/* ============================================================
   算弦 Calcanto — 官网样式
   骨架：Demo B「霓夜赛博」
   主题：五套内置主题的 design token 直接驱动整站 CSS 变量
   ============================================================ */

/* ---------- 1. 主题 token ---------- */
/* 每套主题同时提供「站点变量」与「计算器变量」，
   计算器变量的取值与 docs/03-DESIGN-ui-ux-spec.md §4 保持一致。 */

/* 主题选择器统一带 html 前缀，让它们的优先级高于下面那条 :root 兜底（默认主题 曜黑），
   这样五个主题块在文件里的先后顺序就不影响结果了。 */
html[data-theme="neonnoir"] {
  --bg: #08010F;
  --bg-elev: #150A28;
  --ink: #F5F3FF;
  --dim: #8A7CB8;
  --body: #C7BEE6;

  --c1: #F72585;
  --c2: #B14AED;
  --c3: #4CC9F0;
  --hl: #4CC9F0;

  --line: rgba(177, 74, 237, .22);
  --card-bg: rgba(21, 10, 40, .62);
  --card-brd: rgba(177, 74, 237, .22);
  --pill-bg: rgba(76, 201, 240, .07);

  --grid-c: rgba(177, 74, 237, .075);
  --orb1: rgba(247, 37, 133, .30);
  --orb2: rgba(76, 201, 240, .22);
  --orb3: rgba(177, 74, 237, .18);

  --glow1: rgba(247, 37, 133, .45);
  --glow3: rgba(76, 201, 240, .50);
  --btn-fg: #FFFFFF;
  --scan: .035;
  --frame: linear-gradient(150deg, rgba(247, 37, 133, .70), rgba(76, 201, 240, .55));
  --frame-shadow: 0 0 90px rgba(177, 74, 237, .55);

  --k-bg: #0D0221;
  --k-disp: #F5F3FF;
  --k-disp2: #8A7CB8;
  --k-num-bg: #1A0B33;
  --k-num-fg: #F5F3FF;
  --k-num-brd: rgba(177, 74, 237, .35);
  --k-fn-bg: #3A1F5C;
  --k-fn-fg: #E0AAFF;
  --k-op-bg: #F72585;
  --k-op-fg: #FFFFFF;
  --k-op-brd: #F72585;
  --k-op-glow: rgba(247, 37, 133, .55);
  /* 键形与发光：霓夜是圆键 + 描边发光 */
  --k-radius: 50%;
  --k-rw: 32px;
  --k-keyshadow: 0 0 13px rgba(76, 201, 240, .32);
}

/* 曜黑是默认主题：JS 未执行时 :root 就是它 */
:root,
html[data-theme="onyx"] {
  --bg: #000000;
  --bg-elev: #0E0E10;
  --ink: #FFFDF8;
  --dim: #8A8A8E;
  --body: #B9B9BE;

  --c1: #FF9F0A;
  --c2: #FFC46B;
  --c3: #FFFDF8;
  /* 曜黑的 c3 是近白色，只能用在渐变里；文字高亮必须回到橙色 */
  --hl: #FF9F0A;

  --line: rgba(255, 253, 248, .12);
  --card-bg: rgba(255, 255, 255, .035);
  --card-brd: rgba(255, 253, 248, .12);
  --pill-bg: rgba(255, 159, 10, .08);

  --grid-c: rgba(255, 253, 248, .05);
  --orb1: rgba(255, 159, 10, .22);
  --orb2: rgba(255, 159, 10, .10);
  --orb3: rgba(255, 253, 248, .05);

  --glow1: rgba(255, 159, 10, .45);
  --glow3: rgba(255, 159, 10, .30);
  --btn-fg: #FFFFFF;
  --scan: 0;
  --frame: linear-gradient(160deg, #3A3A3C, #111111);
  --frame-shadow: 0 40px 90px rgba(0, 0, 0, .85);

  --k-bg: #000000;
  --k-disp: #FFFFFF;
  --k-disp2: #A5A5A5;
  --k-num-bg: #333333;
  --k-num-fg: #FFFFFF;
  --k-num-brd: transparent;
  --k-fn-bg: #A5A5A5;
  --k-fn-fg: #000000;
  --k-op-bg: #FF9F0A;
  --k-op-fg: #FFFFFF;
  --k-op-brd: #FF9F0A;
  --k-op-glow: rgba(255, 159, 10, .40);
  /* 曜黑同样是圆键，对齐系统计算器 */
  --k-radius: 50%;
  --k-rw: 32px;
  --k-keyshadow: none;
}

html[data-theme="titanium"] {
  --bg: #101315;
  --bg-elev: #1C1F22;
  --ink: #EAF2F6;
  --dim: #7E8A93;
  --body: #B4C2CB;

