/* ============================================================
   NexBox 官网前端 — v3 设计系统
   黑白灰基调 + 高饱和小面积彩色点缀
   fonts: MiSans(标题) + Noto Sans SC(正文) + 系统等宽(技术)
   ============================================================ */

/* ---------- 字体声明（全部本地自托管） ---------- */
@font-face {
  font-family: "MiSans";
  src: url('fonts/MiSansVF.ttf') format('truetype');
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Noto Sans SC";
  src: url('fonts/NotoSansSC-400.woff2') format('woff2');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Noto Sans SC";
  src: url('fonts/NotoSansSC-500.woff2') format('woff2');
  font-weight: 500; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Noto Sans SC";
  src: url('fonts/NotoSansSC-700.woff2') format('woff2');
  font-weight: 700; font-style: normal; font-display: swap;
}

/* ---------- 设计令牌 ---------- */
:root {
  --sans:  "MiSans", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", ui-sans-serif, system-ui, sans-serif;
  --mono:  ui-monospace, "SF Mono", "Cascadia Mono", "JetBrains Mono", Consolas, monospace;

  --bg: #fafaf9;
  --surface: #ffffff;
  --surface-2: #f4f4f5;
  --border: #e7e5e4;
  --border-strong: #d6d3d1;
  --text: #18181b;
  --text-2: #52525b;
  --text-3: #8e8e93;
  --invert: #18181b;
  --invert-text: #fafaf9;

  --c-blue:   #3b82f6;
  --c-cyan:   #06b6d4;
  --c-amber:  #f59e0b;
  --c-pink:   #ec4899;
  --c-violet: #8b5cf6;
  --c-green:  #22c55e;
  --c-red:    #ef4444;
  --c-yellow: #eab308;

  --radius: 8px;
  --maxw: 1080px;
  --nav-h: 64px;

  /* 悬浮岛毛玻璃：半透明背景 + 背景模糊 */
  --glass-bg: rgba(255, 255, 255, .62);
  --glass-blur: blur(20px) saturate(160%);

  /* 极光背景色球（浅色主题） */
  --a1: color-mix(in srgb, var(--c-blue)  20%, transparent);
  --a2: color-mix(in srgb, var(--c-violet) 17%, transparent);
  --a3: color-mix(in srgb, var(--c-pink)   15%, transparent);
  --a4: color-mix(in srgb, var(--c-cyan)   13%, transparent);

  /* 极光垂幕光带配色（浅色主题） */
  --g1: color-mix(in srgb, #10b981 34%, transparent); /* 翠绿 */
  --g2: color-mix(in srgb, #06b6d4 32%, transparent); /* 青 */
  --g3: color-mix(in srgb, #8b5cf6 30%, transparent); /* 紫 */
  --g4: color-mix(in srgb, #38bdf8 40%, transparent); /* 天蓝 */
}

.dark {
  --bg: #0b0b0e;
  --surface: #141419;
  --surface-2: #1c1c22;
  --border: #26262c;
  --border-strong: #3a3a42;
  --text: #f5f5f7;
  --text-2: #a1a1aa;
  --text-3: #71717a;
  --invert: #f5f5f7;
  --invert-text: #0b0b0e;

  /* 悬浮岛毛玻璃（深色主题） */
  --glass-bg: rgba(20, 20, 25, .6);
  --glass-blur: blur(20px) saturate(160%);

  /* 极光背景色球（深色主题：更收敛，避免刺眼） */
  --a1: color-mix(in srgb, var(--c-blue)   12%, transparent);
  --a2: color-mix(in srgb, var(--c-violet) 10%, transparent);
  --a3: color-mix(in srgb, var(--c-pink)    9%, transparent);
  --a4: color-mix(in srgb, var(--c-cyan)    8%, transparent);

  /* 极光垂幕光带配色（深色主题） */
  --g1: color-mix(in srgb, #34d399 30%, transparent);
  --g2: color-mix(in srgb, #22d3ee 28%, transparent);
  --g3: color-mix(in srgb, #a78bfa 28%, transparent);
  --g4: color-mix(in srgb, #7dd3fc 32%, transparent);
}

/* ---------- Reset ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color .3s ease, color .3s ease;
  overflow-x: hidden;
}

