/* CSS Variables for theming */
:root {
    /* Light theme (default) */
    --color-bg-body: #f5f6fa;
    --color-bg-container: white;
    --color-bg-panel: #f8f9fa;
    --color-bg-input: #fafafa;
    --color-bg-task: #fafafa;
    --color-bg-task-completed: #f0f8f0;
    --color-bg-level2: #f5f8ff;
    --color-bg-level3: #fdf5ff;
    --color-bg-controls: #f8f9fa;
    --color-bg-modal: rgb(0 0 0 / 50%);
    --color-bg-progress: #f0f0f0;
    --color-text-primary: #444;
    --color-text-secondary: #666;
    --color-text-header: #2c3e50;
    --color-text-subheader: #34495e;
    --color-text-muted: #7f8c8d;
    --color-text-completed: #666;
    --color-border-primary: #e0e0e0;
    --color-border-secondary: #ddd;
    --color-border-light: #f0f0f0;
    --color-accent-primary: #3498db;
    --color-accent-success: #27ae60;
    --color-accent-danger: #e74c3c;
    --color-accent-secondary: #95a5a6;
    --color-accent-level2: #3498db;
    --color-accent-level3: #9b59b6;
    --shadow-container: 0 2px 10px rgb(0 0 0 / 10%);
    --shadow-controls: 0 -2px 10px rgb(0 0 0 / 10%);
    --shadow-modal: 0 4px 20px rgb(0 0 0 / 15%);
}

/* Dark theme */
[data-theme="dark"] {
    --color-bg-body: #121212;
    --color-bg-container: #1e1e1e;
    --color-bg-panel: #2d2d2d;
    --color-bg-input: #2d2d2d;
    --color-bg-task: #2a2a2a;
    --color-bg-task-completed: #2d3a2d;
    --color-bg-level2: #2d3240;
    --color-bg-level3: #3d2d40;
    --color-bg-controls: #2d2d2d;
    --color-bg-modal: rgb(0 0 0 / 70%);
    --color-bg-progress: #404040;
    --color-text-primary: #e0e0e0;
    --color-text-secondary: #b0b0b0;
    --color-text-header: #fff;
    --color-text-subheader: #f0f0f0;
    --color-text-muted: #888;
    --color-text-completed: #999;
    --color-border-primary: #404040;
    --color-border-secondary: #505050;
    --color-border-light: #454545;
    --color-accent-primary: #4a9eff;
    --color-accent-level2: #4a9eff;
    --color-accent-level3: #b59bd6;
    --shadow-container: 0 2px 10px rgb(0 0 0 / 30%);
    --shadow-controls: 0 -2px 10px rgb(0 0 0 / 30%);
    --shadow-modal: 0 4px 20px rgb(0 0 0 / 50%);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--color-bg-body);
    min-height: 100vh;
    padding: 20px;
    transition: background-color 0.3s ease;
}

/* Common transitions for interactive elements */
.theme-toggle, .panel-header, .mode-btn, .btn, .task-item, .nav-link {
    transition: all 0.2s ease;
}

/* Layout */
.container {
    max-width: 1400px;
    margin: 0 auto;
    background: var(--color-bg-container);
    border-radius: 8px;
    box-shadow: var(--shadow-container);
    overflow: hidden;
    padding-bottom: 80px;
    transition: background-color 0.3s ease;
}

.header {
    background: #2c3e50;
    color: white;
    padding: 20px 30px;
    text-align: center;
}

.nav {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid rgb(255 255 255 / 20%);
}

.nav-link {
    color: rgb(255 255 255 / 80%);
    text-decoration: none;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 4px;
}

.nav-link:hover { color: white; background: rgb(255 255 255 / 10%); }
.nav-link.active { color: white; background: rgb(255 255 255 / 15%); }

.header h1 { font-size: 1.8rem; margin-bottom: 5px; font-weight: 500; }
.header p { opacity: 0.9; font-size: 0.95rem; }

/* Theme toggle */
.theme-toggle {
    margin-left: auto;
    background: none;
    border: 1px solid rgb(255 255 255 / 30%);
    color: rgb(255 255 255 / 80%);
    padding: 6px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
}

.theme-toggle:hover { background: rgb(255 255 255 / 10%); color: white; }
.theme-toggle-icon { margin-right: 5px; }

/* Main content */
.main-content { display: flex; min-height: 70vh; }

.input-panel, .output-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.input-panel {
    border-right: 1px solid var(--color-border-primary);
    transition: all 0.3s ease;
}

