body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    background-color: #e0f7fa;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.container {
    text-align: center;
    background: white;
    padding: 20px;
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    width: 90%;
    max-width: 500px;
}

h1 { color: #0277bd; font-size: 1.5rem; }

.upload-area { margin: 20px 0; }

/* ファイル選択ボタンを可愛く */
#imageInput { display: none; }
label {
    background-color: #0288d1;
    color: white;
    padding: 12px 24px;
    border-radius: 50px;
    cursor: pointer;
    display: inline-block;
    transition: 0.3s;
}

.canvas-wrapper {
    margin-top: 20px;
    width: 100%;
    overflow: hidden;
    border-radius: 10px;
}

canvas {
    max-width: 100%;
    height: auto;
    border: 3px solid #eee;
}

#downloadBtn {
    margin-top: 20px;
    background-color: #ffb74d;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    font-weight: bold;
    cursor: pointer;
}