/* ---------- 背景光晕：多个蓝色光斑无规则漂移 + 明暗呼吸 ---------- */
.aurora {
  position: fixed; inset: -12%;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}
/* 每个光晕：中心亮心 + 柔和扩散，独立大小/周期/相位 */
.aurora span {
  position: absolute;
  width: var(--sz, 34vmax); height: var(--sz, 34vmax);
  border-radius: 50%;
  filter: blur(38px);
  transform: translateZ(0);
  will-change: transform, opacity;
  background:
    radial-gradient(30% 30% at 50% 50%, rgba(255,255,255,.4), transparent 100%),
    radial-gradient(50% 50% at 50% 50%, var(--gc) 0%, transparent 72%);
  animation:
    glow-drift var(--gd, 15s) ease-in-out infinite alternate,
    glow-breathe var(--gb, 6.5s) ease-in-out infinite;
}
.aurora .b1 { left: -6%;  top: -10%;  --gc: var(--g4); --sz: 40vmax; --gd: 13s; --gb: 5.5s; animation-delay: -2s, -1s; }
.aurora .b2 { right: -8%; top: 6%;    --gc: var(--g4); --sz: 30vmax; --gd: 16s; --gb: 7s;   animation-delay: -6s, -3s; }
.aurora .b3 { left: 26%;  top: -16%;  --gc: var(--g4); --sz: 34vmax; --gd: 14s; --gb: 6s;   animation-delay: -4s, -2s; }
.aurora .b4 { right: 6%;  bottom: -14%; --gc: var(--g4); --sz: 36vmax; --gd: 18s; --gb: 8s; animation-delay: -9s, -5s; }
.aurora .b5 { left: -4%;  bottom: -8%; --gc: var(--g4); --sz: 26vmax; --gd: 15s; --gb: 6.5s; animation-delay: -1s, -4s; }
/* 无规则漂移：多点大幅位移 + 胀缩 */
@keyframes glow-drift {
  0%   { transform: translate3d(0, 0, 0) scale(1); }
  25%  { transform: translate3d(12%, -9%, 0) scale(1.2); }
  50%  { transform: translate3d(-9%, 11%, 0) scale(.9); }
  75%  { transform: translate3d(7%, -13%, 0) scale(1.26); }
  100% { transform: translate3d(2%, 7%, 0) scale(1.02); }
}
/* 明暗呼吸：光晕周期性亮起/隐没 */
@keyframes glow-breathe {
  0%, 100% { opacity: .95; }
  50%      { opacity: .4; }
}
@media (prefers-reduced-motion: reduce) {
  .aurora, .aurora span { animation: none; }
}

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
img { display: block; max-width: 100%; }

::selection { background: var(--invert); color: var(--invert-text); }

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

/* ---------- 布局容器 ---------- */
.container {
  width: 100%; max-width: var(--maxw);
  margin: 0 auto; padding: 0 24px;
}

.section-pad { padding: 96px 0 88px; }
section + section { border-top: 1px solid var(--border); }
/* 锚点跳转时避开固定导航遮挡 */
section[id] { scroll-margin-top: calc(var(--nav-h) + 12px); }

/* ---------- 区块标题 ---------- */
.sec-head {
  max-width: 720px; margin: 0 auto 48px;
  text-align: center;
}

.sec-eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono);
  font-size: 12px; font-weight: 600;
  letter-spacing: .16em; text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 14px;
}
.sec-eyebrow::before {
  content: ""; width: 18px; height: 2px;
  background: currentColor; opacity: .8;
}

.sec-title {
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(1.75rem, 3.6vw, 2.6rem);
  line-height: 1.25; letter-spacing: -.02em;
}

.sec-desc {
  margin-top: 14px;
  font-size: 15px;
  color: var(--text-2);
}

/* 区块着色：eyebrow 与点缀跟随功能区色 */
.sec--blue   { --acc: var(--c-blue); }
.sec--cyan   { --acc: var(--c-cyan); }
.sec--amber  { --acc: var(--c-amber); }
.sec--pink   { --acc: var(--c-pink); }
.sec--violet { --acc: var(--c-violet); }
.sec--acc .sec-eyebrow, .sec--acc .sec-eyebrow::before { color: var(--acc); }

