:root {
    color-scheme: light;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f3f6f9;
    color: #17202a;
}
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; }
.preference-shell { display: grid; min-height: 100vh; padding: 28px 16px; place-items: center; }
.preference-card { background: #fff; border: 1px solid #dce3ea; border-radius: 16px; box-shadow: 0 16px 42px rgba(26, 42, 58, .1); max-width: 680px; padding: 28px; width: 100%; }
header span { color: #176b87; font-size: .78rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
h1 { font-size: clamp(1.55rem, 4vw, 2.15rem); margin: 6px 0 18px; }
p { color: #536272; line-height: 1.55; }
.preference-message { background: #edf8f2; border: 1px solid #b9dec8; border-radius: 10px; color: #235c3c; margin: 0 0 18px; padding: 14px; }
.preference-message.error { background: #fff3f3; border-color: #e7c1c1; color: #812d2d; }
.preference-form { display: grid; gap: 16px; margin-top: 20px; }
.preference-form fieldset { border: 1px solid #dce3ea; border-radius: 12px; display: grid; gap: 11px; margin: 0; padding: 16px; }
.preference-form legend { font-weight: 800; padding: 0 6px; }
.preference-form fieldset label { align-items: flex-start; border-bottom: 1px solid #edf0f3; cursor: pointer; display: flex; gap: 11px; padding: 8px 0 12px; }
.preference-form fieldset label:last-child { border-bottom: 0; padding-bottom: 4px; }
.preference-form input[type="checkbox"] { accent-color: #176b87; margin-top: 4px; }
.preference-form label span { display: grid; gap: 3px; }
.preference-form label small { color: #647383; }
.email-field { display: grid; font-weight: 700; gap: 7px; }
.email-field input { border: 1px solid #bbc7d3; border-radius: 9px; font: inherit; padding: 12px; width: 100%; }
button { background: #176b87; border: 0; border-radius: 9px; color: #fff; cursor: pointer; font: inherit; font-weight: 800; padding: 12px 16px; }
button:hover { background: #10566e; }
.preference-empty { background: #f5f7f9; border-radius: 10px; padding: 14px; }
footer { border-top: 1px solid #e4e9ee; margin-top: 24px; padding-top: 16px; }
footer p { font-size: .84rem; margin: 0 0 7px; }
footer a { color: #105f7a; font-weight: 700; }
@media (max-width: 520px) { .preference-card { padding: 21px; } }