/* ============================================
   base.css V3 — 浅色渐变科技风
   保留酷炫动效，浅色背景 + 渐变点缀
   ============================================ */

:root {
  /* ── 背景层（浅色系） ── */
  --bg-deep: #FAFBFE;
  --bg-card: rgba(255, 255, 255, 0.75);
  --bg-card-solid: #FFFFFF;
  --bg-elevated: #F5F6FA;
  --bg-hover: rgba(0, 0, 0, 0.02);

  /* ── 渐变光晕（浅色下更饱和） ── */
  --glow-primary: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(255,107,94,0.18) 0%, transparent 100%);
  --glow-gold: radial-gradient(ellipse 60% 40% at 30% 50%, rgba(245,166,35,0.12) 0%, transparent 100%);
  --glow-green: radial-gradient(ellipse 50% 40% at 70% 80%, rgba(52,199,89,0.10) 0%, transparent 100%);
  --glow-hero: radial-gradient(ellipse 120% 60% at 50% 0%, rgba(255,107,94,0.15) 0%, rgba(245,166,35,0.08) 40%, transparent 70%);

  /* ── 主色（暖调，无蓝紫） ── */
  --color-primary: #FF6B5E;
  --color-primary-bright: #FF8A7A;
  --color-secondary: #F5A623;
  --color-secondary-bright: #FFBE4F;
  --color-accent: #34C759;
  --color-accent-bright: #5ED87A;

  /* ── 渐变 ── */
  --gradient-primary: linear-gradient(135deg, #FF6B5E, #F5A623);
  --gradient-warm: linear-gradient(135deg, #FF6B5E, #F5A623, #34C759);
  --gradient-text: linear-gradient(135deg, #E8533E, #D4880E);
  --gradient-border: linear-gradient(135deg, rgba(255,107,94,0.4), rgba(245,166,35,0.25), rgba(52,199,89,0.15), transparent);
  --gradient-border-subtle: linear-gradient(135deg, rgba(0,0,0,0.06), rgba(0,0,0,0.02));

  /* ── 文本（深色文字 on 浅色背景） ── */
  --text-bright: #1A1A2E;
  --text-primary: #2D2D3F;
  --text-muted: #6B7280;
  --text-dim: #9CA3AF;

  /* ── 边框 ── */
  --border-glow: rgba(255,107,94,0.25);
  --border-subtle: rgba(0,0,0,0.06);
  --border-card: rgba(0,0,0,0.08);

  /* ── 阴影 ── */
  --shadow-glow-sm: 0 0 20px rgba(255,107,94,0.12);
  --shadow-glow-md: 0 0 40px rgba(255,107,94,0.18);
  --shadow-glow-lg: 0 0 80px rgba(255,107,94,0.22);
  --shadow-card: 0 4px 24px rgba(0,0,0,0.06);
  --shadow-elevated: 0 8px 32px rgba(0,0,0,0.10);

  /* ── 字体 · Editorial Technical Archive ── */
  --font-sans: -apple-system, 'PingFang SC', 'Helvetica Neue', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  --font-serif: 'Fraunces', 'Noto Serif SC', 'Songti SC', 'Source Han Serif SC', 'SimSun', serif;
  --font-display: 'Fraunces', 'Noto Serif SC', 'Songti SC', 'Source Han Serif SC', serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', 'Consolas', monospace;
  --font-family: var(--font-sans);

  /* ── 字号 · 放大标题阶梯，拉开节奏 ── */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2.25rem;
  --text-4xl: 3rem;
  --text-5xl: 4.25rem;
  --text-6xl: 5.5rem;
  --text-7xl: 7rem;

  /* ── 间距 ── */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;
  --space-5xl: 8rem;

  /* ── 圆角 ── */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;

  /* ── 过渡 ── */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.6s ease;
  --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);

  /* ── 层级 ── */
  --z-bg: -1;
  --z-content: 1;
  --z-sticky: 100;
  --z-nav: 200;
  --z-modal: 300;

  /* ── 容器 ── */
  --container-xl: 1200px;
  --container-2xl: 1400px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.75;
  color: var(--text-primary);
  background-color: var(--bg-deep);
  overflow-x: hidden;
  font-feature-settings: "palt" 1, "pnum" 1, "ss01" 1;
}

img, video { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; transition: color var(--transition-fast); }
ul, ol { list-style: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; outline: none; }
input, textarea, select { font-family: inherit; outline: none; border: none; background: none; color: var(--text-primary); }
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.12;
  color: var(--text-bright);
  letter-spacing: -0.02em;
  font-feature-settings: "palt" 1, "pnum" 1, "ss01" 1, "ss02" 1;
}
/* 中英混排正文精修：中文微开字距、英文启用样式集 */
p {
  color: var(--text-muted);
  line-height: 1.92;
  letter-spacing: 0.01em;
  text-spacing: space-all;
  hanging-punctuation: allow-end;
}

/* ── 容器 ── */
.container {
  width: 100%;
  max-width: var(--container-xl);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.container-2xl { max-width: var(--container-2xl); }

/* ── 区块 ── */
.section { padding: var(--space-4xl) 0; position: relative; }
.section-sm { padding: var(--space-3xl) 0; }

/* ── 区块标题 · Editorial Kicker ── */
.section-label {
  display: inline-flex;
  align-items: baseline;
  gap: 0.6em;
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  font-size: 0.95rem;
  font-variation-settings: "opsz" 14, "SOFT" 50;
  letter-spacing: 0.02em;
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
  text-transform: none;
  position: relative;
  padding-left: 1.4em;
}

.section-label::before {
  content: '§';
  position: absolute;
  left: 0;
  top: 0;
  width: auto;
  height: auto;
  background: none;
  box-shadow: none;
  border-radius: 0;
  font-family: var(--font-serif);
  font-style: normal;
  font-weight: 600;
  color: var(--color-primary);
  font-size: 1.15em;
  opacity: 0.55;
}

.section-label::after {
  content: '';
  display: inline-block;
  width: 2em;
  height: 1px;
  margin-left: 0.5em;
  background: currentColor;
  opacity: 0.35;
  align-self: center;
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: 700;
  font-variation-settings: "opsz" 96, "SOFT" 30, "WONK" 0;
  color: var(--text-bright);
  margin-bottom: var(--space-lg);
  letter-spacing: -0.025em;
  line-height: 1.08;
}

.section-title .gradient-text {
  font-style: italic;
  font-weight: 600;
  font-variation-settings: "opsz" 144, "SOFT" 100, "WONK" 1;
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto var(--space-2xl);
  line-height: 1.95;
  letter-spacing: 0.01em;
}

/* ── 渐变文字 ── */
.gradient-text {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── 文本工具 ── */
.text-center { text-align: center; }
.text-bright { color: var(--text-bright); }
.text-muted { color: var(--text-muted); }

/* ── 背景发光层 ── */
.glow-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: var(--z-bg);
}

/* ── 选中态 ── */
::selection {
  background: rgba(255, 107, 94, 0.15);
  color: var(--text-bright);
}

/* ── 滚动条 ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(0,0,0,0.12); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: rgba(0,0,0,0.2); }

/* ── SR Only ── */
.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;
}