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

body {
    font-family: Arial, sans-serif;
    background: #0b0f19;
    color: #ffffff;
    min-height: 100vh;
}

.navbar {
    border-bottom: 1px solid #1f2937;
    background: #0b0f19;
}

.nav-container {
    max-width: 1100px;
    margin: auto;
    padding: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    text-decoration: none;
    color: white;
    font-size: 20px;
    font-weight: bold;
    display: flex;
    gap: 10px;
    align-items: center;
}

.logo-icon {
    color: #6366f1;
}

.logo-accent {
    color: #6366f1;
}

.back-link {
    color: #9ca3af;
    text-decoration: none;
    font-size: 14px;
}

.back-link:hover {
    color: white;
}

main {
    max-width: 1000px;
    margin: auto;
    padding: 60px 20px;
}

.tool-hero {
    text-align: center;
    margin-bottom: 40px;
}

.tool-badge {
    display: inline-block;
    padding: 7px 12px;
    border: 1px solid #30384a;
    border-radius: 20px;
    color: #818cf8;
    font-size: 12px;
    font-weight: bold;
    letter-spacing: 1px;
    margin-bottom: 18px;
}

.tool-hero h1 {
    font-size: 42px;
    margin-bottom: 12px;
}

.tool-hero p {
    color: #9ca3af;
    font-size: 16px;
}

.converter-card {
    background: #111827;
    border: 1px solid #1f2937;
    border-radius: 20px;
    padding: 30px;
}

.category-box {
    margin-bottom: 30px;
}

label {
    display: block;
    color: #d1d5db;
    font-size: 14px;
    font-weight: bold;
    margin-bottom: 10px;
}

select,
input {
    width: 100%;
    background: #0b0f19;
    color: #ffffff;
    border: 1px solid #374151;
    border-radius: 10px;
    padding: 13px 14px;
    font-size: 15px;
    outline: none;
}

select:focus,
input:focus {
    border-color: #6366f1;
}

.converter-grid {
    display: grid;
    grid-template-columns: 1fr 60px 1fr;
    gap: 20px;
    align-items: end;
}

.input-box input {
    margin-bottom: 12px;
}

.swap-box {
    display: flex;
    justify-content: center;
    padding-bottom: 5px;
}

.swap-box button {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    border: 1px solid #374151;
    background: #1f2937;
    color: white;
    font-size: 22px;
    cursor: pointer;
}

.swap-box button:hover {
    background: #374151;
}

.result-box {
    margin-top: 30px;
    padding: 20px;
    border: 1px solid #1f2937;
    background: #0b0f19;
    border-radius: 14px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.result-box span {
    color: #9ca3af;
    font-size: 14px;
}

.result-box strong {
    color: #818cf8;
    font-size: 20px;
    margin-right: auto;
    word-break: break-word;
}

.copy-btn {
    background: #6366f1;
    color: white;
    border: none;
    padding: 10px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
}

.copy-btn:hover {
    opacity: 0.9;
}

.message {
    text-align: center;
    color: #9ca3af;
    font-size: 13px;
    min-height: 18px;
    margin-top: 18px;
}

footer {
    text-align: center;
    padding: 30px 20px;
    color: #6b7280;
    font-size: 13px;
}

@media (max-width: 700px) {

    main {
        padding: 40px 15px;
    }

    .tool-hero h1 {
        font-size: 32px;
    }

    .converter-card {
        padding: 20px;
    }

    .converter-grid {
        grid-template-columns: 1fr;
    }

    .swap-box {
        padding: 0;
    }

    .swap-box button {
        transform: rotate(90deg);
    }

    .result-box {
        flex-wrap: wrap;
    }

    .result-box strong {
        width: 100%;
        order: 2;
    }

    .copy-btn {
        order: 3;
    }
}