  background: var(--amber);
  color: #241703;
}

/* 移动端菜单按钮 */
.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-sm);
  align-items: center;
  justify-content: center;
}
.nav-toggle span {
  position: relative;
  display: block;
  width: 17px;
  height: 1.6px;
  background: var(--cream);
  border-radius: 2px;
  transition: transform 0.22s var(--ease), background-color 0.22s var(--ease);
}
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 17px;
  height: 1.6px;
  background: var(--cream);
  border-radius: 2px;
  transition: transform 0.22s var(--ease), opacity 0.22s 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); }

/* --------------------------------------------------------------------------
   6. Hero
   -------------------------------------------------------------------------- */
.hero { padding: 84px 0 96px; }
.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  align-items: center;
  gap: 64px;
}
.hero__title {
  margin: 22px 0 0;
  font-size: clamp(38px, 5.6vw, 64px);
  line-height: 1.08;
  color: var(--cream-bright);
}
.hero__title .line { display: block; }
.hero__sub {
  margin-top: 24px;
  max-width: 520px;
  font-size: clamp(16px, 1.7vw, 18px);
  color: var(--cream-70);
  line-height: 1.85;
}
.hero__sub strong { color: var(--cream-bright); font-weight: 700; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 13px; margin-top: 34px; }
.hero__note {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  color: var(--cream-34);
  font-size: 13.5px;
}
.hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin-top: 34px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
}
.hero__fact { display: flex; align-items: center; gap: 8px; color: var(--cream-50); font-size: 13.5px; }
.hero__fact::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--amber);
  opacity: 0.75;
}

/* --------------------------------------------------------------------------
   7. 手机样机(App 界面示意)
   -------------------------------------------------------------------------- */
.phone-wrap { position: relative; display: flex; justify-content: center; }

.phone {
  position: relative;
  width: 300px;
  padding: 10px;
  border: 1px solid rgba(242, 231, 201, 0.14);
  border-radius: 46px;
  background: linear-gradient(168deg, #34333a, #1a191d 42%, #131215);
  box-shadow: var(--shadow-lg), 0 0 90px -30px rgba(243, 163, 44, 0.45);
}
.phone::before {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 43px;
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.06), transparent 40%);
  pointer-events: none;
}
.phone__island {
  position: absolute;
  left: 50%;
  top: 20px;
  width: 82px;
  height: 22px;
  transform: translateX(-50%);
  z-index: 3;
  border-radius: var(--r-pill);
  background: #0a0a0b;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.05);
}
.phone__screen {
  position: relative;
  overflow: hidden;
  border-radius: 37px;
  background: #0c0b0d;
}

/* 相机界面 */
.cam { display: flex; flex-direction: column; height: 560px; }

.cam__top {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 34px 16px 12px;
}
.cam__chip {
  padding: 5px 11px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(242, 231, 201, 0.05);
  color: var(--cream-50);
  font-size: 11.5px;
  font-weight: 600;
  white-space: nowrap;
}
.cam__chip.is-active {
  border-color: transparent;
  background: var(--amber);
  color: #241703;
  font-weight: 700;
}
.cam__chip--more { border-style: dashed; }

/* 取景框:高度只由宽度决定,切换画幅时下方操作区不位移 */
.cam__stage { padding: 0 16px; }
.cam__viewfinder {
  position: relative;
  overflow: hidden;
  border-radius: var(--r-md);
  background: #000;
  aspect-ratio: 4 / 3;
}
.cam__viewfinder .scene { width: 100%; height: 100%; }
.cam__watermark {
  position: absolute;
  right: 4.5%;
  bottom: 4%;
  height: auto;
}

/* 变焦表盘 */
.cam__dial {
  display: flex;
  justify-content: center;
  gap: 6px;
  margin-top: 14px;
}
.cam__dial-pill {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding: 6px 13px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(242, 231, 201, 0.07);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}
.cam__stop {
  color: var(--cream-34);
  font-size: 11.5px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
.cam__stop.is-active {
  display: grid;
  place-items: center;
  width: 27px;
  height: 27px;
  margin: -4px 0;
  border-radius: 50%;
  background: rgba(242, 231, 201, 0.96);
  color: #17161a;
}

