/* ═══════════════════════════════════════════════════════════════════════
   P016 app.css — 全局样式 · 响应式布局 · Desktop First
   品牌色: 百盛橙 #ED6A2E
   ═══════════════════════════════════════════════════════════════════════ */

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--typography-font-family);
  font-size: var(--typography-font-size-base);
  line-height: var(--typography-line-height-normal);
  color: var(--color-text-primary);
  background: var(--color-bg-page);
  min-height: 100vh;
  min-height: 100dvh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-text-link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

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

input, textarea {
  font-family: inherit;
  font-size: inherit;
  border: none;
  outline: none;
}

/* ── Focus-visible: keyboard-only outline, no mouse ring ── */
:focus:not(:focus-visible) {
  outline: none;
}

:focus-visible {
  outline: 2px solid #ED6A2E;
  outline-offset: 2px;
}

ul, ol {
  list-style: none;
}

/* ── Layout ── */
#app {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.page-container {
  flex: 1;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-lg);
}

/* ── Typography ── */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--typography-font-weight-semibold);
  line-height: var(--typography-line-height-tight);
  color: var(--color-text-primary);
}

h1 { font-size: var(--typography-font-size-xxl); }
h2 { font-size: var(--typography-font-size-xl); }
h3 { font-size: var(--typography-font-size-lg); }
h4 { font-size: var(--typography-font-size-md); }

.text-center { text-align: center; }
.text-right  { text-align: right; }
.text-hint   { color: var(--color-text-hint); }
.text-secondary { color: var(--color-text-secondary); }
.text-brand  { color: var(--color-brand-primary); }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  min-width: var(--btn-min-width);
  height: var(--btn-height);
  padding: 0 var(--spacing-xl);
  font-size: var(--typography-font-size-md);
  font-weight: var(--typography-font-weight-medium);
  border-radius: var(--radius-full);
  transition: all var(--anim-duration-fast) var(--anim-easing-default);
  white-space: nowrap;
  user-select: none;
}

.btn:active {
  transform: scale(var(--anim-scale-press));
}

.btn-primary {
  background: var(--btn-primary-bg);
  color: var(--btn-primary-text);
  box-shadow: var(--shadow-button);
}

.btn-primary:hover {
  background: var(--color-brand-dark);
}

.btn-secondary {
  background: var(--btn-secondary-bg);
  color: var(--btn-secondary-text);
}

.btn-secondary:hover {
  background: rgba(237, 106, 46, 0.15);
}

.btn-danger {
  background: var(--btn-danger-bg);
  color: var(--btn-danger-text);
}

.btn-danger:hover {
  background: #C0392B;
}

.btn-ghost {
  background: transparent;
  color: var(--color-brand-primary);
  min-width: auto;
}

.btn-ghost:hover {
  background: var(--color-brand-ghost);
}

.btn:disabled, .btn[disabled] {
  background: var(--btn-disabled-bg);
  color: var(--btn-disabled-text);
  box-shadow: none;
  cursor: not-allowed;
  opacity: var(--anim-opacity-disabled);
}

.btn-block {
  width: 100%;
}

.btn-lg {
  height: 52px;
  padding: 0 var(--spacing-xxl);
  font-size: var(--typography-font-size-lg);
}

.btn-sm {
  height: 32px;
  min-width: auto;
  padding: 0 var(--spacing-md);
  font-size: var(--typography-font-size-sm);
}

/* ── Forms ── */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-size: var(--typography-font-size-sm);
  font-weight: var(--typography-font-weight-medium);
  color: var(--color-text-primary);
}

.form-input {
  width: 100%;
  height: var(--btn-height);
  padding: 0 var(--spacing-md);
  background: var(--color-bg-input);
  border: var(--border-width-thin) solid var(--border-input);
  border-radius: var(--radius-sm);
  color: var(--color-text-primary);
  transition: border-color var(--anim-duration-fast) var(--anim-easing-default);
}

.form-input::placeholder {
  color: var(--color-text-hint);
}

.form-input:focus {
  border-color: var(--border-input-focus);
  box-shadow: 0 0 0 3px var(--color-brand-ghost);
}

.form-input.error {
  border-color: var(--border-input-error);
}

.form-error {
  margin-top: var(--spacing-xs);
  font-size: var(--typography-font-size-xs);
  color: var(--color-status-error);
}

.form-hint {
  margin-top: var(--spacing-xs);
  font-size: var(--typography-font-size-xs);
  color: var(--color-text-hint);
}

/* ── Cards ── */
.card {
  background: var(--color-bg-card);
  border: var(--border-width-thin) solid var(--border-card);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  padding: var(--spacing-lg);
  transition: box-shadow var(--anim-duration-fast) var(--anim-easing-default);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-clickable {
  cursor: pointer;
}

