{
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background: linear-gradient(135deg, #fdf2f8, #f9a8d4); 
    color: #111827;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: #be185d; 
    color: #fdf2f8;
    padding: 1rem 2rem;
    box-shadow: 0 2px 8px rgba(190, 24, 93, 0.5);
}

header h1 {
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

nav a {
    color: #ffe4f1;
    text-decoration: none;
    font-size: 0.95rem;
    padding-bottom: 0.2rem;
}

nav a:hover {
    color: #ffffff;
}

nav a.active {
    color: #ffffff;
}

main {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem 1rem;
}

.calculator {
    background: #fdf2f8; 
    padding: 2rem 2.5rem;
    border-radius: 12px;
    width: 100%;
    max-width: 420px;
    box-shadow: 0 10px 25px rgba(190, 24, 93, 0.25);
}

.calculator label {
    display: block;
    font-size: 0.95rem;
    margin-bottom: 0.3rem;
    margin-top: 1rem;
    color: #9d174d;
}

.calculator input[type="number"] {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border-radius: 8px;
    border: 1px solid #f9a8d4;
    font-size: 0.95rem;
    outline: none;
    background-color: #fff;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.calculator input[type="number"]:focus {
    border-color: #ec4899;
    box-shadow: 0 0 0 2px rgba(236, 72, 153, 0.3);
    background-color: #fff5fa;
}

.calculator button {
    margin-top: 1.5rem;
    width: 100%;
    padding: 0.7rem 1rem;
    border-radius: 999px;
    border: none;
    background: #ec4899; /* main pink */
    color: #ffffff;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.1s ease, box-shadow 0.2s ease;
    box-shadow: 0 6px 14px rgba(236, 72, 153, 0.5);
}

.calculator button:hover {
    background: #db2777;
    box-shadow: 0 8px 18px rgba(219, 39, 119, 0.6);
}

.calculator button:active {
    transform: translateY(1px);
    box-shadow: 0 4px 10px rgba(219, 39, 119, 0.45);
}

#result {
    margin-top: 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    color: #be185d;
}

footer {
    text-align: center;
    padding: 0.9rem 1rem;
    font-size: 0.85rem;
    color: #fdf2f8;
    background: #9d174d;
    border-top: 1px solid rgba(248, 187, 208, 0.6);
}

footer a {
    color: #ffe4f1;
    text-decoration: none;
}

footer a:hover {
    color: #ffffff;
    text-decoration: underline;
}

.copyright {
    margin-top: 0.25rem;
    font-size: 0.8rem;
    opacity: 0.9;
}

@media (max-width: 600px) {
    header {
        padding: 0.8rem 1rem;
    }

    header h1 {
        font-size: 1.3rem;
    }

    nav ul {
        gap: 1rem;
    }

    .calculator {
        padding: 1.5rem 1.6rem;
    }
}