/* 操作区:上方预览 + 下方独立控制区(与 App 的页面结构一致)。
   控制区用 flex:1 吃掉剩余高度并垂直居中,所以不会出现一大片死白。 */
.cam__controls {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 6px 22px 0;
}
.cam__modes { display: flex; gap: 8px; }

.cam__pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 11px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  color: var(--cream-70);
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
}
/* 水印开关处于打开态 */
.cam__pill--on {
  border-color: var(--amber-line);
  background: var(--amber-wash);
  color: var(--amber);
}

/* 底部 home indicator */
.cam__home { display: flex; justify-content: center; padding: 16px 0 12px; }
.cam__home span {
  width: 104px;
  height: 4px;
  border-radius: 2px;
  background: rgba(242, 231, 201, 0.22);
}

/* 快门:图标里的奶油白圆环 */
.cam__shutter {
  position: relative;
  flex: none;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  border: 3.5px solid var(--cream-bright);
  background: transparent;
}
.cam__shutter::after {
  content: "";
  position: absolute;
  inset: 4px;
  border-radius: 50%;
  background: rgba(242, 231, 201, 0.14);
}
.hero .cam__shutter { animation: shutter-breathe 3.6s var(--ease) infinite; }
@keyframes shutter-breathe {
  0%, 100% { box-shadow: 0 0 0 0 rgba(243, 163, 44, 0); }
  50% { box-shadow: 0 0 0 8px rgba(243, 163, 44, 0.10); }
}

/* 样机上的浮动标注 */
.phone-tag {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-pill);
  background: rgba(23, 22, 26, 0.86);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-md);
  color: var(--cream-90);
  font-size: 12.5px;
  font-weight: 600;
  white-space: nowrap;
  z-index: 4;
}
.phone-tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
}
.phone-tag--album { top: 78px; left: -46px; }
.phone-tag--watermark { bottom: 268px; right: -52px; }
.phone-tag--shutter { bottom: 96px; left: -34px; }

/* --------------------------------------------------------------------------
   8. 三步流程
   -------------------------------------------------------------------------- */
.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  counter-reset: step;
}
.step {
  position: relative;
  padding: 30px 26px 26px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900));
}
.step__num {
  display: flex;
  align-items: flex-end;
  height: 40px;
  margin-bottom: 18px;
  color: var(--amber);
}
/* 尺寸由 seven-segment.js 按 viewBox 决定,这里不干预 */
.step__num svg { display: block; }
.step__title { font-size: 18px; color: var(--cream-bright); }
.step__text { margin-top: 10px; color: var(--cream-70); font-size: 14.5px; line-height: 1.75; }
/* 步骤之间的连接线 */
.step:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 46px;
  right: -13px;
  width: 6px;
  height: 6px;
  border-top: 1.5px solid var(--amber-line);
  border-right: 1.5px solid var(--amber-line);
  transform: rotate(45deg);
}

/* --------------------------------------------------------------------------
   9. 功能网格
   -------------------------------------------------------------------------- */
.features {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.feature__icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: 20px;
  border: 1px solid var(--amber-line);
  border-radius: var(--r-sm);
  background: var(--amber-wash);
  color: var(--amber);
}
.feature__icon svg { width: 21px; height: 21px; }
.feature__title { font-size: 16.5px; color: var(--cream-bright); }
.feature__text { margin-top: 10px; color: var(--cream-70); font-size: 14.5px; line-height: 1.75; }
.feature__tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 16px; }
.tag {
  padding: 3px 9px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  color: var(--cream-50);
  font-size: 11.5px;
  font-weight: 600;
  font-family: var(--font-mono);
}

