:root {
    --primary-font-size: 1rem;
    --h1-font-size: calc(var(--primary-font-size) * 2.25);
    --h2-font-size: calc(var(--primary-font-size) * 1.8);
    --h3-font-size: calc(var(--primary-font-size) * 2.5);
    --h4-font-size: calc(var(--primary-font-size) * 1.25);
    --h5-font-size: calc(var(--primary-font-size) * 1.1);
    --small-font-size: calc(var(--primary-font-size) * 1.2);
}

body {
    font-family: 'Inter', sans-serif;
    font-size: var(--primary-font-size);
    background-color: #f8f9fa;
    min-height: 100vh;
    line-height: 1.6;
}

h1 { font-size: var(--h1-font-size); font-weight: 700; }
h2 { font-size: var(--h2-font-size); font-weight: 600; }
h3 { font-size: var(--h3-font-size); font-weight: 600; }
h4 { font-size: var(--h4-font-size); }
h5 { font-size: var(--h5-font-size); font-weight: 600; }

.upload-area, .download-area {
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    padding: 28px;
    height: calc(100vh - 48px);
    overflow-y: auto;
}

.upload-dropzone {
    border: 2.5px dashed #ced4da;
    border-radius: 12px;
    padding: 56px 24px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-dropzone:hover {
    border-color: #0d6efd;
    background-color: #f8f9fa;
    transform: translateY(-2px);
}

.upload-dropzone.active {
    border-color: #0d6efd;
    background-color: rgba(13,110,253,0.05);
}

.file-item {
    border: 1px solid #e9ecef;
    border-radius: 10px;
    padding: 18px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.file-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.08);
}

.status-badge {
    font-size: 1.2rem;
    padding: 0.4rem 0.75rem;
    border-radius: 6px;
}

.progress-container {
    display: none;
    margin-top: 20px;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
}

.text-muted {
    font-size: var(--small-font-size);
}

.btn {
    font-size: 1.6rem;
    padding: 0.5rem 1.25rem;
    border-radius: 8px;
}

.btn-sm {
    font-size: 1.55rem;
    padding: 0.4rem 0.9rem;
}

.list-group-item {
    padding: 0.9rem 1.25rem;
    font-size: 1rem;
}

.progress {
    height: 10px;
    border-radius: 5px;
    margin-bottom: 1rem;
}

.section-title {
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid #eaecef;
}

.file-icon {
    color: #6c757d;
    margin-right: 15px;
    font-size: 1.8rem;
}

.input-group {
    border-radius: 8px;
}

.form-control {
    font-size: 1rem;
    padding: 0.75rem 1rem;
    border-radius: 8px;
}

@media (max-width: 768px) {
    :root {
        --primary-font-size: 0.95rem;
    }

    .upload-area, .download-area {
        padding: 20px;
        height: auto;
        margin-bottom: 20px;
    }

    .upload-dropzone {
        padding: 40px 20px;
    }
}

/* 高级感Sweetalert2主题 */
.swal2-popup.advanced-popup {
    border-radius: 16px !important;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2) !important;
    padding: 2rem !important;
    max-width: 380px !important;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%) !important;
    border: 1px solid rgba(255, 255, 255, 0.2) !important;
    backdrop-filter: blur(10px) !important;
}

.advanced-popup .swal2-title {
    font-size: 1.4rem !important;
    font-weight: 600 !important;
    color: #1e293b !important;
    margin-bottom: 1rem !important;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%) !important;
    -webkit-background-clip: text !important;
    -webkit-text-fill-color: transparent !important;
    background-clip: text !important;
}

.advanced-popup .swal2-html-container {
    font-size: 1rem !important;
    color: #64748b !important;
    line-height: 1.6 !important;
    margin: 1rem 0 !important;
}

.advanced-popup .swal2-icon {
    width: 60px !important;
    height: 60px !important;
    margin: 1rem auto !important;
    border: 3px solid #e2e8f0 !important;
}

.advanced-popup .swal2-success [class^=swal2-success-line] {
    background-color: #10b981 !important;
}

.advanced-popup .swal2-error [class^=swal2-x-mark-line] {
    background-color: #ef4444 !important;
}

.advanced-popup .swal2-actions {
    margin: 1.5rem 0 0 0 !important;
}

.advanced-popup .swal2-confirm {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%) !important;
    border: none !important;
    border-radius: 10px !important;
    padding: 12px 28px !important;
    font-weight: 500 !important;
    font-size: 1rem !important;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3) !important;
    transition: all 0.3s ease !important;
}

.advanced-popup .swal2-confirm:hover {
    transform: translateY(-2px) !important;
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4) !important;
}

.advanced-popup .swal2-close {
    color: #94a3b8 !important;
    font-size: 1.5rem !important;
    transition: color 0.3s ease !important;
}

.advanced-popup .swal2-close:hover {
    color: #64748b !important;
}

/* 响应式设计 */
@media (max-width: 640px) {
    .swal2-popup.advanced-popup {
        max-width: 90% !important;
        margin: 1rem !important;
        padding: 1.5rem !important;
    }

    .advanced-popup .swal2-title {
        font-size: 1.2rem !important;
    }

    .advanced-popup .swal2-html-container {
        font-size: 0.95rem !important;
    }
}
/* 错误提示：柔和红 + 半透明背景 */
.advanced-popup .swal2-icon.swal2-error {
    border: 2px solid rgba(248, 113, 113, 0.5) !important; /* 柔和红边框 */
    background: rgba(254, 226, 226, 0.5) !important;      /* 半透明淡红背景 */
    box-shadow: 0 4px 12px rgba(248, 113, 113, 0.2) !important; /* 柔和阴影 */
}

.advanced-popup .swal2-error [class^=swal2-x-mark-line] {
    background-color: #f87171 !important; /* 柔和红，避免刺眼 */
}

/* 调整 X 图标线条更圆润 */
.advanced-popup .swal2-x-mark-line-left,
.advanced-popup .swal2-x-mark-line-right {
    border-radius: 2px !important;
}