/* ========================================
   Design System & CSS Variables
   ======================================== */
:root {
    /* Color Palette */
    --color-bg-primary: #0a0e1a;
    --color-bg-secondary: #131824;
    --color-bg-tertiary: #1a2030;
    --color-bg-glass: rgba(26, 32, 48, 0.7);

    --color-accent-primary: #3b82f6;
    --color-accent-secondary: #2563eb;
    --color-accent-gradient: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);

    --color-text-primary: #e2e8f0;
    --color-text-secondary: #94a3b8;
    --color-text-tertiary: #64748b;

    --color-border: rgba(148, 163, 184, 0.1);
    --color-border-hover: rgba(148, 163, 184, 0.2);

    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;

    /* Typography */
    --font-family-base: "Kosugi Maru", Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-family-mono: 'JetBrains Mono', 'Courier New', monospace;

    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.3);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Layout Dimensions */
    --header-height: 72px;
    --toolbar-height: 56px;
    --statusbar-height: 32px;
    --sidebar-width: 280px;
}

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

body {
    font-family: var(--font-family-base);
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow: hidden;
    transition: background var(--transition-base), color var(--transition-base);
}

/* Light Theme */
[data-theme="light"] {
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8fafc;
    --color-bg-tertiary: #f1f5f9;
    --color-bg-glass: rgba(248, 250, 252, 0.8);

    --color-text-primary: #0f172a;
    --color-text-secondary: #475569;
    --color-text-tertiary: #94a3b8;

    --color-border: rgba(15, 23, 42, 0.1);
    --color-border-hover: rgba(15, 23, 42, 0.2);

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.2);
}

/* ========================================
   Layout
   ======================================== */
.container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    width: 100vw;
    padding-top: var(--header-height);
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    height: calc(100vh - var(--header-height) - var(--statusbar-height));
    /* Full height minus header and status bar */
}

/* ========================================
   Header
   ======================================== */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--header-height);
    padding: 0 var(--spacing-lg);
    background: var(--color-bg-glass);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 200;
    width: 100%;
    position: fixed;
    top: 0;
    left: 0;
    margin: 0;
    transition: none;
}

/* Header is now stable, no need for sidebar.hidden sibling rules */

.header-left,
.header-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.search-container {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs) var(--spacing-md);
    transition: all var(--transition-fast);
    max-width: 250px;
}

.search-container:focus-within {
    border-color: var(--color-accent-primary);
    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.1);
}

.search-icon {
    color: var(--color-text-tertiary);
    flex-shrink: 0;
    margin-right: var(--spacing-xs);
}

.search-input {
    flex: 1;
    border: none;
    background: transparent;
    color: var(--color-text-primary);
    font-size: var(--font-size-sm);
    outline: none;
    min-width: 150px;
}

.search-input::placeholder {
    color: var(--color-text-tertiary);
}

.search-clear {
    display: none;
    padding: var(--spacing-xs);
    background: transparent;
    border: none;
    color: var(--color-text-tertiary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.search-clear:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text-primary);
}

.search-container:has(.search-input:not(:placeholder-shown)) .search-clear {
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-lg);
    font-weight: 600;
    background: var(--color-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo svg {
    color: var(--color-accent-primary);
}

/* ========================================
   Buttons
   ======================================== */
.btn-icon,
.btn-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: none;
    border-radius: var(--radius-md);
    background: transparent;
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
}

.btn-icon:hover,
.btn-toggle:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text-primary);
    transform: translateY(-1px);
}

.btn-icon:active,
.btn-toggle:active {
    transform: translateY(0);
}

.btn-toggle.active {
    background: var(--color-accent-gradient);
    color: white;
    box-shadow: var(--shadow-glow);
}

/* ========================================
   Toolbar
   ======================================== */
.toolbar {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    height: var(--toolbar-height);
    padding: 0 var(--spacing-lg);
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
    flex-wrap: nowrap;
    overflow: visible;
    position: relative;
    z-index: 50;
    /* Above main-content but below sidebar/header */
    width: calc(100% - var(--sidebar-width));
    margin-left: var(--sidebar-width);
    transition: margin-left var(--transition-base), width var(--transition-base);
    /* Smooth transition */
}

.sidebar.hidden~.toolbar {
    width: 100%;
    margin-left: 0;
}

.color-picker-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

#colorPicker {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
    pointer-events: none;
}

