/* CSS Variables for theming and maintainability */
:root {
    /* Color palette - new professional scheme */
    --bg-color: #0f172a;
    --bg-color-light: #1e293b;
    --bg-color-lighter: #334155;

    /* Primary colors */
    --primary-color: #3b82f6;
    --primary-light: #60a5fa;
    --primary-dark: #2563eb;

    /* Secondary colors */
    --secondary-color: #8b5cf6;
    --secondary-light: #a78bfa;
    --secondary-dark: #7c3aed;

    /* Tertiary/accent colors */
    --accent-color: #f97316;
    --accent-light: #fb923c;
    --accent-dark: #ea580c;

    /* UI Colors */
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #0ea5e9;

    /* RGBY Drawing colors - maintaining existing drawing colors */
    --red-color: #ef4444;
    --green-color: #10b981;
    --blue-color: #3b82f6;
    --yellow-color: #f59e0b;

    /* UI Elements */
    --text-color: #f1f5f9;
    --text-muted: #94a3b8;
    --border-color: rgba(255, 255, 255, 0.12);
    --glass-bg: rgba(15, 23, 42, 0.30);
    --glass-border: rgba(255, 255, 255, 0.10);
    --button-bg: rgba(30, 41, 59, 0.5);
    --button-hover: rgba(51, 65, 85, 0.8);

    /* Layout */
    --header-height: 70px;
    --active-color-border: 3px solid white;
    --border-radius-sm: 6px;
    --border-radius-md: 10px;
    --border-radius-lg: 16px;

    /* Effects */
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 6px 15px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.2);

    /* Animation */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --hover-lift: translateY(-2px);
    --active-scale: scale(0.98);
}

/* Reset and base styles */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
}

body {
    font-family: 'Inter', 'Segoe UI', 'Roboto', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    overflow: hidden;
    background-image:
        radial-gradient(circle at 15% 15%, rgba(139, 92, 246, 0.15) 0%, transparent 25%),
        radial-gradient(circle at 85% 25%, rgba(59, 130, 246, 0.12) 0%, transparent 30%),
        radial-gradient(circle at 50% 80%, rgba(249, 115, 22, 0.1) 0%, transparent 40%);
    background-size: 100% 100%;
    background-attachment: fixed;
    height: 100vh;
    width: 100vw;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Layout container */
.container {
    display: flex;
    flex-direction: column;
    width: 100%;
    height: 100vh;
    overflow: hidden;
}

/* Header styles */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    padding: 12px 20px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    background: var(--glass-bg);
    box-shadow: var(--shadow-md);
    z-index: 100;
    border-bottom: 1px solid var(--glass-border);
    transition: all var(--transition-normal);
}

.header-left,
.header-center,
.header-right {
    display: flex;
    align-items: center;
}

.header-left {
    font-size: 1.8rem; /* bigger */
    font-weight: 800;
    cursor: pointer;
    padding: 6px 12px;
    border-radius: var(--border-radius-md);
    color: #fff; /* white title */
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    letter-spacing: -0.5px;
    text-shadow: 0 2px 6px rgba(0, 0, 0, 0.25);
}

/* Full minimalist header: hide the brand label when in minimal mode */
/* Keep brand visible in minimal mode */
body.minimal .header-left { display: flex; }

.header-left:hover {
    transform: translateY(-1px);
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.header-center {
    display: flex;
    align-items: center;
    gap: 20px;
    flex-wrap: nowrap;
    justify-content: center;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* Button styles */
button {
    background: var(--button-bg);
    color: var(--text-color);
    border: 1px solid var(--glass-border);
    padding: 8px 14px;
    border-radius: var(--border-radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-weight: 500;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    box-shadow: var(--shadow-sm);
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    height: 40px;
    position: relative;
    overflow: hidden;
    vertical-align: middle;
}

button:hover {
    background: var(--button-hover);
    transform: var(--hover-lift);
    box-shadow: var(--shadow-md);
    border-color: rgba(255, 255, 255, 0.2);
}

button:hover::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0));
    pointer-events: none;
}

