/* ========== 全局重置 ========== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --primary: #4A90D9;
  --primary-dark: #357ABD;
  --accent: #5CB85C;
  --accent-dark: #4A9A4A;
  --danger: #e74c3c;
  --danger-dark: #c0392b;
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text: #2c3e50;
  --text-secondary: #7f8c8d;
  --text-light: #bdc3c7;
  --border: #e8ecf1;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  --radius: 12px;
  --radius-sm: 8px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

html {
  font-size: 16px;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ========== App 容器 ========== */
#app {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  background: var(--bg);
}

/* ========== 页面通用 ========== */
.page {
  padding-bottom: 80px;
  min-height: 100vh;
}

.page-loading, .loading-text {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-secondary);
  font-size: 15px;
}

.error-page {
  text-align: center;
  padding: 80px 20px;
  color: var(--text-secondary);
}

.error-page p {
  margin-bottom: 20px;
}

.empty-state {
  text-align: center;
  padding: 50px 20px;
  color: var(--text-light);
  font-size: 14px;
  line-height: 1.8;
}

/* ========== 首页 ========== */
.home-page {
  padding: 0;
}

.home-hero {
  text-align: center;
  padding: 40px 20px 30px;
  background: linear-gradient(135deg, var(--primary), #6BB5FF);
  color: #fff;
}

.hero-icon {
  font-size: 48px;
  margin-bottom: 12px;
}

.home-hero h1 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 6px;
}

.hero-desc {
  font-size: 14px;
  opacity: 0.85;
}

.home-cards {
  padding: 24px 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 24px 20px;
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
  border: 1px solid var(--border);
}

.card:active {
  transform: scale(0.98);
}

.card:hover {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.12);
}

.card-icon {
  font-size: 32px;
  margin-bottom: 10px;
}

.card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 4px;
  color: var(--text);
}

.card p {
  font-size: 13px;
  color: var(--text-secondary);
}

.home-footer {
  text-align: center;
  padding: 24px 16px;
  font-size: 12px;
  color: var(--text-light);
}

/* ========== 团内页 ========== */
.team-header {
  display: flex;
  align-items: center;
  padding: 14px 16px;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.btn-back {
  background: none;
  border: none;
  font-size: 22px;
  color: var(--primary);
  cursor: pointer;
  padding: 4px 10px 4px 0;
  line-height: 1;
}

.team-header-info {
  flex: 1;
  min-width: 0;
}

.team-header-info h2 {
  font-size: 17px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.team-code-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 2px;
}

.team-code {
  font-size: 12px;
  color: var(--text-secondary);
  font-family: monospace;
  letter-spacing: 2px;
}

.btn-text {
  background: none;
  border: none;
  color: var(--primary);
  font-size: 12px;
  cursor: pointer;
  padding: 2px 4px;
}

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

/* ========== Tabs ========== */
.tabs {
  display: flex;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 60px;
  z-index: 99;
}

.tab {
  flex: 1;
  padding: 12px 8px;
  border: none;
  background: none;
  font-size: 14px;
  color: var(--text-secondary);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
  font-family: var(--font);
}

.tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 600;
}

/* ========== 账单列表 ========== */
.expense-list {
  padding: 8px 0;
}

.expense-date-group {
  margin-bottom: 4px;
}

.date-header {
  padding: 10px 16px 6px;
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 600;
}

.expense-item {
  background: var(--card-bg);
  margin: 4px 12px;
  border-radius: var(--radius-sm);
  padding: 14px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  border: 1px solid var(--border);
}

.expense-main {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 8px;
}

.expense-info {
  flex: 1;
  min-width: 0;
}

.expense-payer {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.expense-note {
  display: block;
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.expense-amount {
  font-size: 18px;
  font-weight: 700;
  color: var(--danger);
  white-space: nowrap;
  margin-left: 12px;
}

.expense-splits {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.splits-label {
  color: var(--text-light);
}

.expense-actions {
  display: flex;
  gap: 12px;
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}

/* ========== 结算 ========== */
.balance-cards {
  padding: 12px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.balance-card {
  background: var(--card-bg);
  border-radius: var(--radius-sm);
  padding: 12px;
  text-align: center;
  border: 1px solid var(--border);
}

.balance-card.positive {
  border-color: var(--accent);
  background: #f0faf5;
}

.balance-card.negative {
  border-color: var(--danger);
  background: #fef5f5;
}

.balance-nickname {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.balance-amount {
  font-size: 16px;
  font-weight: 700;
}

