html, body {
    margin: 0; padding: 0;
    width: 100vw; height: 100vh;
    overflow: hidden;
    position: fixed;
    touch-action: none;
    background: #fff;
}

#canvas { display: block; z-index: 1; }

#main-toolbar {
    position: fixed;
    bottom: 20px;
    left: 20px;
    display: flex;
    gap: 6px;
    background: #8e8e8e; /* Dark grey from Screenshot 1 */
    padding: 10px;
    border-radius: 12px;
    z-index: 1000;
}

.tool-btn {
    width: 48px; height: 48px;
    background: #7a7a7a;
    border: 2px solid transparent;
    border-radius: 10px;
    color: white;
    cursor: pointer;
}

.tool-btn.active {
    background: #ffffff;
    color: #333;
    border: 2px solid #0091ff; /* Blue Ring from Screenshot 2 */
}

/* Enabled arrows turn black like the image */
.tool-btn:not(:disabled) i { color: #000000; }
.tool-btn:disabled { opacity: 0.4; }

/* Wide Pen Settings Menu */
.wide-pop-up {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%);
    background: #fdfdfd;
    width: 90%;
    max-width: 800px;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 5px 25px rgba(0,0,0,0.2);
    z-index: 2000;
}

.squiggle-container {
    background: #eeeeee;
    border-radius: 10px;
    margin: 15px 0;
    height: 80px;
    display: flex;
    align-items: center;
}

.color-row {
    display: flex;
    justify-content: space-around;
    padding: 15px 0;
}

.color-dot {
    width: 40px; height: 40px;
    border-radius: 50%;
    cursor: pointer;
    border: 3px solid transparent;
}

.color-dot.active { border-color: #0091ff; }

.hidden { display: none !important; }