:root {
    --win10-blue: #0F7BFF;
    --win10-blue-light: #3B9BFF;
    --win10-blue-dark: #0063D1;
    --win10-gray: #E5E5E5;
    --win10-gray-dark: #C4C4C4;
    --win10-bg: #F3F6F9;
    --win10-card-bg: rgba(255, 255, 255, 0.95);
    --win10-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    --win10-shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.12);
    --win10-radius: 8px;
    --win10-radius-sm: 4px;
}

.sidebar-header {
    padding: 1.5rem;
    text-align: center;
    border-bottom: 1px solid #333;
}

.sidebar-logo {
    display: flex;
    align-items: center;
    justify-content: center;
}

.sidebar-logo img {
    max-width: 80%;
    height: auto;
    max-height: 60px;
    object-fit: contain;
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, 'Microsoft YaHei', sans-serif;
    background: var(--win10-bg);
    color: #1A1A1A;
    line-height: 1.5;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header样式 */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--win10-blue);
    text-decoration: none;
}

.logo img {
    height: 40px;
    vertical-align: middle;
}

.nav {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav a {
    color: #1A1A1A;
    text-decoration: none;
    transition: color 0.2s;
}

.nav a:hover {
    color: var(--win10-blue);
}

/* Footer样式 */
.footer {
    background: #1A1A1A;
    color: #999;
    padding: 3rem 0 2rem;
    margin-top: 3rem;
}

.footer .container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.footer-section h4 {
    color: white;
    margin-bottom: 1rem;
    font-size: 1rem;
}

.footer-section a {
    color: #999;
    text-decoration: none;
    display: block;
    margin-bottom: 0.5rem;
    transition: color 0.2s;
}

.footer-section a:hover {
    color: var(--win10-blue);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    margin-top: 2rem;
    border-top: 1px solid #333;
    font-size: 0.875rem;
}

/* 工具卡片 */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 1.5rem;
    padding: 2rem 0;
}

.tool-card {
    background: var(--win10-card-bg);
    border-radius: var(--win10-radius);
    padding: 1.5rem;
    transition: all 0.25s ease;
    box-shadow: var(--win10-shadow);
    border: 1px solid rgba(0, 0, 0, 0.05);
    cursor: pointer;
    text-align: center;
}

.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--win10-shadow-hover);
    border-color: var(--win10-blue);
}

.tool-icon {
    width: 64px;
    height: 64px;
    object-fit: contain;
    margin: 0 auto 1rem;
    display: block;
}

.tool-icon-large {
    width: 128px;
    height: 128px;
    object-fit: contain;
    margin: 0 auto 1rem;
}

.tool-name {
    font-size: 1.125rem;
    font-weight: 600;
    margin: 0.5rem 0;
    color: #1A1A1A;
}

.tool-intro {
    font-size: 0.875rem;
    color: #6B6B6B;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 响应式 */
@media (max-width: 1200px) {
    .tools-grid { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 992px) {
    .tools-grid { grid-template-columns: repeat(3, 1fr); }
}

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

@media (max-width: 480px) {
    .tools-grid { grid-template-columns: 1fr; }
    .footer .container { grid-template-columns: 1fr; }
    .header .container { flex-direction: column; gap: 1rem; }
}

/* 按钮样式 */
.btn-win10 {
    background: var(--win10-blue);
    color: white;
    border: none;
    padding: 0.5rem 1.25rem;
    border-radius: var(--win10-radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-win10:hover {
    background: var(--win10-blue-light);
}

.btn-win10-outline {
    background: transparent;
    border: 1px solid var(--win10-blue);
    color: var(--win10-blue);
    padding: 0.5rem 1.25rem;
    border-radius: var(--win10-radius-sm);
    cursor: pointer;
}

/* 加载更多 */
.load-more {
    text-align: center;
    padding: 2rem 0;
}

/* 分类页头部 */
.category-header {
    text-align: center;
    padding: 2rem 0 1rem;
}

.category-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.category-header p {
    color: #666;
}

/* 广告位 */
.ad-top {
    text-align: center;
    margin: 1rem 0;
}

.ad-bottom {
    text-align: center;
    margin: 2rem 0;
}

.ad-sidebar {
    margin-bottom: 1.5rem;
}