:root { color-scheme: light; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: #172c49; background: #f0f4fa; }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100svh; }
main { width: min(100% - 40px, 520px); margin: 0 auto; padding: clamp(32px, 8vh, 88px) 0 32px; }
header { margin-bottom: 30px; }
.eyebrow { color: #365fd2; font-size: .75rem; font-weight: 750; letter-spacing: .14em; margin: 0 0 14px; }
h1 { font-size: clamp(2rem, 6vw, 2.6rem); letter-spacing: -.035em; margin: 0 0 10px; line-height: 1.15; }
.intro { font-size: 1rem; color: #52627a; margin: 0; line-height: 1.6; }
.practice { background: white; border: 1px solid #dce3ef; border-radius: 22px; padding: 28px; box-shadow: 0 14px 40px #1d386b08; }
.card-top { display: flex; flex-wrap: wrap; gap: 8px 16px; justify-content: space-between; font-size: .875rem; color: #52627a; }
.card-top span:first-child { color: #24499c; font-weight: 650; }
h2 { font-size: clamp(3rem, 13vw, 4.7rem); letter-spacing: -.025em; line-height: 1.2; text-align: center; margin: 40px 0; font-variant-numeric: tabular-nums; }
label { display: block; font-size: .875rem; font-weight: 650; margin: 0 0 10px; }
.answer-row { display: flex; gap: 10px; }
input { min-width: 0; width: 100%; border: 1.5px solid #b6c4da; border-radius: 10px; padding: 12px 14px; font: inherit; font-size: 1.4rem; color: #172c49; background: white; }
button { border: 0; border-radius: 10px; background: #315bd5; color: white; font: inherit; font-weight: 650; padding: 14px 22px; cursor: pointer; }
button:hover { background: #2249b9; }
input:focus-visible, button:focus-visible { outline: 3px solid #8baafa; outline-offset: 3px; }
.hint { font-size: .875rem; color: #637087; margin: 12px 0 0; }
.feedback { min-height: 3.2em; margin: 24px 0 16px; font-size: 1rem; line-height: 1.6; color: #52627a; }
.feedback.right { color: #13613e; }
.feedback.wrong { color: #ad3038; }
.stats { border-top: 1px solid #e4eaf2; padding-top: 22px; display: grid; grid-template-columns: 1fr 1fr; }
.stats > div { display: flex; align-items: baseline; gap: 10px; color: #52627a; font-size: .875rem; }
.stats > div + div { border-left: 1px solid #e4eaf2; padding-left: 26px; }
.number { color: #172c49; font-size: 1.8rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.footer { color: #637087; font-size: .875rem; text-align: center; margin: 22px 12px 0; line-height: 1.6; }
@media (max-width: 380px) { main { width: calc(100% - 24px); } .practice { padding: 20px; } button { padding: 14px 16px; } }