:root {
            --spacing-unit: 8px;
            --font-size-base: 16px;
            --primary-color: #00adb5;
            --secondary-color: #f5f5f5;
            --text-color: #212121;
            --border-color: #e0e0e0;
            --available-color: #00c853;
            --inactive-color: #757575;
        }

        body {
            margin: 0;
            padding: 0;
            font-family: 'Noto Sans TC', sans-serif;
            background-color: #f8f8f8;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: calc(var(--spacing-unit) * 2.5);
            background: white;
            box-shadow: 0 0 10px rgba(0,0,0,0.1);
            min-height: 100vh;
        }

        .header-container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: calc(var(--spacing-unit) * 3);
            padding-bottom: calc(var(--spacing-unit) * 1.25);
            border-bottom: 2px solid var(--primary-color);
        }

        .header-title {
            color: var(--primary-color);
            font-size: 1.8em;
            font-weight: 500;
        }

        .charger-count {
            color: var(--text-color);
            font-size: 1.1em;
            font-weight: 500;
        }

        .charger-count span {
            color: var(--available-color);
            font-weight: bold;
        }

        .mobile-main-title {
            display: none;
            text-align: center;
            font-size: 1.4em;
            padding: calc(var(--spacing-unit) * 1.25);
            background: var(--primary-color);
            color: white;
            margin: 0 0 calc(var(--spacing-unit) * 1.25);
        }

        .mobile-title {
            display: none;
            text-align: center;
            font-size: 1em;
            margin: calc(var(--spacing-unit) * 1.25) 0 calc(var(--spacing-unit) * 2);
            padding: calc(var(--spacing-unit) * 1.25);
            background: var(--primary-color);
            color: white;
            border-radius: 4px;
        }

        .district-nav {
            display: grid;
            grid-template-columns: repeat(6, 1fr);
            gap: var(--spacing-unit);
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

        .district-item {
            background: white;
            border-radius: 4px;
            padding: calc(var(--spacing-unit) * 1.25) calc(var(--spacing-unit) * 0.625);
            text-align: center;
            text-decoration: none;
            color: var(--text-color);
            border: 1px solid var(--border-color);
            font-size: 0.9em;
            transition: all 0.2s ease;
            cursor: pointer;
        }

        .district-item:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-2px);
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }

        .district-item.active {
            background: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
            font-weight: 500;
        }

        .station-list {
            margin-top: calc(var(--spacing-unit) * 1.875);
        }

        .station-card {
            --card-padding: calc(var(--spacing-unit) * 2);
            background: white;
            border-radius: 6px;
            padding: var(--card-padding);
            margin-bottom: calc(var(--spacing-unit) * 1.5);
            border: 1px solid var(--border-color);
            box-shadow: 0 1px 3px rgba(0,0,0,0.05);
            transition: transform 0.2s;
            will-change: transform;
        }

        .station-card:hover {
            transform: translateY(-3px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }

        .station-name {
            font-weight: 500;
            font-size: 1.1em;
            color: var(--primary-color);
            margin-bottom: var(--spacing-unit);
        }

        .station-detail {
            font-size: 0.9em;
            color: var(--inactive-color);
            margin-bottom: calc(var(--spacing-unit) * 0.625);
            line-height: 1.5;
        }

        .available {
            color: var(--available-color);
            font-weight: bold;
        }

        .no-data {
            text-align: center;
            padding: calc(var(--spacing-unit) * 3.75);
            color: var(--inactive-color);
            background: white;
            border-radius: 6px;
            margin: calc(var(--spacing-unit) * 2.5);
            border: 1px dashed var(--border-color);
            font-size: 1em;
        }

        .last-update {
            text-align: center;
            color: var(--inactive-color);
            margin: calc(var(--spacing-unit) * 1.875) 0;
            font-size: 0.85em;
            padding: var(--spacing-unit);
            background: var(--secondary-color);
            border-radius: 4px;
        }

        .loading {
            text-align: center;
            padding: calc(var(--spacing-unit) * 2.5);
        }

        .loading-spinner {
            border: 3px solid rgba(0,0,0,0.1);
            border-top: 3px solid var(--primary-color);
            border-radius: 50%;
            width: 24px;
            height: 24px;
            animation: spin 1s linear infinite;
            margin: 0 auto calc(var(--spacing-unit) * 1.25);
        }

        .footer {
            text-align: center;
            color: var(--inactive-color);
            margin-top: calc(var(--spacing-unit) * 2.5);
            padding: var(--spacing-unit);
            font-size: 0.9em;
        }

        .footer a {
            color: var(--primary-color);
            text-decoration: none;
        }

        .footer a:hover {
            text-decoration: underline;
        }

        /* New Back to Top Button Styles */
        .back-to-top {
            position: fixed;
            bottom: 20px;
            right: 20px;
            width: 50px;
            height: 50px;
            background: var(--primary-color);
            color: white;
            border: none;
            border-radius: 50%;
            cursor: pointer;
            opacity: 0;
            transition: opacity 0.3s;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2em;
            box-shadow: 0 2px 5px rgba(0,0,0,0.2);
        }

        .back-to-top.visible {
            opacity: 0.8;
        }

        .back-to-top:hover {
            opacity: 1;
            transform: scale(1.1);
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        @media (max-width: 1200px) {
            .container {
                padding: calc(var(--spacing-unit) * 2);
            }
        }

        @media (max-width: 768px) {
            .container {
                max-width: 100%;
                padding: calc(var(--spacing-unit) * 1.25);
            }

            .header-container {
                display: none;
            }

            .mobile-main-title {
                display: block;
            }

            .mobile-title {
                display: block;
            }

            .district-nav {
                grid-template-columns: repeat(3, 1fr);
                gap: calc(var(--spacing-unit) * 0.75);
            }

            .district-item {
                padding: var(--spacing-unit) calc(var(--spacing-unit) * 0.375);
                font-size: 0.8em;
            }

            .station-card {
                padding: calc(var(--spacing-unit) * 1.5);
            }

            .station-name {
                font-size: 1em;
            }
        }