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

[hidden] {
    display: none !important;
}

:root {
    --bg: #f3f4f8;
    --card: #ffffff;
    --ink: #151a2d;
    --muted: #5d6480;
    --accent: #4338ca;
    --accent-dark: #3730a3;
    --border: #dcdfea;
    --error: #b42318;
    --warn-bg: #fff6e0;
    --warn-ink: #7a4a00;
}

body {
    font-family: system-ui, -apple-system, "Segoe UI", Tahoma, sans-serif;
    background-color: var(--bg);
    color: var(--ink);
    line-height: 1.5;
}

.container {
    max-width: 640px;
    margin: 0 auto;
    padding: 32px 16px 48px;
}

.page-header {
    margin-bottom: 20px;
}

.page-header h1 {
    font-size: 1.8rem;
}

.subtitle {
    color: var(--muted);
}

.card {
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 20px;
    margin-bottom: 16px;
}

.converter {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.pair {
    display: flex;
    align-items: flex-end;
    gap: 10px;
}

.pair .field {
    flex: 1;
}

.field {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

label {
    font-size: 0.9rem;
    font-weight: 600;
}

input,
select,
button {
    font: inherit;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background-color: #fff;
    color: var(--ink);
}

#amount {
    font-size: 1.4rem;
    font-variant-numeric: tabular-nums;
}

.converted {
    font-size: 1.8rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    overflow-wrap: anywhere;
}

.rate {
    color: var(--muted);
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
    white-space: nowrap;
}

.swap {
    flex: none;
    width: 46px;
    height: 46px;
    padding: 0;
    font-size: 1.3rem;
    line-height: 1;
    border-radius: 50%;
    background-color: var(--accent);
    border-color: var(--accent);
    color: #fff;
    cursor: pointer;
}

.swap:hover {
    background-color: var(--accent-dark);
}

.small-title {
    font-size: 0.9rem;
    color: var(--muted);
    margin-bottom: 8px;
}

.others {
    list-style: none;
}

.others li {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}

.others li:last-child {
    border-bottom: none;
}

.others strong {
    font-variant-numeric: tabular-nums;
}

.meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 6px 12px;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border);
    font-size: 0.9rem;
    color: var(--muted);
}

.link-btn {
    padding: 4px 8px;
    border: none;
    background: none;
    color: var(--accent);
    font-weight: 600;
    text-decoration: underline;
    cursor: pointer;
}

.link-btn:disabled {
    color: var(--muted);
    cursor: wait;
}

.field-error {
    min-height: 1.2em;
    font-size: 0.85rem;
    color: var(--error);
}

input[aria-invalid="true"] {
    border-color: var(--error);
}

.status {
    padding: 10px 14px;
    border-radius: 10px;
    margin-bottom: 16px;
    font-weight: 600;
}

.status.warn {
    background-color: var(--warn-bg);
    color: var(--warn-ink);
}

.status.error {
    background-color: #fdecea;
    color: var(--error);
}

:focus-visible {
    outline: 3px solid #f59e0b;
    outline-offset: 2px;
}

select {
    width: 100%;
    min-width: 0;
}

@media (max-width: 480px) {
    .container {
        padding: 20px 12px 32px;
    }

    .page-header h1 {
        font-size: 1.5rem;
    }

    .card {
        padding: 14px;
    }

    .pair {
        flex-direction: column;
        align-items: stretch;
    }

    .swap {
        align-self: center;
        transform: rotate(90deg);
    }

    .converted {
        font-size: 1.4rem;
    }
}