* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: Arial, sans-serif;

    background:
        radial-gradient(
            circle at 10% 20%,
            rgba(6, 182, 212, 0.08),
            transparent 30%
        ),
        radial-gradient(
            circle at 90% 80%,
            rgba(14, 165, 233, 0.06),
            transparent 30%
        ),
        #f4f7f9;

    display: flex;
    justify-content: center;
    align-items: center;
}

.calculator {
    width: 90%;
    max-width: 480px;

    background: #ffffff;

    padding: 30px;

    border-radius: 18px;

    border-top: 5px solid #06b6d4;

    box-shadow:
        0 10px 30px rgba(15, 23, 42, 0.10);

    transition: 0.2s;
}

.calculator:hover {
    box-shadow:
        0 14px 35px rgba(15, 23, 42, 0.13);
}

h1 {
    text-align: center;

    margin: 0 0 8px;

    font-size: 27px;

    color: #0f172a;
}

.subtitle {
    text-align: center;

    color: #64748b;

    margin-bottom: 25px;

    font-size: 15px;
}

label {
    display: block;

    font-weight: bold;

    margin-top: 18px;
    margin-bottom: 7px;

    color: #334155;
}

input {
    width: 100%;

    padding: 13px;

    font-size: 16px;

    border: 1px solid #cbd5e1;

    border-radius: 9px;

    background: #ffffff;

    color: #0f172a;

    transition:
        border-color 0.2s,
        box-shadow 0.2s;
}

input::placeholder {
    color: #94a3b8;
}

input:hover {
    border-color: #67e8f9;
}

input:focus {
    outline: none;

    border-color: #06b6d4;

    box-shadow:
        0 0 0 3px rgba(6, 182, 212, 0.12);
}

button {
    width: 100%;

    margin-top: 25px;

    padding: 14px;

    border: none;

    border-radius: 9px;

    background: #06b6d4;

    color: #ffffff;

    font-size: 17px;

    font-weight: bold;

    cursor: pointer;

    transition:
        background 0.2s,
        transform 0.2s,
        box-shadow 0.2s;
}

button:hover {
    background: #0891b2;

    transform: translateY(-1px);

    box-shadow:
        0 5px 12px rgba(6, 182, 212, 0.20);
}

button:active {
    transform: translateY(0);
}

.result {
    display: none;

    margin-top: 25px;

    padding: 20px;

    border-radius: 12px;

    background: #ecfeff;

    border: 1px solid #a5f3fc;

    text-align: center;
}

.score {
    margin-top: 5px;

    font-size: 40px;

    font-weight: bold;

    color: #0891b2;
}

.max-score {
    color: #64748b;

    margin-top: 4px;

    font-size: 14px;
}

.breakdown {
    margin-top: 18px;

    text-align: left;

    border-top: 1px solid #a5f3fc;

    padding-top: 15px;
}

.breakdown div {
    display: flex;

    justify-content: space-between;

    align-items: center;

    margin: 8px 0;

    color: #334155;
}

.breakdown strong {
    color: #0891b2;
}

.error {
    display: none;

    margin-top: 15px;

    padding: 12px;

    border-radius: 8px;

    background: #fef2f2;

    color: #b91c1c;

    text-align: center;

    font-weight: bold;

    border: 1px solid #fecaca;
}

.field-error {
    color: #dc2626;

    font-size: 14px;

    font-weight: bold;

    margin-top: 6px;
}

@media (max-width: 520px) {

    body {
        padding: 20px 0;
    }

    .calculator {
        width: 92%;

        padding: 24px 20px;

        border-radius: 15px;
    }

    h1 {
        font-size: 24px;
    }

    .subtitle {
        font-size: 14px;
    }

    .score {
        font-size: 36px;
    }
}