body {
    font-family: 'Poppins', sans-serif;
    background-color: #1a1a2e;
    color: #e9ecef;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

#app {
    width: 100%;
    max-width: 400px;
    height: 100%;
    background-color: #16213e;
    border-radius: 15px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
    box-sizing: border-box;
}

.container {
    padding: 20px;
    text-align: center;
}

h1 {
    margin-bottom: 20px;
}

button {
    background-color: #0f3460;
    color: #e9ecef;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 18px;
    margin: 10px 5px;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

button:hover {
    background-color: #e94560;
    transform: translateY(-2px);
}

button:active {
    transform: translateY(1px);
}

input[type="text"] {
    width: calc(100% - 24px);
    padding: 12px;
    margin-bottom: 10px;
    border: 1px solid #0f3460;
    border-radius: 8px;
    font-size: 16px;
    background-color: #1a1a2e;
    color: #e9ecef;
}

.hidden {
    display: none;
}

#coin {
    width: 100px;
    height: 100px;
    position: relative;
    transform-style: preserve-3d;
    animation: flip 2s ease-in-out forwards;
}

@keyframes flip {
    0% { transform: rotateY(0deg); }
    100% { transform: rotateY(1800deg); }
}

#coin div {
    width: 100%;
    height: 100%;
    position: absolute;
    backface-visibility: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    border-radius: 50%;
    border: 2px solid #333;
}

.heads {
    background: radial-gradient(circle, #ffd700 0%, #f1c40f 100%);
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.7);
    transform: rotateY(0deg);
}

.tails {
    background: radial-gradient(circle, #c0c0c0 0%, #95a5a6 100%);
    box-shadow: 0 0 15px rgba(192, 192, 192, 0.7);
    transform: rotateY(180deg);
}

#result {
    font-size: 24px;
    margin-top: 20px;
}

#options-list {
    list-style: none;
    padding: 0;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#options-list li {
    padding: 12px;
    border-bottom: 1px solid #0f3460;
    background-color: #1a1a2e;
    margin-bottom: 5px;
    border-radius: 5px;
    animation: slideDown 0.3s ease-out;
}

#decide-btn {
    margin-top: 20px;
}

#wheel-container {
    position: relative;
    width: 300px;
    height: 300px;
    margin: 20px auto;
}

#wheel {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 5px solid #0f3460;
    position: relative;
    overflow: hidden;
    transition: transform 4s ease-out;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
}

.wheel-slice {
    position: absolute;
    width: 50%;
    height: 50%;
    transform-origin: 100% 100%;
    clip-path: polygon(0 0, 100% 0, 100% 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: #fff;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
}

#wheel-pointer {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 15px solid transparent;
    border-right: 15px solid transparent;
    border-top: 30px solid #e74c3c;
}

.back-btn {
    background-color: #535353;
}

.back-btn:hover {
    background-color: #e94560;
}