  --c1: #00B4D8;
  --c2: #00E5FF;
  --c3: #A8DADC;
  --hl: #00E5FF;

  --line: rgba(234, 242, 246, .12);
  --card-bg: rgba(28, 31, 34, .66);
  --card-brd: rgba(0, 229, 255, .16);
  --pill-bg: rgba(0, 229, 255, .07);

  --grid-c: rgba(0, 229, 255, .06);
  --orb1: rgba(0, 180, 216, .22);
  --orb2: rgba(0, 229, 255, .16);
  --orb3: rgba(126, 138, 147, .16);

  --glow1: rgba(0, 229, 255, .40);
  --glow3: rgba(0, 180, 216, .40);
  --btn-fg: #06181D;
  --scan: .02;
  --frame: linear-gradient(150deg, #8C9AA3, #3A4249);
  --frame-shadow: 0 30px 70px rgba(0, 0, 0, .6);

  --k-bg: #1C1F22;
  --k-disp: #EAF2F6;
  --k-disp2: #7E8A93;
  --k-num-bg: #2E343A;
  --k-num-fg: #EAF2F6;
  --k-num-brd: rgba(234, 242, 246, .07);
  --k-fn-bg: #454D55;
  --k-fn-fg: #EAF2F6;
  --k-op-bg: #00B4D8;
  --k-op-fg: #0A0E12;
  --k-op-brd: #00B4D8;
  --k-op-glow: rgba(0, 229, 255, .45);
  /* 玄铁是圆角矩形键 */
  --k-radius: 16px;
  --k-rw: 16px;
  --k-keyshadow: none;
}

html[data-theme="seaglass"] {
  --bg: #F3FBF7;
  --bg-elev: #FFFFFF;
  --ink: #1E3A34;
  --dim: #5E9585;
  --body: #47645C;

  --c1: #3DDC97;
  --c2: #4CC9F0;
  --c3: #FF8B6B;
  /* 浅底上薄荷绿当正文色只有 1.9:1，高亮取加深版，5.1:1 */
  --hl: #0B7A55;

  --line: rgba(30, 58, 52, .12);
  --card-bg: rgba(255, 255, 255, .72);
  --card-brd: rgba(30, 58, 52, .09);
  --pill-bg: rgba(255, 255, 255, .6);

  --grid-c: rgba(30, 58, 52, .05);
  --orb1: rgba(61, 220, 151, .35);
  --orb2: rgba(255, 139, 107, .30);
  --orb3: rgba(76, 201, 240, .26);

  --glow1: rgba(61, 220, 151, .35);
  --glow3: rgba(255, 139, 107, .30);
  --btn-fg: #08241D;
  --scan: 0;
  --frame: linear-gradient(160deg, #FFFFFF, #DCEFE7);
  --frame-shadow: 0 26px 60px rgba(30, 58, 52, .18);

  --k-bg: #F3FBF7;
  --k-disp: #1E3A34;
  --k-disp2: #7FB8A6;
  --k-num-bg: #FFFFFF;
  --k-num-fg: #1E3A34;
  --k-num-brd: rgba(30, 58, 52, .07);
  --k-fn-bg: #CDEFE1;
  --k-fn-fg: #1E3A34;
  --k-op-bg: #3DDC97;
  /* 白字压 #3DDC97 只有 1.6:1，取值与 theme_summer_fresh.json 一致 */
  --k-op-fg: #0B3D2E;
  --k-op-brd: #3DDC97;
  --k-op-glow: rgba(61, 220, 151, .40);
  --k-radius: 16px;
  --k-rw: 16px;
  --k-keyshadow: none;
}

html[data-theme="bubblegum"] {
  --bg: #FFF6E5;
  --bg-elev: #FFFFFF;
  --ink: #3B2F2F;
  --dim: #9A7B58;
  --body: #6B564A;

  --c1: #EF476F;
  --c2: #FFD166;
  --c3: #06D6A0;
  /* 取主题 accent #118AB2 的加深版，5.4:1 */
  --hl: #0C6E8C;