/* ---------- 导航（DeepSeek 风格：下拉后缩为灵动岛悬浮） ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  margin: 0 auto; /* 避免 transform 建立 containing block，fixed 抽屉不被裁切 */
  width: 100%; /* 显式宽度：保证 width 过渡可动画（auto 无法过渡） */
  z-index: 200;
  height: var(--nav-h);
  background: var(--bg); /* 完全不透明：避免下方极光透过形成底部色差线 */
  border-bottom: none;
  /* 不使用 backdrop-filter：其边缘会与未模糊内容形成对比线（深色白/浅色黑） */
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
  transition: width .42s cubic-bezier(.22,1,.36,1),
              height .42s cubic-bezier(.22,1,.36,1),
              top .42s cubic-bezier(.22,1,.36,1),
              border-radius .42s cubic-bezier(.22,1,.36,1);
  /* 背景不参与过渡：surface↔bg 插值会在胶囊展开时于底部形成 1px 过渡色线 */
}
.nav.is-pinned {
  top: 12px;
  width: min(680px, calc(100% - 16px));
  height: 50px;
  border-radius: 16px;
  border: none;
  border-bottom: none;
  /* 不可用 overflow:hidden：backdrop-filter 会建立 containing block，
     裁切 fixed 定位的抽屉导致悬浮岛下无法展开菜单 */
  /* 悬浮岛毛玻璃：半透明背景 + backdrop 模糊，随下方内容透出 */
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  box-shadow: none;
}
.nav-inner {
  height: 100%;
  padding: 0 18px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 12px;
  transition: padding .42s cubic-bezier(.22,1,.36,1), gap .42s ease;
}
.nav-brand {
  justify-self: start;
  display: flex; align-items: center; gap: 10px;
  transition: gap .42s cubic-bezier(.22,1,.36,1);
}
.nav-logo {
  height: 27px; width: auto;
  transition: height .42s cubic-bezier(.22,1,.36,1);
}
.nav-logo-light { display: none; }
.nav-logo-dark { display: block; }
.dark .nav-logo-light { display: block; }
.dark .nav-logo-dark { display: none; }
.nav-word {
  height: 21px; width: auto;
  transition: height .42s cubic-bezier(.22,1,.36,1);
}
.nav-word-light { display: none; }
.nav-word-dark { display: block; }
.dark .nav-word-light { display: block; }
.dark .nav-word-dark { display: none; }

/* 中间链接组绝对居中 */
.nav-links {
  justify-self: center;
  display: flex; align-items: center; gap: 4px;
  list-style: none;
  white-space: nowrap;
  transition: gap .42s cubic-bezier(.22,1,.36,1);
}
.nav-links a {
  display: block; padding: 8px 12px;
  font-size: 14px; color: var(--text-2);
  border-radius: var(--radius);
  transition: color .2s ease, background .2s ease;
}
.nav-links a:hover { color: var(--text); background: var(--surface-2); }
.nav-links a.active { color: var(--text); font-weight: 600; }

/* 灵动岛收紧：内容仍在，仅紧凑化布局 */
.nav.is-pinned .nav-inner { padding: 0 14px; gap: 8px; }
.nav.is-pinned .nav-logo { height: 24px; }
.nav.is-pinned .nav-word { height: 19.5px; }
.nav.is-pinned .nav-brand { gap: 7px; }
.nav.is-pinned .nav-links { gap: 0; }
.nav.is-pinned .nav-links a { padding: 7px 8px; font-size: 13px; }
.nav.is-pinned .nav-right { gap: 8px; }
.nav.is-pinned .nav-right .btn { padding: 7px 14px; font-size: 13px; }

/* 灵动岛抽屉跟随胶囊居中（fixed 定位必须用固定像素，不能用百分比） */
.nav.is-pinned ~ .nav-drawer {
  top: 62px; /* 胶囊 top:12 + height:50，无缝衔接无间隙 */
  left: 0; right: 0;
  width: min(680px, calc(100% - 16px));
  margin: 0 auto;
  border: none;
  border-radius: 0 0 16px 16px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  box-shadow: 0 18px 40px -18px rgba(0,0,0,.3);
}
/* 抽屉内链接描边在底部圆角处避免被白线切割 */
.nav.is-pinned ~ .nav-drawer .nav-drawer-links li:last-child a {
  border-bottom: none;
}
/* is-pinned 下抽屉展开也保持无边框：压过 .nav-drawer.open 的 border-bottom-color */
.nav.is-pinned ~ .nav-drawer,
.nav.is-pinned ~ .nav-drawer.open {
  border-bottom: none;
}

.nav-right {
  justify-self: end;
  display: flex; align-items: center; gap: 10px;
}
.theme-toggle {
  width: 38px; height: 38px;
  display: inline-flex; align-items: center; justify-content: center;
  color: var(--text-2);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: color .2s, background .2s, border-color .2s;
}
.theme-toggle:hover { color: var(--text); border-color: var(--border-strong); }
.theme-toggle svg { width: 19px; height: 19px; }
.icon-sun { display: block; }
.icon-moon { display: none; }
.dark .icon-sun { display: none; }
.dark .icon-moon { display: block; }

