:root {
    /* Colors */
    --color-bg-primary: #0d1117;
    --color-bg-secondary: #161b22;
    --color-bg-tertiary: #21262d;
    --color-border-default: #30363d;
    --color-border-muted: #21262d;

    --color-text-primary: #e6edf3;
    --color-text-secondary: #8b949e;
    --color-text-muted: #6e7681;

    --color-accent-primary: #238636;
    --color-accent-secondary: #2ea043;
    --color-accent-blue: #58a6ff;
    --color-accent-purple: #bc8cff;

    --color-danger: #f85149;
    --color-warning: #d29922;
    --color-success: #2ea043;

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

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 12px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;

    /* Font */
    --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans', Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* Header */
.header {
    background-color: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border-default);
    padding: var(--spacing-md) var(--spacing-lg);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--color-text-primary);
    font-size: 1.25rem;
    font-weight: 600;
}

.user-stats {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.stats-badge {
    background-color: var(--color-bg-tertiary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border-default);
}

/* Main Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

/* Upload Area */
.upload-section {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

@media (max-width: 768px) {
    .upload-section {
        grid-template-columns: 1fr;
    }
}

.upload-panel {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
}

.upload-panel h2 {
    font-size: 1rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
    font-weight: 500;
}

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--color-border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    background-color: var(--color-bg-tertiary);
}

.drop-zone:hover,
.drop-zone.dragover {
    border-color: var(--color-accent-blue);
    background-color: rgba(88, 166, 255, 0.1);
}

.drop-zone-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--spacing-md);
    opacity: 0.6;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%238b949e'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z'/%3E%3C/svg%3E");
    background-size: contain;
}

.drop-zone p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.drop-zone small {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

/* Markdown Input */
.markdown-input {
    width: 100%;
    min-height: 200px;
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    color: var(--color-text-primary);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    resize: vertical;
    line-height: 1.5;
    transition: border-color var(--transition-fast);
}

.markdown-input:focus {
    outline: none;
    border-color: var(--color-accent-blue);
    box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.2);
}

.markdown-input::placeholder {
    color: var(--color-text-muted);
}

/* Preview Panel */
.preview-section {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: var(--spacing-sm);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border-default);
}

.preview-header h2 {
    font-size: 1rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.preview-content {
    min-height: 100px;
    max-height: 200px;
    overflow-y: auto;
    padding: var(--spacing-md);
}

.preview-placeholder {
    color: var(--color-text-muted);
    text-align: center;
    padding: var(--spacing-2xl);
}

/* Markdown Rendered Content */
.markdown-body {
    color: var(--color-text-primary);
    line-height: 1.7;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
    border-bottom: 1px solid var(--color-border-muted);
    padding-bottom: var(--spacing-sm);
}

.markdown-body h1 {
    font-size: 2rem;
}

.markdown-body h2 {
    font-size: 1.5rem;
}

.markdown-body h3 {
    font-size: 1.25rem;
    border-bottom: none;
}

.markdown-body h4 {
    font-size: 1rem;
    border-bottom: none;
}

.markdown-body p {
    margin-bottom: var(--spacing-md);
}

.markdown-body a {
    color: var(--color-accent-blue);
    text-decoration: none;
}

.markdown-body a:hover {
    text-decoration: underline;
}

.markdown-body code {
    background-color: var(--color-bg-tertiary);
    padding: 0.2em 0.4em;
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.875em;
}

.markdown-body pre {
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    overflow-x: auto;
    margin-bottom: var(--spacing-md);
}

.markdown-body pre code {
    background: none;
    padding: 0;
    font-size: 0.875rem;
}

.markdown-body blockquote {
    border-left: 4px solid var(--color-accent-blue);
    padding-left: var(--spacing-md);
    margin-left: 0;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

.markdown-body ul,
.markdown-body ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
}

.markdown-body li {
    margin-bottom: var(--spacing-xs);
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--spacing-md);
}

.markdown-body th,
.markdown-body td {
    border: 1px solid var(--color-border-default);
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
}

.markdown-body th {
    background-color: var(--color-bg-tertiary);
    font-weight: 600;
}

.markdown-body img {
    max-width: 100%;
    border-radius: var(--radius-md);
}

.markdown-body hr {
    border: none;
    border-top: 1px solid var(--color-border-default);
    margin: var(--spacing-lg) 0;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
    text-decoration: none;
}

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

.btn-primary:hover {
    background-color: var(--color-accent-secondary);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-secondary {
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-primary);
    border-color: var(--color-border-default);
}

.btn-secondary:hover {
    background-color: var(--color-border-default);
}

.btn-danger {
    background-color: var(--color-danger);
    color: white;
}

.btn-danger:hover {
    opacity: 0.9;
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
}

.actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

/* Share Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    max-width: 500px;
    width: 90%;
    transform: scale(0.9);
    transition: transform var(--transition-normal);
}

.modal-overlay.active .modal {
    transform: scale(1);
}

.modal h2 {
    margin-bottom: var(--spacing-md);
    color: var(--color-success);
}

.modal p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.share-link-container {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.share-link-input {
    flex: 1;
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text-primary);
    font-family: var(--font-mono);
    font-size: 0.875rem;
}

.expires-info {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-lg);
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 1001;
}

.toast {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-top: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    animation: slideIn var(--transition-normal);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.toast.success {
    border-color: var(--color-success);
}

.toast.error {
    border-color: var(--color-danger);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }

    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Loading Spinner */
.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--color-border-default);
    border-top-color: var(--color-accent-blue);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* View Page Specific */
.view-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.view-meta {
    display: flex;
    gap: var(--spacing-lg);
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