  --line: rgba(59, 47, 47, .12);
  --card-bg: rgba(255, 255, 255, .70);
  --card-brd: rgba(59, 47, 47, .08);
  --pill-bg: rgba(255, 255, 255, .6);

  --grid-c: rgba(59, 47, 47, .045);
  --orb1: rgba(239, 71, 111, .28);
  --orb2: rgba(255, 209, 102, .35);
  --orb3: rgba(6, 214, 160, .24);

  --glow1: rgba(239, 71, 111, .35);
  --glow3: rgba(6, 214, 160, .30);
  --btn-fg: #FFFFFF;
  --scan: 0;
  --frame: linear-gradient(160deg, #FFFFFF, #F3E4C8);
  --frame-shadow: 0 26px 60px rgba(59, 47, 47, .18);

  --k-bg: #FFF6E5;
  --k-disp: #3B2F2F;
  --k-disp2: #C7A17A;
  --k-num-bg: #FFD166;
  --k-num-fg: #3B2F2F;
  --k-num-brd: rgba(59, 47, 47, .05);
  --k-fn-bg: #06D6A0;
  --k-fn-fg: #FFFFFF;
  --k-op-bg: #EF476F;
  --k-op-fg: #FFFFFF;
  --k-op-brd: #EF476F;
  --k-op-glow: rgba(239, 71, 111, .40);
  --k-radius: 16px;
  --k-rw: 16px;
  --k-keyshadow: none;
}

/* ---------- 2. 基础 ---------- */

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  overflow-x: hidden;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Helvetica Neue", sans-serif;
  -webkit-font-smoothing: antialiased;
  transition: background-color .3s ease, color .3s ease;
}

.mono { font-family: "SF Mono", ui-monospace, SFMono-Regular, Menlo, monospace; }

.wrap { max-width: 1200px; margin: 0 auto; padding: 0 32px; position: relative; z-index: 2; }

a { color: inherit; }

/* 折行控制：
   pretty 避免末行孤字，balance 让标题各行长度均衡；
   auto-phrase 让中文按词组断行，而不是在词中间随便切（不支持的浏览器会忽略它，
   所以关键词另外用 .nb 兜底）。 */
p, li { text-wrap: pretty; }
h1, h2, h3, h4 { text-wrap: balance; }
html[lang="zh-Hans"] p,
html[lang="zh-Hans"] h1,
html[lang="zh-Hans"] h2,
html[lang="zh-Hans"] .lab em { word-break: auto-phrase; }
.nb { white-space: nowrap; }

/* 译文为空时不留空行 */
.hero .en:empty, .th .lab small:empty, .voice .r small:empty { display: none; }

::selection { background: var(--c1); color: #fff; }

/* 背景光场 */
.field { position: fixed; inset: 0; z-index: 0; pointer-events: none; }
.field .grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--grid-c) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-c) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 20%, transparent 75%);
          mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 20%, transparent 75%);
  transition: background-image .3s ease;
}
.orb { position: absolute; border-radius: 50%; filter: blur(90px); transition: background-color .35s ease; }
.o1 { width: 620px; height: 620px; left: -140px; top: -180px; background: var(--orb1); }
.o2 { width: 560px; height: 560px; right: -120px; top: 60px;   background: var(--orb2); }
.o3 { width: 700px; height: 400px; left: 30%;    top: 760px;   background: var(--orb3); }

/* ---------- 3. 导航 ---------- */

nav {
  position: sticky; top: 0; z-index: 60;
  background: color-mix(in srgb, var(--bg) 74%, transparent);
  backdrop-filter: saturate(150%) blur(18px);
  border-bottom: 1px solid var(--line);
  transition: background-color .3s ease, border-color .3s ease;
}
nav .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 24px; }

.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; flex-shrink: 0; }
.brand img { width: 26px; height: 26px; border-radius: 7px; display: block; }
.brand b { font-size: 17px; font-weight: 600; letter-spacing: .04em; }
.brand span { font-size: 12px; letter-spacing: .12em; color: var(--dim); font-weight: 500; }

.navlinks { display: flex; gap: 26px; font-size: 13.5px; color: var(--dim); margin-left: auto; }
.navlinks a { text-decoration: none; transition: color .2s, text-shadow .2s; }
.navlinks a:hover { color: var(--hl); text-shadow: 0 0 12px color-mix(in srgb, var(--hl) 34%, transparent); }

