:root {
            --primary: #f59e0b;
            --primary-dark: #d97706;
            --bg-gradient: linear-gradient(90deg, #a6ddff 0%, #4c8fff 100%);
            --card-bg: #ffffff;
            --text-main: #1e293b;
            --text-muted: #64748b;
            --accent-red: #ef4444;
            --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            -webkit-tap-highlight-color: transparent;
        }header {
            text-align: center;
            padding: 20px 0;
            color: white;
            position: relative;
        }

        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 5px;
        }

        .logo {
            font-size: 2.5rem;
            font-weight: 800;
            letter-spacing: -1px;
            margin-bottom: 4px;
        }

        .logo span {
            color: var(--primary);
        }

        .menu-btn {
            background: none;
            border: none;
            color: white;
            font-size: 2.2rem;
            cursor: pointer;
            line-height: 1;
            transition: transform 0.2s;
        }

        .menu-btn:hover {
            transform: scale(1.1);
        }

        .tagline {
            font-size: 0.95rem;
            opacity: 0.8;
            font-weight: 300;
            text-align: left;
            width: 100%;
            padding: 0 5px;
        }

        .card {
            background: var(--card-bg);
            border-radius: 28px;
            padding: 24px;
            box-shadow: var(--shadow);
        }

        .card h2 {
            font-size: 1.4rem;
            font-weight: 800;
            margin-bottom: 8px;
            color: var(--text-main);
        }

        .desc {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-bottom: 18px;
        }

        .form-grid {
            display: grid;
            gap: 14px;
        }

        label {
            font-size: 0.85rem;
            color: var(--text-muted);
            font-weight: 600;
            display: block;
            margin-bottom: 6px;
        }

        input {
            width: 100%;
            padding: 12px 14px;
            border-radius: 14px;
            border: 1px solid #e2e8f0;
            font-size: 0.95rem;
            font-family: inherit;
            color: var(--text-main);
            background: #f8fafc;
        }

        .row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
        }

        .hint {
            font-size: 0.8rem;
            color: var(--text-muted);
        }

.result {
    margin-top: 18px;
    padding: 16px;
    background: #f8fafc;
    border-radius: 18px;
    border: 1px solid #e2e8f0;
    display: grid;
    gap: 8px;
}

.result-heading {
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 6px;
}

        .result-total {
            font-size: 1.6rem;
            font-weight: 800;
            color: var(--accent-red);
        }

        .result-line {
            display: flex;
            justify-content: space-between;
            font-size: 0.95rem;
            color: var(--text-main);
        }

        .note {
            margin-top: 12px;
            font-size: 0.85rem;
            color: var(--text-muted);
        }

        .side-menu {
            position: fixed;
            top: 0;
            right: -280px;
            width: 280px;
            height: 100%;
            background: white;
            box-shadow: -5px 0 15px rgba(0, 0, 0, 0.2);
            z-index: 2000;
            transition: right 0.3s ease-out;
            padding: 20px;
            color: #0f172a;
            text-align: left;
        }

        .side-menu.active {
            right: 0;
        }

        .menu-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-bottom: 1px solid #e2e8f0;
            padding-bottom: 15px;
            margin-bottom: 20px;
        }

        .menu-header h2 {
            font-size: 1.5rem;
            font-weight: 800;
        }

        .close-btn {
            background: none;
            border: none;
            font-size: 2rem;
            cursor: pointer;
            color: #0f172a;
            line-height: 1;
        }

        .menu-nav ul {
            list-style: none;
            padding: 0;
        }

        .menu-nav li {
            margin-bottom: 12px;
        }

        .menu-nav a {
            text-decoration: none;
            font-size: 1rem;
            color: #0f172a;
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 8px 12px;
            border-radius: 10px;
            transition: background 0.2s;
        }

        .menu-nav a:hover {
            background: #f1f5f9;
        }

        .menu-nav .icon {
            font-size: 1.2rem;
        }

        .menu-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.6);
            z-index: 1000;
            display: none;
            backdrop-filter: blur(4px);
        }

        .menu-overlay.active {
            display: block;
        }

        @media (max-width: 520px) {
            .row {
                grid-template-columns: 1fr;
            }
        }