:root {
    --bg: #F8F9FA;
    --card-bg: #FFFFFF;
    --text-main: #1E293B;
    --text-sub: #64748B;
    --accent: #3B82F6;
    --border: #E2E8F0;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text-main);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 40px 20px;
}

header {
    text-align: center;
    margin-bottom: 48px;
    animation: fadeInUp 0.6s ease-out;
}

h1 {
    font-size: 2.5rem;
    margin: 0 0 16px 0;
    color: var(--text-main);
}

h1::before {
    content: '🛠️';
    margin-right: 8px;
}

.subtitle {
    font-size: 1.125rem;
    color: var(--text-sub);
    margin: 0 0 16px 0;
}

.intro-text {
    font-size: 1rem;
    color: var(--text-sub);
    line-height: 1.6;
    max-width: 720px;
    margin: 0 auto 32px auto;
    text-align: center;
}

.search-wrapper {
    max-width: 480px;
    margin: 0 auto;
    position: relative;
}

.search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: var(--text-sub);
}

#search-input {
    width: 100%;
    height: 48px;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 0 16px 0 48px;
    font-size: 1rem;
    box-sizing: border-box;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

#search-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

@media (max-width: 768px) {
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .grid {
        grid-template-columns: 1fr;
    }
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 24px;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    animation: fadeInUp 0.6s ease-out backwards;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.08);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.card-icon {
    font-size: 24px;
}

.card-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin: 0;
    color: var(--text-main);
    transition: color 0.2s;
}

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

.card-desc {
    font-size: 0.875rem;
    color: var(--text-sub);
    margin: 0;
    line-height: 1.5;
}

.card.coming-soon {
    background: #f1f5f9;
    border: 1px dashed #cbd5e1;
    box-shadow: none;
    cursor: default;
    opacity: 0.8;
}

.card.coming-soon:hover {
    transform: none;
    box-shadow: none;
}

.card.coming-soon .card-title {
    color: var(--text-sub);
}

#no-results {
    text-align: center;
    color: var(--text-sub);
    padding: 40px 0;
    display: none;
    grid-column: 1 / -1;
    font-size: 1rem;
}

footer {
    margin-top: 64px;
}

.content-section {
    background: #ffffff;
    border-radius: 20px;
    padding: 48px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
    margin-bottom: 48px;
    text-align: left;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

@media (max-width: 768px) {
    .content-section {
        grid-template-columns: 1fr;
        padding: 32px 24px;
        gap: 32px;
    }
}

.content-block {
    display: flex;
    flex-direction: column;
}

.content-block.full-width {
    grid-column: 1 / -1;
}

.section-title {
    font-size: 1.25rem;
    color: var(--text-main);
    font-weight: 600;
    margin: 0 0 16px 0;
    display: flex;
    align-items: center;
    gap: 8px;
}

.section-title::before {
    content: '';
    display: block;
    width: 4px;
    height: 16px;
    background: var(--accent);
    border-radius: 2px;
}

.text-content {
    font-size: 0.9375rem;
    color: var(--text-sub);
    line-height: 1.7;
    margin: 0;
}

.feature-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.feature-list li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 12px;
    font-size: 0.9375rem;
    color: var(--text-sub);
    line-height: 1.6;
}

.feature-list li::before {
    content: '•';
    color: var(--accent);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.feature-list strong {
    color: var(--text-main);
    font-weight: 600;
}

.faq-item {
    margin-bottom: 16px;
}

.faq-q {
    font-weight: 600;
    color: var(--text-main);
    margin: 0 0 8px 0;
    font-size: 0.9375rem;
}

.faq-a {
    color: var(--text-sub);
    margin: 0;
    font-size: 0.9375rem;
    line-height: 1.6;
}

.footer-bottom {
    text-align: center;
    padding: 32px 0;
    border-top: 1px solid var(--border);
    color: var(--text-sub);
    font-size: 0.875rem;
}

.footer-bottom p {
    margin: 0 0 8px 0;
}

.footer-bottom p:last-child {
    margin: 0;
}

.beian a {
    color: var(--text-sub);
    text-decoration: none;
    transition: color 0.2s;
}

.beian a:hover {
    color: var(--accent);
}

#back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background-color: var(--accent);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease, background-color 0.3s ease, box-shadow 0.3s ease;
    z-index: 999;
}

#back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

#back-to-top:hover {
    background-color: #2563EB;
    transform: translateY(-4px);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.4);
}

@media (max-width: 768px) {
    #back-to-top {
        bottom: 24px;
        right: 24px;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (prefers-reduced-motion: reduce) {
    .card, header {
        animation: none;
    }
    .card {
        transition: box-shadow 0.2s ease;
    }
    .card:hover {
        transform: none;
    }
}