.card-clickable:active {
  background: var(--color-bg-card-hover);
}

/* ── Toast ── */
.toast-container {
  position: fixed;
  top: var(--spacing-xl);
  left: 50%;
  transform: translateX(-50%);
  z-index: 10000;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  pointer-events: none;
}

.toast {
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-full);
  font-size: var(--typography-font-size-sm);
  color: var(--color-text-inverse);
  background: var(--color-bg-toast);
  box-shadow: var(--shadow-md);
  animation: toast-in var(--anim-duration-normal) var(--anim-easing-spring);
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.toast.toast-success { background: var(--color-status-success); }
.toast.toast-error   { background: var(--color-status-error); }
.toast.toast-warning { background: var(--color-status-warning); }
.toast.toast-info    { background: var(--color-status-info); }

.toast-exit {
  animation: toast-out var(--anim-duration-normal) var(--anim-easing-default) forwards;
}

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

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

/* ── Loading ── */
.loading-spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-brand-ghost);
  border-top-color: var(--color-brand-primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

.loading-spinner.lg {
  width: 40px;
  height: 40px;
  border-width: 3px;
}

.loading-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-bg-mask);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

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

@keyframes pulse-orange {
  0%, 100% { box-shadow: 0 0 0 0 rgba(237, 106, 46, 0.4); }
  50%      { box-shadow: 0 0 0 8px rgba(237, 106, 46, 0); }
}

@keyframes pulse-green {
  0%, 100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.4); }
  50%      { box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
}

/* ── Layout Utilities ── */
.flex       { display: flex; }
.flex-col   { flex-direction: column; }
.flex-wrap  { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-xs     { gap: var(--spacing-xs); }
.gap-sm     { gap: var(--spacing-sm); }
.gap-md     { gap: var(--spacing-md); }
.gap-lg     { gap: var(--spacing-lg); }
.gap-xl     { gap: var(--spacing-xl); }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.hidden    { display: none !important; }
.sr-only   { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }

/* ── Responsive ── */
@media (max-width: 768px) {
  html { font-size: 15px; }

  .page-container {
    padding: var(--spacing-md);
  }

  .btn {
    min-width: auto;
    padding: 0 var(--spacing-md);
  }

  .hide-mobile {
    display: none !important;
  }
}

@media (max-width: 480px) {
  html { font-size: 14px; }
}

/* ═══════════════════════════════════════════════════════════════════════
   Phase 3: 主题切换器 · 分享卡片 · Skeleton屏
   ═══════════════════════════════════════════════════════════════════════ */

/* ── Theme Switcher ── */
.theme-switcher {
  position: fixed;
  top: 12px;
  right: 12px;
  z-index: 10000;
  display: flex;
  gap: 6px;
  background: var(--color-bg-card);
  padding: 6px 8px;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  border: var(--border-width-thin) solid var(--border-card);
}

.theme-dot {
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.25s ease;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  outline: none;
  position: relative;
  background: transparent;
}

.theme-dot::after {
  content: '';
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--theme-dot-color, #ED6A2E);
  display: block;
  transition: transform 0.25s ease;
}

.theme-dot:hover {
  box-shadow: 0 0 0 3px var(--color-brand-ghost);
}

.theme-dot:hover::after {
  transform: scale(1.2);
}

.theme-dot.active {
  border-color: var(--color-text-primary);
  box-shadow: 0 0 0 2px var(--color-bg-card), 0 0 0 4px var(--color-text-primary);
}

.theme-dot.active::after {
  transform: scale(1.15);
}

@media (max-width: 480px) {
  .theme-switcher {
    top: 8px;
    right: 8px;
    gap: 4px;
    padding: 4px 6px;
  }
  .theme-dot {
    width: 44px;
    height: 44px;
    min-width: 44px;
    min-height: 44px;
  }
  .theme-dot::after {
    width: 18px;
    height: 18px;
  }
}

/* ── Share Card ── */
.share-card {
  background: var(--color-bg-card);
  border: var(--border-width-thin) solid var(--border-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  max-width: 400px;
  margin: 0 auto;
  box-shadow: var(--shadow-md);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.share-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.share-card-header {
  background: var(--color-brand-gradient);
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.share-card-badge {
  color: white;
  font-size: 13px;
  font-weight: var(--typography-font-weight-medium);
}

.share-card-time {
  color: rgba(255, 255, 255, 0.75);
  font-size: 11px;
}

.share-card-body {
  padding: 16px;
}

.share-card-title {
  font-size: var(--typography-font-size-lg);
  font-weight: var(--typography-font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: 8px;
}

.share-card-desc {
  font-size: var(--typography-font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.share-card-stats {
  display: flex;
  gap: 16px;
  padding: 12px 0;
  border-top: var(--border-width-thin) solid var(--border-divider);
  border-bottom: var(--border-width-thin) solid var(--border-divider);
}

.share-stat {
  flex: 1;
  text-align: center;
}

.share-stat-value {
  display: block;
  font-size: var(--typography-font-size-xl);
  font-weight: var(--typography-font-weight-bold);
  color: var(--color-brand-primary);
}

