/* ============================================
   基础样式重置与排版
   ============================================ */

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

html {
  font-size: 16px;
  -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: var(--leading-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color var(--transition-slow), color var(--transition-slow);
  overflow-x: hidden;
  min-height: 100vh;
  -webkit-tap-highlight-color: transparent;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  font-size: inherit;
  color: inherit;
  outline: none;
}

button:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

input, textarea, select {
  font-family: inherit;
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  min-height: 44px;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus, textarea:focus, select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-bg);
}

textarea {
  resize: vertical;
  min-height: 80px;
}

select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%2364748b' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

/* ---- 滚动条 ---- */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--color-text-tertiary);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-secondary);
}

/* ---- 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);
  white-space: nowrap;
  border: 0;
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-xs { gap: var(--space-xs); }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

.text-center { text-align: center; }
.text-sm { font-size: var(--text-sm); }
.text-xs { font-size: var(--text-xs); }
.text-lg { font-size: var(--text-lg); }
.font-medium { font-weight: var(--font-medium); }
.font-semibold { font-weight: var(--font-semibold); }
.font-bold { font-weight: var(--font-bold); }

.truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.w-full { width: 100%; }

/* ---- 图标占位 ---- */
.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* ---- 动画关键帧 ---- */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes slideInRight {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

@keyframes slideOutRight {
  from { transform: translateX(0); }
  to { transform: translateX(100%); }
}

.animate-fade-in { animation: fadeIn var(--transition-base); }
.animate-fade-in-up { animation: fadeInUp var(--transition-slow); }
.animate-scale-in { animation: scaleIn var(--transition-base); }

/* ---- 移动端触摸优化 ---- */
button,
a,
select,
.nav-item,
.tab,
.timer-mode-btn,
.category-chip,
.toggle-switch,
.mobile-nav-item {
  touch-action: manipulation;
}

/* ---- 减少动画偏好 ---- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}