body {
            background-image: linear-gradient(135deg, #7f7fd5 0%, #91eae4 100%);
            background-size: cover;
            background-repeat: no-repeat;
            background-position: center;
            margin: 0;
            min-height: 100vh;
            font-family: Arial, sans-serif;
            display: flex;
            flex-direction: column;
            align-items: center;
            padding: 0;
        }

        .welcome-banner {
            width: 100%;
            text-align: center;
            margin: 0 auto 40px auto;
            padding-top: 42px;
            padding-bottom: 14px;
        }

        .welcome-title {
            color: #ffd700;
            font-size: 2.6rem;
            font-weight: 900;
            letter-spacing: 0.018em;
            text-shadow: 0 2px 18px rgba(60, 60, 60, 0.13);
            margin-bottom: 13px;
        }

        .welcome-description {
            color: #e8ecf7;
            font-size: 1.25rem;
            font-weight: 500;
            margin-bottom: 24px;
        }

        .link-buttons-row {
            display: flex;
            justify-content: center;
            gap: 28px;
            flex-wrap: wrap;
            margin-top: 11px;
        }

        .link-button {
            text-decoration: none;
            background: #ffd600;
            color: #2c2f36;
            padding: 19px 33px;
            font-size: 1.27rem;
            font-weight: 700;
            border: none;
            border-radius: 18px;
            box-shadow: 0 8px 24px rgba(80, 80, 150, 0.15);
            cursor: pointer;
            transition: filter 0.12s, transform 0.13s;
            margin-bottom: 14px;
        }

        .link-button:hover {
            color: #0077ff;
            filter: brightness(0.94);
            transform: translateY(-2px) scale(1.04);
        }

        @media (max-width: 1100px) {
            .welcome-title {
                font-size: 2.2rem;
            }

            .welcome-description {
                font-size: 1.1rem;
            }

            .link-buttons-row {
                gap: 19px;
            }

            .link-button {
                font-size: 1.15rem;
                padding: 17px 24px;
            }
        }

        @media (max-width: 650px) {
            .welcome-banner {
                margin-bottom: 12px;
                padding-top: 28px;
            }

            .welcome-title {
                font-size: 1.15rem;
            }

            .welcome-description {
                font-size: 0.91rem;
            }

            .link-buttons-row {
                gap: 10px;
            }

            .link-button {
                font-size: 1rem;
                padding: 11px 8vw;
            }
        }

        .card {
            background: transparent;
            box-shadow: 0 6px 18px rgba(0, 0, 0, 0.12);
            border-radius: 24px;
            max-width: 760px;
            width: 90%;
            text-align: center;
            padding: 28px 44px 36px;
            margin-top: 36px;
            margin-left: auto;
            margin-right: auto;
        }

        h2 {
            color: #ffd600;
            text-align: center;
            font-size: 2.1rem;
            font-weight: 800;
            margin-bottom: 22px;
            margin-top: 0;
            letter-spacing: 0.01em;
            text-shadow: 0 2px 18px rgba(60, 60, 60, 0.10);
        }

        .row {
            display: flex;
            gap: 12px;
            flex-wrap: wrap;
            justify-content: center;
            margin-bottom: 25px;
            align-items: baseline;
        }

        .label {
            font-weight: 600;
            color: #2c2f36;
            margin-top: 13px;
            margin-bottom: 7px;
        }

        select,
        .unit-input {
            padding: 9px 10px;
            border: 1.5px solid #d6e6f6;
            border-radius: 8px;
            background: #f6faff;
            color: #323447;
            margin-bottom: 7px;
            max-width: 85%;
            font-size: 1rem;
            transition: border 0.22s;
            font-family: inherit;
            font-weight: 500;
        }

        .unit-input:focus,
        select:focus {
            border: 1.5px solid #7f7fd5;
        }

        .result {
            margin-top: 24px;
            font-size: 1.12rem;
            font-weight: bold;
            color: #272921;
            text-align: center;
            min-height: 32px;
        }

        @media (max-width:670px) {
            .card {
                max-width: 97vw;
                padding: 16px 4vw 14px 4vw;
            }

            .button-row {
                gap: 14px;
                flex-direction: column;
            }
        }

        @media (max-width:480px) {
            h1 {
                font-size: 2em;
            }

            .description {
                font-size: 1.01rem;
            }
        }