button:active {
    transform: var(--active-scale);
    box-shadow: var(--shadow-sm);
    transition: all 0.1s cubic-bezier(0.4, 0, 0.2, 1);
}

button.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

button i {
    font-size: 1.05em;
}

/* Whiteboard area */
#whiteboard {
    width: 100%;
    height: calc(100vh - var(--header-height));
    margin-top: var(--header-height);
    background-color: var(--bg-color-light);
    position: relative;
    overflow: hidden;
    box-shadow: 0 -5px 20px rgba(0, 0, 0, 0.2);
    touch-action: none;
}

#drawing-canvas {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    touch-action: none;
    cursor: crosshair;
    transform-origin: 0 0;
    will-change: transform;
}

/* Color and tool sections */
.color-section,
.toolbox {
    background: rgba(15, 23, 42, 0.6);
    border-radius: var(--border-radius-lg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.color-section {
    padding: 10px 16px;
}

.color-section:hover,
.toolbox:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-0.5px);
    border-color: rgba(255, 255, 255, 0.2);
}

.toolbox {
    padding: 10px 16px;
    display: flex;
    gap: 10px;
}

.color-buttons {
    display: flex;
    gap: 12px;
}

/* Color buttons */
.color-btn {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.2);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.color-btn::after {
    content: attr(data-shortcut);
    position: absolute;
    bottom: -20px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 10px;
    color: var(--text-muted);
    transition: all var(--transition-normal);
    opacity: 0;
}

.color-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3), 0 0 0 4px rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.4);
}

.color-btn:hover::after {
    opacity: 1;
    bottom: -16px;
}

.color-btn:active {
    transform: var(--active-scale);
    transition: all 0.1s cubic-bezier(0.4, 0, 0.2, 1);
}

.color-btn.active {
    border: var(--active-color-border);
    transform: scale(1.15);
    box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.2), 0 0 10px rgba(255, 255, 255, 0.1);
    animation: subtle-pulse 2s infinite ease-in-out;
}

@keyframes subtle-pulse {
    0% { box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.2), 0 0 0px rgba(255, 255, 255, 0.1); }
    50% { box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.25), 0 0 15px rgba(255, 255, 255, 0.25); }
    100% { box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.2), 0 0 0px rgba(255, 255, 255, 0.1); }
}

.color-btn.red { background-color: var(--red-color); }
.color-btn.green { background-color: var(--green-color); }
.color-btn.blue { background-color: var(--blue-color); }
.color-btn.yellow { background-color: var(--yellow-color); }

/* Tool containers & dropdowns */
.tool-container {
    position: relative;
}

.pen-size-dropdown,
.eraser-size-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-md);
    padding: 8px 0;
    width: 120px;
    display: none;
    flex-direction: column;
    z-index: 100;
    box-shadow: var(--shadow-lg);
    margin-top: 8px;
    max-height: 300px;
    overflow-y: auto;
}

.pen-size-dropdown.show,
.eraser-size-dropdown.show {
    display: flex;
}

.pen-size-dropdown::before,
.eraser-size-dropdown::before {
    content: '';
    position: absolute;
    top: -8px;
    left: 20px;
    width: 0;
    height: 0;
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-bottom: 8px solid var(--glass-bg);
}

.pen-size-option,
.eraser-size-option {
    padding: 8px 15px;
    cursor: pointer;
    transition: all var(--transition-fast);
    border-left: 3px solid transparent;
}

.pen-size-option:hover,
.eraser-size-option:hover {
    background-color: var(--bg-color-lighter);
    border-left: 3px solid var(--primary-light);
    padding-left: 18px;
}

.pen-size-option.active,
.eraser-size-option.active {
    background-color: rgba(59, 130, 246, 0.2);
    color: var(--primary-light);
    font-weight: 500;
    border-left: 3px solid var(--primary-color);
}