.input-panel.minimized {
    flex: 0 0 50px;
    width: 50px;
}

.input-panel.minimized .textarea-container { display: none; }
.input-panel.minimized .mode-toggle { display: none; }

.input-panel.minimized .panel-header {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    padding: 20px 15px;
}
.input-panel.minimized .panel-title { transform: rotate(180deg); }
.input-panel.minimized .minimize-icon { transform: rotate(180deg); }

/* Panel headers */
.panel-header {
    background: var(--color-bg-panel);
    padding: 15px 20px;
    border-bottom: 1px solid var(--color-border-primary);
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
}

.panel-header:hover { background: #f0f0f0; }
[data-theme="dark"] .panel-header:hover { background: #3a3a3a; }

.panel-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-header);
    display: flex;
    align-items: center;
}

.minimize-icon {
    margin-left: 8px;
    font-size: 0.8em;
    color: var(--color-text-secondary);
    transition: transform 0.3s ease;
}

/* Mode toggle */
.mode-toggle {
    display: flex;
    background: var(--color-bg-container);
    border-radius: 6px;
    overflow: hidden;
    border: 1px solid var(--color-border-secondary);
}

.mode-btn {
    padding: 6px 12px;
    border: none;
    background: var(--color-bg-container);
    color: var(--color-text-secondary);
    cursor: pointer;
    font-size: 0.85rem;
}

.mode-btn.active { background: var(--color-accent-primary); color: white; }
.mode-btn:hover:not(.active) { background: var(--color-bg-panel); }

/* Input/Output areas */
.textarea-container { flex: 1; padding: 20px; }
.output-container { flex: 1; padding: 20px; overflow-y: auto; }

#markdownInput {
    width: 100%;
    height: 100%;
    border: 1px solid var(--color-border-secondary);
    border-radius: 6px;
    padding: 15px;
    font-family: Consolas, Monaco, monospace;
    font-size: 13px;
    line-height: 1.5;
    resize: none;
    background: var(--color-bg-input);
    color: var(--color-text-primary);
}

#markdownInput:focus {
    outline: none;
    border-color: var(--color-accent-primary);
    background: white;
}

[data-theme="dark"] #markdownInput:focus { background: #333; }

#output {
    background: var(--color-bg-container);
    border-radius: 6px;
    padding: 20px;
    min-height: 100%;
    border: 1px solid var(--color-border-light);
}

/* Markdown styling */
#output h1 {
    color: var(--color-text-header);
    border-bottom: 2px solid var(--color-accent-primary);
    padding-bottom: 8px;
    margin-bottom: 20px;
    font-size: 1.6rem;
}

#output h2 {
    color: var(--color-text-subheader);
    border-bottom: 1px solid var(--color-border-light);
    padding-bottom: 6px;
    margin: 25px 0 15px;
    font-size: 1.3rem;
}

#output h3 { color: var(--color-text-secondary); margin: 20px 0 10px; font-size: 1.1rem; }
#output h4 { color: var(--color-text-secondary); margin: 15px 0 8px; font-size: 1rem; }
#output p { margin-bottom: 15px; line-height: 1.7; color: var(--color-text-primary); }
#output ul, #output ol { margin: 15px 0; padding-left: 0; }
#output li { margin: 8px 0; line-height: 1.6; color: var(--color-text-secondary); }

/* Collapsible headers */
.collapsible-header {
    cursor: pointer;
    display: flex;
    align-items: center;
}

.collapsible-header:hover {
    background: var(--color-bg-panel);
    padding: 5px 10px;
    margin: -5px -10px;
    border-radius: 4px;
}

.collapse-icon {
    margin-right: 8px;
    font-size: 0.8em;
    color: var(--color-text-secondary);
    transition: transform 0.2s ease;
}

.collapsed .collapse-icon { transform: rotate(-90deg); }
.collapsible-content { overflow: hidden; transition: max-height 0.3s ease; }
.collapsed .collapsible-content { max-height: 0; }

/* Task items */
.custom-list { list-style: none; padding: 0; margin: 0; }

.task-item {
    display: flex;
    align-items: flex-start;
    margin: 8px 0;
    padding: 8px 12px;
    border-radius: 4px;
    background: var(--color-bg-task);
}

.task-item:hover { background: #f0f0f0; }
[data-theme="dark"] .task-item:hover { background: #333; }

.task-item.completed {
    background: var(--color-bg-task-completed);
    opacity: 0.8;
}

