/* =============================================================
   reset.css
   职责：设计令牌（Design Tokens）、浏览器重置、主题变量、
        背景光斑、排版基线、无障碍与降级策略
   ============================================================= */

/* -------------------------------------------------------------
   1. 设计令牌：所有可变数值集中在此，改一处即全局生效
   ------------------------------------------------------------- */
:root {
  /* 字体：完全使用系统字体栈，零网络请求 */
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
               "PingFang SC", "HarmonyOS Sans SC", "Helvetica Neue",
               "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "SF Mono", ui-monospace, "JetBrains Mono", Menlo, Consolas,
               "Liberation Mono", "Courier New", monospace;

  /* 圆角梯度 */
  --r-sm: 14px;
  --r-md: 20px;
  --r-lg: 26px;
  --r-xl: 32px;
  --r-pill: 999px;

  /* 玻璃模糊与饱和度 */
  --blur-sm: 12px;
  --blur-md: 24px;
  --blur-lg: 34px;
  --glass-saturate: 180%;

  /* 动效 */
  --ease: cubic-bezier(0.25, 0.8, 0.25, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --dur-fast: 200ms;
  --dur: 300ms;
  --dur-slow: 400ms;

  /* 布局 */
  --page-max: 1180px;
  --page-pad: 24px;
  --nav-h: 68px;

  /* 光斑配色（深浅主题共用，靠透明度与混合模式调节） */
  --blob-1: #4d7cff;
  --blob-2: #a05cff;
  --blob-3: #00d4c8;
  --blob-4: #ff5f9e;
  --blob-5: #ffb35c;
}

/* ---------- 深色主题（默认） ---------- */
:root,
[data-theme="dark"] {
  color-scheme: dark;

  --bg-base:   #05070d;
  --bg-deep:   #02040a;

  --text-1: rgba(255, 255, 255, 0.94);
  --text-2: rgba(255, 255, 255, 0.66);
  --text-3: rgba(255, 255, 255, 0.42);

  /* 玻璃三层：背景 / 描边 / 高光 */
  --glass-bg:        rgba(255, 255, 255, 0.07);
  --glass-bg-hover:  rgba(255, 255, 255, 0.11);
  --glass-bg-strong: rgba(255, 255, 255, 0.13);
  --glass-fallback:  rgba(20, 26, 40, 0.92); /* 不支持 backdrop-filter 时的回退 */

  --glass-brd-top:    rgba(255, 255, 255, 0.55);
  --glass-brd-bottom: rgba(255, 255, 255, 0.04);
  --glass-brd-soft:   rgba(255, 255, 255, 0.12);
  --glass-sheen:      rgba(255, 255, 255, 0.10);
  --glass-sheen-2:    rgba(255, 255, 255, 0.05);
  --glass-inner-line: rgba(255, 255, 255, 0.16);

  --shadow-1: 0 8px 32px rgba(0, 0, 0, 0.34);
  --shadow-2: 0 18px 50px rgba(0, 0, 0, 0.45);
  --shadow-3: 0 30px 80px rgba(0, 0, 0, 0.55);

  --accent:     #6ea8ff;
  --accent-2:   #b58bff;
  --accent-3:   #5ce1d6;
  --accent-ink: #06122c;

  --scrim: rgba(3, 5, 12, 0.62);
  --hairline: rgba(255, 255, 255, 0.10);
  --blob-alpha: 0.55;
  --blob-blur: 90px;
  --grain-opacity: 0.035;

  /* 代码高亮配色（深色） */
  --tok-comment:  rgba(255, 255, 255, 0.36);
  --tok-string:   #9fe6a8;
  --tok-number:   #ffb877;
  --tok-keyword:  #c39bff;
  --tok-literal:  #ff9bb5;
  --tok-fn:       #6fd6ff;
  --tok-op:       rgba(255, 255, 255, 0.62);
  --tok-punc:     rgba(255, 255, 255, 0.44);
  --tok-tag:      #ff8fa8;
  --tok-attr:     #ffd494;
  --tok-prop:     #6fd6ff;
  --tok-at:       #c39bff;
  --tok-selector: #ffd494;
  --tok-hex:      #9fe6a8;
  --code-bg:      rgba(10, 14, 24, 0.55);
}

/* ---------- 浅色主题 ---------- */
[data-theme="light"] {
  color-scheme: light;

  --bg-base:   #e9edf6;
  --bg-deep:   #dfe5f1;

  --text-1: rgba(14, 20, 38, 0.92);
  --text-2: rgba(14, 20, 38, 0.64);
  --text-3: rgba(14, 20, 38, 0.44);