.nav-menu-btn {
  display: none;
  width: 38px; height: 38px;
  align-items: center; justify-content: center;
  color: var(--text-2);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.nav-menu-btn:hover { color: var(--text); }
.nav-menu-btn svg { width: 20px; height: 20px; }

.nav-drawer {
  position: fixed; top: var(--nav-h); left: 0; right: 0; z-index: 199;
  background: var(--bg);
  border-bottom: 0; /* 收起状态 0 边框：border-box 下 max-height:0 无法压缩 border，会残留 1px 白/黑线 */
  max-height: 0;
  overflow: hidden;
  visibility: hidden; /* 完全脱离渲染，杜绝子像素 1px 残留 */
  transition: max-height .3s ease, border-color .3s ease, visibility .3s ease;
}
.nav-drawer.open {
  max-height: 320px;
  visibility: visible;
  border-bottom: 1px solid var(--border);
}
.nav-drawer-links { list-style: none; padding: 12px 24px 20px; }
.nav-drawer-links a {
  display: block; padding: 12px 4px;
  font-size: 15px; color: var(--text-2);
  border-bottom: 1px solid var(--border);
}
.nav-drawer-links li:last-child a { border-bottom: none; }
.nav-drawer-links a:active { color: var(--text); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 9px 18px;
  font-size: 14px; font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: all .2s ease;
  white-space: nowrap;
}
.btn svg { width: 17px; height: 17px; flex: none; }
.btn img.btn-icon { width: 17px; height: 17px; object-fit: contain; flex: none; }

.btn-invert {
  background: var(--invert); color: var(--invert-text);
  border-color: var(--invert);
}
.btn-invert:hover { background: var(--c-blue); border-color: var(--c-blue); color: #fff; }

.btn-ghost {
  background: transparent; color: var(--text);
  border-color: var(--border-strong);
}
.btn-ghost:hover { border-color: var(--text); }

.btn-lg { padding: 12px 26px; font-size: 15px; }
.btn-lg svg, .btn-lg img.btn-icon { width: 19px; height: 19px; }

.btn-white {
  background: #fff; color: #111; border-color: #fff;
}
.btn-white:hover { transform: translateY(-1px); box-shadow: 0 6px 18px rgba(0,0,0,.18); }
.btn-ghost-dark {
  background: transparent; color: var(--invert-text);
  border-color: color-mix(in srgb, var(--invert-text) 45%, transparent);
}
.btn-ghost-dark:hover { border-color: var(--invert-text); }

/* ---------- Hero（文案居中，下方截图渐隐） ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex; flex-direction: column; justify-content: center;
  padding: calc(var(--nav-h) + 48px) 0 84px;
  overflow: hidden;
  isolation: isolate;
}
.hero-inner {
  display: flex; flex-direction: column; align-items: center;
  gap: clamp(36px, 6vh, 58px);
}
.hero-copy {
  display: flex; flex-direction: column; align-items: center;
  text-align: center;
}

/* 背景极光由 body::before 全局提供，Hero 不再叠网格 */
.hero::before, .hero::after { content: none; }

.hero-chip {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 5px 12px;
  font-size: 12.5px; font-weight: 600;
  color: var(--text-2);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  margin-bottom: 22px;
  background: var(--surface);
}
.hero-chip .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--c-green);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--c-green) 22%, transparent);
  animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 3px color-mix(in srgb, var(--c-green) 22%, transparent); }
  50% { box-shadow: 0 0 0 7px color-mix(in srgb, var(--c-green) 6%, transparent); }
}

.hero-title {
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(2.3rem, 5.2vw, 4.1rem);
  line-height: 1.16; letter-spacing: -.025em;
}
.hero-title em {
  font-style: normal;
  background: linear-gradient(100deg, #2563eb, #60a5fa);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-sub {
  margin-top: 18px;
  max-width: 640px;
  font-size: 16.5px;
  color: var(--text-2);
}
.hero-actions {
  margin-top: 30px;
  display: flex; flex-wrap: wrap; gap: 12px; justify-content: center;
}