.navtools { display: flex; align-items: center; gap: 14px; }

/* 导航里的主题小圆点 */
.navthemes { display: flex; gap: 7px; align-items: center; padding-left: 22px; border-left: 1px solid var(--line); }

/* 语言开关 */
.langsw { display: flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; flex-shrink: 0; }
.langsw button {
  padding: 5px 9px; font-size: 11.5px; font-family: inherit; line-height: 1.4;
  background: transparent; color: var(--dim); border: 0; cursor: pointer; transition: .18s;
}
.langsw button:hover { color: var(--ink); }
.langsw button[aria-pressed="true"] { background: var(--c1); color: var(--btn-fg); }
.dot {
  width: 18px; height: 18px; border-radius: 50%; border: 0; cursor: pointer; padding: 0;
  box-shadow: 0 0 0 1.5px color-mix(in srgb, var(--ink) 22%, transparent);
  transition: transform .18s, box-shadow .18s;
}
.dot:hover { transform: scale(1.18); }
.dot[aria-pressed="true"] { box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--c1); transform: scale(1.1); }

.btn {
  display: inline-flex; align-items: center; gap: 8px; text-decoration: none;
  border-radius: 11px; padding: 12px 22px; font-size: 14.5px; font-weight: 600;
  color: var(--btn-fg); background: linear-gradient(100deg, var(--c1), var(--c2));
  box-shadow: 0 0 28px var(--glow1); border: 0; cursor: pointer;
  transition: box-shadow .2s, transform .2s, background .3s;
}
.btn:hover { box-shadow: 0 0 44px var(--glow1); transform: translateY(-2px); }
.btn.ghost {
  background: transparent; border: 1px solid var(--hl); color: var(--hl);
  box-shadow: 0 0 20px color-mix(in srgb, var(--c3) 18%, transparent);
}
.btn.ghost:hover { box-shadow: 0 0 34px color-mix(in srgb, var(--c3) 30%, transparent); }
.btn.small { padding: 8px 16px; font-size: 12.5px; flex-shrink: 0; }

/* App Store 下载按钮 */
.stores { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 36px; }
.stores.center { justify-content: center; margin-top: 38px; }
.store {
  display: inline-flex; align-items: center; gap: 12px; text-decoration: none;
  padding: 10px 22px 11px; border-radius: 13px;
  color: var(--btn-fg); background: linear-gradient(100deg, var(--c1), var(--c2));
  box-shadow: 0 0 28px var(--glow1);
  transition: box-shadow .2s, transform .2s, background .3s;
}
.store:hover { box-shadow: 0 0 44px var(--glow1); transform: translateY(-2px); }

/* 还没上架：按钮保持原来的形状和位置，只是明确地不可点。
   上架当天去掉 .soon 就回到可点状态，不需要动布局。 */
.store.soon { opacity: .62; box-shadow: none; cursor: default; }
.store.soon:hover { box-shadow: none; transform: none; }
.soonnote {
  margin-top: 14px; text-align: center;
  font-size: 13px; color: var(--dim);
}
.store svg { width: 21px; height: 25px; fill: currentColor; flex-shrink: 0; margin-top: -3px; }
.store .t { display: flex; flex-direction: column; align-items: flex-start; line-height: 1.2; }
.store .t small { font-size: 10.5px; opacity: .72; letter-spacing: .01em; }
.store .t b { font-size: 17.5px; font-weight: 600; letter-spacing: -.01em; }

.themelink { margin-top: 18px; font-size: 14px; }
.themelink a { color: var(--hl); text-decoration: none; }
.themelink a:hover { text-shadow: 0 0 14px color-mix(in srgb, var(--hl) 34%, transparent); }

/* ---------- 4. 首屏 ---------- */

header { padding: 92px 0 74px; }
.hero { display: grid; grid-template-columns: 1.05fr .95fr; gap: 54px; align-items: center; }

.tag {
  display: inline-flex; align-items: center; gap: 8px;
  border: 1px solid var(--line); border-radius: 6px; padding: 6px 12px;
  font-size: 11px; letter-spacing: .2em; color: var(--hl);
  background: var(--pill-bg); margin-bottom: 26px;
}

h1 { font-size: 70px; line-height: 1.06; font-weight: 700; letter-spacing: -.03em; }
.grad {
  background: linear-gradient(92deg, var(--c1), var(--c2) 45%, var(--c3));
  -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 22px var(--glow1));
}
.hero .sub { margin-top: 24px; font-size: 17px; line-height: 1.8; color: var(--body); text-align: justify; }
.hero .en { margin-top: 12px; font-size: 12.5px; letter-spacing: .18em; color: var(--dim); }
.cta { display: flex; gap: 14px; margin-top: 36px; flex-wrap: wrap; }