.balance-card.positive .balance-amount { color: var(--accent); }
.balance-card.negative .balance-amount { color: var(--danger); }
.balance-card.zero .balance-amount { color: var(--text-light); }

.settlement-instructions {
  padding: 16px;
}

.settlement-instructions h4 {
  font-size: 15px;
  margin-bottom: 12px;
  color: var(--text);
}

.instruction-list {
  list-style: none;
  counter-reset: ins;
  padding: 0;
}

.instruction-list li {
  counter-increment: ins;
  padding: 12px 16px;
  background: var(--card-bg);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  border: 1px solid var(--border);
}

.instruction-list li::before {
  content: counter(ins) ".";
  color: var(--text-light);
  font-size: 13px;
  min-width: 20px;
}

.ins-from {
  color: var(--danger);
  font-weight: 600;
}

.ins-arrow {
  color: var(--text-light);
  margin: 0 4px;
}

.ins-to {
  color: var(--accent);
  font-weight: 600;
}

.ins-amount {
  margin-left: auto;
  font-weight: 700;
  color: var(--text);
  font-family: monospace;
  font-size: 16px;
}

.settlement-note {
  text-align: center;
  color: var(--text-light);
  font-size: 12px;
  margin-top: 16px;
}

/* ========== 成员列表 ========== */
.member-section {
  padding: 8px 12px;
}

.member-section h4 {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 4px 6px;
}

.member-card {
  background: var(--card-bg);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 1px solid var(--border);
}

.member-card.highlight {
  border-color: var(--primary);
  background: #f5f9fd;
}

.member-nickname {
  font-size: 15px;
  font-weight: 500;
}

.badge {
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 10px;
  font-weight: 500;
}

.badge-owner {
  background: #F0AD4E;
  color: #fff;
  font-size: 10px;
  padding: 2px 6px;
  border-radius: 8px;
  margin-left: 4px;
  vertical-align: middle;
}

/* ========== 统计面板 ========== */
.stats-summary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding: 12px;
}

.stat-card {
  background: var(--card-bg);
  border-radius: var(--radius-sm);
  padding: 16px 12px;
  text-align: center;
  border: 1px solid var(--border);
}

.stat-value {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}

.stat-label {
  font-size: 12px;
  color: var(--text-secondary);
}

.stats-chart-title {
  padding: 16px 12px 8px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.bar-chart {
  display: block;
  margin: 0 auto;
}

/* ========== 底部操作栏 ========== */
.bottom-bar {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 480px;
  display: flex;
  gap: 10px;
  padding: 10px 16px;
  padding-bottom: max(10px, env(safe-area-inset-bottom));
  background: var(--card-bg);
  border-top: 1px solid var(--border);
  z-index: 200;
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
}

.bottom-bar .btn {
  flex: 1;
}

/* ========== 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  font-family: var(--font);
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

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

.btn-accent {
  background: var(--accent);
  color: #fff;
}

.btn-accent:hover {
  background: var(--accent-dark);
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
}

.btn-danger:hover {
  background: var(--danger-dark);
}

/* ========== 表单 ========== */
.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  color: var(--text);
  background: var(--card-bg);
  font-family: var(--font);
  transition: border-color 0.2s;
  -webkit-appearance: none;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.1);
}

.checkbox-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.15s;
  user-select: none;
}

.checkbox-label:has(input:checked) {
  border-color: var(--primary);
  background: #f0f6fd;
  color: var(--primary);
}

.checkbox-label input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--primary);
  cursor: pointer;
}

.form-actions {
  display: flex;
  gap: 10px;
  margin-top: 8px;
}

.form-actions .btn {
  flex: 1;
}

.form-hint {
  text-align: center;
  margin-top: 8px;
}

/* ========== 弹窗 ========== */
.modal-header {
  padding: 16px 20px 0;
}

.modal-title {
  font-size: 17px;
  font-weight: 700;
  text-align: center;
}

.modal-body {
  padding: 16px 20px 20px;
}

/* ========== 响应式 ========== */
@media (min-width: 481px) {
  .home-hero {
    padding: 50px 20px 40px;
  }

  .home-hero h1 {
    font-size: 28px;
  }

  .home-cards {
    padding: 32px 20px;
  }

  .card {
    padding: 28px 24px;
  }
}