/* --------------------------------------------------------------------------
   10. 水印实验室
   -------------------------------------------------------------------------- */
.lab {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  gap: 26px;
  align-items: start;
}

.lab__stage {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900));
  box-shadow: var(--shadow-md);
}
.lab__frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--r-md);
  background: #000;
  aspect-ratio: 4 / 3;
}
.lab__frame .scene { width: 100%; height: 100%; }
/* 水印容器:位置模式只改这里的定位与内边距 */
.lab__wm {
  position: absolute;
  pointer-events: none;
  transition: top 0.28s var(--ease), right 0.28s var(--ease), bottom 0.28s var(--ease),
    left 0.28s var(--ease), transform 0.28s var(--ease);
}
.lab__wm svg { display: block; }
.lab__frame[data-position="bottomRight"] .lab__wm { right: 4.5%; bottom: 4%; }
.lab__frame[data-position="bottomCenter"] .lab__wm { left: 50%; bottom: 4%; transform: translateX(-50%); }
/* 左侧竖排:与 App 的 leftSide 一致 —— 整段逆时针旋转 90°,自下而上、字顶朝左。
   锚点 x = 水平内边距(4.5%),y = 短边 10%,所以旋转原点取元素左下角。 */
.lab__frame[data-position="leftSide"] .lab__wm {
  left: 4.5%;
  bottom: 10%;
  transform-origin: 0 100%;
  transform: rotate(-90deg);
}
.lab__frame[data-position="custom"] .lab__wm {
  left: var(--wm-x, 50%);
  top: var(--wm-y, 50%);
  transform: translate(-50%, -50%);
}
/* 自定义模式:整个预览都是拖动热区 —— 水印本身只有几个像素高,点它太难了 */
.lab__frame[data-position="custom"] { cursor: grab; touch-action: none; }
.lab__frame[data-position="custom"].is-dragging { cursor: grabbing; }
.lab__frame[data-position="custom"] .lab__wm { transition: none; }
.lab__frame[data-position="custom"]::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px dashed var(--amber-line);
  border-radius: var(--r-md);
  opacity: 0;
  transition: opacity 0.2s var(--ease);
  pointer-events: none;
}
.lab__frame[data-position="custom"]:hover::after { opacity: 1; }

.lab__hint {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 14px;
  color: var(--cream-34);
  font-size: 12.5px;
}
.lab__code {
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: var(--r-xs);
  background: rgba(242, 231, 201, 0.04);
  color: var(--cream-50);
  font-family: var(--font-mono);
  font-size: 11.5px;
}

/* 控件面板 */
.lab__panel {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900));
  box-shadow: var(--shadow-md);
}
.control { margin-bottom: 22px; }
.control:last-child { margin-bottom: 0; }
.control__label {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 11px;
  color: var(--cream-50);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.10em;
  text-transform: uppercase;
}
.control__value {
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0;
  text-transform: none;
}

.seg { display: flex; flex-wrap: wrap; gap: 7px; }
.seg__btn {
  padding: 7px 14px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(242, 231, 201, 0.03);
  color: var(--cream-70);
  font-size: 13px;
  font-weight: 600;
  transition: all 0.18s var(--ease);
}
.seg__btn:hover { border-color: var(--line-3); color: var(--cream-bright); }
.seg__btn.is-active {
  border-color: transparent;
  background: var(--amber);
  color: #241703;
  font-weight: 700;
}

/* 颜色色板 */
.swatches { display: flex; flex-wrap: wrap; gap: 9px; }
.swatch {
  position: relative;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 2px solid transparent;
  box-shadow: 0 0 0 1px var(--line-2) inset;
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease);
}
.swatch:hover { transform: scale(1.08); }
.swatch.is-active { border-color: var(--cream-bright); box-shadow: 0 0 0 3px var(--ink-900), 0 0 0 4px var(--cream-34); }
.swatch__name {
  position: absolute;
  inset: auto 0 -19px;
  color: var(--cream-34);
  font-size: 10.5px;
  text-align: center;
  white-space: nowrap;
}
.swatches { padding-bottom: 20px; }

