:root {
    --primary-color: #d32f2f;
    --text-color: #333;
    --bg-overlay: rgba(255, 255, 255, 0.8);
}

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

body {
    overflow: hidden;
    font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
}

#canvas-container {
    width: 100vw;
    height: 100vh;
    background-color: #222; /* 暗めの背景で提灯の明かりを目立たせる */
}

#ui-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    padding: 20px;
    pointer-events: none; /* 3D操作を邪魔しないように */
    display: flex;
    flex-direction: column;
    align-items: center;
}

h1 {
    color: #fff;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.controls {
    pointer-events: auto;
    background: var(--bg-overlay);
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    backdrop-filter: blur(5px);
}

.upload-btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 10px 20px;
    border-radius: 25px;
    cursor: pointer;
    font-weight: bold;
    transition: background-color 0.3s;
}

.upload-btn:hover {
    background-color: #b71c1c;
}

input[type="file"] {
    display: none;
}

.hint {
    margin-top: 8px;
    font-size: 0.8rem;
    color: #666;
}

@media (max-width: 600px) {
    h1 {
        font-size: 1.2rem;
    }
    .controls {
        padding: 15px;
        width: 90%;
    }
}