:root {
    /* 现代 SaaS 色板 */
    --brand-50: #eef2ff;
    --brand-100: #e0e7ff;
    --brand-500: #4f46e5;
    --brand-600: #4338ca;
    
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-800: #1e293b;
    --gray-900: #0f172a;

    --success-bg: #ecfdf5;
    --success-text: #065f46;
    --success-border: #a7f3d0;
    
    --warning-bg: #fffbeb;
    --warning-text: #92400e;
    --warning-border: #fde68a;
    
    --error-bg: #fef2f2;
    --error-text: #991b1b;
    --error-border: #fecaca;

    --bg-body: var(--gray-50);
    --bg-card: #ffffff;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-glow: 0 0 0 4px var(--brand-100);

    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-body);
    color: var(--gray-800);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    /* 顶部细微渐变增加质感 */
    background-image: linear-gradient(180deg, #e2e8f0 0%, var(--gray-50) 400px);
    background-repeat: no-repeat;
    min-height: 100vh;
}

.container {
    max-width: 640px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

/* Header */
.page-header {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 2.5rem;
    text-align: center;
}

.logo-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 1rem;
    color: var(--brand-500);
}

.title-group h1 {
    font-size: 1.875rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    color: var(--gray-900);
    margin-bottom: 0.25rem;
}

.subtitle {
    font-size: 0.875rem;
    color: var(--gray-500);
    font-weight: 500;
}

/* Card */
.main-card {
    background-color: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg), 0 0 0 1px rgba(15, 23, 42, 0.05); /* 柔和阴影加细微边框 */
    position: relative;
    overflow: hidden;
}

/* 顶部细微高光线 */
.main-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--brand-500), #818cf8);
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1.25rem;
}

label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-600);
    margin-bottom: 0.375rem;
}

input[type="text"],
select {
    width: 100%;
    padding: 0.625rem 0.875rem;
    font-size: 0.9375rem;
    line-height: 1.5;
    color: var(--gray-900);
    background-color: var(--bg-card);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
    -webkit-appearance: none;
    appearance: none;
}

/* 自定义下拉箭头 */
select {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%2364748b' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}

input[type="text"]::placeholder {
    color: var(--gray-400);
}

input[type="text"]:hover,
select:hover {
    border-color: var(--gray-400);
}

input[type="text"]:focus,
select:focus {
    outline: none;
    border-color: var(--brand-500);
    box-shadow: var(--shadow-glow);
}

/* Advanced Panel */
.advanced-panel {
    margin: 1.5rem 0;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    background-color: var(--gray-50);
    transition: all var(--transition-fast);
}

.advanced-panel[open] {
    background-color: var(--bg-card);
    box-shadow: var(--shadow-md);
    border-color: var(--gray-300);
}

.advanced-panel summary {
    padding: 0.875rem 1rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-600);
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    user-select: none;
}

.advanced-panel summary::-webkit-details-marker {
    display: none;
}

.advanced-panel summary::before {
    content: '';
    display: inline-block;
    width: 1.25rem;
    height: 1.25rem;
    margin-right: 0.5rem;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2364748b'%3e%3cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M9 5l7 7-7 7'/%3e%3c/svg%3e");
    background-size: contain;
    transition: transform var(--transition-fast);
}

.advanced-panel[open] summary::before {
    transform: rotate(90deg);
}

.advanced-content {
    padding: 1rem;
    border-top: 1px solid var(--gray-200);
}

/* Checkbox */
.checkbox-group label {
    display: flex;
    align-items: center;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-600);
    cursor: pointer;
}

.checkbox-group input[type="checkbox"] {
    width: 1.125rem;
    height: 1.125rem;
    margin-right: 0.5rem;
    border-radius: 0.25rem;
    border: 1px solid var(--gray-300);
    accent-color: var(--brand-500);
    cursor: pointer;
}

/* Button */
.btn-primary {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 0.75rem 1.5rem;
    font-size: 0.9375rem;
    font-weight: 600;
    color: white;
    background-color: var(--brand-500);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05), inset 0 1px 0 rgba(255, 255, 255, 0.15);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--brand-600);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px -1px rgba(67, 56, 202, 0.2), 0 2px 4px -1px rgba(67, 56, 202, 0.1);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: none;
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    background-color: var(--gray-400);
}

.loader-icon {
    animation: spin 1s linear infinite;
    margin-right: 0.5rem;
    width: 1.25rem;
    height: 1.25rem;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Results */
.result-container {
    margin-top: 2rem;
    animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-container h2 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 1rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-200);
}

.result-card {
    background-color: var(--bg-card);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    padding: 1rem;
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
    line-height: 1.6;
    box-shadow: var(--shadow-sm);
    word-break: break-all;
}

.result-card strong {
    color: var(--gray-800);
    font-weight: 600;
}

/* Status Cards */
.status-card {
    display: flex;
    align-items: center;
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    font-weight: 500;
}

.status-icon {
    width: 1.5rem;
    height: 1.5rem;
    margin-right: 0.75rem;
    flex-shrink: 0;
}

.result-success {
    background-color: var(--success-bg);
    border: 1px solid var(--success-border);
    color: var(--success-text);
}

.result-warning {
    background-color: var(--warning-bg);
    border: 1px solid var(--warning-border);
    color: var(--warning-text);
}

.result-error {
    background-color: var(--error-bg);
    border: 1px solid var(--error-border);
    color: var(--error-text);
}

/* Links */
.download-link {
    display: inline-flex;
    align-items: center;
    margin-top: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: white;
    color: var(--gray-800);
    font-size: 0.875rem;
    font-weight: 600;
    text-decoration: none;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.download-link svg {
    width: 1rem;
    height: 1rem;
    margin-right: 0.375rem;
    color: var(--gray-500);
}

.download-link:hover {
    background-color: var(--gray-50);
    border-color: var(--gray-400);
}

button.download-link {
    font-family: inherit;
    cursor: pointer;
}

.payload-panel {
    margin-top: 0.75rem;
    border-top: 1px dashed var(--gray-200);
    padding-top: 0.75rem;
}

.payload-toolbar {
    margin-bottom: 0.5rem;
}

.payload-search {
    font-size: 0.875rem;
}

.payload-empty {
    padding: 0.75rem 0;
    color: var(--gray-500);
    font-size: 0.875rem;
}

.payload-partition {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto auto;
    gap: 0.75rem;
    align-items: center;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--gray-100);
}

.payload-partition span:first-child {
    word-break: break-all;
}

.payload-download {
    padding: 0.375rem 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    background: white;
    color: var(--gray-800);
    font: inherit;
    cursor: pointer;
}

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

.payload-error {
    grid-column: 1 / -1;
    color: var(--error-text);
    font-size: 0.8125rem;
}

.text-meta {
    display: block;
    margin-top: 0.25rem;
    font-size: 0.8125rem;
    color: var(--gray-500);
}

.text-warning { color: var(--warning-text); }
.text-error { color: var(--error-text); }

/* Responsive */
@media (max-width: 640px) {
    .container {
        padding: 1.5rem 1rem;
    }

    .main-card {
        padding: 1.5rem;
        border-radius: var(--radius-lg);
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }
    
    .form-row .form-group {
        margin-bottom: 1.25rem;
    }
    
    input[type="text"],
    select,
    .btn-primary,
    .advanced-panel summary {
        padding-top: 0.75rem;
        padding-bottom: 0.75rem;
    }
}