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

:root {
    --primary: #4f6df5;
    --primary-hover: #3b5de0;
    --secondary: #6c757d;
    --danger: #dc3545;
    --bg: #f5f7fa;
    --card-bg: #ffffff;
    --text: #2d3748;
    --text-light: #718096;
    --border: #e2e8f0;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.page-wrapper {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 20px;
    min-height: calc(100vh - 60px);
    padding: 20px;
}

.ad-sidebar {
    width: 200px;
    flex-shrink: 0;
    position: sticky;
    top: 20px;
    min-height: 200px;
}

.main-content {
    flex: 1;
    max-width: 900px;
    min-width: 0;
}

.tool-header {
    text-align: center;
    margin-bottom: 30px;
}

.tool-header h1 {
    font-size: 28px;
    color: var(--text);
    margin-bottom: 8px;
}

.tool-header p {
    color: var(--text-light);
    font-size: 15px;
}

.tool-section {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
}

.tool-section h2 {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--text);
}

.drop-zone {
    border: 2px dashed var(--border);
    border-radius: 10px;
    padding: 50px 20px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
}

.drop-zone:hover,
.drop-zone.dragover {
    border-color: var(--primary);
    background: rgba(79, 109, 245, 0.05);
}

.drop-icon {
    font-size: 40px;
    display: block;
    margin-bottom: 12px;
}

.drop-zone-text p {
    color: var(--text-light);
    font-size: 15px;
    margin-bottom: 4px;
}

.drop-hint {
    font-size: 13px !important;
    color: var(--text-light) !important;
    opacity: 0.8;
}

.config-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.config-item {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.config-item label {
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
}

.config-item input[type="text"],
.config-item select,
.config-item input[type="color"] {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 14px;
    background: var(--card-bg);
    color: var(--text);
}

.config-item input[type="text"]:focus,
.config-item select:focus {
    outline: none;
    border-color: var(--primary);
}

.config-item input[type="color"] {
    height: 38px;
    padding: 4px;
    cursor: pointer;
}

.config-item input[type="range"] {
    width: 100%;
    cursor: pointer;
    accent-color: var(--primary);
}

.value-display {
    color: var(--primary);
    font-weight: 600;
}

.position-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 4px;
}

.pos-btn {
    width: 100%;
    height: 32px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.15s;
}

.pos-btn:hover {
    border-color: var(--primary);
    background: rgba(79, 109, 245, 0.08);
}

.pos-btn.active {
    background: var(--primary);
    border-color: var(--primary);
}

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
}

.btn {
    padding: 10px 24px;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
}

.btn-secondary {
    background: #e2e8f0;
    color: var(--text);
}

.btn-secondary:hover:not(:disabled) {
    background: #cbd5e0;
}

.btn-danger {
    background: var(--danger);
    color: #fff;
}

.btn-danger:hover:not(:disabled) {
    background: #c82333;
}

.preview-container {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    justify-content: center;
}

.preview-item {
    position: relative;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    background: #f0f0f0;
}

.preview-item img {
    display: block;
    max-width: 100%;
    max-height: 400px;
    object-fit: contain;
}

.preview-item .item-actions {
    display: flex;
    gap: 8px;
    padding: 8px;
    background: var(--card-bg);
    border-top: 1px solid var(--border);
}

.preview-item .item-actions button {
    flex: 1;
    padding: 6px 12px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    border-radius: 4px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.15s;
}

.preview-item .item-actions button:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.preview-item .item-name {
    padding: 6px 8px;
    font-size: 12px;
    color: var(--text-light);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.empty-tip {
    text-align: center;
    color: var(--text-light);
    padding: 40px;
    width: 100%;
}

.info-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
}

.info-card {
    padding: 16px;
    background: var(--bg);
    border-radius: 8px;
}

.info-card h3 {
    font-size: 15px;
    margin-bottom: 8px;
    color: var(--primary);
}

.info-card p {
    font-size: 13px;
    color: var(--text-light);
    line-height: 1.5;
}

.ad-footer {
    width: 100%;
}

@media (max-width: 1200px) {
    .ad-sidebar {
        display: none;
    }
}

@media (max-width: 768px) {
    .page-wrapper {
        padding: 12px;
        gap: 0;
    }

    .tool-section {
        padding: 16px;
    }

    .tool-header h1 {
        font-size: 22px;
    }

    .config-grid {
        grid-template-columns: 1fr;
    }

    .actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}

/* SEO 内容区 */
.seo-content {
    max-width: 900px;
    margin: 0 auto;
    padding: 24px 20px 40px;
    color: #374151;
    font-size: 14px;
    line-height: 1.9;
}

.seo-content h2 {
    font-size: 17px;
    color: #1f2937;
    margin: 22px 0 10px;
    padding-left: 10px;
    border-left: 3px solid #409eff;
}

.seo-content h2:first-child { margin-top: 0; }

.seo-content h3 {
    font-size: 14px;
    color: #1f2937;
    margin: 14px 0 4px;
}

.seo-content ul,
.seo-content ol { padding-left: 22px; }

.seo-content li { margin-bottom: 4px; }