.task-item.completed .task-text {
    text-decoration: line-through;
    color: var(--color-text-completed);
}

.task-checkbox {
    width: 16px;
    height: 16px;
    margin-right: 10px;
    margin-top: 2px;
    cursor: pointer;
    accent-color: var(--color-accent-success);
}

.task-text {
    flex: 1;
    color: var(--color-text-primary);
    line-height: 1.5;
}

/* Task levels */
.task-item.level-1 { margin-left: 0; }

.task-item.level-2 {
    margin-left: 30px;
    background: var(--color-bg-level2);
    border-left: 3px solid var(--color-accent-level2);
}

.task-item.level-3 {
    margin-left: 60px;
    background: var(--color-bg-level3);
    border-left: 3px solid var(--color-accent-level3);
    font-size: 0.95em;
}

.task-item.level-2:hover { background: #e8f2ff; }
.task-item.level-3:hover { background: #f3e8ff; }
[data-theme="dark"] .task-item.level-2:hover { background: #353b4a; }
[data-theme="dark"] .task-item.level-3:hover { background: #4a3548; }

.task-item.level-2.completed,
.task-item.level-3.completed {
    background: var(--color-bg-task-completed);
    border-left-color: var(--color-accent-success);
}

/* Stats and progress */
.stats {
    background: var(--color-bg-panel);
    color: var(--color-text-secondary);
    padding: 12px 15px;
    border-radius: 4px;
    margin-bottom: 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--color-border-light);
}

.stat-item { text-align: center; }

.stat-number {
    font-size: 1.1rem;
    font-weight: 600;
    display: block;
    color: var(--color-text-header);
}
.stat-label { font-size: 0.8rem; color: var(--color-text-secondary); }

.progress-bar {
    background: var(--color-bg-progress);
    border-radius: 4px;
    height: 6px;
    margin: 15px 0;
    overflow: hidden;
}

.progress-fill {
    background: var(--color-accent-success);
    height: 100%;
    border-radius: 4px;
    transition: width 0.4s ease;
}

/* Controls */
.controls {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 15px 20px;
    background: var(--color-bg-controls);
    border-top: 1px solid var(--color-border-primary);
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
    box-shadow: var(--shadow-controls);
    z-index: 100;
}

/* Buttons */
.btn {
    padding: 8px 16px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 500;
    text-decoration: none;
    display: inline-block;
    font-size: 0.9rem;
}

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

.btn-primary:hover { background: #2980b9; }
.btn-secondary:hover { background: #7f8c8d; }
.btn-danger:hover { background: #c0392b; }
.btn-success:hover { background: #229954; }

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: var(--color-bg-modal);
}

.modal.show { display: flex; align-items: center; justify-content: center; }

.modal-content {
    background: var(--color-bg-container);
    padding: 0;
    border-radius: 8px;
    width: 90%;
    max-width: 700px;
    max-height: 80vh;
    box-shadow: var(--shadow-modal);
    display: flex;
    flex-direction: column;
}

.modal-header {
    background: #2c3e50;
    color: white;
    padding: 20px 30px;
    border-radius: 8px 8px 0 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title { font-size: 1.2rem; font-weight: 600; margin: 0; }

.close-btn {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
}

.close-btn:hover { background: rgb(255 255 255 / 10%); }

.modal-body {
    padding: 20px 30px;
    flex: 1;
    overflow-y: auto;
    color: var(--color-text-primary);
}

.modal-textarea {
    width: 100%;
    height: 300px;
    border: 1px solid var(--color-border-secondary);
    border-radius: 6px;
    padding: 15px;
    font-family: Consolas, Monaco, monospace;
    font-size: 13px;
    line-height: 1.5;
    resize: vertical;
    background: var(--color-bg-input);
    color: var(--color-text-primary);
}

.modal-textarea:focus {
    outline: none;
    border-color: var(--color-accent-primary);
    background: white;
}

[data-theme="dark"] .modal-textarea:focus { background: #333; }

.modal-footer {
    padding: 20px 30px;
    border-top: 1px solid var(--color-border-primary);
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

/* Syntax help */
.syntax-help {
    margin-top: 10px;
    border-top: 1px solid var(--color-border-primary);
    padding-top: 15px;
}

.syntax-toggle {
    display: flex;
    align-items: center;
    cursor: pointer;
    padding: 8px 0;
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    user-select: none;
}

