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

body {
    --bg-primary: #1e1e1e;
    --bg-secondary: #252526;
    --bg-tertiary: #2d2d2d;
    --border-color: #333;
    --text-primary: #d4d4d4;
    --text-secondary: #6a6a6a;
    --accent-blue: #569cd6;
    --accent-teal: #4ec9b0;
    --accent-purple: #c586c0;
    --accent-yellow: #dcdcaa;
    --accent-orange: #ce9178;
    --accent-link: #4fc1ff;
    --accent-quote: #9cdcfe;
    --scrollbar-track: #1e1e1e;
    --scrollbar-thumb: #424242;
    --scrollbar-thumb-hover: #4e4e4e;

    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    height: 100vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

body.light-mode {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #e8e8e8;
    --border-color: #d0d0d0;
    --text-primary: #1e1e1e;
    --text-secondary: #6a6a6a;
    --accent-blue: #0066cc;
    --accent-teal: #008080;
    --accent-purple: #a31ea3;
    --accent-yellow: #795e26;
    --accent-orange: #a31515;
    --accent-link: #0066cc;
    --accent-quote: #005cc5;
    --scrollbar-track: #f5f5f5;
    --scrollbar-thumb: #c0c0c0;
    --scrollbar-thumb-hover: #a0a0a0;
}

.toolbar {
    background-color: var(--bg-secondary);
    padding: 10px;
    display: flex;
    gap: 10px;
    border-bottom: 1px solid var(--border-color);
    align-items: center;
}

.toolbar-spacer {
    flex: 1;
}

/* Help button and popup */
#help-btn {
    width: 28px;
    height: 28px;
    padding: 0;
    border-radius: 50%;
    font-weight: bold;
}

.help-popup {
    position: absolute;
    right: 10px;
    top: 45px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 10px 14px;
    font-size: 12px;
    line-height: 1.8;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.help-popup.hidden {
    display: none;
}

.help-popup kbd {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 3px;
    padding: 2px 6px;
    font-family: inherit;
    font-size: 11px;
    margin-right: 8px;
}

.help-popup hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 8px 0;
}

/* Save indicator */
.save-indicator {
    font-size: 12px;
    color: var(--text-secondary);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.save-indicator.visible {
    opacity: 1;
}

/* Tab bar styles */
.tab-bar {
    display: flex;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 0 10px;
    gap: 2px;
    align-items: flex-end;
    min-height: 36px;
    overflow-x: auto;
    scrollbar-width: none; /* Firefox */
}

.tab-bar::-webkit-scrollbar {
    display: none; /* Chrome, Safari */
}

.tab {
    display: flex;
    align-items: center;
    gap: 8px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-bottom: none;
    padding: 6px 12px;
    font-size: 13px;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 4px 4px 0 0;
    max-width: 180px;
    transition: all 0.15s;
}

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

.tab.active {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    border-bottom: 1px solid var(--bg-primary);
    margin-bottom: -1px;
}

.tab-name {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1;
    min-width: 0;
}

.tab-name-input {
    background: transparent;
    border: 1px solid var(--accent-blue);
    color: var(--text-primary);
    font-size: 13px;
    padding: 0 4px;
    width: 100%;
    outline: none;
    border-radius: 2px;
}

.tab-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 14px;
    cursor: pointer;
    padding: 0 2px;
    line-height: 1;
    border-radius: 3px;
}

.tab-close:hover {
    background-color: rgba(255, 0, 0, 0.3);
    color: var(--text-primary);
}

.tab.confirm-delete {
    background-color: rgba(220, 60, 60, 0.3);
    border-color: #dc3c3c;
}

.tab.confirm-delete .tab-close {
    background-color: #dc3c3c;
    color: white;
}

.tab.shake {
    animation: shake 0.3s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-4px); }
    75% { transform: translateX(4px); }
}

.new-tab-btn {
    background-color: transparent;
    border: 1px dashed var(--border-color);
    color: var(--text-secondary);
    padding: 6px 12px;
    font-size: 13px;
    cursor: pointer;
    border-radius: 4px 4px 0 0;
    transition: all 0.15s;
    margin-left: 4px;
}

.new-tab-btn:hover {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border-style: solid;
}

.container {
    flex: 1;
    background-color: var(--bg-primary);
    overflow: hidden;
}

.container.split-mode {
    display: flex;
    background-color: var(--bg-primary);
}

.resizer {
    width: 1px;
    background-color: var(--border-color);
    cursor: col-resize;
    flex-shrink: 0;
    transition: all 0.15s;
}

.resizer:hover {
    width: 4px;
    background-color: var(--accent-blue);
}

.container.split-mode .input-section,
.container.split-mode .output-section {
    flex: 1;
    min-width: 100px;
}

.container.full-mode .input-section {
    display: none;
}

.container.full-mode .output-section {
    display: block;
}

.input-section {
    background-color: var(--bg-primary);
    overflow: hidden;
    height: 100%;
}

.output-section {
    background-color: var(--bg-primary);
    overflow-y: auto;
    height: 100%;
}

#markdown-input {
    width: 100%;
    height: 100%;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border: none;
    padding: 20px;
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.6;
    resize: none;
    outline: none;
}

.toolbar button {
    background-color: var(--border-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
    border-radius: 3px;
}

.toolbar button:hover {
    background-color: var(--bg-tertiary);
}

.toolbar button.active {
    background-color: #0e639c;
    color: #ffffff;
    border-color: #0e639c;
}

.toolbar button.active:hover {
    background-color: #1177bb;
}

#markdown-input::placeholder {
    color: var(--text-secondary);
}

#markdown-output {
    padding: 20px;
    line-height: 1.6;
}

/* Markdown output styling */
#markdown-output h1 {
    color: var(--accent-blue);
    margin: 20px 0 10px 0;
    font-size: 2em;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 5px;
}

#markdown-output h2 {
    color: var(--accent-teal);
    margin: 18px 0 8px 0;
    font-size: 1.5em;
}

#markdown-output h3 {
    color: var(--accent-purple);
    margin: 16px 0 8px 0;
    font-size: 1.25em;
}

#markdown-output h4,
#markdown-output h5,
#markdown-output h6 {
    color: var(--accent-yellow);
    margin: 14px 0 6px 0;
}

#markdown-output p {
    margin: 10px 0;
}

#markdown-output code {
    background-color: var(--bg-tertiary);
    color: var(--accent-orange);
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 0.9em;
}

#markdown-output pre {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 15px;
    overflow-x: auto;
    margin: 10px 0;
}

#markdown-output pre code {
    background-color: transparent;
    padding: 0;
    color: var(--text-primary);
}

#markdown-output blockquote {
    border-left: 4px solid var(--accent-blue);
    padding-left: 15px;
    margin: 10px 0;
    color: var(--accent-quote);
    font-style: italic;
}

#markdown-output ul,
#markdown-output ol {
    margin: 10px 0;
    padding-left: 30px;
}

#markdown-output li {
    margin: 5px 0;
}

#markdown-output a {
    color: var(--accent-link);
    text-decoration: none;
}

#markdown-output a:hover {
    text-decoration: underline;
}

#markdown-output table {
    border-collapse: collapse;
    margin: 10px 0;
    width: 100%;
}

#markdown-output table th,
#markdown-output table td {
    border: 1px solid var(--border-color);
    padding: 8px 12px;
}

#markdown-output table th {
    background-color: var(--bg-tertiary);
    color: var(--accent-blue);
}

#markdown-output hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 20px 0;
}

#markdown-output img {
    max-width: 100%;
    height: auto;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 12px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 6px;
}

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