/* ============================================
   PDF 终极工具箱 - Apple 级别设计系统
   纯白背景 · 无渐变 · 极致简洁
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors - Apple Inspired */
    --color-white: #ffffff;
    --color-bg: #f5f5f7;
    --color-text-primary: #1d1d1f;
    --color-text-secondary: #86868b;
    --color-text-tertiary: #aeaeb2;
    --color-border: #d2d2d7;
    --color-border-light: #e8e8ed;
    --color-accent: #0071e3;
    --color-accent-hover: #0077ed;
    --color-accent-active: #006edb;
    --color-danger: #ff3b30;
    --color-success: #34c759;
    --color-warning: #ff9500;
    --color-card-bg: #ffffff;
    --color-hover: #f5f5f7;
    --color-row-hover: #fafafa;
    --color-banner-bg: #f0f4ff;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "Segoe UI", Arial, sans-serif;
    --font-mono: "SF Mono", "SFMono-Regular", "Menlo", "Consolas", monospace;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-2xl: 24px;
    --spacing-3xl: 32px;
    --spacing-4xl: 40px;
    --spacing-5xl: 48px;

    /* Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 10px;
    --radius-xl: 12px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 8px 32px rgba(0, 0, 0, 0.1);

    /* Transitions */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    background: var(--color-bg);
    color: var(--color-text-primary);
    line-height: 1.5;
    min-height: 100vh;
}

/* --- App Container --- */
.app-container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    padding-bottom: var(--spacing-5xl);
}

/* --- Top Bar --- */
.top-bar {
    max-width: 960px;
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-xl) 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Back to Home Button */
.back-home-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: #e8f0fe;
    border: 1px solid var(--color-accent);
    color: var(--color-accent);
    padding: 8px 16px;
    border-radius: 9999px;
    font-size: 13px;
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-fast);
    font-family: var(--font-family);
    cursor: pointer;
}

.back-home-btn:hover {
    background: var(--color-accent);
    color: #FFFFFF;
    box-shadow: 0 4px 12px rgba(0, 113, 227, 0.25);
}

.back-home-btn svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.brand-text {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.brand-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text-primary);
    letter-spacing: -0.02em;
}

.brand-subtitle {
    font-size: 12px;
    color: var(--color-text-secondary);
    font-weight: 400;
}

.brand-logo {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.brand-logo img {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

/* --- Description Banner --- */
.description-banner {
    background: var(--color-banner-bg);
    border: 1px solid #d0deff;
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin-top: var(--spacing-xl);
    display: flex;
    gap: var(--spacing-3xl);
}

.desc-section {
    flex: 1;
}

.desc-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.desc-text {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.desc-steps {
    list-style: none;
    counter-reset: step-counter;
}

.desc-steps li {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.8;
    counter-increment: step-counter;
    padding-left: 28px;
    position: relative;
}

.desc-steps li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: 2px;
    width: 20px;
    height: 20px;
    background: var(--color-accent);
    color: white;
    border-radius: 50%;
    font-size: 11px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    font-size: 13px;
    font-weight: 500;
    font-family: var(--font-family);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
    line-height: 1.4;
    text-decoration: none;
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn:active:not(:disabled) {
    transform: scale(0.97);
}

.btn-primary {
    background: var(--color-accent);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
    background: var(--color-accent-hover);
    box-shadow: var(--shadow-md);
}

.btn-primary:active:not(:disabled) {
    background: var(--color-accent-active);
}

.btn-secondary {
    background: var(--color-white);
    color: var(--color-accent);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--color-hover);
    border-color: #c0c0c5;
}

.btn-ghost {
    background: transparent;
    color: var(--color-text-secondary);
}

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

.btn-sm {
    padding: 5px 12px;
    font-size: 12px;
}

.btn-reselect {
    background: var(--color-accent);
    color: white;
    padding: 8px 20px;
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.btn-reselect:hover {
    background: var(--color-accent-hover);
    box-shadow: var(--shadow-md);
}

/* --- Function Tabs --- */
.function-tabs {
    display: flex;
    gap: 0;
    border-bottom: 1px solid var(--color-border-light);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    overflow-x: auto;
    white-space: nowrap;
}

.tab-btn {
    padding: 10px 20px;
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-secondary);
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: var(--font-family);
}

.tab-btn:hover {
    color: var(--color-text-primary);
}

.tab-btn.active {
    color: var(--color-accent);
    border-bottom-color: var(--color-accent);
    font-weight: 600;
}

/* --- Main Content --- */
.main-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

/* --- Card --- */
.card {
    background: var(--color-card-bg);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-normal);
}

