@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600&display=swap');

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

body {
    background: #ffffff;

    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    color: #333;
}

.container {
    width: 400px;
    background: #ffffff;
    padding: 30px;
    border-radius: 20px;

    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    text-align: center;
    border: 1px solid #f0f0f0;
}

header h1 {
    font-size: 24px;
    margin-bottom: 25px;
    color: #2d3436;
    font-weight: 700;
}

.input-group {
    text-align: left;
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    color: #636e72;
    font-weight: 500;
}

input,
select {
    width: 100%;
    padding: 12px;
    border: 1px solid #dfe6e9;
    border-radius: 8px;
    background: #f9f9f9;
    color: #2d3436;
    font-size: 16px;
    outline: none;
    transition: 0.2s;
}

input:focus,
select:focus {
    border-color: #6c5ce7;
    background: #fff;
    box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.1);
}

.units-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    gap: 10px;
}

.units-row .input-group {
    width: 45%;
}

.swap-btn {
    background: #6c5ce7;

    color: white;
    border: none;
    height: 44px;
    width: 44px;
    padding: 0;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    transition: 0.3s;
}

.swap-btn:hover {
    background: #5b4cc4;
    transform: rotate(180deg);
}

.convert-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #6c5ce7, #a29bfe);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    margin-top: 25px;
    transition: 0.3s;
    box-shadow: 0 4px 15px rgba(108, 92, 231, 0.3);
}

.convert-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(108, 92, 231, 0.4);
}

.result-area {
    margin-top: 30px;
    padding: 20px;
    background: #fdfdfd;
    border-radius: 12px;
    border: 1px solid #f0f0f0;
    display: none;
}

.result-area.active {
    display: block;
}

.result-label {
    font-size: 14px;
    color: #b2bec3;
    margin-bottom: 5px;
}

#output-temp {
    font-size: 36px;
    font-weight: 700;
    color: #2d3436;
}

.result-unit {
    color: #6c5ce7;
    font-weight: 600;
}

.main-footer {
    margin-top: 30px;
    font-size: 12px;
    color: #b2bec3;
}