.share-stat-label {
  display: block;
  font-size: 10px;
  color: var(--color-text-hint);
  margin-top: 2px;
}

.share-card-footer {
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.share-card-brand {
  margin-left: auto;
  font-size: 11px;
  color: var(--color-text-hint);
}

/* ── Share Modal ── */
.share-modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-bg-mask);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10001;
  animation: fade-in 200ms ease;
}

.share-modal {
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  max-width: 440px;
  width: calc(100% - 32px);
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  animation: slide-up 300ms var(--anim-easing-spring);
}

.share-modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.share-modal-header h3 {
  font-size: var(--typography-font-size-lg);
}

.share-modal-close {
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  border-radius: 50%;
  background: var(--color-bg-input);
  color: var(--color-text-secondary);
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
}

.share-modal-close:hover {
  background: var(--color-status-error);
  color: white;
}

.share-modal-body {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.share-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
}

.share-action-btn {
  min-width: auto !important;
}

@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slide-up {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ── Skeleton Screens ── */
@keyframes skeleton-shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-bg-skeleton) 25%,
    var(--color-bg-page) 50%,
    var(--color-bg-skeleton) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

.skeleton-text {
  height: 14px;
  margin-bottom: 8px;
  width: 100%;
}

.skeleton-text.short { width: 60%; }
.skeleton-text.medium { width: 80%; }

.skeleton-title {
  height: 20px;
  margin-bottom: 12px;
  width: 70%;
}

.skeleton-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
}

.skeleton-card {
  height: 100px;
  margin-bottom: 12px;
  border-radius: var(--radius-md);
}

.skeleton-btn {
  height: var(--btn-height);
  width: 120px;
  border-radius: var(--radius-full);
}

.skeleton-row {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 12px;
}

.skeleton-sidebar {
  width: 280px;
  min-width: 280px;
  padding: 16px;
}

.skeleton-chat-area {
  flex: 1;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

@media (max-width: 768px) {
  .skeleton-sidebar {
    display: none;
  }
}

/* ── PWA Install Banner ── */
.pwa-install-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--color-bg-card);
  border-top: var(--border-width-thin) solid var(--border-card);
  padding: 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  z-index: 9999;
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.08);
  animation: slide-up 300ms var(--anim-easing-spring);
}

.pwa-install-icon {
  font-size: 36px;
  min-width: 44px;
}

.pwa-install-text {
  flex: 1;
}

.pwa-install-text strong {
  display: block;
  font-size: var(--typography-font-size-md);
  color: var(--color-text-primary);
  margin-bottom: 2px;
}

.pwa-install-text span {
  font-size: var(--typography-font-size-xs);
  color: var(--color-text-secondary);
}

.pwa-install-close {
  position: absolute;
  top: 8px;
  right: 12px;
  width: 44px;
  height: 44px;
  font-size: 18px;
  color: var(--color-text-hint);
  cursor: pointer;
  border: none;
  background: none;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ── SW Update Toast ── */
.sw-update-toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-bg-card);
  border: var(--border-width-thin) solid var(--color-brand-primary);
  border-radius: var(--radius-full);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
  z-index: 10001;
  box-shadow: var(--shadow-lg);
  animation: slide-up 300ms var(--anim-easing-spring);
  font-size: var(--typography-font-size-sm);
}

.sw-update-toast .btn {
  min-width: auto;
  height: 32px;
  padding: 0 16px;
  font-size: 13px;
}

/* ═══════════════════════════════════════════════════════════════════════
   Accessibility: prefers-reduced-motion — override all motion
   ═══════════════════════════════════════════════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ===== Chat Empty State ===== */
.chat-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-xxl, 48px);
  text-align: center;
  min-height: 300px;
}
.chat-empty-icon {
  font-size: 48px;
  margin-bottom: var(--spacing-md, 16px);
  opacity: 0.5;
}
.chat-empty h3 {
  font-size: var(--typography-font-size-lg, 18px);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm, 8px);
}
.chat-empty p {
  color: var(--color-text-secondary);
  max-width: 400px;
}

/* ===== Notifications ===== */
.btn-read-all {
  background: none;
  border: 1px solid var(--color-brand-primary);
  color: var(--color-brand-primary);
  border-radius: var(--border-radius-sm, 4px);
  padding: 2px 12px;
  cursor: pointer;
  font-size: 13px;
}
.btn-read-all:hover {
  background: var(--color-brand-primary);
  color: white;
}

/* ===== Modal Overlay ===== */
.modal-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:1000;align-items:center;justify-content:center}
.modal-container{background:var(--color-bg-primary,#fff);border-radius:var(--border-radius-lg,8px);padding:var(--spacing-lg,24px);max-width:480px;width:90%}
.modal-actions{display:flex;gap:var(--spacing-sm,8px);justify-content:flex-end;margin-top:var(--spacing-md,16px)}