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

:root {
    --jade-white: #faf8f5;
    --jade-warm: #f5f2ed;
    --jade-light: #ebe7e0;
    --ink-black: #1a1a1a;
    --ink-dark: #2d2d2d;
    --ink-gray: #5a5a5a;
    --ink-light: #8a8a8a;
    --border-color: #d4cfc6;
    --shadow-soft: rgba(26, 26, 26, 0.06);
    --shadow-medium: rgba(26, 26, 26, 0.1);
}

body {
    font-family: "Noto Serif SC", "Source Han Serif CN", "Songti SC", Georgia, serif;
    background: var(--jade-white);
    color: var(--ink-black);
    line-height: 1.8;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 24px;
}

header {
    text-align: center;
    margin-bottom: 48px;
    padding-bottom: 32px;
    border-bottom: 1px solid var(--border-color);
}

header h1 {
    font-size: 32px;
    font-weight: 600;
    letter-spacing: 4px;
    margin-bottom: 12px;
    color: var(--ink-black);
}

.subtitle {
    font-size: 14px;
    color: var(--ink-gray);
    letter-spacing: 2px;
}

main {
    display: flex;
    flex-direction: column;
    gap: 40px;
}

section {
    background: var(--jade-warm);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 28px;
}

section h2 {
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 2px;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
    color: var(--ink-dark);
}

.source-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.source-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 16px;
    background: var(--jade-white);
    border: 1px solid var(--border-color);
    border-radius: 2px;
}

.source-checkbox {
    position: relative;
    display: flex;
    align-items: center;
    cursor: pointer;
}

.source-checkbox input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 2px;
    background: var(--jade-white);
    transition: all 0.15s ease;
}

.source-checkbox input:checked + .checkmark {
    background: var(--ink-black);
    border-color: var(--ink-black);
}

.source-checkbox input:checked + .checkmark::after {
    content: '';
    position: absolute;
    left: 6px;
    top: 2px;
    width: 5px;
    height: 10px;
    border: solid var(--jade-white);
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.source-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
    flex: 1;
}

.source-name {
    font-weight: 500;
    color: var(--ink-dark);
}

.source-url {
    font-size: 13px;
    color: var(--ink-light);
    font-family: "SF Mono", "Consolas", monospace;
}

.custom-section {
    background: var(--jade-warm);
}

.custom-input-group {
    display: flex;
    gap: 12px;
}

.custom-input {
    flex: 1;
    padding: 12px 16px;
    font-size: 14px;
    font-family: inherit;
    background: var(--jade-white);
    border: 1px solid var(--border-color);
    border-radius: 2px;
    color: var(--ink-dark);
    transition: border-color 0.15s ease;
}

.custom-input:focus {
    outline: none;
    border-color: var(--ink-gray);
}

.custom-input::placeholder {
    color: var(--ink-light);
}

.add-btn {
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 500;
    font-family: inherit;
    background: var(--ink-black);
    color: var(--jade-white);
    border: 2px solid var(--ink-black);
    border-radius: 2px;
    cursor: pointer;
    transition: all 0.15s ease;
}

.add-btn:hover {
    background: var(--ink-dark);
    border-color: var(--ink-dark);
}

.custom-url-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 16px;
}

.custom-url-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    background: var(--jade-white);
    border: 1px solid var(--border-color);
    border-radius: 2px;
}

.custom-url-text {
    flex: 1;
    font-size: 13px;
    color: var(--ink-dark);
    font-family: "SF Mono", "Consolas", monospace;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.remove-btn {
    padding: 4px 10px;
    font-size: 12px;
    font-family: inherit;
    background: transparent;
    color: var(--ink-light);
    border: 1px solid var(--border-color);
    border-radius: 2px;
    cursor: pointer;
    transition: all 0.15s ease;
}

.remove-btn:hover {
    background: var(--jade-light);
    color: var(--ink-dark);
}

.action-section {
    background: transparent;
    border: none;
    padding: 0;
    text-align: center;
}

.fetch-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 200px;
    padding: 16px 48px;
    font-size: 16px;
    font-weight: 500;
    letter-spacing: 3px;
    color: var(--jade-white);
    background: var(--ink-black);
    border: 2px solid var(--ink-black);
    border-radius: 2px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.fetch-btn:hover {
    background: var(--ink-dark);
    border-color: var(--ink-dark);
}

.fetch-btn:active {
    transform: translateY(1px);
}

.fetch-btn:disabled {
    background: var(--ink-light);
    border-color: var(--ink-light);
    cursor: not-allowed;
}

.stats-section {
    background: transparent;
    border: none;
    padding: 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 24px;
    background: var(--jade-warm);
    border: 1px solid var(--border-color);
    border-radius: 2px;
}

.stat-value {
    font-size: 36px;
    font-weight: 600;
    color: var(--ink-black);
    line-height: 1;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 13px;
    color: var(--ink-gray);
    letter-spacing: 1px;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.section-header h2 {
    margin: 0;
    padding: 0;
    border: none;
}

.format-tabs {
    display: flex;
    gap: 4px;
}

.format-tab {
    padding: 8px 16px;
    font-size: 13px;
    background: var(--jade-white);
    border: 1px solid var(--border-color);
    border-radius: 2px;
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: inherit;
    color: var(--ink-gray);
}

.format-tab:hover {
    border-color: var(--ink-light);
}

.format-tab.active {
    background: var(--ink-black);
    border-color: var(--ink-black);
    color: var(--jade-white);
}

.preview-container {
    background: var(--jade-white);
    border: 1px solid var(--border-color);
    border-radius: 2px;
    max-height: 400px;
    overflow: auto;
}

.preview-container pre {
    padding: 20px;
    font-size: 13px;
    line-height: 1.6;
    color: var(--ink-dark);
    font-family: "SF Mono", "Consolas", "Liberation Mono", monospace;
    white-space: pre-wrap;
    word-break: break-all;
}

.download-section {
    background: transparent;
    border: none;
    padding: 0;
}

.download-section h2 {
    background: transparent;
    padding: 0;
    margin-bottom: 16px;
    border: none;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.download-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 20px;
    font-size: 14px;
    background: var(--jade-warm);
    border: 1px solid var(--border-color);
    border-radius: 2px;
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: inherit;
    color: var(--ink-dark);
}

.download-btn:hover {
    background: var(--jade-light);
    border-color: var(--ink-light);
}

.download-icon {
    font-size: 16px;
}

footer {
    text-align: center;
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--border-color);
}

.footer-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--ink-light);
    letter-spacing: 1px;
    text-decoration: none;
    transition: color 0.15s ease;
}

.footer-link:hover {
    color: var(--ink-dark);
}

.github-icon {
    flex-shrink: 0;
}

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

.fade-in {
    animation: fadeIn 0.3s ease forwards;
}

::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--jade-light);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--ink-light);
}

@media (max-width: 600px) {
    .container {
        padding: 40px 16px;
    }

    header h1 {
        font-size: 24px;
        letter-spacing: 2px;
    }

    .source-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    .source-url {
        font-size: 12px;
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .format-tabs {
        width: 100%;
    }

    .format-tab {
        flex: 1;
        text-align: center;
    }

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

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

    .custom-input-group {
        flex-direction: column;
    }

    .add-btn {
        width: 100%;
    }
}