  --glass-bg:        rgba(255, 255, 255, 0.55);
  --glass-bg-hover:  rgba(255, 255, 255, 0.72);
  --glass-bg-strong: rgba(255, 255, 255, 0.78);
  --glass-fallback:  rgba(255, 255, 255, 0.96);

  --glass-brd-top:    rgba(255, 255, 255, 0.95);
  --glass-brd-bottom: rgba(20, 30, 60, 0.10);
  --glass-brd-soft:   rgba(20, 30, 60, 0.10);
  --glass-sheen:      rgba(255, 255, 255, 0.55);
  --glass-sheen-2:    rgba(255, 255, 255, 0.28);
  --glass-inner-line: rgba(255, 255, 255, 0.85);

  --shadow-1: 0 8px 32px rgba(30, 45, 80, 0.12);
  --shadow-2: 0 18px 50px rgba(30, 45, 80, 0.18);
  --shadow-3: 0 30px 80px rgba(30, 45, 80, 0.24);

  --accent:     #2f6bff;
  --accent-2:   #8a4dff;
  --accent-3:   #00a89c;
  --accent-ink: #ffffff;

  --scrim: rgba(226, 232, 244, 0.66);
  --hairline: rgba(20, 30, 60, 0.10);
  --blob-alpha: 0.62;
  --blob-blur: 80px;
  --grain-opacity: 0.03;

  /* 代码高亮配色（浅色） */
  --tok-comment:  #7b8494;
  --tok-string:   #0a7a4c;
  --tok-number:   #b45309;
  --tok-keyword:  #7c3aed;
  --tok-literal:  #c026a8;
  --tok-fn:       #0369a1;
  --tok-op:       #475569;
  --tok-punc:     #64748b;
  --tok-tag:      #be123c;
  --tok-attr:     #a16207;
  --tok-prop:     #0369a1;
  --tok-at:       #7c3aed;
  --tok-selector: #a16207;
  --tok-hex:      #0a7a4c;
  --code-bg:      rgba(255, 255, 255, 0.55);
}

/* 主题切换时让整页平滑过渡（避免 background 生硬跳变） */
html {
  transition: background-color var(--dur) var(--ease);
}

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

* { margin: 0; }

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

body {
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-1);
  background-color: var(--bg-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

/* 打开模态框时锁定滚动 */
body.is-locked { overflow: hidden; }

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

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

button { background: none; border: 0; cursor: pointer; }

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

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

code, pre, kbd { font-family: var(--font-mono); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

::selection {
  background: rgba(110, 168, 255, 0.42);
  background: color-mix(in srgb, var(--accent) 45%, transparent);
  color: var(--text-1);
}

/* 细滚动条（WebKit + Firefox） */
* { scrollbar-width: thin; scrollbar-color: var(--hairline) transparent; }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--hairline);
  border-radius: var(--r-pill);
  border: 3px solid transparent;
  background-clip: content-box;
}
::-webkit-scrollbar-thumb:hover { background: var(--glass-brd-soft); background-clip: content-box; }

/* 隐藏 <svg> 图标精灵容器 */
.svg-sprite { position: absolute; width: 0; height: 0; overflow: hidden; }

/* 通用内联 SVG 图标：继承 currentColor 的描边风格 */
.icon {
  width: 1.15em;
  height: 1.15em;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* -------------------------------------------------------------
   3. 背景：多层缓慢流动的彩色光斑
      液态玻璃之所以"好看"，底层必须有丰富的色彩可供折射
   ------------------------------------------------------------- */
.aurora {
  position: fixed;
  inset: -20vmax;
  z-index: -2;
  pointer-events: none;
  /* 兜底：不支持 color-mix() 的浏览器使用纯色渐变 */
  background: linear-gradient(180deg, var(--bg-base) 0%, var(--bg-deep) 100%);
  background:
    radial-gradient(120% 90% at 50% 0%, rgba(77, 124, 255, 0.14), transparent 60%),
    linear-gradient(180deg, var(--bg-base) 0%, var(--bg-deep) 100%);
}

.blob {
  position: absolute;
  display: block;
  border-radius: 50%;
  filter: blur(var(--blob-blur));
  opacity: var(--blob-alpha);
  will-change: transform;
}