/* Tooltip */
.tooltip {
    position: absolute;
    background: var(--glass-bg);
    color: var(--text-color);
    padding: 6px 10px;
    border-radius: var(--border-radius-md);
    font-size: 12px;
    z-index: 1000;
    pointer-events: none;
    opacity: 0;
    transition: opacity var(--transition-normal), transform var(--transition-normal);
    white-space: nowrap;
    max-width: 250px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--glass-border);
    transform: translateY(5px);
}

.tooltip.visible {
    opacity: 1;
    transform: translateY(0);
}

.tooltip::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 50%;
    transform: translateX(-50%);
    border-width: 5px 5px 0;
    border-style: solid;
    border-color: var(--glass-bg) transparent transparent;
}

/* Tool buttons */
.tool-btn {
    position: relative;
    display: flex;
    align-items: center;
    gap: 6px;
    min-width: 100px;
    justify-content: center;
}

.tool-btn.active {
    background: rgba(59, 130, 246, 0.2);
    border-color: var(--primary-color);
    color: #fff;
    font-weight: 500;
    box-shadow: 0 0 0 1px var(--primary-color), inset 0 0 0 1px rgba(255, 255, 255, 0.1);
}

.tool-btn.active::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.2), rgba(139, 92, 246, 0.1));
    pointer-events: none;
    border-radius: var(--border-radius-md);
    z-index: -1;
}

.tool-btn .size-indicator {
    font-size: 0.8em;
    opacity: 0.8;
    background: rgba(0, 0, 0, 0.2);
    padding: 2px 4px;
    border-radius: var(--border-radius-sm);
    margin-left: 4px;
}

/* Size visualizer */
.size-visualizer {
    position: absolute;
    border: 2px solid rgba(255, 255, 255, 0.7);
    border-radius: 50%;
    pointer-events: none;
    z-index: 10;
    opacity: 0;
    transition: opacity var(--transition-normal), transform var(--transition-normal);
    will-change: transform;
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.3);
}

.size-visualizer.visible {
    opacity: 1;
    animation: fade-pulse 1.5s infinite alternate ease-in-out;
}

@keyframes fade-pulse {
    0% { box-shadow: 0 0 0px rgba(255, 255, 255, 0.15); }
    100% { box-shadow: 0 0 15px rgba(255, 255, 255, 0.3); }
}

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

::-webkit-scrollbar-track {
    background: var(--bg-color);
    border-radius: 8px;
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    border: 2px solid transparent;
    background-clip: padding-box;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
    background-clip: padding-box;
}

/* Export button */
#exportBtn {
    position: relative;
    overflow: hidden;
    background: linear-gradient(45deg, rgba(59, 130, 246, 0.2), rgba(139, 92, 246, 0.2));
}

#exportBtn:hover {
    background: linear-gradient(45deg, rgba(59, 130, 246, 0.3), rgba(139, 92, 246, 0.3));
}

#exportBtn:hover::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: -100%;
    background: linear-gradient(90deg,
        rgba(255, 255, 255, 0),
        rgba(255, 255, 255, 0.2),
        rgba(255, 255, 255, 0));
    animation: shine 1.5s ease-in-out;
}

@keyframes shine {
    to {
        left: 100%;
    }
}

#clearBtn {
    color: var(--text-color);
    border-color: rgba(239, 68, 68, 0.3);
}

#clearBtn:hover {
    background: rgba(239, 68, 68, 0.15);
    border-color: rgba(239, 68, 68, 0.5);
}

#helpBtn {
    min-width: auto;
    width: 40px;
    justify-content: center;
}

/* Context menu */
.context-menu {
    position: fixed;
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 160px;
    max-width: 240px;
    border: 1px solid var(--glass-border);
    display: none;
    padding: 6px 0;
    overflow: hidden;
}

.context-menu.visible {
    display: block;
}

.context-menu-item {
    padding: 8px 16px;
    cursor: pointer;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all var(--transition-fast);
    border-left: 3px solid transparent;
}

.context-menu-item:hover {
    background-color: var(--bg-color-lighter);
    border-left: 3px solid var(--primary-light);
    padding-left: 19px;
}

.context-menu-item i {
    width: 16px;
    text-align: center;
    color: var(--text-muted);
}

