:root {
  --color-primary: #165DFF;
  --color-primary-hover: #0E42D2;
  --color-primary-active: #0A35B0;
  --color-primary-light: #E8F3FF;
  --color-success: #00B42A;
  --color-success-light: #E8FFEA;
  --color-warning: #FF7D00;
  --color-warning-light: #FFF3E8;
  --color-danger: #F53F3F;
  --color-danger-light: #FFECE8;
  --color-info: #86909C;
  --color-gold: #F7BA1E;

  --color-text-1: #1D2129;
  --color-text-2: #4E5969;
  --color-text-3: #86909C;
  --color-text-4: #C9CDD4;
  --color-border: #E5E6EB;
  --color-border-light: #F2F3F5;
  --color-bg-page: #F2F3F5;
  --color-bg-card: #FFFFFF;
  --color-bg-hover: #F7F8FA;
  --color-bg-active: #EDF0F5;
  --color-bg-disabled: #F7F8FA;
  --color-fill-1: #F7F8FA;
  --color-fill-2: #F2F3F5;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 32px;
  --space-6: 40px;
  --space-7: 48px;
  --space-8: 64px;

  --radius-1: 4px;
  --radius-2: 8px;
  --radius-3: 12px;
  --radius-4: 16px;

  --shadow-1: 0 2px 12px 0 rgba(0, 0, 0, 0.06);
  --shadow-2: 0 4px 16px 0 rgba(0, 0, 0, 0.08);
  --shadow-3: 0 8px 32px 0 rgba(0, 0, 0, 0.12);
  --shadow-focus: 0 0 0 3px rgba(22, 93, 255, 0.15);

  --font-size-1: 24px;
  --font-size-2: 20px;
  --font-size-3: 16px;
  --font-size-4: 14px;
  --font-size-5: 12px;

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;

  --line-height-tight: 1.4;
  --line-height-normal: 1.6;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.35s ease;

  --navbar-height: 56px;
  --tabbar-height: 56px;

  --gradient-primary: linear-gradient(135deg, #165DFF 0%, #4080FF 100%);
  --gradient-success: linear-gradient(135deg, #00B42A 0%, #23C343 100%);
  --gradient-warning: linear-gradient(135deg, #FF7D00 0%, #FF9A2E 100%);
  --gradient-danger: linear-gradient(135deg, #F53F3F 0%, #F76560 100%);
  --gradient-purple: linear-gradient(135deg, #722ED1 0%, #9254DE 100%);
  --gradient-gold: linear-gradient(135deg, #F7BA1E 0%, #FFC53D 100%);
}

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

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

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Helvetica Neue', 'Microsoft YaHei', Arial, sans-serif;
  font-size: var(--font-size-4);
  line-height: var(--line-height-normal);
  color: var(--color-text-1);
  background-color: var(--color-bg-page);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-weight: 600;
  line-height: 1.3;
}

p {
  margin: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

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

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

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

ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

::-webkit-scrollbar {
  width: 0;
  height: 0;
  background: transparent;
}

.safe-area-top {
  padding-top: env(safe-area-inset-top, 0px);
}

.safe-area-bottom {
  padding-bottom: env(safe-area-inset-bottom, 0px);
}

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

.text-ellipsis-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flex-1 {
  flex: 1;
}

.hidden {
  display: none !important;
}

.show {
  display: block !important;
}

/* ========== Button System ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-2);
  font-size: var(--font-size-4);
  font-weight: var(--font-weight-medium);
  font-family: inherit;
  line-height: 1.5;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  background: transparent;
  transition: all var(--transition-normal);
  -webkit-tap-highlight-color: transparent;
  user-select: none;
  white-space: nowrap;
}

.btn:disabled,
.btn.is-disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.btn--primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn--primary:hover:not(:disabled) {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  box-shadow: 0 4px 12px rgba(22, 93, 255, 0.3);
}
.btn--primary:active:not(:disabled) {
  background: var(--color-primary-active);
  border-color: var(--color-primary-active);
  transform: scale(0.98);
}
.btn--primary:focus-visible {
  outline: none;
  box-shadow: var(--shadow-focus);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-2);
  border-color: var(--color-border);
}
.btn--ghost:hover:not(:disabled) {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}
.btn--ghost:active:not(:disabled) {
  background: var(--color-primary-light);
}
.btn--ghost:focus-visible {
  outline: none;
  box-shadow: var(--shadow-focus);
}

.btn--danger {
  background: var(--color-danger);
  color: #fff;
  border-color: var(--color-danger);
}
.btn--danger:hover:not(:disabled) {
  background: #d9363e;
  border-color: #d9363e;
  box-shadow: 0 4px 12px rgba(245, 63, 63, 0.3);
}
.btn--danger:active:not(:disabled) {
  transform: scale(0.98);
}