.card:hover {
    box-shadow: var(--shadow-md);
}

.card-header {
    padding: var(--spacing-lg) var(--spacing-2xl);
    border-bottom: 1px solid var(--color-border-light);
}

.card-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text-primary);
    letter-spacing: -0.01em;
}

.card-body {
    padding: var(--spacing-2xl);
}

/* --- Upload Area --- */
.upload-area {
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-4xl) var(--spacing-2xl);
    text-align: center;
    background: #fafafc;
    transition: all var(--transition-fast);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    cursor: pointer;
}

.file-upload-btn {
    pointer-events: none;
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--color-accent);
    background: #f0f7ff;
}

.upload-hint {
    font-size: 13px;
    color: var(--color-text-secondary);
}

/* --- File List --- */
.file-list-container {
    margin-top: var(--spacing-2xl);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.file-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-hover);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-md);
    font-size: 13px;
}

.file-item-name {
    font-weight: 500;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 400px;
}

.file-item-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.file-item-btn {
    background: none;
    border: none;
    color: var(--color-text-secondary);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.file-item-btn:hover {
    background: var(--color-white);
    color: var(--color-text-primary);
}

.file-item-btn.btn-delete:hover {
    color: var(--color-danger);
    background: rgba(255, 59, 48, 0.1);
}

/* --- Viewer Controls --- */
.viewer-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--color-hover);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.page-num-info {
    font-size: 13px;
    font-family: var(--font-mono);
    color: var(--color-text-primary);
}

.pdf-canvas-container {
    max-width: 100%;
    overflow: auto;
    display: flex;
    justify-content: center;
    background: #e4e4e7;
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    min-height: 200px;
}

#pdfViewerCanvas {
    box-shadow: var(--shadow-lg);
    background: white;
    max-width: 100%;
}

/* --- Form Fields --- */
.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--color-text-secondary);
    text-transform: uppercase;
}

.form-input {
    width: 100%;
    padding: 8px 12px;
    font-size: 13px;
    font-family: var(--font-family);
    color: var(--color-text-primary);
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    outline: none;
    transition: all var(--transition-fast);
}

.form-input:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(0, 113, 227, 0.15);
}

select.form-input {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2386868b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    padding-right: 32px;
}

.form-hint {
    font-size: 12px;
    color: var(--color-text-tertiary);
}

/* --- Radio Group --- */
.radio-group {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.radio-label {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--color-text-primary);
    cursor: pointer;
}

.radio-label input[type="radio"] {
    accent-color: var(--color-accent);
}

/* --- Range Slider --- */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    height: 6px;
    background: var(--color-border);
    border-radius: 3px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
}

input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow-sm);
}

/* --- Paste Area --- */
.paste-area {
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-5xl) var(--spacing-2xl);
    text-align: center;
    background: #fafafc;
    transition: all var(--transition-fast);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    cursor: pointer;
    position: relative;
}

.paste-area .file-upload-btn {
    pointer-events: none;
}

.paste-area:hover, .paste-area.dragover {
    border-color: var(--color-accent);
    background: #f0f7ff;
}

.paste-area.paste-active {
    border-color: var(--color-success);
    background: #f0fff4;
}

.paste-icon {
    font-size: 48px;
    line-height: 1;
}

.paste-text {
    font-size: 15px;
    font-weight: 500;
    color: var(--color-text-primary);
}

.paste-text kbd {
    display: inline-block;
    padding: 2px 6px;
    font-size: 12px;
    font-family: var(--font-mono);
    color: var(--color-text-primary);
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    box-shadow: 0 1px 0 var(--color-border);
}

.paste-preview-thumb {
    width: 80px;
    height: 80px;
    object-fit: cover;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border-light);
    box-shadow: var(--shadow-sm);
}

/* --- Footer --- */
.footer {
    text-align: center;
    padding: var(--spacing-4xl) 0 var(--spacing-xl);
    color: var(--color-text-tertiary);
    font-size: 12px;
}

/* --- Toast --- */
.toast-container {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    pointer-events: none;
}

.toast {
    padding: 12px 24px;
    background: var(--color-text-primary);
    color: var(--color-white);
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    animation: toastIn 0.3s ease-out;
    pointer-events: auto;
    display: flex;
    align-items: center;
    gap: 8px;
}

.toast.toast-success { background: var(--color-success); }
.toast.toast-error { background: var(--color-danger); }
.toast.toast-warning { background: var(--color-warning); }

@keyframes toastIn {
    from { opacity: 0; transform: translateY(16px) scale(0.95); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.toast-out { animation: toastOut 0.25s ease-in forwards; }