#colorIndicator {
    transition: fill var(--transition-fast);
}

.toolbar::-webkit-scrollbar {
    height: 4px;
}

.toolbar::-webkit-scrollbar-track {
    background: transparent;
}

.toolbar::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 2px;
}

.toolbar-group {
    display: flex;
    gap: var(--spacing-xs);
    align-items: center;
}

/* Color Palette */
.color-palette-container {
    position: relative;
    display: flex;
    align-items: center;
}

.color-palette {
    position: absolute;
    top: 100%;
    left: 0;
    margin-top: var(--spacing-xs);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--spacing-xs);
    box-shadow: var(--shadow-lg);
    z-index: 100;
    min-width: 160px;
}

.color-palette.hidden {
    display: none;
}

.color-swatch {
    width: 24px;
    height: 24px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    border: 1px solid var(--color-border);
    transition: transform var(--transition-fast);
}

.color-swatch:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-sm);
    border-color: var(--color-text-primary);
}

/* Font Size Menu */
.font-size-menu {
    position: absolute;
    top: 100%;
    left: 0;
    margin-top: var(--spacing-xs);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    box-shadow: var(--shadow-lg);
    z-index: 100;
    min-width: 80px;
}

.font-size-menu.hidden {
    display: none;
}

.font-size-item {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: var(--spacing-sm);
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.font-size-item:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-accent-primary);
}


.toolbar-divider {
    width: 1px;
    height: 24px;
    background: var(--color-border);
    margin: 0 var(--spacing-sm);
}



.toolbar-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 36px;
    padding: 0 var(--spacing-sm);
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.toolbar-btn:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-accent-primary);
    transform: translateY(-1px);
}

.toolbar-btn:active {
    transform: translateY(0);
}

/* ========================================
   Editor Container
   ======================================== */
.editor-container {
    display: flex;
    flex: 1;
    width: calc(100% - var(--sidebar-width));
    overflow: hidden;
    background: var(--color-bg-secondary);
    margin-left: var(--sidebar-width);
    transition: margin-left var(--transition-base), width var(--transition-base);
    /* Smooth transition */
}

.sidebar.hidden~.main-content .editor-container {
    width: 100%;
    margin-left: 0;
}

.editor-container.editor-hidden .editor-wrapper {
    width: 0;
    border-left: none;
}

.editor-wrapper {
    width: 0;
    flex: none;
    display: flex;
    flex-direction: row;
    /* Ensure line numbers and editor are side-by-side */
    background: var(--color-bg-secondary);
    overflow: hidden;
    transition: width var(--transition-base);
    border-left: 1px solid var(--color-border);
    position: relative;
}

.editor-wrapper.visible {
    width: 50%;
}

.preview-panel {
    flex: 1;
    display: flex;
    flex-direction: row;
    /* Keep line numbers and preview side-by-side */
    background: var(--color-bg-secondary);
    overflow: hidden;
}

.preview-panel.hidden {
    display: none;
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-bg-tertiary);
    border-bottom: 1px solid var(--color-border);
}

.panel-title {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.char-count {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    font-family: var(--font-family-mono);
}

/* ========================================
   Editor Textarea
   ======================================== */
/* Consolidated with definition above */

.line-numbers {
    padding: var(--spacing-lg) var(--spacing-sm);
    background: var(--color-bg-tertiary);
    color: var(--color-text-tertiary);
    font-family: var(--font-family-mono);
    font-size: var(--font-size-base);
    line-height: 1.8;
    text-align: right;
    user-select: none;
    overflow-y: hidden;
    border-right: 1px solid var(--color-border);
    min-width: 50px;
    height: 100%;
}

.line-numbers span {
    display: block;
    counter-increment: line;
}

.line-numbers span::before {
    content: counter(line);
}

.editor-textarea {
    flex: 1;
    padding: var(--spacing-lg);
    border: none;
    outline: none;
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    font-family: var(--font-family-mono);
    font-size: var(--font-size-base);
    line-height: 1.8;
    resize: none;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) transparent;
}

.editor-textarea::-webkit-scrollbar {
    width: 8px;
}

.editor-textarea::-webkit-scrollbar-track {
    background: transparent;
}

.editor-textarea::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 4px;
}

.editor-textarea::-webkit-scrollbar-thumb:hover {
    background: var(--color-border-hover);
}

.editor-textarea::placeholder {
    color: var(--color-text-tertiary);
}

/* ========================================
   Preview Content
   ======================================== */
.preview-content {
    flex: 1;
    padding: var(--spacing-lg);
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) transparent;
}