/* 滑杆 */
.range {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--amber) var(--fill, 50%), rgba(242, 231, 201, 0.14) var(--fill, 50%));
  outline: none;
}
.range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 17px;
  height: 17px;
  border-radius: 50%;
  background: var(--cream-bright);
  border: 3px solid var(--ink-900);
  box-shadow: 0 0 0 1px var(--cream-34), var(--shadow-sm);
  cursor: pointer;
}
.range::-moz-range-thumb {
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--cream-bright);
  border: 3px solid var(--ink-900);
  cursor: pointer;
}

.lab__preview-note {
  margin-top: 18px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: rgba(242, 231, 201, 0.03);
  color: var(--cream-50);
  font-size: 12.5px;
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   11. 画幅对比
   -------------------------------------------------------------------------- */
.ratios {
  /* 三种画幅共用同一条短边基准(= --ratio-h),这正是产品里的几何:
     画幅只改变长边,短边恒定,所以水印大小不变、取景区高度不变。 */
  --ratio-h: 148px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.ratio {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900));
  text-align: center;
  transition: border-color 0.24s var(--ease), transform 0.24s var(--ease);
}
.ratio:hover { border-color: var(--amber-line); transform: translateY(-3px); }
.ratio__box {
  display: grid;
  place-items: center;
  height: 190px;
  margin-bottom: 20px;
}
.ratio__frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line-2);
  border-radius: var(--r-sm);
  background: #000;
  box-shadow: var(--shadow-md);
}
/* 短边恒为 --ratio-h,长边按比例算出来:1:1 不裁切、4:3 铺满、16:9 最宽 */
.ratio__frame[data-ratio="1x1"] { width: calc(var(--ratio-h)); height: var(--ratio-h); }
.ratio__frame[data-ratio="4x3"] { width: calc(var(--ratio-h) * 4 / 3); height: var(--ratio-h); }
.ratio__frame[data-ratio="16x9"] { width: calc(var(--ratio-h) * 16 / 9); height: var(--ratio-h); }
.ratio__frame .scene { width: 100%; height: 100%; }
.ratio__frame .cam__watermark { right: 4.5%; bottom: 4%; }
.ratio__name { font-size: 16.5px; color: var(--cream-bright); font-family: var(--font-mono); }
.ratio__desc { margin-top: 8px; color: var(--cream-50); font-size: 13.5px; }
.ratio__state {
  display: inline-block;
  margin-top: 12px;
  padding: 3px 10px;
  border-radius: var(--r-pill);
  background: var(--amber-wash);
  color: var(--amber);
  font-size: 11.5px;
  font-weight: 700;
}
.ratio.is-default { border-color: var(--amber-line); }

/* --------------------------------------------------------------------------
   12. 隐私 / 技术条
   -------------------------------------------------------------------------- */
.privacy {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 48px;
  align-items: center;
  padding: 52px;
  border: 1px solid var(--amber-line);
  border-radius: var(--r-xl);
  background:
    radial-gradient(120% 140% at 88% 0%, rgba(243, 163, 44, 0.13), transparent 62%),
    linear-gradient(180deg, var(--ink-850), var(--ink-900));
  box-shadow: var(--shadow-lg);
}
.privacy__list { display: grid; gap: 16px; }
.privacy__item { display: flex; gap: 13px; }
.privacy__check {
  flex: none;
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  margin-top: 3px;
  border-radius: 50%;
  background: var(--amber-wash-2);
  color: var(--amber);
}
.privacy__check svg { width: 13px; height: 13px; }
.privacy__item b { display: block; color: var(--cream-bright); font-size: 15px; font-weight: 700; }
.privacy__item span { color: var(--cream-70); font-size: 14px; line-height: 1.7; }

