/* ========================================
   QUANTUM CHEMISTRY SIMULATOR - MAIN STYLES
   ======================================== */

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
}

body {
    background: radial-gradient(ellipse at center, #0a0a15 0%, #000000 100%);
    overflow: hidden;
    font-family: 'Segoe UI', system-ui, sans-serif;
    touch-action: none;
    color: #64c8ff;
}

canvas {
    display: block;
    touch-action: none;
}

/* Hint Notification */
#hint {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.9);
    padding: 16px 24px;
    border-radius: 12px;
    border: 1px solid rgba(100, 200, 255, 0.3);
    font-size: 14px;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
    text-align: center;
    z-index: 102;
}

#hint.show {
    opacity: 1;
}

/* Buttons */
.control-btn {
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(100, 200, 255, 0.3);
    color: #64c8ff;
    padding: 10px 14px;
    border-radius: 12px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.2s;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
    white-space: nowrap;
}

.control-btn:hover {
    background: rgba(20, 20, 35, 0.95);
    border-color: #64c8ff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(100, 200, 255, 0.3);
}

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

.collapse-btn {
    position: fixed;
    background: rgba(0, 0, 0, 0.85);
    border: 1px solid rgba(100, 200, 255, 0.3);
    color: #64c8ff;
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    transition: all 0.2s;
    z-index: 101;
}

.collapse-btn:hover {
    background: rgba(20, 20, 35, 0.95);
    border-color: #64c8ff;
}