body {
    margin: 0;
    padding: 0;
    background: linear-gradient(to bottom, #1a2a6c, #b21f1f, #fdbb2d);
    background-color: #1a2a6c;
    height: 100vh;
    overflow: hidden;
    font-family: 'Helvetica Neue', Arial, sans-serif;
    color: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
}
.back-btn {
    position: absolute;
    top: 20px;
    left: 16px;
    z-index: 20;
    padding: 8px 14px;
    background: rgba(255,255,255,0.9);
    color: #222;
    text-decoration: none;
    font-weight: bold;
    border-radius: 20px;
    font-size: 0.85rem;
}
/* SEO・AdSense用テキストボックス */
.seo-text-box {
            position: absolute;
            bottom: 20px;
            left: 20px;
            right: 20px;
            background-color: rgba(0, 0, 0, 0.6);
            color: #ccc;
            padding: 15px 20px;
            border-radius: 12px;
            font-size: 0.9rem;
            line-height: 1.5;
            /* pointer-events: none; を入れることで、文字の上からでも花火がタップできます */
            pointer-events: none;
            z-index: 10;
        }
#status-bar {
    position: absolute;
    top: 20px;
    text-align: center;
    z-index: 10;
    background: rgba(0, 0, 0, 0.4);
    padding: 10px 20px;
    border-radius: 20px;
    backdrop-filter: blur(5px);
    max-width: 90%;
    box-sizing: border-box;
}
#fish-name {
    font-size: 1.3rem;
    font-weight: bold;
    margin-bottom: 5px;
}
#fish-size {
    font-size: 1rem;
    color: #ffeaa7;
}
#message {
    font-size: 0.95rem;
    margin-top: 8px;
    color: #55efc4;
    line-height: 1.4;
    min-height: 1.4em;
}
#aquarium {
    position: relative;
    width: 100vw;
    height: 100vh;
}
.swimming-creature {
    position: absolute;
    cursor: pointer;
    user-select: none;
    transition: transform 0.1s linear;
    z-index: 5;
    white-space: nowrap;
}
#feed-btn {
    position: absolute;
    bottom: 50%;
    left: 50%;
    transform: translateX(-50%);
    background-color: #00b894;
    color: white;
    border: none;
    border-radius: 30px;
    padding: 15px 35px;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    z-index: 10;
    transition: background-color 0.2s;
}
#feed-btn:hover {
    background-color: #55efc4;
    color: #2d3436;
}
#feed-btn:disabled {
    background-color: #b2bec3;
    cursor: not-allowed;
}
#settings-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
}
#settings-btn:hover {
    background: rgba(255, 255, 255, 0.4);
}
#modal {
    display: none;
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.6);
    z-index: 100;
    justify-content: center;
    align-items: center;
}
.modal-content {
    background: #2d3436;
    padding: 30px;
    border-radius: 12px;
    width: 90%;
    max-width: 350px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0,0,0,0.5);
}
.modal-content h3 { margin-top: 0; color: #dfe6e9; }
.modal-btn {
    display: block;
    width: 100%;
    padding: 12px;
    margin: 10px 0;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
}
.btn-rename { background-color: #0984e3; color: white; }
.btn-reset { background-color: #d63031; color: white; }
.btn-close { background-color: #636e72; color: white; }
#welcome-modal {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.8);
    z-index: 200;
    display: flex;
    justify-content: center;
    align-items: center;
}
.welcome-box {
    background: #2d3436;
    padding: 30px;
    border-radius: 12px;
    width: 90%;
    max-width: 350px;
    text-align: center;
}
.welcome-box input {
    width: 80%;
    padding: 10px;
    font-size: 1rem;
    margin: 15px 0;
    border-radius: 5px;
    border: 1px solid #636e72;
    background: #1e272c;
    color: white;
    text-align: center;
}