.popup-overlay_nick {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    backdrop-filter: blur(5px);
}


/* ポップアップコンテナ */

.popup-container_nick {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    padding: 30px;
    width: 90%;
    max-width: 400px;
    z-index: 1001;
    animation: popupFadeIn_nick 0.3s ease-out;
}

@keyframes popupFadeIn_nick {
    from {
        opacity: 0;
        transform: translate(-50%, -50%) scale(0.9);
    }
    to {
        opacity: 1;
        transform: translate(-50%, -50%) scale(1);
    }
}


/* ポップアップヘッダー */

.popup-header_nick {
    text-align: center;
    margin-bottom: 20px;
}

.popup-title_nick {
    font-size: 1.2em;
    font-weight: bold;
    color: #333;
    margin-bottom: 8px;
}

.popup-subtitle_nick {
    font-size: 14px;
    color: #666;
    line-height: 1.5;
}


/* 入力フィールド */

.input-group_nick {
    margin-bottom: 20px;
}

.input-label_nick {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #333;
    font-size: 14px;
}

.input-field_nick {
    width: 100%;
    max-width: 200px;
    padding: 12px 16px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.2s ease;
    box-sizing: border-box;
    margin: 0 auto;
    display: block;
}

.input-field_nick:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}

.input-field_nick.error {
    border-color: #dc3545 !important;
    background-color: #fff5f5 !important;
}

.input-field_nick.valid {
    border-color: #28a745 !important;
    background-color: #f8fff8 !important;
}


/* エラーメッセージ */

.error-message_nick {
    color: #dc3545;
    font-size: 12px;
    margin-top: 4px;
    display: none;
    animation: errorSlideIn_nick 0.2s ease-out;
}

@keyframes errorSlideIn_nick {
    from {
        opacity: 0;
        transform: translateY(-5px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}


/* 文字数カウンター */

.char-counter_nick {
    text-align: right;
    font-size: 12px;
    color: #666;
    margin-top: 4px;
}


/* ボタングループ */

.button-group_nick {
    display: flex;
    justify-content: center;
    margin-top: 25px;
}

.btn_nick {
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    font-size: 1.1em;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: center;
    min-width: 80px;
    max-width: 160px;
}

.btn-primary_nick {
    background-color: #007bff;
    color: white;
}

.btn-primary_nick:hover:not(:disabled) {
    background-color: #0056b3;
    transform: translateY(-1px);
}

.btn-primary_nick:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
    transform: none;
}

.cancel_nick {
    background-color: #6da6e2;
    color: white;
    margin-left: 10px;
}

.cancel_nick:hover:not(:disabled) {
    background-color: #3573b5;
    transform: translateY(-1px);
}


/* レスポンシブ対応 */

@media screen and (max-width: 768px) {
    .popup-container_nick {
        padding: 20px 15px;
        width: 80%;
    }
    .popup-title_nick {
        font-size: 1.1em;
    }
    .input-field_nick {
        max-width: 180px;
    }
    .btn_nick {
        min-width: 70px;
        max-width: 100px;
        padding: 12px 16px;
    }
}

@media (max-height: 600px) {
    .popup-container_nick {
        position: absolute;
        top: 20px;
        transform: translateX(-50%);
        max-height: calc(100vh - 40px);
        overflow-y: auto;
    }
}

.current-nickname {
    margin-top: 20px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid #007bff;
}

.input-group_nick {
    margin-bottom: 20px;
    text-align: center;
}

.input-label_nick {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #333;
    font-size: 14px;
    text-align: center;
}

.char-counter_nick {
    text-align: center;
    font-size: 12px;
    color: #666;
    margin-top: 4px;
}