* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f4f6f8;
    color: #1d2630;
}
.container {
    width: min(920px, calc(100% - 28px));
    margin: 36px auto;
}
.card {
    background: #fff;
    border-radius: 18px;
    padding: clamp(22px, 4vw, 42px);
    box-shadow: 0 14px 40px rgba(0,0,0,.09);
}
h1 { margin-top: 0; font-size: clamp(2rem, 5vw, 3.2rem); }
h2 { margin-top: 32px; }
.lead { font-size: 1.1rem; line-height: 1.55; }
.grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}
.names { margin: 28px 0; }
fieldset {
    border: 1px solid #d8dee5;
    border-radius: 12px;
    padding: 18px;
    margin: 0 0 16px;
}
legend { font-weight: 700; padding: 0 8px; }
label { display: grid; gap: 7px; font-weight: 650; }
input[type="text"], input[type="number"] {
    width: 100%;
    border: 1px solid #aeb9c4;
    border-radius: 9px;
    padding: 12px 13px;
    font: inherit;
}
input:focus {
    outline: 3px solid rgba(2,133,253,.18);
    border-color: #0285fd;
}
.check {
    display: flex;
    grid-template-columns: none;
    align-items: flex-start;
    gap: 10px;
    margin: 24px 0;
    font-weight: 500;
}
button {
    border: 0;
    border-radius: 10px;
    padding: 14px 22px;
    font: inherit;
    font-weight: 800;
    cursor: pointer;
    background: #0285fd;
    color: #fff;
}
button:hover { filter: brightness(.94); }
.message {
    border-radius: 10px;
    padding: 14px 16px;
    margin: 20px 0;
}
.message.success { background: #e8f8ee; border: 1px solid #62b77e; }
.message.error { background: #fff0f0; border: 1px solid #d66; }
@media (max-width: 650px) {
    .grid { grid-template-columns: 1fr; }
    .container { margin: 14px auto; }
    .card { border-radius: 12px; }
}