:root { color-scheme: light; font-family: system-ui, sans-serif; color: #17334c; background: #f7fbfc; }
body { margin: 0; padding: 2rem 1rem; }
main { max-width: 38rem; margin: 9vh auto 0; padding: clamp(1.5rem, 4vw, 3rem); background: white; border: 1px solid #dbe8ed; border-radius: 1rem; box-shadow: 0 12px 40px #17334c0d; }
.mark { color: #087c84; font-size: .9rem; font-weight: 800; letter-spacing: .14em; }
h1 { font-size: clamp(1.8rem, 4vw, 2.5rem); line-height: 1.15; }
p { font-size: 1rem; line-height: 1.6; }
button { margin-top: 1rem; padding: .9rem 1.25rem; border: 0; border-radius: .6rem; color: white; background: #087c84; font: inherit; font-weight: 700; cursor: pointer; }
button:focus-visible { outline: 3px solid #17334c; outline-offset: 3px; }
button:disabled { opacity: .6; cursor: wait; }
.note { margin-top: 2.5rem; padding-top: 1rem; border-top: 1px solid #dbe8ed; color: #486176; font-size: .9rem; }