@keyframes toastOut {
    to { opacity: 0; transform: translateY(8px) scale(0.95); }
}

/* --- Loading Overlay --- */
.loading-overlay {
    position: fixed;
    inset: 0;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 3000;
    display: none;
    align-items: center;
    justify-content: center;
}

.loading-overlay.show {
    display: flex;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border-light);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loading-text {
    margin-top: var(--spacing-lg);
    font-size: 14px;
    color: var(--color-text-secondary);
}

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

/* --- Responsive --- */
@media (max-width: 768px) {
    .app-container {
        padding: 0 var(--spacing-lg);
    }

    .top-bar {
        padding: var(--spacing-lg) var(--spacing-lg) 0;
    }

    .description-banner {
        flex-direction: column;
        gap: var(--spacing-lg);
    }

    .radio-group {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .form-row {
        flex-direction: column;
    }
}


/* ============================================
   SEO 内容区块（独立站点功能页）
   ============================================ */
.seo-breadcrumb {
    font-size: 13.5px;
    color: var(--color-text-tertiary);
    margin: 18px 0 4px;
}
.seo-breadcrumb a {
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}
.seo-breadcrumb a:hover { color: var(--color-accent); }
.seo-breadcrumb .sep { margin: 0 6px; color: var(--color-text-tertiary); }
.seo-h1 {
    font-size: 34px;
    font-weight: 700;
    letter-spacing: -0.3px;
    margin: 10px 0 10px;
    line-height: 1.2;
}
.seo-lead {
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin-bottom: 26px;
}
.seo-section {
    margin-top: 44px;
    padding-top: 30px;
    border-top: 1px solid var(--color-border-light);
}
.seo-section h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 14px;
}
.seo-section p,
.seo-section li {
    font-size: 15px;
    line-height: 1.7;
    color: var(--color-text-secondary);
}
.seo-section ol,
.seo-section ul {
    padding-left: 22px;
}
.seo-section li { margin-bottom: 8px; }
.faq-item {
    border: 1px solid var(--color-border-light);
    border-radius: 10px;
    margin-bottom: 10px;
    overflow: hidden;
    background: var(--color-card-bg);
}
.faq-item summary {
    padding: 14px 16px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    position: relative;
    font-family: var(--font-family);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: '+';
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 18px;
    color: var(--color-text-tertiary);
}
.faq-item[open] summary::after { content: '\2212'; }
.faq-item p {
    padding: 0 16px 14px;
    font-size: 14.5px;
}
.related-links {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.related-links a {
    display: inline-block;
    padding: 8px 16px;
    border-radius: 9999px;
    background: var(--color-hover);
    color: var(--color-text-primary);
    text-decoration: none;
    font-size: 14px;
    border: 1px solid var(--color-border-light);
    transition: all var(--transition-fast);
}
.related-links a:hover {
    background: #e8f0fe;
    color: var(--color-accent);
    border-color: var(--color-accent);
}
.footer-nav {
    display: flex;
    justify-content: center;
    gap: 22px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}
.footer-nav a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 14px;
    transition: color var(--transition-fast);
}
.footer-nav a:hover { color: var(--color-accent); }
.site-footer { text-align: center; margin-top: 60px; }

/* ============================================
   移动端适配（独立站点功能页）
   ============================================ */
@media (max-width: 768px) {
    .viewer-controls {
        flex-wrap: wrap;
        gap: var(--spacing-sm) var(--spacing-md);
    }
    .viewer-controls .btn {
        margin: 0;
    }
    .seo-h1 {
        font-size: 26px;
    }
    .seo-lead {
        font-size: 15px;
    }
    .file-item {
        flex-wrap: wrap;
        row-gap: var(--spacing-sm);
    }
    .file-item-name {
        max-width: 100%;
        flex: 1 1 auto;
        min-width: 0;
    }
    .file-item-actions {
        margin-left: auto;
    }
    .upload-area,
    .paste-area {
        padding: var(--spacing-3xl) var(--spacing-lg);
    }
    .seo-section {
        margin-top: 36px;
    }
}

@media (max-width: 480px) {
    .app-container {
        padding: 0 var(--spacing-md);
    }
    .seo-breadcrumb {
        font-size: 12.5px;
        margin-top: 14px;
    }
    .seo-h1 {
        font-size: 23px;
    }
    .seo-section h2 {
        font-size: 20px;
    }
    .seo-section p,
    .seo-section li {
        font-size: 14px;
    }
    .viewer-controls .btn {
        flex: 1 1 auto;
        min-width: 72px;
    }
    .footer-nav {
        gap: 14px;
    }
    .related-links a {
        padding: 7px 12px;
        font-size: 13px;
    }
}