/* --------------------------------------------------------------------------
   13. 规格表
   -------------------------------------------------------------------------- */
.specs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 48px;
  border-top: 1px solid var(--line);
}
.spec {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 20px;
  padding: 17px 0;
  border-bottom: 1px solid var(--line);
}
.spec__key { color: var(--cream-50); font-size: 14px; }
.spec__val {
  color: var(--cream-bright);
  font-size: 14px;
  font-weight: 600;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.spec__val--mono { font-family: var(--font-mono); font-size: 13px; }

/* --------------------------------------------------------------------------
   14. FAQ
   -------------------------------------------------------------------------- */
.faq { display: grid; gap: 12px; max-width: 820px; margin: 0 auto; }
.faq__item {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900));
  overflow: hidden;
  transition: border-color 0.2s var(--ease);
}
.faq__item[open] { border-color: var(--amber-line); }
.faq__q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 19px 22px;
  cursor: pointer;
  color: var(--cream-bright);
  font-size: 15.5px;
  font-weight: 600;
  list-style: none;
}
.faq__q::-webkit-details-marker { display: none; }
.faq__q:hover { color: var(--amber-bright); }
.faq__icon {
  position: relative;
  flex: none;
  width: 17px;
  height: 17px;
}
.faq__icon::before,
.faq__icon::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--amber);
  border-radius: 2px;
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}
.faq__icon::before { width: 13px; height: 1.6px; transform: translate(-50%, -50%); }
.faq__icon::after { width: 1.6px; height: 13px; transform: translate(-50%, -50%); }
.faq__item[open] .faq__icon::after { transform: translate(-50%, -50%) scaleY(0); opacity: 0; }
.faq__a {
  padding: 0 22px 21px;
  color: var(--cream-70);
  font-size: 14.5px;
  line-height: 1.8;
}
.faq__a p + p { margin-top: 12px; }

/* --------------------------------------------------------------------------
   15. 结尾 CTA
   -------------------------------------------------------------------------- */
.cta {
  position: relative;
  padding: 66px 40px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-xl);
  background:
    radial-gradient(90% 130% at 50% 118%, rgba(243, 163, 44, 0.20), transparent 60%),
    linear-gradient(180deg, var(--ink-850), var(--ink-950));
  box-shadow: var(--shadow-lg);
  text-align: center;
  overflow: hidden;
}
.cta__icon {
  width: 76px;
  height: 76px;
  margin: 0 auto 24px;
  border-radius: 18px;
  box-shadow: var(--shadow-lg), 0 0 60px -18px rgba(243, 163, 44, 0.6);
}
.cta__title {
  font-size: clamp(26px, 3.4vw, 38px);
  color: var(--cream-bright);
  text-wrap: balance;
}
.cta__text { margin: 16px auto 0; max-width: 520px; color: var(--cream-70); font-size: 15.5px; }
.cta__actions { display: flex; flex-wrap: wrap; gap: 13px; justify-content: center; margin-top: 32px; }

/* --------------------------------------------------------------------------
   16. 页脚
   -------------------------------------------------------------------------- */
.footer {
  margin-top: 96px;
  padding: 54px 0 34px;
  border-top: 1px solid var(--line);
}
.footer__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) repeat(3, minmax(0, 1fr));
  gap: 36px;
}
.footer__brand { display: flex; align-items: center; gap: 11px; margin-bottom: 14px; }
.footer__tagline { max-width: 280px; color: var(--cream-50); font-size: 13.5px; line-height: 1.75; }
.footer__title {
  margin-bottom: 14px;
  color: var(--cream-bright);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.10em;
  text-transform: uppercase;
}
.footer__links { display: grid; gap: 9px; }
.footer__links a, .footer__links span { color: var(--cream-50); font-size: 14px; }
.footer__links a:hover { color: var(--amber); }
.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 44px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  color: var(--cream-34);
  font-size: 13px;
}
.footer__legal { display: flex; flex-wrap: wrap; gap: 18px; }
.footer__legal a { color: var(--cream-50); }
.footer__legal a:hover { color: var(--amber); }