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

.view-actions {
    display: flex;
    gap: var(--spacing-sm);
}

/* Line-numbered content for comments */
.line-numbered-content {
    counter-reset: line;
}

.code-line {
    display: flex;
    align-items: flex-start;
    padding: var(--spacing-xs) 0;
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-fast);
    position: relative;
}

.code-line:hover {
    background-color: var(--color-bg-tertiary);
}

.line-number {
    min-width: 40px;
    padding-right: var(--spacing-md);
    text-align: right;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    cursor: pointer;
    user-select: none;
    transition: color var(--transition-fast);
}

.line-number:hover {
    color: var(--color-accent-blue);
}

.line-content {
    flex: 1;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    white-space: pre-wrap;
    word-break: break-word;
}

.code-line.has-comment {
    background-color: rgba(88, 166, 255, 0.1);
}

.code-line.has-comment .line-number {
    color: var(--color-accent-blue);
}

/* Comments Sidebar */
.view-layout {
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: var(--spacing-lg);
}

@media (max-width: 1024px) {
    .view-layout {
        grid-template-columns: 1fr;
    }
}

.comments-panel {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    height: fit-content;
    position: sticky;
    top: calc(60px + var(--spacing-lg));
}

.comments-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border-default);
}

.comments-header h3 {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.comment-count {
    background-color: var(--color-bg-tertiary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.comments-list {
    max-height: 400px;
    overflow-y: auto;
}

.comment-item {
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-muted);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.comment-meta {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.comment-line {
    color: var(--color-accent-blue);
    cursor: pointer;
}

.comment-line:hover {
    text-decoration: underline;
}

.comment-text {
    font-size: 0.875rem;
    line-height: 1.5;
}

.comments-empty {
    text-align: center;
    color: var(--color-text-muted);
    padding: var(--spacing-lg);
}

/* Comment Form */
.comment-form {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border-default);
}

.comment-form-header {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.comment-input {
    width: 100%;
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    color: var(--color-text-primary);
    font-size: 0.875rem;
    resize: vertical;
    min-height: 80px;
    margin-bottom: var(--spacing-sm);
}

.comment-input:focus {
    outline: none;
    border-color: var(--color-accent-blue);
}

.author-input {
    width: 100%;
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    color: var(--color-text-primary);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-sm);
}

.author-input:focus {
    outline: none;
    border-color: var(--color-accent-blue);
}

/* Not Found Page */
.not-found {
    text-align: center;
    padding: var(--spacing-2xl);
}

.not-found h1 {
    font-size: 4rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.not-found p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

/* Syntax Highlighting - GitHub Dark Theme */
.hljs {
    background: var(--color-bg-tertiary) !important;
    color: var(--color-text-primary) !important;
}

.hljs-keyword,
.hljs-selector-tag,
.hljs-literal,
.hljs-section,
.hljs-link {
    color: #ff7b72;
}

.hljs-string,
.hljs-title,
.hljs-name,
.hljs-type,
.hljs-attribute,
.hljs-symbol,
.hljs-bullet,
.hljs-addition,
.hljs-variable,
.hljs-template-tag,
.hljs-template-variable {
    color: #a5d6ff;
}

.hljs-comment,
.hljs-quote,
.hljs-deletion,
.hljs-meta {
    color: #8b949e;
}

.hljs-number {
    color: #79c0ff;
}

.hljs-function .hljs-title {
    color: #d2a8ff;
}

.hljs-built_in {
    color: #ffa657;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border-default);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-muted);
}

/* GitHub Link */
.github-link {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
    padding: var(--spacing-xs);
}

.github-link:hover {
    color: var(--color-text-primary);
}

/* Mobile View Optimizations */
@media (max-width: 768px) {
    .header {
        padding: var(--spacing-sm) var(--spacing-md);
    }

    .header-content {
        flex-wrap: wrap;
        gap: var(--spacing-sm);
    }

    .logo {
        font-size: 1.1rem;
    }

    .view-actions {
        flex-wrap: wrap;
        justify-content: flex-end;
    }

    .view-actions .btn {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.75rem;
    }

    .container {
        padding: var(--spacing-sm);
    }

    .view-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .view-meta {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .view-layout {
        grid-template-columns: 1fr;
    }

    .comments-panel {
        position: static;
        margin-top: var(--spacing-md);
    }

    .upload-panel {
        padding: var(--spacing-sm);
    }

    .line-number {
        min-width: 30px;
        padding-right: var(--spacing-sm);
        font-size: 0.7rem;
    }

    .line-content {
        font-size: 0.8rem;
    }

    .markdown-body h1 {
        font-size: 1.5rem;
    }

    .markdown-body h2 {
        font-size: 1.25rem;
    }

    .markdown-body h3 {
        font-size: 1.1rem;
    }

    .markdown-body pre {
        padding: var(--spacing-sm);
    }

    .markdown-body pre code {
        font-size: 0.8rem;
    }

    .comment-form {
        padding-top: var(--spacing-sm);
    }

    .actions {
        flex-direction: column;
    }

    .actions .btn {
        width: 100%;
    }

    .modal {
        padding: var(--spacing-md);
        margin: var(--spacing-sm);
    }

    .share-link-container {
        flex-direction: column;
    }

    .share-link-input {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .header-content {
        justify-content: center;
    }

    .user-stats {
        width: 100%;
        justify-content: center;
    }

    .view-actions {
        width: 100%;
        justify-content: center;
    }

    .code-line {
        padding: var(--spacing-xs) 0;
    }
}

/* Hidden utility */
.hidden {
    display: none !important;
}