.context-menu-separator {
    height: 1px;
    background-color: var(--glass-border);
    margin: 6px 0;
}

/* Help panel */
.help-panel {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.95);
    width: 400px;
    max-width: 90vw;
    max-height: 80vh;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    z-index: 200;
    padding: 25px;
    transition: all var(--transition-slow);
    box-shadow: var(--shadow-lg);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
}

.help-panel.show {
    opacity: 1;
    visibility: visible;
    transform: translate(-50%, -50%) scale(1);
}

.help-panel h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--text-color);
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 10px;
    display: flex;
    align-items: center;
    font-weight: 600;
}

.shortcut-list {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 10px 16px;
}

.shortcut-key {
    background: var(--bg-color-light);
    padding: 4px 8px;
    border-radius: var(--border-radius-sm);
    font-family: monospace;
    font-size: 0.9rem;
    border: 1px solid var(--glass-border);
    text-align: center;
}

.shortcut-desc {
    font-size: 0.9rem;
}

.help-close {
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    color: var(--text-color);
    font-size: 1.2rem;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    padding: 0;
    border-radius: 50%;
    transition: all var(--transition-fast);
    box-shadow: none;
}

.help-close:hover {
    background: var(--bg-color-lighter);
    transform: rotate(90deg);
}

/* Toast notifications */
.toast-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 10px;
    max-width: 320px;
}

.toast {
    background: var(--glass-bg);
    color: var(--text-color);
    border-radius: var(--border-radius-md);
    padding: 12px 16px;
    box-shadow: var(--shadow-md);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1), transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    border-left: 4px solid var(--primary-color);
    font-size: 0.9rem;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    max-width: 100%;
    overflow: hidden;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

.toast::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    height: 2px;
    width: 100%;
    background: linear-gradient(90deg,
        var(--primary-light),
        var(--secondary-light));
    animation: toast-timer 5s linear forwards;
    transform-origin: left;
}

@keyframes toast-timer {
    from { transform: scaleX(1); }
    to { transform: scaleX(0); }
}

.toast.success { border-left-color: var(--success-color); }
.toast.error { border-left-color: var(--error-color); }
.toast.info { border-left-color: var(--info-color); }
.toast.hint { border-left-color: var(--warning-color); }

/* Canvas overlay for panning */
.canvas-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 5;
    pointer-events: none;
    cursor: grab;
    background-color: transparent;
}

.canvas-overlay.panning {
    cursor: grabbing;
    pointer-events: all;
}

/* Feature button styles */
.feature-btn {
    background: rgba(255, 255, 255, 0.07);
    color: var(--text-color);
    border: 1px solid var(--glass-border);
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: all var(--transition-normal);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 6px;
}

.feature-btn.active {
    background: rgba(56, 189, 248, 0.2);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeOut {
    from { opacity: 1; }
    to { opacity: 0; }
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

/* Media Queries */
@media (max-width: 768px) {
    header {
        padding: 10px;
        height: auto;
        min-height: var(--header-height);
        flex-direction: column;
        gap: 10px;
    }

    .header-left, .header-center, .header-right {
        width: 100%;
        justify-content: center;
        margin-bottom: 5px;
    }

    #whiteboard {
        height: calc(100vh - 150px);
        margin-top: 150px;
    }

    .toolbox, .color-section {
        width: 100%;
        justify-content: center;
    }

    .help-panel {
        width: 90vw;
        max-height: 70vh;
        top: 50%;
        left: 50%;
    }
}

@media (max-width: 480px) {
    .header-center {
        flex-direction: column;
        gap: 8px;
    }

    .color-section, .toolbox {
        width: 100%;
    }

    #whiteboard {
        height: calc(100vh - 200px);
        margin-top: 200px;
    }

    .toast-container {
        left: 10px;
        right: 10px;
        transform: none;
        max-width: none;
    }

    .help-panel {
        padding: 15px;
    }

    .shortcut-list {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .shortcut-key {
        margin-bottom: 4px;
    }
}