.stats { display: flex; gap: 36px; margin-top: 46px; }
.stats b {
  display: block; font-size: 27px; font-weight: 700; color: var(--hl);
  text-shadow: 0 0 20px color-mix(in srgb, var(--hl) 34%, transparent); line-height: 1.2;
}
.stats span { font-size: 11.5px; letter-spacing: .14em; color: var(--dim); }

/* ---------- 5. 可交互计算器 ---------- */

.stage { display: flex; flex-direction: column; align-items: center; gap: 16px; }

.stage-hint {
  font-size: 11px; letter-spacing: .2em; color: var(--dim);
  display: flex; align-items: center; gap: 8px;
}
.stage-hint i {
  width: 5px; height: 5px; border-radius: 50%; background: var(--c1);
  box-shadow: 0 0 10px var(--c1); animation: blink 1.8s ease-in-out infinite;
}
@keyframes blink { 0%, 100% { opacity: 1 } 50% { opacity: .25 } }

.phone {
  width: 290px; border-radius: 44px; padding: 10px;
  background: var(--frame); box-shadow: var(--frame-shadow);
  transition: background .3s ease, box-shadow .3s ease;
}
.screen {
  background: var(--k-bg); border-radius: 36px; padding: 20px 15px 18px;
  position: relative; overflow: hidden; transition: background-color .3s ease;
}
.screen::before {
  content: ""; position: absolute; inset: 0; pointer-events: none; z-index: 1;
  background: repeating-linear-gradient(0deg, rgba(255, 255, 255, .5) 0 1px, transparent 1px 3px);
  opacity: var(--scan);
}
.expr {
  text-align: right; color: var(--k-disp2); font-size: 13px; height: 18px;
  overflow: hidden; white-space: nowrap;
}
.disp {
  display: block; width: 100%;
  text-align: right; font-size: 54px; font-weight: 300; color: var(--k-disp);
  padding: 6px 2px 14px; font-variant-numeric: tabular-nums; line-height: 1.16;
  white-space: nowrap; overflow: hidden; direction: ltr;
  text-shadow: 0 0 24px color-mix(in srgb, var(--k-disp) 22%, transparent);
  transition: color .3s ease, font-size .12s ease;
}
.disp.s1 { font-size: 44px; }
.disp.s2 { font-size: 35px; }
.disp.s3 { font-size: 28px; }

.pad { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; position: relative; z-index: 2; }
/* 键形跟着主题走：曜黑 / 霓夜是圆键，其余三套是圆角矩形，与 App 内一致 */
.k {
  aspect-ratio: 1; border-radius: var(--k-radius); display: flex; align-items: center; justify-content: center;
  font-size: 19px; font-family: inherit; cursor: pointer; user-select: none;
  background: var(--k-num-bg); color: var(--k-num-fg);
  border: 1px solid var(--k-num-brd);
  box-shadow: var(--k-keyshadow);
  transition: background-color .3s ease, color .3s ease, border-radius .3s ease, transform .08s ease, filter .15s ease;
}
.k:hover { filter: brightness(1.18); }
.k:active, .k.hit { transform: scale(.93); filter: brightness(1.35); }
.k.f { background: var(--k-fn-bg); color: var(--k-fn-fg); border-color: transparent; }
.k[data-k="neg"] { font-size: 16px; letter-spacing: -.02em; }
.k.o {
  background: var(--k-op-bg); color: var(--k-op-fg); border-color: var(--k-op-brd);
  box-shadow: 0 0 16px var(--k-op-glow);
}
/* 选中的运算符：反色，与系统计算器一致 */
.k.o[aria-pressed="true"] { background: var(--k-disp); color: var(--k-op-brd); }
.k.z { aspect-ratio: auto; grid-column: span 2; border-radius: var(--k-rw); justify-content: flex-start; padding-left: 24px; }

