* {
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
    box-sizing: border-box;
}

.container {
    width: 100%;
    min-height: 100vh;
    background: linear-gradient(135deg, #4203a9, #90bafc);
    color: #fff;
    padding: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.calculator {
    width: 100%;
    max-width: 600px;
    padding: 20px;
    text-align: center;
}

.calculator h1 {
    font-size: 60px;
    line-height: 1.2;
}

.calculator h1 span {
    color: #ffff76;
}

.input-box {
    margin: 40px 0;
    padding: 25px;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.3);
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
    justify-content: center;
}

.input-box input {
    flex: 1;
    min-width: 220px;
    padding: 14px 20px;
    border: none;
    outline: none;
    font-size: 18px;
    border-radius: 5px;
    position: relative;
    background-color: #fff;
    color: #333;
}

.input-box button {
    background: #ffff76;
    border: none;
    outline: none;
    padding: 14px 25px;
    border-radius: 5px;
    font-weight: 600;
    color: #333;
    cursor: pointer;
    transition: background 0.3s ease;
}

.input-box button:hover {
    background: #ffeb3b;
}

.input-box input::-webkit-calendar-picker-indicator {
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    width: auto;
    height: auto;
    position: absolute;
    background-position: calc(100% - 10px);
    background-size: 25px;
    cursor: pointer;
}

/* Tablet & Mobile */
@media (max-width: 768px) {
    .calculator h1 {
        font-size: 40px;
    }

    .input-box {
        flex-direction: column;
        padding: 20px;
    }

    .input-box input,
    .input-box button {
        width: 100%;
        font-size: 16px;
        padding: 12px;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .calculator h1 {
        font-size: 28px;
    }

    .input-box {
        padding: 15px;
    }

    .input-box input,
    .input-box button {
        font-size: 14px;
    }
}