:root{
    --bg: #0b1020;
    --panel: #121a33;
    --accent: #6ea8fe;
    --text: #e6e9f2;
    --muted: #9aa3b2;
}

@media (max-width: 360px) {
    body {
        font-size: 12px;
    }
}

@media (min-width: 361px) and (max-width: 720px) {
    body {
        font-size: 14px;
    }
}

@media (min-width: 721px) and (max-width: 1080px) {
    body {
        font-size: 16px;
    }
}

@media (min-width: 1081px) and (max-width: 1440px) {
    body {
        font-size: 18px;
    }
}

@media (min-width: 1441px) {
    body {
        font-size: 20px;
    }
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 28px;
    font-family: system-ui,Segoe UI,Roboto,Arial;
    color: var(--text);
    background: radial-gradient(900px 600px at 60% -10%,#1f2a53 0%,var(--bg) 55%);
}

.card {
    width: min(780px,94vw);
    max-width: 720px;
    background: linear-gradient(180deg,#182447,var(--panel));
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 20px 60px rgba(0,0,0,.45);
}

h1 {
    margin: 0 0 8px;
    font-size: 20px;
}

.controls {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.output {
    flex: 1;
    min-width: 220px;
    padding: 12px;
    border-radius: 10px;
    border: 0;
    background: rgba(255,255,255,.03);
    color: var(--text);
    font-weight: 700;
}

button {
    appearance: none;
    border: 0;
    padding: 10px 14px;
    border-radius: 10px;
    font-weight: 700;
    cursor: pointer;
    background: linear-gradient(180deg,#2b3a6e,#24315b);
    color: var(--text);
}

button.secondary {
    background: linear-gradient(180deg,#36455f,#273246);
}

.options {
    display: flex;
    gap: 12px;
    align-items: center;
    margin-top: 14px;
    flex-wrap: wrap;
}

label {
    font-size: 13px;
    color: var(--muted);
    display: flex;
    gap: 6px;
    align-items: center;
}

input[type=number] {
    width: 64px;
    padding: 6px;
    border-radius: 8px;
    border: 0;
    background: rgba(255,255,255,.03);
    color: var(--text);
    font-weight: 700;
}

footer {
    margin-top: 16px;
    text-align: right;
}

a.link {
    color: var(--accent);
    text-decoration: none;
    font-weight: 700;
}