.pdf-split-container {
    max-width: 960px;
    margin: 0 auto;
    padding: 20px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

.tool-header h1 {
    font-size: 28px;
    color: #333;
    margin: 0 0 10px;
    font-weight: 600;
}

.tool-header h1 i {
    color: #e74c3c;
    margin-right: 10px;
}

.tool-desc {
    color: #666;
    font-size: 15px;
    margin: 0;
}

/* 权限限制提示 */
.limit-notice {
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    border-radius: 8px;
    padding: 40px 20px;
    text-align: center;
    color: #856404;
}

.limit-notice i {
    font-size: 48px;
    margin-bottom: 15px;
    display: block;
}

.limit-notice p {
    font-size: 16px;
    margin: 0;
}

/* 上传区域 */
.upload-section {
    margin-bottom: 25px;
}

.upload-area {
    border: 2px dashed #ccc;
    border-radius: 12px;
    padding: 50px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: #3498db;
    background: #f0f8ff;
}

.upload-content i {
    font-size: 48px;
    color: #3498db;
    margin-bottom: 15px;
    display: block;
}

.upload-text {
    font-size: 16px;
    color: #333;
    margin: 0 0 8px;
    font-weight: 500;
}

.upload-hint {
    font-size: 13px;
    color: #999;
    margin: 0;
}

/* 文件信息 */
.file-info {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 15px 20px;
    margin-bottom: 25px;
    border-left: 4px solid #e74c3c;
}

.file-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.file-meta i {
    font-size: 20px;
    color: #e74c3c;
}

.file-name {
    font-weight: 600;
    color: #333;
    word-break: break-all;
    flex: 1;
}

.file-size,
.file-pages {
    color: #666;
    font-size: 13px;
    background: #fff;
    padding: 3px 10px;
    border-radius: 12px;
    border: 1px solid #e0e0e0;
}

.btn-change {
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 6px 14px;
    font-size: 13px;
    color: #666;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-change:hover {
    border-color: #3498db;
    color: #3498db;
}

/* 拆分设置 */
.split-settings {
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 25px;
}

.settings-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 25px;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 15px;
}

.tab-btn {
    background: #f5f5f5;
    border: none;
    border-radius: 8px;
    padding: 12px 24px;
    font-size: 14px;
    color: #666;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 8px;
}

.tab-btn:hover {
    background: #e8e8e8;
}

.tab-btn.active {
    background: #3498db;
    color: #fff;
}

.tab-panel {
    display: none;
}

.tab-panel.active {
    display: block;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
}

.form-group input {
    width: 100%;
    max-width: 300px;
    padding: 10px 14px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.2s;
    box-sizing: border-box;
}

.form-group input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.form-hint {
    display: block;
    font-size: 12px;
    color: #999;
    margin-top: 6px;
}

.preview-info {
    background: #f0f8ff;
    border-radius: 8px;
    padding: 15px;
    margin-top: 15px;
    font-size: 13px;
    color: #555;
    line-height: 1.6;
}

/* 页面缩略图 */
.page-thumbnails {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 12px;
    margin-top: 15px;
    max-height: 320px;
    overflow-y: auto;
    padding: 10px;
    background: #fafafa;
    border-radius: 8px;
}

.thumbnail-item {
    background: #fff;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    padding: 8px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
}

.thumbnail-item:hover {
    border-color: #3498db;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.08);
}

.thumbnail-item.selected {
    border-color: #3498db;
    background: #f0f8ff;
}

.thumbnail-item .thumb-page-num {
    font-size: 12px;
    color: #666;
    margin-top: 4px;
}

.thumbnail-item .thumb-placeholder {
    width: 100%;
    height: 80px;
    background: linear-gradient(135deg, #f5f5f5 0%, #e0e0e0 100%);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #999;
    font-size: 12px;
}

/* 按钮 */
.btn-split,
.btn-download-all,
.btn-reset {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-split {
    background: #e74c3c;
    color: #fff;
    width: 100%;
    margin-top: 10px;
}

.btn-split:hover {
    background: #c0392b;
}

.btn-split:disabled {
    background: #ccc;
    cursor: not-allowed;
}

/* 结果区域 */
.result-section {
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 25px;
}

.result-section h3 {
    margin: 0 0 20px;
    font-size: 18px;
    color: #27ae60;
    display: flex;
    align-items: center;
    gap: 8px;
}

.result-list {
    margin-bottom: 20px;
}

.result-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 16px;
    background: #f8f9fa;
    border-radius: 8px;
    margin-bottom: 10px;
    border-left: 3px solid #3498db;
}

.result-item:last-child {
    margin-bottom: 0;
}

.result-info {
    flex: 1;
}

.result-name {
    font-weight: 600;
    color: #333;
    font-size: 14px;
    margin-bottom: 4px;
}

.result-range {
    font-size: 12px;
    color: #666;
}

.result-pages {
    font-size: 12px;
    color: #999;
    background: #fff;
    padding: 2px 8px;
    border-radius: 10px;
    margin-left: 10px;
}

.btn-download-single {
    background: #3498db;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 8px 16px;
    font-size: 13px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: background 0.2s;
}

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

.result-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #f0f0f0;
}

.btn-download-all {
    background: #27ae60;
    color: #fff;
}

.btn-download-all:hover {
    background: #219a52;
}

.btn-reset {
    background: #f5f5f5;
    color: #666;
    border: 1px solid #ddd;
}

.btn-reset:hover {
    background: #e8e8e8;
}

/* 加载状态 */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.85);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-spinner {
    text-align: center;
}

.loading-spinner i {
    font-size: 40px;
    color: #3498db;
    margin-bottom: 15px;
    display: block;
}

.loading-spinner p {
    color: #666;
    font-size: 14px;
    margin: 0;
}

/* 错误提示 */
.error-message {
    background: #fee;
    border: 1px solid #fcc;
    border-radius: 8px;
    padding: 12px 16px;
    color: #c33;
    font-size: 14px;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* 响应式 */
@media (max-width: 600px) {
    .pdf-split-container {
        padding: 15px;
    }

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

    .settings-tabs {
        flex-direction: column;
    }

    .tab-btn {
        width: 100%;
        justify-content: center;
    }

    .file-meta {
        flex-direction: column;
        align-items: flex-start;
    }

    .result-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .result-actions {
        flex-direction: column;
    }

    .btn-download-all,
    .btn-reset {
        width: 100%;
    }
}