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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-primary);
  background: var(--bg-base);
  background-image: var(--grad-bg-radial);
  background-attachment: fixed;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

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

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

a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: color var(--dur-base) var(--ease-out);
}
a:hover { color: var(--accent-primary-2); }

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: .02em;
  color: var(--text-primary);
}

p {
  line-height: 1.6;
}

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

::selection {
  background: var(--accent-primary);
  color: var(--text-on-accent);
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: rgba(72, 230, 199, .3);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover { background: rgba(72, 230, 199, .5); }

/* 工具类 */
.hidden { display: none !important; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-tertiary { color: var(--text-tertiary); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-danger { color: var(--danger); }
.text-info { color: var(--info); }
.text-accent { color: var(--accent-primary-2); }

.text-mono { font-family: var(--font-mono); }
.text-display { font-family: var(--font-display); }

/* 通用容器 */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}
@media (max-width: 640px) {
  .container { padding: 0 var(--space-4); }
}

.grid { display: grid; gap: var(--space-4); }
.flex { display: flex; gap: var(--space-3); }
.flex-col { flex-direction: column; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }