:root {
    --bg-color: #1a1a20;
    --card-bg: #25252b;
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --danger: #ef4444;
    --success: #10b981;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.captcha-container {
    background-color: var(--card-bg);
    padding: 24px;
    border-radius: 12px;
    width: 100%;
    max-width: 650px;
    text-align: center;
}

.header h2 {
    margin-bottom: 16px;
    font-size: 1.5rem;
    font-weight: 600;
}

.instruction-box {
    background: rgba(255, 255, 255, 0.05);
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.instruction-box strong {
    color: var(--text-primary);
    font-weight: 700;
    color: var(--accent);
}

.canvas-wrapper {
    position: relative;
    width: 100%;
    /* Aspect Ratio 3:2 */
    aspect-ratio: 3 / 2; 
    background: #000;
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 20px;
    cursor: crosshair;
}

.canvas-wrapper img, 
.canvas-wrapper canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /* Critical for preventing selection/dragging */
    user-select: none;
    -webkit-user-select: none;
    -webkit-user-drag: none;
    touch-action: none; 
}

.controls {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-bottom: 16px;
}

button {
    padding: 10px 24px;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: transform 0.1s, opacity 0.2s;
}

button:active {
    transform: scale(0.96);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background-color: var(--accent);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--accent-hover);
}

.btn-secondary {
    background-color: transparent;
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--text-secondary);
}

.btn-secondary:hover:not(:disabled) {
    border-color: var(--text-secondary);
    color: var(--text-primary);
}

#status-msg {
    min-height: 24px;
    font-size: 0.9rem;
    font-weight: 500;
}

.status-error {
    color: var(--danger);
}

.status-success {
    color: var(--success);
}