/* 播报气泡 */
.speak {
  display: flex; align-items: center; gap: 12px;
  border: 1px solid var(--card-brd); background: var(--card-bg);
  backdrop-filter: blur(12px); border-radius: 14px; padding: 10px 16px;
  font-size: 14px; min-height: 44px; max-width: 290px;
}
.speak .eqbars { display: flex; gap: 3px; align-items: flex-end; height: 16px; flex-shrink: 0; }
.speak .eqbars i { width: 3px; border-radius: 2px; background: var(--c1); display: block; }
.speak .eqbars i:nth-child(1) { height: 6px }
.speak .eqbars i:nth-child(2) { height: 15px }
.speak .eqbars i:nth-child(3) { height: 9px }
.speak .eqbars i:nth-child(4) { height: 12px }
.speak.on .eqbars i { animation: eq .85s ease-in-out infinite; }
.speak.on .eqbars i:nth-child(2) { animation-delay: .12s }
.speak.on .eqbars i:nth-child(3) { animation-delay: .24s }
.speak.on .eqbars i:nth-child(4) { animation-delay: .36s }
@keyframes eq { 0%, 100% { transform: scaleY(1) } 50% { transform: scaleY(.4) } }
.speak .txt { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.speak .lang { display: flex; gap: 4px; flex-shrink: 0; }
.speak .lang button {
  border: 1px solid var(--line); background: transparent; color: var(--dim);
  font-size: 10.5px; padding: 3px 7px; border-radius: 5px; cursor: pointer;
  font-family: inherit; transition: .18s;
}
.speak .lang button[aria-pressed="true"] { color: var(--btn-fg); background: var(--c1); border-color: var(--c1); }

/* ---------- 6. 跑马灯（来自 Demo A） ---------- */

.strip {
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  padding: 16px 0; overflow: hidden; margin-top: 64px;
  position: relative; z-index: 2;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
          mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}
.track {
  display: flex; gap: 56px; white-space: nowrap; width: max-content;
  font-size: 12.5px; color: var(--body); opacity: .8; letter-spacing: .2em; text-transform: uppercase;
  animation: slide 34s linear infinite;
}
.strip:hover .track { animation-play-state: paused; }
.track span { display: inline-flex; align-items: center; gap: 12px; }
.track span::before {
  content: ""; width: 5px; height: 5px; border-radius: 50%;
  background: var(--c1); opacity: .8; flex-shrink: 0;
}
@keyframes slide { to { transform: translateX(-50%) } }

/* ---------- 7. 通用区块 ---------- */

/* 每个 .sec 上下各 56px，相邻两块之间的净间距 112px */
.sec { padding: 56px 0; position: relative; z-index: 2; }
.stitle { font-size: 11px; letter-spacing: .3em; color: var(--hl); margin-bottom: 18px; }
h2 { font-size: 44px; line-height: 1.16; font-weight: 700; letter-spacing: -.025em; }
/* 导语与卡片组同宽、两端对齐：右边缘和下面的卡片对齐，中英文都不再出现半截的短行 */
.lead {
  margin-top: 18px; color: var(--body); font-size: 16.5px; line-height: 1.85;
  max-width: none; text-align: justify;
}
.earcon { margin-top: 34px; }

.card {
  position: relative; border-radius: 18px; padding: 32px 28px;
  background: var(--card-bg); border: 1px solid var(--card-brd);
  backdrop-filter: blur(12px); overflow: hidden;
  transition: border-color .25s, box-shadow .25s, transform .25s, background-color .3s;
}
.card:hover { border-color: var(--c1); box-shadow: 0 0 40px color-mix(in srgb, var(--c1) 18%, transparent); }
.card::before {
  content: ""; position: absolute; top: 0; left: 22px; right: 22px; height: 1px;
  background: linear-gradient(90deg, transparent, var(--c1), transparent);
}
.card .n { font-size: 11px; letter-spacing: .24em; color: var(--dim); }
.card h3 { margin: 14px 0 10px; font-size: 21px; font-weight: 600; }
.card h3 .s { color: var(--hl); text-shadow: 0 0 16px color-mix(in srgb, var(--hl) 30%, transparent); }
.card p { font-size: 14.5px; line-height: 1.8; color: var(--body); text-align: justify; }
.card strong { color: var(--ink); font-weight: 600; }

.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 52px; }

/* ---------- 8. 主题区 ---------- */

.themehead { display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; flex-wrap: wrap; }
.nowplaying { font-size: 12.5px; color: var(--dim); }
.nowplaying b { color: var(--hl); font-weight: 600; }