/* --------------------------------------------------------------------------
   17. 内页(隐私政策 / 支持)
   -------------------------------------------------------------------------- */
.doc-hero { padding: 68px 0 34px; }
.doc-hero__title { font-size: clamp(30px, 4.2vw, 46px); color: var(--cream-bright); }
.doc-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-top: 18px;
  color: var(--cream-34);
  font-size: 13.5px;
}
.doc-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 52px;
  align-items: start;
}
.doc-toc {
  position: sticky;
  top: calc(var(--header-h) + 28px);
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900));
}
.doc-toc__title {
  margin-bottom: 12px;
  color: var(--amber);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.doc-toc__list { display: grid; gap: 3px; }
.doc-toc__list a {
  display: block;
  padding: 6px 10px;
  border-left: 2px solid transparent;
  border-radius: 0 var(--r-xs) var(--r-xs) 0;
  color: var(--cream-50);
  font-size: 13.5px;
  line-height: 1.5;
  transition: all 0.18s var(--ease);
}
.doc-toc__list a:hover { border-left-color: var(--amber); background: rgba(242, 231, 201, 0.05); color: var(--cream-bright); }

.doc { max-width: 760px; }
.doc__section { padding: 30px 0; border-bottom: 1px solid var(--line); }
.doc__section:last-child { border-bottom: 0; }
.doc h2 {
  margin-bottom: 14px;
  font-size: 21px;
  color: var(--cream-bright);
  scroll-margin-top: calc(var(--header-h) + 28px);
}
.doc h3 { margin: 22px 0 8px; font-size: 15.5px; color: var(--cream-90); }
.doc p { margin-bottom: 13px; color: var(--cream-70); font-size: 15px; line-height: 1.85; }
.doc p:last-child { margin-bottom: 0; }
.doc strong { color: var(--cream-bright); }
.doc ul { display: grid; gap: 9px; margin: 14px 0; }
.doc ul li {
  position: relative;
  padding-left: 22px;
  color: var(--cream-70);
  font-size: 15px;
  line-height: 1.8;
}
.doc ul li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 12px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--amber);
}
.doc__callout {
  margin: 20px 0;
  padding: 18px 20px;
  border: 1px solid var(--amber-line);
  border-left-width: 3px;
  border-radius: var(--r-sm);
  background: var(--amber-wash);
  color: var(--cream-90);
  font-size: 14.5px;
  line-height: 1.8;
}
.doc__callout strong { color: var(--amber-bright); }
.doc table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 14px; }
.doc table th, .doc table td {
  padding: 11px 14px;
  border: 1px solid var(--line);
  text-align: left;
  color: var(--cream-70);
  vertical-align: top;
}
/* 表头不换行:auto 布局会把窄列表头压到刚好放不下,于是「是否可关闭」
   被拆成「是否可关 / 闭」。表头一行放得下,同列的单元格也就跟着放得下了。 */
.doc table th {
  background: rgba(242, 231, 201, 0.04);
  color: var(--cream-bright);
  font-weight: 700;
  white-space: nowrap;
}
/* 首列是短标签(相机 / 照片图库 …),同样不换行 —— 否则表头不换行会挤窄首列,
   「照片图库」就被拆成「照片图 / 库」。 */
.doc table th:first-child,
.doc table td:first-child { white-space: nowrap; }
.doc table td code {
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(242, 231, 201, 0.07);
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: 12.5px;
}
.doc__back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 34px;
  color: var(--amber);
  font-size: 14.5px;
  font-weight: 600;
}
.doc__back:hover { gap: 12px; }

/* 支持页的快捷卡片 */
.support-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.support-card { padding: 22px; }
.support-card__title { font-size: 15.5px; color: var(--cream-bright); }
.support-card__text { margin-top: 9px; color: var(--cream-70); font-size: 14px; line-height: 1.75; }
.support-card__list { display: grid; gap: 7px; margin-top: 12px; }
.support-card__list li {
  position: relative;
  padding-left: 18px;
  color: var(--cream-70);
  font-size: 13.5px;
  line-height: 1.7;
}
.support-card__list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 10px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--amber);
}