/* Hero 大图：顶部完整、底部渐隐融入页面 */
.hero-visual {
  position: relative;
  width: 100%;
  max-width: 940px;
}
.shot-frame {
  /* 固定比例占位：图片未加载/加载失败时高度不塌陷，页面不跳动 */
  width: 100%;
  aspect-ratio: 1538 / 964;
  max-height: min(40svh, 480px);
  border: 1px solid var(--border-strong);
  border-bottom: 0;
  border-radius: var(--radius) var(--radius) 0 0;
  background: var(--surface);
  overflow: hidden;
  -webkit-mask-image: linear-gradient(180deg, #000 42%, rgba(0,0,0,0) 100%);
  mask-image: linear-gradient(180deg, #000 42%, rgba(0,0,0,0) 100%);
}
.shot-img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
}
.shot-glow {
  position: absolute; inset: 0; z-index: -1;
  background: color-mix(in srgb, var(--c-blue) 18%, transparent);
  filter: blur(46px);
  border-radius: 50%;
  transform: translate(8%, 10%) scale(.92);
}

.scroll-hint {
  position: absolute; left: 50%; bottom: 22px;
  transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center;
  color: var(--text-3);
  font-size: 11px; letter-spacing: .18em;
  text-decoration: none;
  transition: color .2s ease;
  animation: floaty 2.4s ease-in-out infinite;
}
.scroll-hint:hover { color: var(--text-2); }
.scroll-hint svg { width: 20px; height: 20px; }
@keyframes floaty {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(7px); }
}

/* 矮屏（如 1280×720）：压缩留白，保证文案 + 截图 + 下滚提示同屏可见 */
@media (max-height: 820px) and (min-width: 769px) {
  .hero { padding: calc(var(--nav-h) + 28px) 0 68px; }
  .hero-inner { gap: 28px; }
  .shot-frame { max-height: min(32svh, 420px); }
}

/* ---------- 卡片网格 ---------- */
.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.cell {
  padding: 22px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.cell:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: 0 10px 26px -14px rgba(0,0,0,.22);
}
.cell-icon {
  width: 52px; height: 52px;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius);
  margin-bottom: 16px;
}
.cell-icon svg { width: 26px; height: 26px; }
.cell-name { font-weight: 700; font-size: 15.5px; }
.cell-desc { margin-top: 6px; font-size: 13.5px; color: var(--text-2); line-height: 1.65; }

/* 点睛色图标底 */
.ic-blue   { background: color-mix(in srgb, var(--c-blue) 12%, transparent); color: var(--c-blue); }
.ic-cyan   { background: color-mix(in srgb, var(--c-cyan) 12%, transparent); color: var(--c-cyan); }
.ic-amber  { background: color-mix(in srgb, var(--c-amber) 14%, transparent); color: var(--c-amber); }
.ic-pink   { background: color-mix(in srgb, var(--c-pink) 12%, transparent); color: var(--c-pink); }
.ic-violet { background: color-mix(in srgb, var(--c-violet) 12%, transparent); color: var(--c-violet); }
.ic-green  { background: color-mix(in srgb, var(--c-green) 12%, transparent); color: var(--c-green); }

/* ---------- 图文交替区 ---------- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}
.split--flip .split-text { order: 2; }
.split--flip .split-visual { order: 1; }
.split-text { padding: 8px 0; }
.split-visual { position: relative; }

.split-title {
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(1.6rem, 3.2vw, 2.3rem);
  line-height: 1.25; letter-spacing: -.02em;
  margin-top: 14px;
}
.split-desc { margin-top: 16px; color: var(--text-2); font-size: 15px; }

.feat-list { margin-top: 24px; list-style: none; }
.feat-item {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--border);
  font-size: 14.5px;
}
.feat-item:last-child { border-bottom: none; }
.feat-dot {
  flex: none; width: 8px; height: 8px;
  border-radius: 50%;
  margin-top: 8px;
  background: var(--acc, var(--c-blue));
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--acc, var(--c-blue)) 16%, transparent);
}

/* 图文区图片 */
.split-img {
  display: block;
  width: 100%;
  height: auto; /* 按原始比例完整显示，不裁切 */
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  box-shadow: 0 20px 48px -22px rgba(0,0,0,.3);
}

/* ---------- 小标签 chips ---------- */
.chip-wrap { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 22px; }
.chip {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 6px 13px;
  font-size: 12.5px; font-weight: 500;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
}
.chip svg { width: 15px; height: 15px; flex: none; }
.chip-lg { padding: 8px 15px; font-size: 13px; }

.chip-group { margin-top: 18px; }
.chip-group-label {
  font-family: var(--mono);
  font-size: 11.5px; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 10px;
}

