/* ============================================================
   Base · Reset + Typography + Utilities + Animation
   ============================================================ */

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

* { margin: 0; padding: 0; }

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

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  color: var(--color-text-primary);
  background: var(--color-bg);
  min-height: 100vh;
  overflow-x: hidden;
  font-feature-settings: 'ss01', 'cv11';
  -webkit-tap-highlight-color: transparent;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

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

ul, ol { list-style: none; }

::selection {
  background: rgba(196, 176, 154, 0.25);
  color: var(--color-text-primary);
}

/* ---------- Scrollbar ---------- */
*::-webkit-scrollbar { width: 10px; height: 10px; }
*::-webkit-scrollbar-track { background: transparent; }
*::-webkit-scrollbar-thumb {
  background: var(--color-border-strong);
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  background-clip: padding-box;
}
*::-webkit-scrollbar-thumb:hover { background: var(--color-text-muted); background-clip: padding-box; }

* { scrollbar-width: thin; scrollbar-color: var(--color-border-strong) transparent; }

/* ============================================================
   Typography
   ============================================================ */
.h-display {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--fs-display);
  line-height: var(--lh-tight);
  letter-spacing: var(--letter-tight);
}

.h-1 {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--fs-5xl);
  line-height: var(--lh-tight);
  letter-spacing: var(--letter-tight);
}

.h-2 {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--fs-4xl);
  line-height: var(--lh-snug);
  letter-spacing: var(--letter-tight);
}

.h-3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-2xl);
  line-height: var(--lh-snug);
  letter-spacing: var(--letter-snug);
}

.h-4 {
  font-size: var(--fs-lg);
  font-weight: 600;
  line-height: var(--lh-snug);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: var(--letter-wider);
  color: var(--color-text-muted);
}

.eyebrow::before {
  content: '';
  width: 24px;
  height: 1px;
  background: var(--brand-grad);
}

/* 品牌渐变文字 */
.text-brand-grad {
  background: var(--brand-grad-text);
  -webkit-background-clip: text;
          background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* 文字修饰 */
.text-mono      { font-family: var(--font-mono); }
.text-display   { font-family: var(--font-display); font-weight: 500; }
.text-secondary { color: var(--color-text-secondary); }
.text-muted     { color: var(--color-text-muted); }
.text-accent    { color: var(--color-primary); }
.text-success   { color: var(--color-success); }
.text-warning   { color: var(--color-warning); }
.text-danger    { color: var(--color-danger); }
.italic         { font-style: italic; }

/* ============================================================
   Backgrounds · 背景装饰
   ============================================================ */

/* 品牌径向光晕 */
.bg-grad-radial {
  background: var(--bg-radial);
}

/* 网格背景 */
.bg-grad-grid {
  background-image: var(--bg-grid);
  background-size: 48px 48px;
  background-position: center top;
  -webkit-mask-image: radial-gradient(ellipse 60% 60% at 50% 30%, #000 30%, transparent 75%);
          mask-image: radial-gradient(ellipse 60% 60% at 50% 30%, #000 30%, transparent 75%);
}

/* 噪点纹理叠加（提升质感） */
.bg-noise::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image: var(--noise);
  pointer-events: none;
  opacity: 0.6;
  mix-blend-mode: overlay;
}

/* 全局背景组合（推广页/产品页 body） */
.bg-stage {
  position: relative;
  background:
    var(--bg-radial),
    var(--color-bg);
}
.bg-stage::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: var(--bg-grid);
  background-size: 48px 48px;
  -webkit-mask-image: radial-gradient(ellipse 60% 50% at 50% 0%, #000 20%, transparent 70%);
          mask-image: radial-gradient(ellipse 60% 50% at 50% 0%, #000 20%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

/* ============================================================
   Utility Classes · 工具类（app.js / 模板共用）
   ============================================================ */
.hidden          { display: none !important; }
.text-center     { text-align: center; }
.text-left       { text-align: left; }
.text-right      { text-align: right; }
.text-sm         { font-size: var(--fs-sm); }
.text-xs         { font-size: var(--fs-xs); }
.text-lg         { font-size: var(--fs-lg); }
.text-bold       { font-weight: 600; }
.text-normal     { font-weight: 400; }

.flex            { display: flex; }
.inline-flex     { display: inline-flex; }
.flex-col        { flex-direction: column; }
.flex-1          { flex: 1; }
.flex-shrink-0   { flex-shrink: 0; }
.gap-1           { gap: var(--space-2); }
.gap-2           { gap: var(--space-3); }
.gap-3           { gap: var(--space-4); }
.gap-4           { gap: var(--space-6); }
.wrap            { flex-wrap: wrap; }
.nowrap          { flex-wrap: nowrap; }
.justify-between { justify-content: space-between; }
.justify-center  { justify-content: center; }
.justify-end     { justify-content: flex-end; }
.items-center    { align-items: center; }
.items-start     { align-items: flex-start; }
.items-end       { align-items: flex-end; }
.w-full          { width: 100%; }
.w-auto          { width: auto; }
.mt-1 { margin-top: var(--space-2); }
.mt-2 { margin-top: var(--space-4); }
.mt-3 { margin-top: var(--space-6); }
.mt-4 { margin-top: var(--space-8); }
.mb-1 { margin-bottom: var(--space-2); }
.mb-2 { margin-bottom: var(--space-4); }
.mb-3 { margin-bottom: var(--space-6); }
.mb-4 { margin-bottom: var(--space-8); }

/* 无障碍：仅屏幕阅读器 */
.u-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;
}

/* 分隔线 */
.u-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border-strong), transparent);
  border: 0;
}

/* 容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}
.container--narrow { max-width: var(--container-narrow); }

/* ============================================================
   Reveal Animation · 滚动渐现（main.js 触发）
   ============================================================ */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 800ms var(--ease-out), transform 800ms var(--ease-out);
  will-change: transform, opacity;
}

[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

[data-reveal-delay="1"] { transition-delay: 80ms; }
[data-reveal-delay="2"] { transition-delay: 160ms; }
[data-reveal-delay="3"] { transition-delay: 240ms; }
[data-reveal-delay="4"] { transition-delay: 320ms; }
[data-reveal-delay="5"] { transition-delay: 400ms; }
[data-reveal-delay="6"] { transition-delay: 480ms; }
[data-reveal-delay="7"] { transition-delay: 560ms; }
[data-reveal-delay="8"] { transition-delay: 640ms; }

/* 通用淡入 */
@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: none; }
}
@keyframes fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes scale-in {
  from { opacity: 0; transform: scale(0.96); }
  to   { opacity: 1; transform: scale(1); }
}
@keyframes slide-in-right {
  from { opacity: 0; transform: translateX(24px); }
  to   { opacity: 1; transform: none; }
}

.animate-fade-in-up { animation: fade-in-up var(--dur-slow) var(--ease-out) both; }
.animate-fade-in    { animation: fade-in var(--dur-slow) var(--ease-out) both; }
.animate-scale-in   { animation: scale-in var(--dur-base) var(--ease-out) both; }

/* 光晕脉冲（用于状态点） */
@keyframes glow-pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 var(--color-primary-glow); }
  50%      { opacity: 0.7; box-shadow: 0 0 0 8px transparent; }
}

/* 品牌流光（用于按钮/边框装饰） */
@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

/* ============================================================
   Focus State · 键盘焦点
   ============================================================ */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: 4px;
}

/* 去除按钮聚焦默认轮廓（保留 :focus-visible） */
button:focus:not(:focus-visible),
a:focus:not(:focus-visible) { outline: none; }