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

:root {
    --bg-primary: #0d0d0d;
    --bg-secondary: #161616;
    --bg-tertiary: #252525;
    --text-primary: #e0e0e0;
    --text-secondary: #888888;
    --accent: #e94560;
    --accent-hover: #ff6b6b;
    --border: #2a2a2a;
    --success: #4ade80;
}

html, body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
}

.app-container {
    display: flex;
    height: 100%;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

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

.sidebar-header h1 {
    font-size: 1.2rem;
    font-weight: 600;
}

.btn-new {
    background: var(--accent);
    border: none;
    border-radius: 8px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: white;
    transition: background 0.2s;
}

.btn-new:hover {
    background: var(--accent-hover);
}

.note-list {
    flex: 1;
    overflow-y: auto;
    padding: 10px;
}

.note-item {
    padding: 12px 15px;
    border-radius: 8px;
    cursor: pointer;
    margin-bottom: 5px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.2s;
}

.note-item:hover {
    background: var(--bg-tertiary);
}

.note-item.active {
    background: var(--bg-tertiary);
    border-left: 3px solid var(--accent);
}

.note-info {
    flex: 1;
    min-width: 0;
}

.note-title {
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.note-date {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.btn-delete {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 5px;
    border-radius: 4px;
    transition: background 0.2s, color 0.2s;
}

.btn-delete:hover {
    color: var(--accent);
    background: rgba(233, 69, 96, 0.15);
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.mobile-header {
    display: none;
    padding: 10px 15px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    align-items: center;
    gap: 10px;
}

.btn-menu {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 5px;
}

.desktop-title {
    padding: 15px 20px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 15px;
}

.title-input {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.25rem;
    font-weight: 600;
    outline: none;
}

.title-input::placeholder {
    color: var(--text-secondary);
}

.btn-copy {
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 6px 10px;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.btn-copy:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.btn-copy.copied {
    border-color: var(--success);
    color: var(--success);
}

.save-status {
    font-size: 0.8rem;
    color: var(--success);
    white-space: nowrap;
}

.mobile-tabs {
    display: none;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
}

.tab-btn {
    flex: 1;
    padding: 12px;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.9rem;
    transition: color 0.2s, border-color 0.2s;
    border-bottom: 2px solid transparent;
}

.tab-btn.active {
    color: var(--text-primary);
    border-bottom-color: var(--accent);
}

/* Content Wrapper */
.content-wrapper {
    flex: 1;
    display: flex;
    overflow: hidden;
    min-height: 0;
}

.editor-pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border);
    min-height: 0;
    overflow: hidden;
}

.preview-pane {
    flex: 1;
    overflow-y: auto;
    background: var(--bg-primary);
    min-height: 0;
}

.preview-content {
    padding: 20px;
    line-height: 1.7;
}

/* CodeMirror Customization */
.CodeMirror {
    height: 100% !important;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
    font-size: 14px;
    background: var(--bg-primary) !important;
}

.CodeMirror-gutters {
    background: var(--bg-secondary) !important;
    border-right: 1px solid var(--border) !important;
}

/* Preview Styles */
.preview-content h1, .preview-content h2, .preview-content h3,
.preview-content h4, .preview-content h5, .preview-content h6 {
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    font-weight: 600;
    line-height: 1.3;
}

.preview-content h1 { font-size: 2em; border-bottom: 1px solid var(--border); padding-bottom: 0.3em; }
.preview-content h2 { font-size: 1.5em; border-bottom: 1px solid var(--border); padding-bottom: 0.3em; }
.preview-content h3 { font-size: 1.25em; }

.preview-content p {
    margin-bottom: 1em;
}

.preview-content code {
    background: var(--bg-secondary);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
    font-size: 0.9em;
}

.preview-content pre {
    background: var(--bg-secondary);
    padding: 16px;
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: 1em;
}

.preview-content pre code {
    background: none;
    padding: 0;
}

.preview-content blockquote {
    border-left: 4px solid var(--accent);
    padding-left: 16px;
    margin: 1em 0;
    color: var(--text-secondary);
}

.preview-content ul, .preview-content ol {
    margin-bottom: 1em;
    padding-left: 2em;
}

.preview-content li {
    margin-bottom: 0.25em;
}

.preview-content a {
    color: var(--accent);
    text-decoration: none;
}

.preview-content a:hover {
    text-decoration: underline;
}

.preview-content table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1em;
}

.preview-content th, .preview-content td {
    border: 1px solid var(--border);
    padding: 8px 12px;
    text-align: left;
}

.preview-content th {
    background: var(--bg-secondary);
}

.preview-content img {
    max-width: 100%;
    border-radius: 8px;
}

.preview-content hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 2em 0;
}

/* Mermaid */
.mermaid {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    margin: 1em 0;
    text-align: center;
}

/* Overlay */
.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
}

.overlay.show {
    display: block;
}

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

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

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

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

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -280px;
        top: 0;
        bottom: 0;
        z-index: 100;
        transition: left 0.3s ease;
    }

    .sidebar.open {
        left: 0;
    }

    .mobile-header {
        display: flex;
        flex-shrink: 0;
    }

    .desktop-title {
        display: none;
    }

    .mobile-tabs {
        display: flex;
        flex-shrink: 0;
    }

    .main-content {
        height: 100vh;
        height: 100dvh;
        display: flex;
        flex-direction: column;
        overflow: hidden;
    }

    .content-wrapper {
        flex: 1;
        min-height: 0;
        overflow: hidden;
        display: flex;
        flex-direction: column;
    }

    .editor-pane {
        border-right: none;
        flex: 1;
        min-height: 0;
        overflow: hidden;
        position: relative;
    }

    .editor-pane.hidden {
        display: none;
    }

    .editor-pane .CodeMirror {
        position: absolute !important;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        height: 100% !important;
    }

    .preview-pane {
        display: none;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
    }

    .preview-pane.show {
        display: flex;
        flex: 1;
        min-height: 0;
        flex-direction: column;
    }

    .preview-content {
        flex: 1;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
    }

    .CodeMirror-scroll {
        overflow-y: scroll !important;
        -webkit-overflow-scrolling: touch;
    }
}

/* Hint styles */
.CodeMirror-hints {
    background: var(--bg-secondary) !important;
    border: 1px solid var(--border) !important;
    border-radius: 8px !important;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3) !important;
}

.CodeMirror-hint {
    color: var(--text-primary) !important;
    padding: 6px 12px !important;
}

.CodeMirror-hint-active {
    background: var(--bg-tertiary) !important;
    color: var(--text-primary) !important;
}