:root {
    --primary-color: #2563eb;
    --bg-color: #f3f4f6;
    --surface-color: #ffffff;
    --text-color: #1f2937;
    --toolbar-bg: rgba(255, 255, 255, 0.95);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

* {
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html,
body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    user-select: none;
    -webkit-user-select: none;
    cursor: none;
    /* Hide default cursor to use custom one */
    overscroll-behavior: none;
    /* Prevent rubber banding */
}

/* Custom Cursor */
#cursor-circle {
    position: fixed;
    top: 0;
    left: 0;
    width: 20px;
    height: 20px;
    border: 1.5px solid rgba(0, 0, 0, 0.5);
    border-radius: 50%;
    pointer-events: none;
    transform: translate(-50%, -50%);
    z-index: 9999;
    display: none;
    /* Hidden until moved */
    transition: width 0.1s, height 0.1s;
}

/* --- UI Header --- */
header {
    height: 60px;
    background: var(--toolbar-bg);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    border-bottom: 1px solid #e5e7eb;
    z-index: 50;
    /* Restore cursor for UI elements */
    cursor: auto;
}

.header-title {
    font-weight: 600;
    font-size: 1.1rem;
}

.header-actions {
    display: flex;
    gap: 12px;
}

.icon-btn {
    background: none;
    border: none;
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.icon-btn:active {
    background: #e5e7eb;
}

.icon-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* --- Canvas Area --- */
#workspace {
    flex: 1;
    position: relative;
    overflow: auto;
    /* Allow scrolling if paper is big */
    display: flex;
    justify-content: center;
    align-items: center;
    background: #ccc;
    /* Darker bg to distinguish paper */
    touch-action: none;
    /* Let JS handle touches */
    padding: 0;
    cursor: none;
    /* Ensure cursor is hidden in workspace */
}

/* The Paper */
.paper-container {
    background: white;
    box-shadow: none;
    position: relative;
    margin: 0;
    /* Spacing from edges */
    min-width: 100%;
    min-height: 100%;
    transition: width 0.3s, height 0.3s;
}

canvas {
    display: block;
    cursor: none;
    /* Hide default here too */
}

/* --- Floating Toolbar (Bottom) --- */
.toolbar {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--toolbar-bg);
    backdrop-filter: blur(10px);
    padding: 10px 20px;
    border-radius: 99px;
    display: flex;
    gap: 16px;
    align-items: center;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.15);
    z-index: 100;
    width: 90%;
    max-width: 450px;
    justify-content: space-between;
    cursor: auto;
    /* Show pointer for tools */
}

/* Size Bar */
.size-bar {
    position: fixed;
    bottom: 90px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--toolbar-bg);
    backdrop-filter: blur(10px);
    padding: 12px 20px;
    border-radius: 99px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.15);
    z-index: 100;
    width: 200px;
    cursor: auto;
}

/* Make sure UI elements show normal cursor */
button,
input,
.modal,
.popup-menu {
    cursor: auto;
}

.tool-group {
    display: flex;
    gap: 8px;
    align-items: center;
}

.tool-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 2px solid transparent;
    background: #f3f4f6;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
}

.tool-btn.active {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(37, 99, 235, 0.3);
}

/* Style for Size/Color pickers */
.popup-menu {
    position: absolute;
    bottom: 70px;
    background: white;
    padding: 16px;
    border-radius: 16px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.15);
    display: none;
    /* Hidden by default */
    flex-direction: column;
    gap: 12px;
    width: 200px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 101;
}

.popup-menu.show {
    display: flex;
    animation: slideUp 0.2s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translate(-50%, 10px);
    }

    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}

/* Range Slider Styling */
input[type=range] {
    width: 100%;
    accent-color: var(--primary-color);
    cursor: pointer;
}

/* Color options */
.color-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}

.color-opt {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 2px solid #e5e7eb;
    cursor: pointer;
}

.color-opt.selected {
    border-color: var(--text-color);
    transform: scale(1.1);
}

/* Modal for Resize/Settings */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 200;
    display: none;
    justify-content: center;
    align-items: center;
    backdrop-filter: blur(2px);
    cursor: auto;
}

.modal {
    background: white;
    padding: 24px;
    border-radius: 16px;
    width: 90%;
    max-width: 320px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

.modal h3 {
    margin-top: 0;
}

.modal-btn {
    width: 100%;
    padding: 12px;
    margin-top: 8px;
    border: 1px solid #e5e7eb;
    background: white;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    text-align: left;
}

.modal-btn:active {
    background: #f3f4f6;
}

.modal-close {
    margin-top: 16px;
    background: #f3f4f6;
    text-align: center;
}

/* SVG Icons fill */
svg {
    width: 24px;
    height: 24px;
    fill: currentColor;
}

/* Grid Background Pattern */
.bg-grid {
    background-image:
        linear-gradient(#e5e7eb 1px, transparent 1px),
        linear-gradient(90deg, #e5e7eb 1px, transparent 1px);
    background-size: 20px 20px;
}

.bg-lines {
    background-image: repeating-linear-gradient(white 0px, white 24px, #e5e7eb 25px);
}

.bg-dots {
    background-image: radial-gradient(#e5e7eb 1px, transparent 1px);
    background-size: 20px 20px;
}