.syntax-toggle:hover { color: var(--color-text-primary); }

.help-icon {
    background: var(--color-accent-primary);
    color: white;
    border-radius: 50%;
    width: 18px;
    height: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: bold;
    margin-right: 8px;
}

.help-text { flex: 1; font-weight: 500; }
.expand-icon { font-size: 0.7rem; transition: transform 0.2s ease; }
.syntax-toggle.expanded .expand-icon { transform: rotate(180deg); }

.syntax-content {
    padding: 15px 0 5px;
    border-top: 1px solid var(--color-border-light);
    margin-top: 10px;
}

.syntax-content h4 {
    margin: 0 0 12px;
    color: var(--color-text-header);
    font-size: 0.95rem;
}

.syntax-examples { margin-bottom: 12px; }

.syntax-level {
    display: flex;
    align-items: center;
    margin: 8px 0;
    justify-content: space-between;
    padding: 4px 0;
}

.syntax-level code {
    background: var(--color-bg-panel);
    padding: 6px 10px;
    border-radius: 4px;
    font-family: Consolas, Monaco, monospace;
    font-size: 0.85rem;
    color: var(--color-text-primary);
    flex: 1;
    margin-right: 12px;
}

.level-indicator {
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 12px;
    font-weight: 500;
    white-space: nowrap;
    min-width: 60px;
    text-align: center;
}

.level-1-indicator {
    background: var(--color-bg-task);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border-secondary);
}

.level-2-indicator {
    background: var(--color-bg-level2);
    color: var(--color-accent-level2);
    border: 1px solid var(--color-accent-level2);
}

.level-3-indicator {
    background: var(--color-bg-level3);
    color: var(--color-accent-level3);
    border: 1px solid var(--color-accent-level3);
}

.syntax-note {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin: 0;
    line-height: 1.4;
    padding: 8px 12px;
    background: var(--color-bg-level2);
    border-radius: 4px;
    border-left: 3px solid var(--color-accent-primary);
}

/* Footer */
.footer {
    background: var(--color-bg-panel);
    border-top: 1px solid var(--color-border-primary);
    padding: 20px;
    margin-top: 40px;
}

.footer-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.footer-content p {
    margin: 10px 0;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

.footer-content p:first-child {
    color: var(--color-text-secondary);
    font-weight: 500;
}

.footer a {
    color: var(--color-accent-primary);
    text-decoration: none;
}

.footer a:hover { text-decoration: underline; }

/* Empty state */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--color-text-muted);
}

.empty-state h3 {
    margin-bottom: 15px;
    color: #95a5a6;
}

.empty-state p { margin-bottom: 0; }

/* Mobile responsive */
@media (width <= 768px) {
    .main-content { flex-direction: column; }
    .input-panel { border-right: none; border-bottom: 1px solid var(--color-border-primary); }
    .input-panel.minimized { width: auto; flex: 0 0 auto; }
    .input-panel.minimized .panel-header { writing-mode: initial; text-orientation: initial; padding: 15px 20px; }
    .input-panel.minimized .panel-title { transform: none; }
    .controls { padding: 12px 15px; gap: 8px; }
    .btn { padding: 6px 12px; font-size: 0.85rem; }
    .footer-content p { font-size: 0.8rem; }
    .nav { gap: 15px; }
    .nav-link { padding: 6px 12px; font-size: 0.9rem; }
}

/* Table Styling - GitHub-inspired clean style */
.output-container table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: transparent;
    border: 1px solid #d1d9e0;
    border-radius: 6px;
    overflow: hidden;
}

.output-container table th {
    background: #f6f8fa;
    color: #24292f;
    padding: 12px 16px;
    text-align: left;
    font-weight: 600;
    border-bottom: 1px solid #d1d9e0;
    font-size: 14px;
}

.output-container table td {
    padding: 12px 16px;
    border-bottom: 1px solid #d1d9e0;
    vertical-align: top;
    font-size: 14px;
    color: #24292f;
}

.output-container table tr:last-child td {
    border-bottom: none;
}

.output-container table tr:hover {
    background: #f6f8fa;
}

/* Dark theme adjustments for tables */
[data-theme="dark"] .output-container table {
    border-color: #30363d;
}

[data-theme="dark"] .output-container table th {
    background: #21262d;
    color: #f0f6fc;
    border-bottom-color: #30363d;
}

[data-theme="dark"] .output-container table td {
    color: #f0f6fc;
    border-bottom-color: #30363d;
}

[data-theme="dark"] .output-container table tr:hover {
    background: #30363d;
}