.preview-content::-webkit-scrollbar {
    width: 8px;
}

.preview-content::-webkit-scrollbar-track {
    background: transparent;
}

.preview-content::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 4px;
}

.preview-content::-webkit-scrollbar-thumb:hover {
    background: var(--color-border-hover);
}

/* Markdown Preview Styles */
.preview-content h1,
.preview-content h2,
.preview-content h3,
.preview-content h4,
.preview-content h5,
.preview-content h6 {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    line-height: 1.3;
    color: var(--color-text-primary);
}

.preview-content h1 {
    font-size: 2.5rem;
    border-bottom: 2px solid var(--color-border);
    padding-bottom: var(--spacing-sm);
}

.preview-content h2 {
    font-size: 2rem;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: var(--spacing-xs);
}

.preview-content h3 {
    font-size: 1.75rem;
}

.preview-content h4 {
    font-size: 1.5rem;
}

.preview-content h5 {
    font-size: 1.25rem;
}

.preview-content h6 {
    font-size: 1.125rem;
}

.preview-content p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.preview-content a {
    color: var(--color-accent-primary);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition-fast);
}

.preview-content a:hover {
    border-bottom-color: var(--color-accent-primary);
}

.preview-content ul,
.preview-content ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-xl);
}

.preview-content li {
    margin-bottom: var(--spacing-xs);
}

.preview-content blockquote {
    margin: var(--spacing-md) 0;
    padding: var(--spacing-md) var(--spacing-lg);
    border-left: 4px solid var(--color-accent-primary);
    background: var(--color-bg-tertiary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-style: italic;
}

.preview-content code {
    padding: 0.2em 0.4em;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-sm);
    font-family: var(--font-family-mono);
    font-size: 0.9em;
    color: var(--color-accent-secondary);
}

.preview-content pre {
    margin: var(--spacing-md) 0;
    padding: var(--spacing-lg);
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    overflow-x: auto;
    border: 1px solid var(--color-border);
}

.preview-content pre code {
    padding: 0;
    background: transparent;
    color: inherit;
    font-size: 0.9rem;
}

.preview-content table {
    width: 100%;
    margin: var(--spacing-md) 0;
    border-collapse: collapse;
    border-radius: var(--radius-md);
    overflow: hidden;
}

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

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



/* Spreadsheet-like cell focus indicator */
.preview-content td[contenteditable="true"]:focus {
    outline: 2px solid var(--color-accent-primary);
    outline-offset: -2px;
    background-color: rgba(99, 102, 241, 0.05);
}


.preview-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    margin: var(--spacing-md) 0;
}

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

/* ========================================
   Status Bar
   ======================================== */
.status-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-lg);
    background: var(--color-bg-tertiary);
    border-top: 1px solid var(--color-border);
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

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

#autoSaveStatus {
    color: var(--color-success);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 768px) {
    .editor-container {
        grid-template-columns: 1fr;
    }

    .preview-panel {
        display: none;
    }

    .preview-panel.mobile-visible {
        display: flex;
    }

    .editor-panel.mobile-hidden {
        display: none;
    }

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

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

    .logo {
        font-size: var(--font-size-base);
    }
}

/* ========================================
   Animations
   ======================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

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

.preview-content>* {
    animation: fadeIn var(--transition-base) ease-out;
}

/* ========================================
   Utility Classes
   ======================================== */
.hidden {
    display: none !important;
}

.kosugi-maru-regular {
    font-family: "Kosugi Maru", sans-serif;
    font-weight: 400;
    font-style: normal;
}

/* ========================================
   Print Styles
   ======================================== */
@media print {

    /* Hide UI elements */
    .header,
    .toolbar,
    .status-bar,
    .editor-panel,
    .panel-header {
        display: none !important;
    }

    /* Show only preview content */
    .container {
        height: auto;
        overflow: visible;
    }

    .editor-container {
        display: block;
        overflow: visible;
    }

    .preview-panel {
        display: block !important;
        overflow: visible;
        background: white;
    }

    .preview-content {
        padding: 0;
        overflow: visible;
        color: #000;
    }

    /* Optimize text for print */
    .preview-content {
        font-size: 12pt;
        line-height: 1.5;
    }

    .preview-content h1 {
        font-size: 24pt;
    }

    .preview-content h2 {
        font-size: 20pt;
    }

    .preview-content h3 {
        font-size: 16pt;
    }

    .preview-content h4 {
        font-size: 14pt;
    }

    .preview-content h5 {
        font-size: 12pt;
    }

    .preview-content h6 {
        font-size: 12pt;
    }

    /* Ensure links show URLs */
    .preview-content a[href]:after {
        content: " (" attr(href) ")";
        font-size: 10pt;
        color: #666;
    }