/* ---------- 规格行列表 ---------- */
.spec-list { display: flex; flex-direction: column; }
.spec-row {
  display: flex; align-items: flex-start; gap: 18px;
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}
.spec-row:last-child { border-bottom: none; }
.spec-icon {
  flex: none; width: 52px; height: 52px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--acc, var(--text-2));
  background: var(--surface);
}
.spec-icon svg { width: 25px; height: 25px; }
.spec-name { font-weight: 700; font-size: 15.5px; }
.spec-desc { margin-top: 6px; font-size: 13.5px; color: var(--text-2); line-height: 1.7; }

/* ---------- 反色带 ---------- */
.band-invert {
  background: var(--invert);
  color: var(--invert-text);
  border-radius: var(--radius);
  padding: 52px 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
  isolation: isolate;
}
.band-invert::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(420px 320px at 18% 20%, color-mix(in srgb, var(--c-blue) 28%, transparent), transparent 70%),
    radial-gradient(420px 320px at 84% 82%, color-mix(in srgb, var(--c-violet) 26%, transparent), transparent 70%);
}
.band-chip {
  display: inline-block;
  font-family: var(--mono);
  font-size: 12px; letter-spacing: .12em;
  color: var(--c-green);
  border: 1px solid color-mix(in srgb, var(--c-green) 45%, transparent);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 18px;
}
.band-title {
  font-weight: 900;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  letter-spacing: -.02em;
}
.band-desc { margin-top: 12px; color: color-mix(in srgb, var(--invert-text) 72%, transparent); }
.band-invert .hero-actions { justify-content: center; }

/* ---------- Footer ---------- */
footer {
  border-top: 1px solid var(--border);
  padding: 36px 0 44px;
}
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
.footer-brand { display: flex; align-items: center; gap: 12px; }
.footer-logo { height: 32px; width: auto; }
.footer-logo-light { display: none; }
.footer-logo-dark { display: block; }
.dark .footer-logo-light { display: block; }
.dark .footer-logo-dark { display: none; }
.footer-word { height: 24px; width: auto; }
.footer-word-light { display: none; }
.footer-word-dark { display: block; }
.dark .footer-word-light { display: block; }
.dark .footer-word-dark { display: none; }
.footer-note { font-size: 12.5px; color: var(--text-3); line-height: 1.9; }

/* ---------- 特别鸣谢 ---------- */
.thanks-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
.thanks-card {
  display: flex; align-items: center; gap: 12px;
  padding: 16px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: inherit;
  text-decoration: none;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.thanks-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: 0 10px 26px -14px rgba(0,0,0,.22);
}
.thanks-logo {
  flex: none;
  width: 48px; height: 48px;
  object-fit: contain;
}
.thanks-name { font-size: 13.5px; font-weight: 600; color: var(--text-2); }
.thanks-arrow {
  margin-left: auto;
  flex: none;
  width: 15px; height: 15px;
  color: var(--text-3);
  opacity: .55;
  transition: transform .2s ease, opacity .2s ease;
}
.thanks-card:hover .thanks-arrow {
  transform: translateX(2px);
  opacity: 1;
  color: var(--acc, var(--c-blue));
}

/* ---------- 滚动显现（无 JS 时内容默认可见） ---------- */
.reveal { opacity: 1; transform: none; transition: opacity .6s ease, transform .6s ease; }
.js .reveal { opacity: 0; transform: translateY(16px); }
.js .reveal.in { opacity: 1; transform: translateY(0); }

/* ---------- 更新日志（时间轴） ---------- */
.page-head { padding: calc(var(--nav-h) + 64px) 0 40px; }

.log { position: relative; padding-left: 34px; }
.log::before {
  content: ""; position: absolute;
  top: 6px; bottom: 6px; left: 5px;
  width: 1px;
  background: var(--border-strong);
}

.log-entry { position: relative; padding: 26px 0 26px 18px; }
.log-entry::before {
  content: ""; position: absolute;
  left: -33px; top: 34px;
  width: 11px; height: 11px;
  border-radius: 50%;
  background: var(--surface);
  border: 2px solid var(--border-strong);
}
.log-entry.latest::before {
  background: var(--c-green);
  border-color: color-mix(in srgb, var(--c-green) 40%, transparent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--c-green) 16%, transparent);
}

