body {
    margin: 0;
    background-color: #1a1a1a;
    color: white;
    font-family: 'Segoe UI', sans-serif;
}

.main-container {
    display: flex;
    height: 100vh;
}

/* Play Area */
.play-area {
    flex: 2; /* Takes up 2/3 of the screen */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 20px;
}

#counter { font-size: 5rem; font-weight: bold; }

.box {
    width: 200px;
    height: 200px;
    background: red;
    border: 5px solid white;
    border-radius: 20px;
    cursor: pointer;
    transition: transform 0.1s;
    background-image: url("https://3g.co.uk/userfiles/product/66e44ea6ba63e-iphone-16-black-back.jpg");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.shrink { transform: scale(0.8); }

/* Upgrades Menu */
.upgrades-menu {
    flex: 1; /* Takes up 1/3 of the screen */
    background: #252525;
    border-left: 2px solid #444;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.upgrade-item {
    background: #333;
    padding: 15px;
    border-radius: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.info { display: flex; flex-direction: column; }
.name { font-weight: bold; font-size: 1.1rem; }
.cost { color: #00ff00; font-size: 0.9rem; }

button {
    background: #4CAF50;
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
}

button:disabled { background: #555; cursor: not-allowed; }