/* ==========================================================================
   SoundRadar 宣传站 - base.css
   设计 token / CSS 变量 / 三态主题 / 重置 / 排版 / 工具类
   ========================================================================== */

/* ---------- 设计 token：浅色（默认） ---------- */
:root {
  /* 品牌主色 - 科技蓝 Indigo */
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-active: #3730a3;
  --primary-soft: #eef2ff;
  --primary-border: #c7d2fe;

  /* 辅色 - 医疗绿 Emerald（康复关怀） */
  --accent: #10b981;
  --accent-hover: #059669;
  --accent-soft: #ecfdf5;
  --accent-border: #a7f3d0;

  /* 语义色 */
  --danger: #ef4444;
  --danger-soft: #fef2f2;
  --warning: #f59e0b;
  --warning-soft: #fffbeb;
  --success: #10b981;

  /* 中性色 - Slate 梯度 */
  --bg: #ffffff;
  --bg-subtle: #f8fafc;
  --bg-elevated: #ffffff;
  --surface: #f1f5f9;
  --surface-2: #e2e8f0;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text: #0f172a;
  --text-muted: #475569;
  --text-subtle: #64748b;
  --text-inverse: #ffffff;

  /* 渐变 */
  --grad-brand: linear-gradient(135deg, #4f46e5 0%, #6366f1 50%, #10b981 100%);
  --grad-hero: radial-gradient(1200px 600px at 80% -10%, rgba(99, 102, 241, .18), transparent 60%),
               radial-gradient(900px 500px at 0% 20%, rgba(16, 185, 129, .14), transparent 55%);
  --grad-radar: conic-gradient(from 0deg, rgba(79, 70, 229, 0), rgba(79, 70, 229, .35), rgba(16, 185, 129, .35), rgba(79, 70, 229, 0));

  /* 点缀色 - 紫色（readdy 风格第三色，用于特定强调，保留项目绿主辅地位） */
  --accent2: #7c3aed;
  --accent2-hover: #6d28d9;
  --accent2-soft: #f5f3ff;
  --accent2-border: #ddd6fe;

  /* 声波 / 雷达增强渐变（readdy 风格动效，品牌色版） */
  --grad-soundwave: linear-gradient(90deg, #4f46e5 0%, #7c3aed 50%, #10b981 100%);
  --grad-radar-enhanced: conic-gradient(from 0deg,
    rgba(79, 70, 229, 0) 0deg,
    rgba(79, 70, 229, .6) 280deg,
    rgba(16, 185, 129, .6) 350deg,
    rgba(79, 70, 229, .8) 360deg);
  --shadow-accent: 0 10px 24px -6px rgba(16, 185, 129, .35);

  /* 高级视觉效果 - 光晕和氛围 */
  --glow-primary: 0 0 40px rgba(79, 70, 229, .3), 0 0 80px rgba(79, 70, 229, .15);
  --glow-accent: 0 0 40px rgba(16, 185, 129, .3), 0 0 80px rgba(16, 185, 129, .15);
  --glow-purple: 0 0 40px rgba(124, 58, 237, .3), 0 0 80px rgba(124, 58, 237, .15);

  /* 多层渐变背景 */
  --grad-mesh: radial-gradient(at 0% 0%, rgba(79, 70, 229, .08) 0%, transparent 50%),
               radial-gradient(at 100% 0%, rgba(124, 58, 237, .06) 0%, transparent 50%),
               radial-gradient(at 100% 100%, rgba(16, 185, 129, .08) 0%, transparent 50%),
               radial-gradient(at 0% 100%, rgba(99, 102, 241, .06) 0%, transparent 50%);

  /* 玻璃态效果 */
  --glass-bg: rgba(255, 255, 255, .7);
  --glass-border: rgba(255, 255, 255, .9);
  --glass-blur: blur(20px) saturate(180%);

  /* 高光效果 */
  --shimmer: linear-gradient(90deg,
    transparent 0%,
    rgba(255, 255, 255, .6) 50%,
    transparent 100%);

  /* 间距（8px 基准） */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 12px;
  --space-lg: 16px;
  --space-xl: 24px;
  --space-2xl: 48px;
  --space-3xl: 72px;
  --space-4xl: 120px;

  /* 圆角（同心原则） */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  --radius-2xl: 28px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, .08), 0 2px 4px -2px rgba(15, 23, 42, .05);
  --shadow-lg: 0 12px 20px -6px rgba(15, 23, 42, .10), 0 4px 8px -4px rgba(15, 23, 42, .06);
  --shadow-xl: 0 24px 38px -8px rgba(15, 23, 42, .14), 0 8px 16px -8px rgba(15, 23, 42, .08);
  --shadow-2xl: 0 32px 64px -12px rgba(15, 23, 42, .18), 0 12px 24px -8px rgba(15, 23, 42, .10);
  --shadow-primary: 0 10px 24px -6px rgba(79, 70, 229, .45);
  --shadow-primary-lg: 0 20px 40px -8px rgba(79, 70, 229, .5), 0 8px 16px -4px rgba(79, 70, 229, .3);

  /* 字体 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei UI",
               "PingFang SC", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Cascadia Code", "JetBrains Mono", "Fira Code", Consolas, "Courier New", monospace;

  /* 布局 */
  --container: 1200px;
  --container-narrow: 880px;
  --header-h: 68px;

  /* 动效 */
  --ease: cubic-bezier(.4, 0, .2, 1);
  --ease-out: cubic-bezier(.16, 1, .3, 1);
  --t-fast: 150ms var(--ease);
  --t: 220ms var(--ease);
  --t-slow: 400ms var(--ease-out);

