* {
    box-sizing: border-box;
}

html {
    font-family:
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;
    background: #f5f7fa;
    color: #18202a;
}

body {
    margin: 0;
    line-height: 1.6;
}

a {
    color: #1558d6;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    width: min(1100px, calc(100% - 32px));
    margin: 0 auto;
}

.site-header {
    background: #101722;
    color: white;
}

.header-inner {
    min-height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.logo {
    color: white;
    font-size: 1.45rem;
    font-weight: 800;
}

.logo:hover {
    text-decoration: none;
}

nav {
    display: flex;
    gap: 18px;
}

nav a {
    color: #e7edf5;
}

main {
    padding-top: 36px;
    padding-bottom: 60px;
}

.hero {
    background: white;
    padding: 32px;
    border-radius: 16px;
    border: 1px solid #e1e6ec;
    margin-bottom: 24px;
}

.hero h1 {
    margin-top: 0;
    font-size: clamp(2rem, 5vw, 3rem);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
}

.card {
    background: white;
    border: 1px solid #e1e6ec;
    border-radius: 14px;
    padding: 20px;
}

.card h2,
.card h3 {
    margin-top: 0;
}

.converter {
    background: white;
    border: 1px solid #e1e6ec;
    border-radius: 16px;
    padding: 26px;
    margin-bottom: 28px;
}

form {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-full {
    grid-column: 1 / -1;
}

label {
    display: block;
    font-weight: 700;
    margin-bottom: 6px;
}

input,
select,
button {
    width: 100%;
    min-height: 46px;
    border-radius: 9px;
    border: 1px solid #c9d1dc;
    padding: 10px 12px;
    font: inherit;
}

button {
    background: #1558d6;
    color: white;
    font-weight: 700;
    cursor: pointer;
    border: 0;
}

button:hover {
    background: #0f46ad;
}

.result {
    margin-top: 22px;
    padding: 20px;
    border-radius: 12px;
    background: #edf5ff;
    border: 1px solid #c9ddfa;
}

.result strong {
    font-size: 1.5rem;
}

.notice {
    padding: 15px;
    border-radius: 10px;
    background: #fff7df;
    border: 1px solid #eed38b;
}

.breadcrumb {
    margin-bottom: 20px;
    color: #667085;
    font-size: .95rem;
}

.muted {
    color: #667085;
}

.article {
    background: white;
    border: 1px solid #e1e6ec;
    border-radius: 16px;
    padding: 28px;
    margin-top: 24px;
}

.ad-slot {
    min-height: 90px;
    margin: 24px 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px dashed #d3d9e1;
    color: #8a94a3;
    border-radius: 10px;
}

footer {
    background: #101722;
    color: #cbd5e1;
    padding: 30px 0;
}

footer a {
    color: #dbe7ff;
}

@media (max-width: 650px) {
    form {
        grid-template-columns: 1fr;
    }

    .hero,
    .converter,
    .article {
        padding: 20px;
    }
}