.log-head { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; }
.log-version {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 21px; letter-spacing: -.01em;
}
.log-entry.latest .log-version { color: var(--c-green); }
.log-date { font-size: 13px; color: var(--text-3); }
.log-badge {
  font-family: var(--mono);
  font-size: 11px; font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
  border: 1px solid var(--c-green);
  color: var(--c-green);
}
.log-badge.ghost {
  border-color: var(--border-strong);
  color: var(--text-3);
}

.log-groups {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.log-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
}
.log-group-label {
  font-family: var(--mono);
  font-size: 11.5px; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase;
  margin-bottom: 10px;
}
.log-group-label::before { content: "· "; }
.log-group:nth-child(1) .log-group-label { color: var(--c-green); }
.log-group:nth-child(2) .log-group-label { color: var(--c-amber); }
.log-group:nth-child(3) .log-group-label { color: var(--c-blue); }
.log-group ul { list-style: none; }
.log-group li {
  font-size: 13.5px; color: var(--text-2);
  padding: 5px 0 5px 14px;
  position: relative;
}
.log-group li::before {
  content: ""; position: absolute;
  left: 0; top: 13px;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--border-strong);
}
.log-group:nth-child(1) li::before { background: color-mix(in srgb, var(--c-green) 60%, transparent); }
.log-group:nth-child(2) li::before { background: color-mix(in srgb, var(--c-amber) 60%, transparent); }
.log-group:nth-child(3) li::before { background: color-mix(in srgb, var(--c-blue) 60%, transparent); }

/* ---------- 木流（作者页） ---------- */
.profile-grid {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 60px;
  align-items: start;
}
.avatar-frame {
  width: 220px; max-width: 100%;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
}
.avatar-frame img { width: 100%; height: 100%; object-fit: cover; }
.profile-name {
  margin-top: 22px;
  font-weight: 900;
  font-size: 30px; letter-spacing: -.02em;
}
.profile-handle {
  margin-top: 4px;
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--text-3);
}
.profile-role { margin-top: 14px; font-size: 14.5px; color: var(--text-2); }
.profile-age { margin-top: 18px; font-size: 14px; }
.profile-age b { font-family: var(--mono); font-size: 15px; color: var(--c-blue); }
.profile-links { margin-top: 22px; display: flex; flex-wrap: wrap; gap: 10px; }

.experience { padding-top: 6px; }
.exp-row {
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}
.exp-row:last-child { border-bottom: none; }
.exp-title { font-weight: 700; font-size: 16px; }
.exp-desc { margin-top: 8px; font-size: 14px; color: var(--text-2); line-height: 1.7; }

/* ---------- 下载页 ---------- */
/* 平台下载按钮：置于页面顶部，内容自适应宽度、居中排列 */
.dl-platforms {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 12px;
  margin-bottom: 14px;
}
.dl-platform {
  --acc: var(--c-blue);
  display: flex; align-items: center; justify-content: center; gap: 9px;
  min-width: 0;
  padding: 7px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text); text-decoration: none;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.dl-platform--and { --acc: var(--c-green); }
.dl-platform:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--acc) 45%, var(--border));
  box-shadow: 0 8px 22px -14px rgba(0,0,0,.22);
}
.dl-platform svg { width: 19px; height: 19px; flex: none; color: var(--acc); }
.dl-platform-name { font-weight: 700; font-size: 14.5px; }

/* 平台截图：横排在下载按钮下方，两图等高（顶/底对齐），宽度按各图比例自适应；
   显式 aspect-ratio + 禁止 flex 收缩：任何宽度下都不变形，加载前后占位一致 */
.dl-top { display: contents; }
.dl-shots {
  display: flex; justify-content: center;
  gap: 16px;
  margin-bottom: 26px;
}
.dl-shots img {
  flex: 0 0 auto;
  height: clamp(240px, 44vw, 460px);
  width: auto;
  object-fit: contain;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}
.dl-shots .shot-pc { aspect-ratio: 1536 / 963; }
.dl-shots .shot-ad { aspect-ratio: 1220 / 2712; }

.dl-card {
  min-width: 0; /* 避免内部长命令行撑宽栅格列 */
  padding: 22px 20px 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}
.dl-card .cell-icon { width: 40px; height: 40px; margin-bottom: 0; }
.dl-card .cell-icon svg { width: 21px; height: 21px; }
.dl-card-head { display: flex; align-items: center; gap: 12px; }
.dl-card-title { font-weight: 800; font-size: 17.5px; }
.dl-card-desc { margin-top: 12px; font-size: 13.5px; color: var(--text-2); line-height: 1.65; }

