body {
            margin: 0;
            overflow: hidden;
            font-family: 'Helvetica Neue', Arial, sans-serif;
            touch-action: manipulation;
            /* ←これを追加！ズームなどを防ぎ、タップを超高速化します */
        }

        #dark-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.75);
            z-index: -1;
            pointer-events: none;
        }

        #message-ui {
            position: absolute;
            bottom: -200px;
            left: 50%;
            transform: translateX(-50%);
            width: 80%;
            max-width: 400px;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            padding: 20px;
            border-radius: 16px;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
            transition: bottom 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
            z-index: 10;
            text-align: center;
        }

        #message-ui.active {
            bottom: 40px;
        }

        #like-btn {
            background: #ffebee;
            color: #d32f2f;
            border: 2px solid #ffcdd2;
            padding: 8px 16px;
            border-radius: 20px;
            font-size: 16px;
            font-weight: bold;
            cursor: pointer;
            transition: transform 0.1s;
            margin-right: 10px;
        }

        #like-btn:active {
            transform: scale(0.9);
        }

        .action-btn {
            padding: 10px 20px;
            background: #333;
            color: white;
            border: none;
            border-radius: 20px;
            cursor: pointer;
        }

        #open-post-btn {
            position: absolute;
            bottom: 30px;
            right: 30px;
            width: 60px;
            height: 60px;
            border-radius: 30px;
            background: #E0FFFF;
            color: #333;
            font-size: 24px;
            font-weight: bold;
            border: none;
            box-shadow: 0 0 15px rgba(224, 255, 255, 0.6);
            cursor: pointer;
            z-index: 5;
        }

        #post-ui {
            display: none;
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.85);
            z-index: 20;
            flex-direction: column;
            justify-content: center;
            align-items: center;
        }

        #post-ui.active {
            display: flex;
        }

        #new-msg-input {
            width: 80%;
            max-width: 300px;
            height: 100px;
            padding: 15px;
            border-radius: 12px;
            border: none;
            font-size: 16px;
            margin-bottom: 20px;
        }

        .btn-group button {
            padding: 12px 25px;
            margin: 0 10px;
            border: none;
            border-radius: 25px;
            font-size: 16px;
            font-weight: bold;
            cursor: pointer;
        }

        #submit-btn {
            background: #E0FFFF;
            color: #333;
        }

        #cancel-btn {
            background: #666;
            color: white;
        }

        .back-button {
            position: fixed;
            top: 20px;
            left: 20px;
            padding: 10px 18px;
            background-color: rgba(255, 255, 255, 0.85);
            /* 少し透ける白 */
            color: #333;
            text-decoration: none;
            font-weight: bold;
            border-radius: 20px;
            z-index: 9999;
            /* AR画面の裏に隠れないように最前面に出す絶対魔法 */
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            /* 軽い影をつけて浮かせます */
        }