:root {
            --bg-green: #1B4D3E;
            --card-blue: #191970;
            --shadow-yellow: #FFCC33;
            --text-white: #FFFFFF;
            --menu-bg: #FFFFFF;
            --modal-bg: rgba(0, 0, 0, 0.7);
        }

        * {
            box-sizing: border-box;
        }

        body {
            background-color: var(--bg-green);
            color: var(--text-white);
            font-family: 'Zen Maru Gothic', sans-serif;
            margin: 0;
            padding: 20px;
            min-height: 100vh;
        }

        header {
            max-width: 1200px;
            margin: 0 auto 30px auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .menu-label {
            display: inline-block;
            background: var(--menu-bg);
            color: #000;
            padding: 10px 20px;
            font-size: 1.2rem;
            font-weight: 900;
            border: 3px solid #333;
            border-radius: 8px;
            box-shadow: 4px 4px 0px rgba(0, 0, 0, 0.3);
            line-height: 1.2;
            cursor: pointer;
            transition: transform 0.1s;
        }

        .menu-label:active {
            transform: translate(2px, 2px);
            box-shadow: 2px 2px 0px rgba(0, 0, 0, 0.3);
        }

        .add-btn {
            background: var(--shadow-yellow);
            color: #000;
            padding: 10px 20px;
            font-size: 1.1rem;
            font-weight: 900;
            border: 3px solid #333;
            border-radius: 8px;
            box-shadow: 4px 4px 0px rgba(0, 0, 0, 0.3);
            cursor: pointer;
            transition: all 0.1s;
        }

        .add-btn:active {
            transform: translate(2px, 2px);
            box-shadow: 2px 2px 0px rgba(0, 0, 0, 0.3);
        }

        .task-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 40px 30px;
            max-width: 1200px;
            margin: 0 auto;
            width: 100%;
        }

        .task-card {
            background-color: var(--card-blue);
            padding: 25px;
            border-radius: 16px;
            position: relative;
            box-shadow: 12px 12px 0px var(--shadow-yellow);
            display: flex;
            flex-direction: column;
            transition: all 0.2s ease;
            cursor: pointer;
            min-height: 220px;
        }

        .task-card:hover {
            transform: translate(-2px, -2px);
            box-shadow: 14px 14px 0px var(--shadow-yellow);
        }

        .task-card:active {
            transform: translate(8px, 8px);
            box-shadow: 4px 4px 0px var(--shadow-yellow);
        }

        .subject {
            font-size: 1.1rem;
            font-weight: 700;
            margin-bottom: 10px;
            opacity: 0.9;
        }

        .title {
            font-size: 1.8rem;
            font-weight: 900;
            text-align: center;
            margin: 10px 0;
            word-break: break-all;
            flex-grow: 1;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .detail-badge {
            font-size: 1rem;
            text-align: center;
            background: rgba(255, 255, 255, 0.15);
            padding: 8px;
            border-radius: 6px;
            margin-bottom: 15px;
            color: #eee;
            overflow: hidden;
            text-overflow: ellipsis;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
        }

        .deadline {
            font-size: 1.5rem;
            font-weight: 900;
            text-align: right;
            border-top: 2px dashed rgba(255, 255, 255, 0.3);
            padding-top: 10px;
        }

        @media (max-width: 480px) {
            .task-grid {
                grid-template-columns: 1fr;
                gap: 50px;
            }

            .task-card {
                min-height: 350px;
            }

            .title {
                font-size: 2rem;
            }

            header {
                flex-direction: column;
                gap: 20px;
                align-items: flex-start;
            }

            .add-btn {
                align-self: stretch;
                text-align: center;
            }
        }

        #status-msg {
            text-align: center;
            font-size: 1.2rem;
            margin-top: 50px;
        }

        /* モーダル */
        .modal {
            display: none;
            position: fixed;
            z-index: 100;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            background-color: var(--modal-bg);
            justify-content: center;
            align-items: center;
            padding: 20px;
        }

        .modal-content {
            background-color: var(--menu-bg);
            color: #000;
            padding: 30px;
            border-radius: 12px;
            max-width: 500px;
            width: 100%;
            border: 4px solid #333;
            box-shadow: 8px 8px 0px rgba(0, 0, 0, 0.5);
            position: relative;
        }

        .modal-title {
            font-size: 1.5rem;
            font-weight: 900;
            margin-top: 0;
            margin-bottom: 20px;
            border-bottom: 2px solid #ddd;
            padding-bottom: 10px;
        }

        .modal-body {
            margin-bottom: 20px;
        }

        .close-btn {
            position: absolute;
            top: 15px;
            right: 20px;
            font-size: 1.5rem;
            font-weight: bold;
            cursor: pointer;
            color: #666;
        }

