:root{font-family:Inter,system-ui,sans-serif;color:#172033;background:#f4f7fc;--blue:#315ae6;--line:#d7deec}*{box-sizing:border-box}body{margin:0}.learn-shell{max-width:850px;margin:auto;padding:1rem}header{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem}.eyebrow{color:var(--blue);font-weight:800;text-transform:uppercase;margin:0}h1{margin:.2rem 0}.panel,.flashcard{background:#fff;border:1px solid var(--line);border-radius:1rem;padding:clamp(1rem,4vw,2rem);box-shadow:0 8px 28px #1c2d5212}form{display:grid;gap:1rem;max-width:34rem;margin:3rem auto}label{display:grid;gap:.35rem;font-weight:700}input,button{font:inherit;padding:.8rem;border:1px solid var(--line);border-radius:.65rem}button{cursor:pointer;background:var(--blue);color:#fff;font-weight:800}.practice-head{display:flex;justify-content:space-between;margin:.5rem 0}.flashcard{display:grid;gap:1rem;min-height:24rem}.flashcard section+section{border-top:2px solid var(--line);padding-top:1rem}.side-label{color:var(--blue);font-size:.8rem;font-weight:900;text-transform:uppercase}#front{font-size:clamp(1.25rem,4vw,2rem);line-height:1.45}#back{white-space:pre-line;line-height:1.6}.ratings{display:grid;grid-template-columns:repeat(4,1fr);gap:.5rem;margin-top:1rem}.ratings button:nth-child(1){background:#b82e2e}.ratings button:nth-child(2){background:#b36b00}.ratings button:nth-child(3){background:#16815d}.ratings button:nth-child(4){background:#1764b0}.admin-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem}.admin-grid .panel{margin:0}.admin-grid strong{font-size:2.4rem;color:var(--blue)}.message{padding:1rem;border-radius:.6rem;background:#e5f7ef}.message.error{background:#fee3e3;color:#941d1d}@media(max-width:600px){.ratings{grid-template-columns:1fr 1fr}.admin-grid{grid-template-columns:1fr}.flashcard{min-height:20rem}}