.themes { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; margin-top: 44px; }
.th {
  border-radius: 16px; overflow: hidden; border: 1px solid var(--card-brd);
  background: var(--card-bg); cursor: pointer; padding: 0; text-align: left;
  font-family: inherit; color: inherit; transition: transform .25s, border-color .25s, box-shadow .25s;
}
.th:hover { transform: translateY(-6px); border-color: var(--c3); box-shadow: 0 0 30px color-mix(in srgb, var(--c3) 22%, transparent); }
.th[aria-pressed="true"] { border-color: var(--c1); box-shadow: 0 0 34px var(--glow1); }
.swatch { height: 88px; display: grid; grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; }
.th .lab { display: block; padding: 18px 18px 20px; }
.th .lab .nm { display: block; font-size: 15px; font-weight: 600; }
.th .lab small { display: block; font-size: 10px; letter-spacing: .18em; color: var(--dim); margin-top: 7px; font-weight: 500; }
.th .lab em { display: block; font-style: normal; font-size: 12.5px; color: var(--body); margin-top: 13px; line-height: 1.65; font-weight: 400; }
.th .cur {
  display: none; font-size: 10px; letter-spacing: .16em; color: var(--hl); margin-top: 15px;
}
.th[aria-pressed="true"] .cur { display: block; }

/* ---------- 9. 语音区 ---------- */

.voices { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-top: 46px; }
.voice { border-radius: 16px; padding: 26px 24px; background: var(--card-bg); border: 1px solid var(--card-brd); }
.voice .r { font-size: 18px; font-weight: 600; }
.voice .r small { display: block; font-size: 10.5px; letter-spacing: .18em; color: var(--dim); margin-top: 7px; font-weight: 500; }
.voice .w { display: flex; gap: 3px; align-items: flex-end; height: 26px; margin-top: 22px; }
.voice .w i { flex: 1; border-radius: 2px; background: var(--c1); opacity: .55; display: block; }

.reading { margin-top: 22px; border: 1px solid var(--card-brd); border-radius: 16px; overflow: hidden; background: var(--card-bg); }
.reading .row { display: grid; grid-template-columns: 130px 1fr 1fr; gap: 20px; padding: 16px 26px; border-bottom: 1px solid var(--line); font-size: 15px; }
.reading .row:last-child { border-bottom: 0; }
.reading .row.h { font-size: 11px; letter-spacing: .2em; color: var(--dim); text-transform: uppercase; }
.reading .row b { font-weight: 600; color: var(--hl); font-variant-numeric: tabular-nums; }

/* ---------- 10. 功能全景 ---------- */

.feats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-top: 50px; background: var(--line); border: 1px solid var(--line); border-radius: 18px; overflow: hidden; }
.feat { background: var(--bg); padding: 32px 28px; transition: background-color .3s; }
.feat:hover { background: var(--bg-elev); }
.feat h4 { font-size: 17px; font-weight: 600; margin-bottom: 12px; display: flex; align-items: center; gap: 9px; }
.feat h4 i { width: 6px; height: 6px; border-radius: 50%; background: var(--c1); display: block; flex-shrink: 0; }
.feat p { font-size: 14px; line-height: 1.78; color: var(--body); text-align: justify; }

/* ---------- 11. 三端 / 名字 ---------- */

.two { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.platforms { display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; }
.plat {
  border: 1px solid var(--card-brd); background: var(--card-bg); border-radius: 12px;
  padding: 14px 20px; font-size: 14px; display: flex; flex-direction: column; gap: 4px;
}
.plat small { font-size: 11px; color: var(--dim); letter-spacing: .1em; }

.namecard { border-radius: 22px; border: 1px solid var(--card-brd); background: var(--card-bg); padding: 38px 34px; }
.namecard .big { font-size: 60px; font-weight: 700; letter-spacing: .06em; line-height: 1; }
.namecard .big span:last-child { color: var(--hl); text-shadow: 0 0 26px color-mix(in srgb, var(--hl) 32%, transparent); }
.namecard p { margin-top: 22px; font-size: 15.5px; line-height: 1.9; color: var(--body); text-align: justify; }
.namecard .wink { margin-top: 16px; font-size: 13px; color: var(--dim); }

/* ---------- 12. 收尾 ---------- */

.final { text-align: center; padding: 104px 0 116px; position: relative; z-index: 2; }
.final h2 { font-size: 56px; }
.final .fine { margin-top: 26px; font-size: 12.5px; color: var(--dim); }