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

.position-relative {
    position: relative;
}

.backdrop-blur {
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

/* Loading overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-color);
    background-image: linear-gradient(135deg,
        rgba(59, 130, 246, 0.05) 25%,
        transparent 25%,
        transparent 50%,
        rgba(59, 130, 246, 0.05) 50%,
        rgba(59, 130, 246, 0.05) 75%,
        transparent 75%,
        transparent);
    background-size: 20px 20px;
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}

/* Modal backdrop */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
    z-index: 199;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}

.modal-backdrop.show {
    opacity: 1;
    visibility: visible;
}

.loading-overlay.visible {
    opacity: 1;
    visibility: visible;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top: 4px solid var(--primary-color);
    border-right: 4px solid var(--secondary-color);
    border-bottom: 4px solid var(--accent-color);
    animation: spin 1.2s cubic-bezier(0.5, 0.1, 0.5, 0.9) infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Print styles */
@media print {
    body * {
        visibility: hidden;
    }

    #drawing-canvas,
    #drawing-canvas * {
        visibility: visible;
    }

    #drawing-canvas {
        position: absolute;
        left: 0;
        top: 0;
        width: 100%;
        height: 100%;
    }
}

/* Enhanced animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeOut {
    from { opacity: 1; }
    to { opacity: 0; }
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}


/* Minimalist theme overrides */
body.minimal {
    background-image: none;
}

body.minimal header {
    height: 56px;
    padding: 8px 12px;
    background: var(--glass-bg);
    border-bottom: 1px solid var(--glass-border);
    box-shadow: var(--shadow-sm);
}

body.minimal .header-left {
    font-size: 1.4rem; /* slightly bigger in minimal mode too */
    text-shadow: none;
    color: #fff;
}

body.minimal .header-center { gap: 12px; }
body.minimal .header-right { gap: 8px; }

body.minimal .color-section,
body.minimal .toolbox {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-sm);
    padding: 6px 10px;
}

/* Icon-only controls */
body.minimal button {
    width: 40px;
    height: 40px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0;
    line-height: 0; /* ensure no extra inline height */
    font-size: 0; /* hide text labels */
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.08);
}
body.minimal button i {
    font-size: 18px;
    line-height: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    margin: 0;
}
body.minimal #helpBtn { width: 40px; }

/* Show compact size indicator badges in minimal mode */
body.minimal .tool-btn { position: relative; }
body.minimal .tool-btn .size-indicator {
  display: inline-flex;
  position: absolute;
  top: 2px;
  right: 4px;
  font-size: 10px;
  line-height: 1;
  padding: 1px 3px;
  border-radius: 6px;
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.2);
  color: var(--text-color);
  font-weight: 600;
  letter-spacing: -0.2px;
}

/* Tweak color swatches spacing */
body.minimal .color-buttons { gap: 10px; }
body.minimal .color-btn { box-shadow: none; border-color: rgba(255,255,255,0.18); }
body.minimal .color-btn.active { transform: scale(1.1); animation: none; }

/* Reduce chrome on canvas area */
body.minimal #whiteboard {
    /* Match canvas fill to ensure eraser reveals same shade */
    background-color: var(--bg-color-light);
    box-shadow: none;
}

/* Subtle hover without lifts */
body.minimal button:hover {
    transform: none;
    background: rgba(255,255,255,0.1);
}

/* Dropdowns remain usable but cleaner */
body.minimal .pen-size-dropdown,
body.minimal .eraser-size-dropdown {
    background: rgba(15, 23, 42, 0.9);
    border-color: rgba(255,255,255,0.08);
    box-shadow: var(--shadow-sm);
}

/* Toasts quieter */
body.minimal .toast { border-left-width: 2px; box-shadow: var(--shadow-sm); }

/* Overlay and helpers remain subtle */
body.minimal .size-visualizer { box-shadow: none; border-width: 1px; }

/* Add elegant hover effect for all clickable elements */
.tool-btn:hover, .feature-btn:hover {
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2), 0 0 0 1px rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}