.dl-group {
  display: flex; align-items: center; gap: 8px;
  margin: 22px 0 9px;
  font-family: var(--mono);
  font-size: 11.5px; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--text-3);
}
.dl-tag {
  padding: 2px 8px;
  font-family: var(--sans);
  font-size: 10.5px; font-weight: 600; letter-spacing: .02em; text-transform: none;
  border-radius: 999px;
  background: color-mix(in srgb, var(--c-green) 16%, transparent);
  color: var(--c-green);
}
.dl-list { display: flex; flex-direction: column; gap: 9px; }
.dl-list .btn {
  width: 100%;
  justify-content: flex-start;
  padding: 11px 14px;
  white-space: normal;
}
/* 仓库按钮横排：整卡宽度下三个按钮平分一行，窄屏自动换行 */
.dl-list--row { flex-direction: row; flex-wrap: wrap; }
.dl-list--row .btn { width: auto; flex: 1 1 200px; }
.dl-meta {
  margin-left: auto;
  padding-left: 10px;
  font-family: var(--mono);
  font-size: 11px; font-weight: 500;
  color: var(--text-3);
}
.dl-list .btn.btn-invert .dl-meta { color: var(--invert-text); opacity: .72; }

/* 源码构建命令：单击即整段选中，方便复制；长 URL 视觉折行但不插入换行符 */
.dl-code {
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-2);
  font-family: var(--mono);
  font-size: 12.5px; line-height: 1.8;
  color: var(--text);
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  -webkit-user-select: all;
  user-select: all;
}
.dl-code .cm { color: var(--text-3); }

.dl-note {
  margin-top: 22px;
  padding: 15px 18px;
  border: 1px solid var(--border);
  border-left: 2px solid var(--c-blue);
  border-radius: var(--radius);
  background: var(--surface);
  font-size: 13.5px; color: var(--text-2); line-height: 1.8;
}
.dl-note b { color: var(--text); }
.dl-note a { color: var(--text); text-decoration: none; border-bottom: 1px solid var(--border-strong); }
.dl-note a:hover { border-color: var(--text-3); }

/* 手机端：安卓按钮+截图在上，Windows 按钮+截图在下（与桌面端两行横排不同） */
@media (max-width: 640px) {
  .dl-top {
    display: flex; flex-direction: column;
    gap: 12px;
    margin-bottom: 26px;
  }
  .dl-platforms, .dl-shots { display: contents; }
  .dl-platform--and { order: 1; }
  .dl-shots .shot-ad { order: 2; }
  .dl-platform--win { order: 3; }
  .dl-shots .shot-pc { order: 4; }
  /* 手机端：横屏截图保持整宽；竖屏手机截图限宽居中，避免占据整屏高度 */
  .dl-shots img { width: auto; max-width: 100%; height: auto; }
  .dl-shots .shot-ad { width: min(64vw, 280px); align-self: center; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .split { grid-template-columns: 1fr; gap: 32px; }
  .split--flip .split-text { order: 1; }
  .split--flip .split-visual { order: 2; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: 1fr; }
  .log-groups { grid-template-columns: 1fr; }
  .profile-grid { grid-template-columns: 1fr; gap: 36px; }
}

@media (max-width: 768px) {
  .nav-links, .nav-right .btn { display: none; }
  .nav-menu-btn { display: inline-flex; }
  .nav-right { gap: 8px; }
  /* 手机端导航保持左 logo 右按钮的弹性布局 */
  .nav-inner { grid-template-columns: 1fr auto; }
  .nav-brand { justify-self: start; }
  .nav-right { justify-self: end; }
  .section-pad { padding: 72px 0 64px; }
  .hero { padding: calc(var(--nav-h) + 40px) 0 84px; }
  .hero-inner { gap: 34px; }
  .shot-frame { max-height: 40vh; }
  .band-invert { padding: 40px 28px; }
  .thanks-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  /* 只收窄左右留白：不能用 padding 简写，会连带清掉 .page-head 的顶部内边距，
     导致固定导航遮挡标题 */
  .container { padding-left: 18px; padding-right: 18px; }
  .grid-4 { grid-template-columns: 1fr; }
  .hero-actions .btn { flex: 1 1 auto; }
  .sec-head { margin-bottom: 36px; }
  .band-invert .hero-actions { flex-direction: column; }
  .band-invert .btn { width: 100%; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}

/* ---------- 无障碍：尊重减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1 !important; transform: none !important; }
}