        .form-group {
            margin-bottom: 15px;
        }

        .form-group label {
            display: block;
            font-weight: bold;
            margin-bottom: 5px;
        }

        .form-group input,
        .form-group textarea {
            width: 100%;
            padding: 10px;
            border: 2px solid #ccc;
            border-radius: 6px;
            font-family: inherit;
            font-size: 1rem;
        }

        .btn-group {
            display: flex;
            justify-content: flex-end;
            gap: 10px;
        }

        .btn {
            padding: 10px 20px;
            font-size: 1rem;
            font-weight: bold;
            border: 2px solid #333;
            border-radius: 6px;
            cursor: pointer;
            box-shadow: 2px 2px 0px rgba(0, 0, 0, 0.3);
        }

        .btn:active {
            transform: translate(1px, 1px);
            box-shadow: 1px 1px 0px rgba(0, 0, 0, 0.3);
        }

        .btn-primary {
            background-color: var(--bg-green);
            color: white;
        }

        .btn-danger {
            background-color: #d9534f;
            color: white;
        }

        .detail-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 10px;
        }

        .detail-subject {
            font-weight: bold;
            font-size: 1.2rem;
            background: #eee;
            padding: 5px 10px;
            border-radius: 6px;
        }

        /* クラス選択専用UI */
        #class-selection-ui {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: var(--bg-green);
            z-index: 200;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 20px;
        }

        .class-selection-container {
            background-color: var(--menu-bg);
            padding: 40px;
            border-radius: 16px;
            max-width: 600px;
            width: 100%;
            text-align: center;
            box-shadow: 12px 12px 0px rgba(0, 0, 0, 0.5);
            color: #000;
        }

        .class-selection-title {
            font-size: 2rem;
            font-weight: 900;
            margin-bottom: 20px;
        }

        .class-list-container {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
            justify-content: center;
            margin-bottom: 30px;
            max-height: 300px;
            overflow-y: auto;
            padding: 10px;
        }

        .class-btn {
            background: var(--card-blue);
            color: white;
            padding: 15px 25px;
            font-size: 1.2rem;
            font-weight: bold;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            box-shadow: 4px 4px 0px var(--shadow-yellow);
            transition: transform 0.1s;
        }

        .class-btn:active {
            transform: translate(2px, 2px);
            box-shadow: 2px 2px 0px var(--shadow-yellow);
        }

        .new-class-group {
            border-top: 2px dashed #ccc;
            padding-top: 20px;
            margin-top: 10px;
        }

        .new-class-input {
            width: 70%;
            padding: 12px;
            font-size: 1.2rem;
            border: 2px solid #ccc;
            border-radius: 8px;
            margin-right: 10px;
        }

        .new-class-btn {
            padding: 12px 20px;
            font-size: 1.2rem;
            font-weight: bold;
            background-color: var(--shadow-yellow);
            border: 2px solid #333;
            border-radius: 8px;
            cursor: pointer;
        }

        .native-popup {
            display: none;
            position: fixed;
            inset: 0;
            z-index: 999;
            background: rgba(0, 0, 0, 0.45);
            backdrop-filter: blur(4px);
            justify-content: center;
            align-items: center;
            padding: 20px;
        }

        .native-popup.active {
            display: flex;
        }

        .popup-card {
            width: min(100%, 420px);
            background: #fff;
            color: #000;
            border-radius: 18px;
            padding: 24px;
            box-shadow: 0 16px 40px rgba(0, 0, 0, 0.3);
            border: 3px solid #333;
            text-align: center;
        }

        .popup-message {
            font-size: 1rem;
            line-height: 1.6;
            margin-bottom: 20px;
        }

        .popup-actions {
            display: flex;
            gap: 12px;
            justify-content: center;
            flex-wrap: wrap;
        }

        .popup-actions button {
            flex: 1 1 140px;
            padding: 14px 0;
            border: none;
            border-radius: 12px;
            background: var(--bg-green);
            color: #fff;
            font-size: 1rem;
            font-weight: 900;
            cursor: pointer;
            transition: transform 0.1s;
        }

        .popup-actions button.cancel {
            background: #bbb;
            color: #111;
        }

        .popup-actions button:active {
            transform: translateY(1px);
        }

        /* ローディングアニメーション */
        .loader {
            border: 8px solid rgba(255, 255, 255, 0.3);
            border-top: 8px solid var(--shadow-yellow);
            border-radius: 50%;
            width: 60px;
            height: 60px;
            animation: spin 1s linear infinite;
            margin: 20px auto;
        }

        @keyframes spin {
            0% {
                transform: rotate(0deg);
            }

            100% {
                transform: rotate(360deg);
            }
        }

        #loading-ui {
            display: none;
            flex-direction: column;
            align-items: center;
            color: white;
            font-size: 1.5rem;
            font-weight: bold;
        }