.btn--success {
  background: var(--color-success);
  color: #fff;
  border-color: var(--color-success);
}
.btn--success:hover:not(:disabled) {
  background: #009a22;
  border-color: #009a22;
  box-shadow: 0 4px 12px rgba(0, 180, 42, 0.3);
}

.btn--warning {
  background: var(--color-warning);
  color: #fff;
  border-color: var(--color-warning);
}
.btn--warning:hover:not(:disabled) {
  background: #e67000;
  box-shadow: 0 4px 12px rgba(255, 125, 0, 0.3);
}

.btn--sm {
  padding: 6px 14px;
  font-size: var(--font-size-5);
  border-radius: var(--radius-1);
}

.btn--lg {
  padding: 14px 28px;
  font-size: var(--font-size-3);
  border-radius: var(--radius-3);
}

.btn--block {
  display: flex;
  width: 100%;
}

/* ========== Form System ========== */
.form-control {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2);
  font-size: var(--font-size-4);
  color: var(--color-text-1);
  background: var(--color-bg-page);
  font-family: inherit;
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal), background-color var(--transition-normal);
}
.form-control:hover {
  border-color: var(--color-text-4);
}
.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  background: #fff;
  box-shadow: var(--shadow-focus);
}
.form-control:disabled {
  background: var(--color-bg-disabled);
  color: var(--color-text-4);
  cursor: not-allowed;
}
.form-control::placeholder {
  color: var(--color-text-4);
}

.form-label {
  display: block;
  font-size: var(--font-size-4);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-2);
  margin-bottom: 6px;
}

.form-textarea {
  min-height: 80px;
  resize: vertical;
  line-height: var(--line-height-normal);
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2386909C' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

/* ========== Card System ========== */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-3);
  overflow: hidden;
  transition: box-shadow var(--transition-normal), border-color var(--transition-normal);
}
.card:hover {
  box-shadow: var(--shadow-1);
}

.card__header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--color-border-light);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.card__title {
  font-size: var(--font-size-4);
  font-weight: var(--font-weight-semibold);
  margin: 0;
}
.card__link {
  color: var(--color-primary);
  font-size: var(--font-size-5);
  text-decoration: none;
  transition: opacity var(--transition-normal);
}
.card__link:hover {
  opacity: 0.8;
  text-decoration: underline;
}
.card__body {
  padding: 20px;
}

/* ========== Badge System ========== */
.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-1);
  font-size: var(--font-size-5);
  font-weight: var(--font-weight-medium);
  line-height: 1.5;
}
.badge--success { background: var(--color-success-light); color: var(--color-success); }
.badge--warning { background: var(--color-warning-light); color: var(--color-warning); }
.badge--danger  { background: var(--color-danger-light); color: var(--color-danger); }
.badge--info   { background: var(--color-primary-light); color: var(--color-primary); }

/* ========== Alert System ========== */
.alert {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border-radius: var(--radius-2);
  font-size: var(--font-size-4);
  margin-bottom: 16px;
}
.alert--danger  { background: var(--color-danger-light); color: var(--color-danger); }
.alert--success { background: var(--color-success-light); color: var(--color-success); }
.alert--warning { background: var(--color-warning-light); color: var(--color-warning); }
.alert--info    { background: var(--color-primary-light); color: var(--color-primary); }

/* ========== Empty State ========== */
.empty-state {
  text-align: center;
  padding: 48px 20px;
  color: var(--color-text-3);
}
.empty-state__icon {
  display: flex;
  justify-content: center;
  margin-bottom: 12px;
  color: var(--color-text-4);
}
.empty-state__title {
  font-weight: var(--font-weight-medium);
  margin: 0 0 4px;
  color: var(--color-text-2);
}
.empty-state__desc {
  font-size: var(--font-size-5);
  margin: 0;
}

/* ========== Skeleton Loading ========== */
.skeleton {
  background: linear-gradient(90deg, #f2f3f5 25%, #e5e6eb 50%, #f2f3f5 75%);
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
  border-radius: var(--radius-1);
}
@keyframes skeleton-loading {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ========== Page Transitions ========== */
.page-enter {
  animation: pageFadeIn 0.3s ease;
}
@keyframes pageFadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ========== Utility ========== */
.truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
  .btn--lg { padding: 12px 24px; font-size: var(--font-size-4); }
  .card__body { padding: 16px; }
}

/* ========== Focus Ring (Accessibility) ========== */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ========== Scrollbar ========== */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--color-text-4);
  border-radius: 3px;
  transition: background var(--transition-normal);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-3);
}