* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Segoe UI", sans-serif;
}

body {
    background-color: #0f1220;
    color: #ffffff;
    overflow-x: hidden;
    min-height: 100vh;
}

.back {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 10;
}

.back a {
    background: #000;
    color: #fff;
    padding: 10px 16px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: bold;
    transition: background 0.2s;
}

.back a:hover {
    background: #04AA6D;
}

.converter-container {
    text-align: center;
    padding: 120px 20px 40px;
}

.converter-container h1 {
    font-size: 2.5rem;
    margin-bottom: 30px;
}

.converter-card {
    background: #181c3a;
    border-radius: 14px;
    padding: 30px 20px;
    max-width: 450px;
    margin: 0 auto;
    box-shadow: 0 8px 20px rgba(0,0,0,0.4);
    transform: translateY(-50px);
    opacity: 0;
    animation: slideDown 0.5s forwards;
}

@keyframes slideDown {
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.converter-card input {
    width: 100%;
    padding: 12px;
    margin-bottom: 15px;
    border-radius: 8px;
    border: none;
    font-size: 1rem;
    background: #0f1220;
    color: #ffffff;
    outline: none;
    box-shadow: inset 0 0 5px rgba(255,255,255,0.1);
}

.selects {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin-bottom: 15px;
}

.selects select {
    flex: 1;
    padding: 10px;
    border-radius: 8px;
    border: none;
    background: #0f1220;
    color: #ffffff;
    outline: none;
    box-shadow: inset 0 0 5px rgba(255,255,255,0.1);
}

.swap-btn {
    padding: 8px 14px;
    background: #04AA6D;
    color: white;
    font-size: 1.2rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.swap-btn:hover {
    background: #03995f;
}

.converter-card h2 {
    margin-top: 20px;
    font-size: 1.5rem;
    color: #04AA6D;
}