.blob--1 {
  width: 46vmax; height: 46vmax;
  top: 2%;  left: -6%;
  background: radial-gradient(circle at 32% 32%, var(--blob-1), transparent 68%);
  animation: drift-a 26s var(--ease) infinite alternate;
}
.blob--2 {
  width: 40vmax; height: 40vmax;
  top: 18%; right: -8%;
  background: radial-gradient(circle at 60% 40%, var(--blob-2), transparent 68%);
  animation: drift-b 32s var(--ease) infinite alternate;
}
.blob--3 {
  width: 36vmax; height: 36vmax;
  top: 55%; left: 8%;
  background: radial-gradient(circle at 50% 50%, var(--blob-3), transparent 68%);
  animation: drift-c 29s var(--ease) infinite alternate;
}
.blob--4 {
  width: 34vmax; height: 34vmax;
  top: 78%; right: 6%;
  background: radial-gradient(circle at 45% 55%, var(--blob-4), transparent 68%);
  animation: drift-d 35s var(--ease) infinite alternate;
}
.blob--5 {
  width: 30vmax; height: 30vmax;
  top: 38%; left: 42%;
  background: radial-gradient(circle at 50% 50%, var(--blob-5), transparent 66%);
  animation: drift-e 38s var(--ease) infinite alternate;
  opacity: calc(var(--blob-alpha) * 0.7);
}

@keyframes drift-a {
  0%   { transform: translate3d(0, 0, 0) scale(1); }
  50%  { transform: translate3d(8vw, 6vh, 0) scale(1.12); }
  100% { transform: translate3d(-4vw, 12vh, 0) scale(0.95); }
}
@keyframes drift-b {
  0%   { transform: translate3d(0, 0, 0) scale(1.05); }
  50%  { transform: translate3d(-10vw, 10vh, 0) scale(0.92); }
  100% { transform: translate3d(4vw, -6vh, 0) scale(1.15); }
}
@keyframes drift-c {
  0%   { transform: translate3d(0, 0, 0) scale(0.95); }
  50%  { transform: translate3d(12vw, -8vh, 0) scale(1.14); }
  100% { transform: translate3d(-6vw, 4vh, 0) scale(1); }
}
@keyframes drift-d {
  0%   { transform: translate3d(0, 0, 0) scale(1.08); }
  50%  { transform: translate3d(-8vw, -10vh, 0) scale(0.9); }
  100% { transform: translate3d(6vw, 2vh, 0) scale(1.1); }
}
@keyframes drift-e {
  0%   { transform: translate3d(0, 0, 0) scale(1); }
  50%  { transform: translate3d(-14vw, 8vh, 0) scale(1.2); }
  100% { transform: translate3d(10vw, -10vh, 0) scale(0.9); }
}

/* 极细噪点：让玻璃看起来有"磨砂颗粒"而不是纯数字渐变 */
.grain {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: var(--grain-opacity);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* -------------------------------------------------------------
   4. 排版基线
   ------------------------------------------------------------- */
h1, h2, h3, h4 {
  font-weight: 650;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--text-1);
  text-wrap: balance;
}

p { text-wrap: pretty; }

.grad-text {
  background: linear-gradient(100deg, var(--accent) 0%, var(--accent-2) 45%, var(--accent-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* 跳转到主内容（键盘用户） */
.skip-link {
  position: fixed;
  top: 12px;
  left: 50%;
  z-index: 999;
  padding: 10px 18px;
  border-radius: var(--r-pill);
  background: var(--accent);
  color: var(--accent-ink);
  font-size: 14px;
  font-weight: 600;
  transform: translate(-50%, -160%);
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus-visible { transform: translate(-50%, 0); }

/* -------------------------------------------------------------
   5. 滚动入场动画（由 IntersectionObserver 添加 .is-visible）
   ------------------------------------------------------------- */
/* 渐进增强：仅当 <html> 带 .js（即 JS 可用）时，入场元素才先隐藏；
   禁用 JS 或脚本未执行时内容默认完全可见，避免整页白屏（审计 F-01）。 */
.js .reveal {
  opacity: 0;
  transform: translate3d(0, 26px, 0);
  transition:
    opacity var(--dur-slow) var(--ease-out),
    transform var(--dur-slow) var(--ease-out);
  will-change: opacity, transform;
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* -------------------------------------------------------------
   6. 降级与无障碍
   ------------------------------------------------------------- */

/* 浏览器不支持 backdrop-filter 时，回退为不透明背景保证可读性 */
@supports not ((backdrop-filter: blur(2px)) or (-webkit-backdrop-filter: blur(2px))) {
  .glass,
  .glass-soft {
    background: var(--glass-fallback) !important;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
  }
}

/* 尊重系统的"减少动态效果"设置 */
@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;
    scroll-behavior: auto !important;
  }

  .reveal { opacity: 1; transform: none; }
  .blob { animation: none !important; }
}