* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --bg-color: #F5F5F5;
    --card-color: #FFFFFF;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-light: #999999;
    --border-color: #000000;
    --divider-color: #E5E5E5;
    font-size: clamp(0.875rem, 2vw, 1rem); /* 14-16px */
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
}

/* 顶部导航 */
.header {
    background: var(--primary-color);
    color: white;
    padding: clamp(0.75rem, 2vw, 0.9375rem);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.back-btn {
    color: white;
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.25rem;
}

.header-title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 500;
    text-align: center;
    flex: 1;
}

/* 主要内容区 */
.container {
    padding: clamp(1rem, 3vw, 1.25rem);
    max-width: 75rem;
    margin: 0 auto;
}

/* 页面标题 */
.page-header {
    margin-bottom: clamp(1.5rem, 4vw, 2rem);
    text-align: center;
}

.page-title {
    font-size: clamp(1.25rem, 3.5vw, 1.5rem);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.page-subtitle {
    color: var(--text-secondary);
    font-size: clamp(0.9rem, 2.5vw, 1rem);
    max-width: 40rem;
    margin: 0 auto;
}

/* 快速操作提示 */
.quick-tips {
    background: rgba(7, 193, 96, 0.1);
    border: 1px solid rgba(7, 193, 96, 0.2);
    border-radius: 0.75rem;
    padding: 1rem 1.5rem;
    margin-bottom: clamp(1.5rem, 4vw, 2rem);
    text-align: center;
}

.tips-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tip-icon {
    font-size: 1.25rem;
}

.tip-text {
    font-size: clamp(0.9rem, 2.5vw, 1rem);
    color: var(--text-primary);
}

/* 月份选择卡片 */
.month-selection-section {
    background: var(--card-color);
    border-radius: 0.75rem;
    padding: clamp(1.25rem, 3vw, 1.5rem);
    box-shadow: 0 0.125rem 0.75rem rgba(0, 0, 0, 0.05);
    border: 0.0625rem solid var(--border-color);
    margin-bottom: clamp(1.5rem, 4vw, 2rem);
}

.section-title {
    font-size: clamp(1rem, 2.5vw, 1.125rem);
    font-weight: 600;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 0.125rem solid var(--primary-color);
}

.section-description {
    color: var(--text-secondary);
    font-size: clamp(0.9rem, 2.5vw, 1rem);
    margin-bottom: 1.5rem;
}

.months-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 1rem;
    margin-top: 1.5rem;
}

.month-card {
    border: 0.125rem solid var(--border-color);
    border-radius: 0.5rem;
    padding: 1.25rem;
    transition: all 0.3s;
    background: white;
    cursor: pointer;
    position: relative;
}

.month-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(7, 193, 96, 0.1);
}

.month-card.selected {
    border-color: var(--primary-color);
    background: rgba(7, 193, 96, 0.05);
}

.month-card.selected::after {
    content: "✓";
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    width: 1.5rem;
    height: 1.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
}

.month-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.month-name {
    font-weight: 600;
    font-size: clamp(0.9rem, 2.5vw, 1rem);
    color: var(--text-primary);
}

.month-amount {
    font-weight: 700;
    font-size: clamp(1.125rem, 3vw, 1.25rem);
    color: var(--primary-color);
}

.month-details {
    font-size: clamp(0.8rem, 2.2vw, 0.875rem);
    color: var(--text-light);
    margin-bottom: 1rem;
}

.month-actions {
    display: flex;
    gap: 0.5rem;
}

/* 选择汇总 */
.selection-summary {
    background: #f8f9fa;
    border-radius: 0.5rem;
    padding: 1rem;
    margin-top: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    display: none;
}

.selection-summary.show {
    display: flex;
}

.summary-info h3 {
    font-size: clamp(0.9rem, 2.5vw, 1rem);
    margin-bottom: 0.25rem;
}

.summary-amount {
    font-size: clamp(1.25rem, 3.5vw, 1.5rem);
    font-weight: 700;
    color: var(--primary-color);
}

.clear-btn {
    background: none;
    border: 0.0625rem solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.5rem 1rem;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: clamp(0.85rem, 2.3vw, 0.9375rem);
}

/* 按钮样式 */
.btn {
    padding: clamp(0.5rem, 1.5vw, 0.625rem) clamp(1rem, 2.5vw, 1.25rem);
    border-radius: 0.5rem;
    font-size: clamp(0.85rem, 2.3vw, 0.9375rem);
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: #06b057;
}

.btn-secondary {
    background: white;
    color: var(--primary-color);
    border: 0.0625rem solid var(--primary-color);
}

.btn-secondary:hover {
    background: #f8f9fa;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: clamp(0.8rem, 2.2vw, 0.875rem);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* 操作按钮 */
.actions-section {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
}

.submit-btn {
    padding: clamp(0.75rem, 2vw, 1rem) clamp(2rem, 4vw, 3rem);
    font-size: clamp(1rem, 2.5vw, 1.125rem);
}

/* 模态框 */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--modal-overlay);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    padding: 1rem;
}

.modal {
    background: white;
    border-radius: 0.75rem;
    width: 100%;
    max-width: 45rem;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 0.625rem 2.5rem rgba(0, 0, 0, 0.2);
    transform: translateY(1.25rem);
    transition: transform 0.3s ease;
}

.modal-header {
    padding: clamp(1.25rem, 3vw, 1.5rem);
    border-bottom: 0.0625rem solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    font-size: clamp(1rem, 2.5vw, 1.125rem);
    font-weight: 600;
    color: var(--text-primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-light);
    cursor: pointer;
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.25rem;
}

.modal-close:hover {
    background: #f8f9fa;
    color: var(--text-primary);
}

.modal-body {
    padding: clamp(1.25rem, 3vw, 1.5rem);
}

/* 详情模态框内容 */
.details-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
    margin-top: 1rem;
}

.details-table th {
    text-align: left;
    padding: 0.75rem;
    background: #f8f9fa;
    border-bottom: 2px solid var(--border-color);
    color: var(--text-secondary);
    font-weight: 600;
}

.details-table td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    white-space: nowrap;
}

.details-table tr:last-child td {
    border-bottom: none;
}

/* 统计信息样式 */
.summary-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0;
    margin-bottom: 0.5rem;
}

.summary-row:last-child {
    padding-top: 0.5rem;
    border-top: 1px solid var(--border-color);
    margin-top: 0.5rem;
}

.summary-row strong {
    color: var(--text-primary);
}

/* 成功消息 */
.success-message {
    text-align: center;
    padding: 3rem 1rem;
}

.success-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--success-color);
}

.success-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--success-color);
}

.success-content {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* 使用CSS控制模态框显示 */
#detail-modal:target,
#success-modal:target {
    opacity: 1;
    visibility: visible;
}

#detail-modal:target .modal,
#success-modal:target .modal {
    transform: translateY(0);
}

/* 响应式调整 */
@media (max-width: 48rem) {
    .container {
        padding: 1rem;
    }
    
    .months-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .actions-section {
        flex-direction: column;
    }
    
    .submit-btn {
        width: 100%;
    }
    
    .modal {
        max-width: 95vw;
    }
}

@media (max-width: 30rem) {
    .months-grid {
        grid-template-columns: 1fr;
    }
    
    .month-actions {
        flex-direction: column;
    }
    
    .btn-sm {
        width: 100%;
    }
}