/* 角标与脚注 */
sup.fn { font-size: .62em; vertical-align: super; line-height: 0; margin-left: 1px; }
sup.fn a { color: var(--hl); text-decoration: none; }
sup.fn a:hover { text-decoration: underline; }
/* 脚注字号对齐 Apple 官网底部说明文字：12px、紧一点的行高、两端对齐 */
.footnote {
  font-size: 12px; line-height: 1.66; letter-spacing: -.005em;
  color: var(--dim); text-align: justify;
  margin: 0 0 28px; padding-left: 14px; border-left: 2px solid var(--line);
}
:target.footnote { border-left-color: var(--hl); color: var(--body); }

footer {
  border-top: 1px solid var(--line); padding: 34px 0 44px; position: relative; z-index: 2;
  font-size: 12.5px; color: var(--dim);
}
.footrow { display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
footer a { text-decoration: none; opacity: .85; }
footer a:hover { opacity: 1; color: var(--hl); }

/* ---------- 文档页（隐私政策） ---------- */

.doc { padding: 76px 0 90px; position: relative; z-index: 2; }
.doc .wrap { max-width: 780px; }
.doc h1 { font-size: 46px; line-height: 1.14; letter-spacing: -.028em; font-weight: 700; }
.doc .updated { margin-top: 14px; font-size: 12px; letter-spacing: .14em; color: var(--dim); }
.doc .intro {
  margin-top: 30px; font-size: 17px; line-height: 1.85; color: var(--body);
  padding: 22px 24px; border-radius: 16px; background: var(--card-bg); border: 1px solid var(--card-brd);
  text-align: justify;
}
.doc .intro strong { color: var(--ink); }
.doc h2 { font-size: 21px; font-weight: 600; letter-spacing: -.01em; margin-top: 44px; }
.doc p { margin-top: 14px; font-size: 15.5px; line-height: 1.9; color: var(--body); text-align: justify; }
.doc a { color: var(--hl); }
.doc .back { margin-top: 56px; font-size: 14px; }
.doc .back a { text-decoration: none; }

/* 支持页比隐私页多两层结构：FAQ 的问题小标题，和报障清单。 */
.doc h3 {
  margin-top: 32px; font-size: 16.5px; font-weight: 600;
  letter-spacing: -.005em; color: var(--ink);
}
.doc h3 + p { margin-top: 10px; }
.doc ul { margin-top: 14px; padding-left: 20px; }
.doc li {
  margin-top: 9px; font-size: 15.5px; line-height: 1.9; color: var(--body);
}
.doc li::marker { color: var(--hl); }
.doc p strong, .doc li strong { color: var(--ink); }
/* 按键序列和版本号用等宽，读者要能一眼看出哪段是照着敲的。 */
.doc .mono { font-size: .93em; color: var(--hl); }

/* ---------- 13. 出场动画 ---------- */

.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 14. 响应式 ---------- */

@media (max-width: 1080px) {
  .themes { grid-template-columns: repeat(3, 1fr); }
  .voices { grid-template-columns: repeat(2, 1fr); }
  .feats { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 900px) {
  .navlinks { display: none; }
  .hero, .grid3, .two { grid-template-columns: 1fr; }
  header { padding: 56px 0 56px; }
  h1 { font-size: 44px; }
  h2, .final h2 { font-size: 32px; }
  .doc h1 { font-size: 34px; }
  .namecard .big { font-size: 44px; }
  .sec { padding: 40px 0; }
  .final { padding: 72px 0 84px; }
  .reading .row { grid-template-columns: 1fr; gap: 6px; }
  .reading .row.h { display: none; }
  .stores .store { flex: 1 1 auto; }
}
@media (max-width: 640px) {
  .wrap { padding: 0 20px; }
  .themes, .voices, .feats { grid-template-columns: 1fr; }
  .stats { gap: 22px; }
  nav .wrap { gap: 10px; }
  .brand span { display: none; }
  .navtools { gap: 10px; margin-left: auto; }
  .navthemes { padding-left: 0; border-left: 0; gap: 6px; }
  .dot { width: 15px; height: 15px; }
  .btn.small { padding: 7px 12px; font-size: 12px; white-space: nowrap; }
  .langsw button { padding: 4px 7px; font-size: 11px; }
  .store { padding: 9px 18px 10px; }
  .store .t b { font-size: 16px; }
}