:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --background-color: #f8f9fa;
    --text-color: #333;
    --border-color: #ddd;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

.navbar {
    background: var(--primary-color);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1rem;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-link.active {
    background-color: rgba(255, 255, 255, 0.1);
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

.page-header {
    text-align: center;
    margin-bottom: 3rem;
}

.page-header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.subtitle {
    font-size: 1.2rem;
    color: #666;
}

/* ===== 活动列表 ===== */
.events-list {
    display: flex;
    flex-direction: column; /* 纵向排列 */
    gap: 1.5rem;
    width: 100%;
    height: auto;
}

.event-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
}

.event-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.15);
}

.event-card h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.event-card h3 a {
    color: inherit;
    text-decoration: none;
}

.event-card h3 a:hover {
    color: var(--accent-color);
}

.event-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.event-meta p {
    margin: 0.25rem 0;
    color: #666;
}

.progress-container {
    margin: 1rem 0;
}

.progress-label {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: #666;
}

.progress-bar {
    background: #ecf0f1;
    height: 20px;
    border-radius: 10px;
    overflow: hidden;
}

.progress {
    background: var(--accent-color);
    height: 100%;
    border-radius: 10px;
    transition: width 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.8rem;
    font-weight: bold;
}

/* search form */
.search-form-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.search-form {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

.form-group input,
.form-group select {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1rem;
}

.btn-primary {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s;
}

.btn-primary:hover {
    background: #2980b9;
}

.btn-secondary {
    background: #95a5a6;
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s;
}

.btn-secondary:hover {
    background: #7f8c8d;
}

/* Page Navigation */
.back-nav {
    margin-bottom: 1rem;
}

.back-link {
    color: var(--secondary-color);
    text-decoration: none;
}

.back-link:hover {
    text-decoration: underline;
}

/* Event Details */
.event-detail {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.event-detail h1 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.event-detail-section {
    margin-bottom: 2rem;
}

.event-detail-section h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
}

.modal-content {
    background: white;
    margin: 20% auto;
    padding: 2rem;
    border-radius: 8px;
    width: 90%;
    max-width: 400px;
    text-align: center;
}

.loading-spinner,
.no-events,
.no-results {
    text-align: center;
    padding: 3rem;
    color: #666;
}

.error-message {
    background: #f8d7da;
    color: #721c24;
    padding: 1rem;
    border-radius: 4px;
    margin: 1rem 0;
}

.footer {
    background: var(--primary-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .search-form {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .event-meta {
        grid-template-columns: 1fr;
    }
}