  /* z 层级 */
  --z-header: 100;
  --z-overlay: 200;
  --z-modal: 300;
}

/* ---------- 深色主题 ---------- */
[data-theme="dark"] {
  --primary: #818cf8;
  --primary-hover: #a5b4fc;
  --primary-active: #c7d2fe;
  --primary-soft: #1e1b4b;
  --primary-border: #3730a3;

  --accent: #34d399;
  --accent-hover: #6ee7b7;
  --accent-soft: #064e3b;
  --accent-border: #065f46;

  --danger: #f87171;
  --danger-soft: #450a0a;
  --warning: #fbbf24;
  --warning-soft: #451a03;
  --success: #34d399;

  --bg: #0b1120;
  --bg-subtle: #0f172a;
  --bg-elevated: #131c31;
  --surface: #1e293b;
  --surface-2: #334155;
  --border: #1e293b;
  --border-strong: #334155;
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  --text-inverse: #0b1120;

  --grad-hero: radial-gradient(1200px 600px at 80% -10%, rgba(99, 102, 241, .22), transparent 60%),
               radial-gradient(900px 500px at 0% 20%, rgba(16, 185, 129, .16), transparent 55%);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .5), 0 2px 4px -2px rgba(0, 0, 0, .4);
  --shadow-lg: 0 12px 20px -6px rgba(0, 0, 0, .55), 0 4px 8px -4px rgba(0, 0, 0, .4);
  --shadow-xl: 0 24px 38px -8px rgba(0, 0, 0, .65), 0 8px 16px -8px rgba(0, 0, 0, .5);
  --shadow-primary: 0 10px 24px -6px rgba(129, 140, 248, .35);
  --shadow-accent: 0 10px 24px -6px rgba(52, 211, 153, .25);

  /* 紫色点缀 - 深色变体 */
  --accent2: #a78bfa;
  --accent2-hover: #c4b5fd;
  --accent2-soft: #2e1065;
  --accent2-border: #4c1d95;

  /* 深色模式光效 */
  --glow-primary: 0 0 40px rgba(129, 140, 248, .25), 0 0 80px rgba(129, 140, 248, .12);
  --glow-accent: 0 0 40px rgba(52, 211, 153, .25), 0 0 80px rgba(52, 211, 153, .12);
  --glow-purple: 0 0 40px rgba(167, 139, 250, .25), 0 0 80px rgba(167, 139, 250, .12);

  --glass-bg: rgba(30, 41, 59, .7);
  --glass-border: rgba(71, 85, 105, .8);

  --shadow-2xl: 0 32px 64px -12px rgba(0, 0, 0, .7), 0 12px 24px -8px rgba(0, 0, 0, .6);
  --shadow-primary-lg: 0 20px 40px -8px rgba(129, 140, 248, .4), 0 8px 16px -4px rgba(129, 140, 248, .25);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--t), color var(--t);
  overflow-x: hidden;
}

img, svg, video { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }
ul, ol { list-style: none; }
input, textarea, select { font: inherit; color: inherit; }

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

/* ---------- 排版 ---------- */
h1, h2, h3, h4, h5, h6 { line-height: 1.2; font-weight: 700; letter-spacing: -.02em; color: var(--text); }
h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); }
h2 { font-size: clamp(1.8rem, 3.5vw, 2.6rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }
p { color: var(--text-muted); }
strong { color: var(--text); font-weight: 600; }
code { font-family: var(--font-mono); font-size: .9em; background: var(--surface); padding: 2px 6px; border-radius: var(--radius-sm); }

/* ---------- 布局工具类 ---------- */
.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 var(--space-xl); }
.container-narrow { max-width: var(--container-narrow); }

.section { padding: var(--space-4xl) 0; }
.section-sm { padding: var(--space-3xl) 0; }

.section-head {
  max-width: 760px;
  margin: 0 auto var(--space-2xl);
  text-align: center;
}
.section-head .eyebrow {
  display: inline-block;
  font-size: .82rem; font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--primary);
  padding: 8px 16px;
  background: var(--primary-soft);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-lg);
  border: 1px solid var(--primary-border);
  box-shadow: 0 2px 8px rgba(79, 70, 229, .12);
  transition: transform var(--t-fast);
}
.section-head .eyebrow:hover {
  transform: scale(1.02);
}
.section-head h2 {
  margin-bottom: var(--space-lg);
  background: linear-gradient(135deg, var(--text) 0%, var(--text-muted) 100%);
  -webkit-background-clip: text;
  background-clip: text;
}
.section-head p { font-size: 1.1rem; line-height: 1.7; }

.text-gradient {
  background: var(--grad-brand);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
  position: relative;
  display: inline-block;
}
.text-gradient::after {
  content: attr(data-text);
  position: absolute;
  left: 0; top: 0;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: blur(12px);
  opacity: .4;
  z-index: -1;
}

/* ---------- 网格 ---------- */
.grid { display: grid; gap: var(--space-xl); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 980px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

/* ---------- 滚动渐入 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
  will-change: opacity, transform;
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}
.reveal[data-delay="1"] { transition-delay: .1s; }
.reveal[data-delay="2"] { transition-delay: .2s; }
.reveal[data-delay="3"] { transition-delay: .3s; }
.reveal[data-delay="4"] { transition-delay: .4s; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 可访问性 ---------- */
:focus-visible { outline: 2px solid var(--primary); outline-offset: 3px; border-radius: 4px; }
.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; }
.skip-link { position: absolute; left: -9999px; top: 0; z-index: var(--z-modal); background: var(--primary); color: #fff; padding: 12px 20px; border-radius: 0 0 var(--radius-md) 0; }
.skip-link:focus { left: 0; }