    /* Page breaks */
    .preview-content h1,
    .preview-content h2,
    .preview-content h3 {
        page-break-after: avoid;
    }

    .preview-content pre,
    .preview-content blockquote,
    .preview-content table {
        page-break-inside: avoid;
    }

    /* Remove backgrounds and borders for print */
    .preview-content pre,
    .preview-content code,
    .preview-content blockquote {
        background: #f5f5f5 !important;
        border-color: #ddd !important;
    }
}

/* ========================================
   Settings Modal
   ======================================== */
.settings-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.settings-modal {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 500px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    animation: fadeIn var(--transition-base) cubic-bezier(0.16, 1, 0.3, 1);
}

.settings-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-bg-tertiary);
    border-bottom: 1px solid var(--color-border);
}

.settings-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text-primary);
}

.settings-content {
    padding: var(--spacing-lg);
}

.settings-group {
    margin-bottom: var(--spacing-lg);
}

.settings-label {
    display: block;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-secondary);
    font-weight: 600;
}

.settings-description {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-md);
}

.storage-option {
    display: flex;
    align-items: center;
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.storage-option:hover {
    background: var(--color-bg-tertiary);
    border-color: var(--color-accent-primary);
}

.storage-option.active {
    background: rgba(99, 102, 241, 0.1);
    border-color: var(--color-accent-primary);
}

.storage-option input[type="radio"] {
    margin-right: var(--spacing-md);
}

.storage-details {
    margin-left: var(--spacing-md);
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.folder-select-container {
    margin-top: var(--spacing-sm);
    padding-left: 2rem;
    display: none;
}

.storage-option.active+.folder-select-container,
.storage-option.active .folder-select-container {
    display: block;
}

.settings-footer {
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    background: var(--color-bg-tertiary);
}

.btn-primary {
    background: var(--color-accent-gradient);
    color: white;
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: opacity var(--transition-fast);
}

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

.btn-secondary {
    background: transparent;
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

/* Resizable Panes */
.resizer {
    width: 10px;
    /* Wider hit area */
    background-color: transparent;
    cursor: col-resize;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    margin: 0 -5px;
    /* Negative margin to center overlap if needed, or just 0 if in grid */
    position: relative;
}

/* The visible divider line */
.resizer::after {
    content: "";
    width: 1px;
    height: 100%;
    background-color: var(--color-border);
    transition: background-color var(--transition-fast);
}

.resizer:hover::after,
.resizer.active::after {
    background-color: var(--color-accent-primary);
    width: 2px;
    /* Slightly thicker on hover */
}

/* Drag and Drop Overlay */
.drop-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(99, 102, 241, 0.1);
    backdrop-filter: blur(4px);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    pointer-events: none;
    transition: all 0.2s ease;
    opacity: 0;
}

.drop-overlay:not(.hidden) {
    opacity: 1;
}

.drop-overlay-content {
    background-color: var(--color-bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 2px dashed var(--color-accent-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    color: var(--color-accent-primary);
    transform: translateY(20px);
    transition: transform 0.2s ease;
}

.drop-overlay:not(.hidden) .drop-overlay-content {
    transform: translateY(0);
}

.drop-overlay-content p {
    font-size: var(--font-size-lg);
    font-weight: 600;
}

.drop-overlay.hidden {
    display: none;
}

/* Image Modal Specifics */
.image-source-tabs .btn-secondary {
    flex: 1;
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-sm);
}

.image-source-tabs .btn-secondary.active {
    background: var(--color-bg-secondary);
    border-color: var(--color-accent-primary);
    color: var(--color-accent-primary);
}

#imageFileSelectBtn:hover {
    border-color: var(--color-accent-primary) !important;
    color: var(--color-accent-primary) !important;
    background: rgba(99, 102, 241, 0.05) !important;
}

/* Settings Grid Layout */
.settings-grid-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.settings-grid-buttons .btn-secondary {
    width: 100%;
    justify-content: center;
}

/* Sync Controls in Header */
.sync-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}
/* ========================================
   Spreadsheet Component
   ======================================== */
.spreadsheet-wrapper {
    margin: 20px 0;
    overflow: auto;
    background: #ffffff;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    min-height: 100px;
    color: #333333;
    border: 1px solid var(--color-border);
}

.spreadsheet-placeholder {
    padding: 30px;
    text-align: center;
    background: var(--color-bg-secondary);
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    margin: 10px 0;
}