/* ============================================================
   layout.css — 顶栏 / 侧栏 / 主区 / 底部 Tab / 抽屉 / cheat sheet
   ============================================================ */

/* === Topbar === */
.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 12px;
  height: 60px;
  padding: 0 16px;
  background: var(--bg-overlay);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color var(--transition-slow);
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 6px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  letter-spacing: -0.01em;
  flex-shrink: 0;
}
.brand-mark {
  font-size: 22px;
  color: var(--accent);
  line-height: 1;
}
.brand-name { font-size: 18px; }
.brand-sub {
  font-size: 11px;
  font-weight: 500;
  color: var(--text-tertiary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.search {
  flex: 1;
  max-width: 480px;
  position: relative;
  margin: 0 auto;
}
.search input {
  width: 100%;
  height: 38px;
  padding: 0 56px 0 36px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  color: var(--text-primary);
  font: 14px/1 var(--font-stack);
  outline: 0;
  transition: border-color var(--transition), box-shadow var(--transition), background-color var(--transition-slow);
}
.search input::placeholder { color: var(--text-tertiary); }
.search input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-soft);
  background: var(--bg-elevated-2);
}
.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 14px;
  opacity: 0.6;
  pointer-events: none;
}
.search-kbd {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
}

.theme-toggle, .hamburger {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  font-size: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background-color var(--transition), border-color var(--transition);
}
.theme-toggle:hover, .hamburger:hover {
  background: var(--bg-elevated);
  border-color: var(--border-strong);
}
.hamburger { display: none; }

/* === Sidebar (PC fixed) === */
.sidebar {
  position: fixed;
  top: 60px;
  left: 0;
  bottom: 0;
  width: 220px;
  padding: 16px 8px 80px;
  background: var(--bg-overlay);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-right: 1px solid var(--border-subtle);
  overflow-y: auto;
  z-index: 20;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-slow);
}

.groups {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
}
.group-section { margin-top: 12px; }
.group-section:first-child { margin-top: 0; }
.group-section-title {
  font: 600 10px/1.4 var(--font-stack);
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 6px 12px 4px;
}
.group-item {
  display: grid;
  grid-template-columns: 18px 1fr auto;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 8px 12px;
  border-radius: 8px;
  text-align: left;
  color: var(--text-secondary);
  font: 13px/1.3 var(--font-stack);
  transition: background-color var(--transition), color var(--transition);
}
.group-item:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
}
.group-item.active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}
.group-item .g-icon { font-size: 14px; line-height: 1; }
.group-item .g-count {
  font: 10px/1.4 var(--font-mono);
  color: var(--text-tertiary);
  background: var(--bg-elevated-2);
  padding: 2px 6px;
  border-radius: 10px;
  min-width: 18px;
  text-align: center;
}
.group-item.active .g-count {
  background: var(--accent);
  color: var(--bg-base);
}

.sidebar-footer {
  padding: 12px 12px 0;
  border-top: 1px solid var(--border-subtle);
  margin-top: 12px;
}
.stats {
  font: 12px/1.4 var(--font-stack);
  color: var(--text-secondary);
  margin-bottom: 4px;
}
.stats strong { color: var(--accent); font-weight: 600; }
.last-check {
  font: 10px/1.4 var(--font-mono);
  color: var(--text-tertiary);
}

/* === Main === */
.main {
  margin-left: 220px;
  padding: 24px 28px 80px;
  min-height: calc(100vh - 60px);
  transition: margin-left var(--transition-slow);
}
.main-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}
.main-title {
  font: 600 18px/1.3 var(--font-stack);
  color: var(--text-primary);
  margin: 0;
  letter-spacing: -0.01em;
}
.main-meta {
  font: 12px/1.4 var(--font-mono);
  color: var(--text-tertiary);
}

.grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

/* === Empty state === */
.empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 20px;
  color: var(--text-tertiary);
  text-align: center;
}
[hidden] { display: none !important; }
.empty-icon { font-size: 48px; opacity: 0.4; margin-bottom: 12px; }
.empty-text { font-size: 14px; margin-bottom: 16px; }
.empty-reset {
  padding: 8px 16px;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 8px;
  font: 12px/1 var(--font-stack);
  font-weight: 600;
  transition: background-color var(--transition);
}
.empty-reset:hover { background: var(--accent); color: var(--bg-base); }

/* === Bottom tabs (mobile) === */
.bottom-tabs {
  display: none;
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 60px;
  background: var(--bg-overlay-strong);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-top: 1px solid var(--border-subtle);
  z-index: 25;
  justify-content: space-around;
  align-items: stretch;
  padding-bottom: env(safe-area-inset-bottom, 0);
}
.bottom-tab {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  background: none;
  border: 0;
  color: var(--text-secondary);
  font: 10px/1 var(--font-stack);
  font-weight: 500;
  cursor: pointer;
  padding: 8px 4px;
  transition: color var(--transition);
  position: relative;
}
.bottom-tab .icon { font-size: 18px; line-height: 1; }
.bottom-tab.active { color: var(--accent); }
.bottom-tab.active::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 2px;
  background: var(--accent);
  border-radius: 0 0 2px 2px;
}
.bottom-tab:active { background: var(--accent-soft); }

/* === Drawer backdrop (mobile) === */
.drawer-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 28;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-slow);
}
.drawer-backdrop.show {
  opacity: 1;
  pointer-events: auto;
}

/* === Cheat sheet === */
.cheat-sheet {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  animation: fade-in 0.2s ease;
}
.cheat-sheet[hidden] { display: none; }
.cheat-content {
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  max-width: 380px;
  width: 100%;
  box-shadow: var(--shadow-strong);
}
.cheat-content h2 {
  margin: 0 0 16px;
  font: 600 18px/1.3 var(--font-stack);
  color: var(--text-primary);
}
.cheat-content dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px 18px;
  margin: 0 0 12px;
}
.cheat-content dt {
  display: flex;
  align-items: center;
  gap: 4px;
}
.cheat-content dd {
  margin: 0;
  font: 13px/1.4 var(--font-stack);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
}
.cheat-hint {
  font: 12px/1.4 var(--font-stack);
  color: var(--text-tertiary);
  margin: 12px 0 16px;
}
.cheat-close {
  width: 100%;
  padding: 10px;
  background: var(--accent);
  color: var(--bg-base);
  border-radius: 8px;
  font: 600 13px/1 var(--font-stack);
  font-weight: 600;
  transition: background-color var(--transition);
}
.cheat-close:hover { background: var(--accent-strong); }
@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* === Mobile (< 1024px) === */
@media (max-width: 1023px) {
  .hamburger { display: inline-flex; }
  .sidebar {
    transform: translateX(-100%);
    width: 280px;
    z-index: 30;
    top: 0;
    padding-top: 70px;
  }
  .sidebar.open { transform: translateX(0); }
  .main { margin-left: 0; padding: 16px 14px 80px; }
  .bottom-tabs { display: flex; }
  .main-header { margin-bottom: 14px; }
  .main-title { font-size: 16px; }
  .grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
}

@media (max-width: 480px) {
  .grid { grid-template-columns: 1fr; }
  .topbar { padding: 0 10px; gap: 8px; }
  .brand-sub { display: none; }
  .search input { padding: 0 46px 0 34px; height: 36px; font-size: 13px; }
  .search-icon { left: 10px; }
  .search-kbd { right: 8px; }
  .main { padding: 12px 10px 80px; }
  .theme-toggle, .hamburger { width: 36px; height: 36px; }
}

/* === Print === */
@media print {
  .topbar, .sidebar, .bottom-tabs, .cheat-sheet, .toast { display: none; }
  .main { margin-left: 0; }
  .card { break-inside: avoid; }
}

/* === Reduced motion === */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}