/* --------------------------------------------------------------------------
   18. 进场动效(尊重 prefers-reduced-motion)
   -------------------------------------------------------------------------- */
.reveal {
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}
/* 只有确认 JS 可用时才隐藏待进场元素 —— 否则脚本失效会让整页空白。
   `js` 类由 <head> 里的一行内联脚本加上。 */
.js .reveal {
  opacity: 0;
  transform: translateY(18px);
  will-change: opacity, transform;
}
.js .reveal.is-in { opacity: 1; transform: none; }
.reveal--d1 { transition-delay: 0.07s; }
.reveal--d2 { transition-delay: 0.14s; }
.reveal--d3 { transition-delay: 0.21s; }

/* --------------------------------------------------------------------------
   19. 响应式
   -------------------------------------------------------------------------- */
@media (max-width: 1080px) {
  .hero__grid { gap: 44px; }
  .lab { grid-template-columns: 1fr; }
  .ratios { --ratio-h: 126px; }
  .phone-tag--album { left: -18px; }
  .phone-tag--watermark { right: -18px; }
  .phone-tag--shutter { left: -12px; }
}

@media (max-width: 920px) {
  .hero { padding: 56px 0 72px; }
  .hero__grid { grid-template-columns: 1fr; gap: 56px; }
  .hero__sub { max-width: none; }
  .phone-wrap { order: -1; }
  .features { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .privacy { grid-template-columns: 1fr; gap: 34px; padding: 36px 28px; }
  .footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .doc-layout { grid-template-columns: 1fr; gap: 30px; }
  .doc-toc { position: static; }
  .doc-toc__list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .specs { grid-template-columns: 1fr; gap: 0; }
}

@media (max-width: 720px) {
  .section { padding: 72px 0; }
  .section--tight { padding: 56px 0; }
  .section__head { margin-bottom: 38px; }
  .steps { grid-template-columns: 1fr; }
  .step:not(:last-child)::after { display: none; }
  .features { grid-template-columns: 1fr; }
  .ratios { grid-template-columns: 1fr; }
  .support-grid { grid-template-columns: 1fr; }
  .cta { padding: 46px 22px; }
  .nav-toggle { display: inline-flex; }
  .nav {
    position: absolute;
    left: 0;
    right: 0;
    top: var(--header-h);
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    margin: 0;
    padding: 12px var(--gutter) 18px;
    border-bottom: 1px solid var(--line);
    background: rgba(18, 17, 19, 0.97);
    -webkit-backdrop-filter: blur(18px);
    backdrop-filter: blur(18px);
  }
  .nav.is-open { display: flex; }
  .nav__link { padding: 12px 14px; font-size: 15.5px; }
  .footer__grid { grid-template-columns: 1fr; gap: 28px; }
  .doc-toc__list { grid-template-columns: 1fr; }
  .phone { width: 270px; }
  .cam { height: 500px; }
  .phone-tag { font-size: 11.5px; padding: 7px 11px; }
  /* 窄屏上把浮动标注收回一些,否则左右两个标注几乎贴到屏幕边缘 */
  .phone-tag--album { left: -6px; }
  .phone-tag--watermark { right: -6px; bottom: 246px; }
  .phone-tag--shutter { left: -4px; }
}

@media (max-width: 420px) {
  :root { --gutter: 18px; }
  .hero__cta .btn { width: 100%; }
  .lang__btn { padding: 5px 9px; }
  .lab__panel { padding: 18px; }
}

/* --------------------------------------------------------------------------
   20. 动效降级 / 打印
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .js .reveal { opacity: 1; transform: none; }
}

@media print {
  .bg, .header, .footer__grid, .lab__panel, .cta__actions, .nav-toggle { display: none; }
  body { background: #fff; color: #000; }
  .doc p, .doc li { color: #222; }
}