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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* 导航栏 */
.navbar {
    background: var(--card-bg);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo i {
    width: 32px;
    height: 32px;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link i {
    width: 20px;
    height: 20px;
}

.nav-link:hover {
    color: var(--primary-color);
    background: #eef2ff;
}

.nav-link.active {
    color: var(--primary-color);
    background: #eef2ff;
}

/* 主容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

/* A页面：表单样式 */
.form-container {
    max-width: 600px;
    margin: 2rem auto;
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.form-container h2 {
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.link-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.form-group input {
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.select-wrapper {
    position: relative;
}

.form-group select {
    width: 100%;
    padding: 0.75rem 3rem 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background: white;
    cursor: pointer;
    transition: all 0.3s;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
}

.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group select:hover {
    border-color: var(--primary-color);
}

.select-icon {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 18px;
    height: 18px;
    color: var(--text-secondary);
    pointer-events: none;
    transition: transform 0.3s;
}

.select-wrapper:focus-within .select-icon {
    transform: translateY(-50%) rotate(180deg);
    color: var(--primary-color);
}

.form-hint {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn i {
    width: 20px;
    height: 20px;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-icon {
    font-size: 1.2rem;
}

/* B页面：列表样式 */
.list-header {
    margin-bottom: 2rem;
}

.list-header h2 {
    margin-bottom: 1.5rem;
}

.filter-section {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.search-box {
    width: 100%;
}

.search-input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 1rem;
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 3rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.category-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}

.filter-btn i {
    width: 16px;
    height: 16px;
}

.filter-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.2);
}

.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.3);
}

/* 瀑布流布局 */
.cards-container {
    column-count: 4;
    column-gap: 1rem;
}

@media (max-width: 1400px) {
    .cards-container {
        column-count: 3;
    }
}

@media (max-width: 1024px) {
    .cards-container {
        column-count: 2;
    }
}

@media (max-width: 640px) {
    .cards-container {
        column-count: 1;
    }
}

/* 卡片样式 */
.card {
    break-inside: avoid;
    margin-bottom: 1rem;
    background: var(--card-bg);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    position: relative;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.card-image-link {
    display: block;
    text-decoration: none;
}

.card-image {
    width: 100%;
    height: 140px;
    object-fit: cover;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    transition: transform 0.3s;
}

.card-image-link:hover .card-image {
    transform: scale(1.05);
}

.card-favicon {
    width: 100%;
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.card-favicon i {
    width: 48px;
    height: 48px;
    color: white;
}

.card-content {
    padding: 0.875rem;
}

.card-category {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    background: #eef2ff;
    color: var(--primary-color);
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.card-title-link {
    text-decoration: none;
    color: inherit;
}

.card-title {
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 0.4rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    transition: color 0.3s;
}

.card-title-link:hover .card-title {
    color: var(--primary-color);
}

.card-description {
    color: var(--text-primary);
    font-size: 0.875rem;
    line-height: 1.4;
    margin-bottom: 0.75rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border-color);
}

.card-url {
    color: var(--text-secondary);
    font-size: 0.75rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 140px;
    text-decoration: none;
    transition: color 0.3s;
}

.card-url:hover {
    color: var(--primary-color);
}

.card-actions {
    display: flex;
    gap: 0.35rem;
}

.card-btn {
    padding: 0.35rem;
    border: none;
    background: transparent;
    cursor: pointer;
    opacity: 0.6;
    transition: opacity 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-btn i {
    width: 16px;
    height: 16px;
}

.card-btn:hover {
    opacity: 1;
}

.card-btn.delete:hover {
    color: #ef4444;
}

.card-btn.delete:hover i {
    color: #ef4444;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
}

.empty-icon {
    margin-bottom: 1rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.empty-icon i {
    width: 64px;
    height: 64px;
    color: var(--text-secondary);
}

.empty-state h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

/* Loading 状态 */
.loading-state {
    text-align: center;
    padding: 4rem 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading-text {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-container {
        padding: 1rem;
    }

    .container {
        padding: 1rem;
    }

    .form-container {
        padding: 1.5rem;
        margin: 1rem;
    }

    .nav-links {
        gap: 1rem;
    }
}

/* 动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card {
    animation: fadeIn 0.3s ease-out;
}