:root{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:#192332;background:#f4f6f9;font-synthesis:none;font-size:16px;--blue:#174ee3;--line:#e2e6ed;--muted:#657082}*{box-sizing:border-box}body{margin:0}
.sign-in{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:26px;padding:24px}
.brand{display:flex;align-items:center;gap:11px;font-weight:720;font-size:1.25rem;letter-spacing:-.6px}.brandmark{display:grid;place-items:center;width:34px;height:34px;background:var(--blue);color:white;border-radius:9px;font-size:27px}
form{width:100%;max-width:380px;padding:30px;background:white;border:1px solid var(--line);border-radius:14px;box-shadow:0 4px 20px #1c2b420f}
h1{margin:0 0 20px;font-size:1.375rem;letter-spacing:-.4px}
label{display:block;margin:16px 0 6px;font-size:.875rem;font-weight:550}
input{width:100%;font:inherit;padding:11px 12px;border:1px solid #cfd6e2;border-radius:8px;background:white;color:inherit}input:focus{outline:2px solid #b7caff;border-color:var(--blue)}
button{width:100%;margin-top:24px;font:inherit;font-weight:550;padding:12px 15px;border:0;border-radius:8px;background:var(--blue);color:white;cursor:pointer}button:disabled{opacity:.55;cursor:wait}
.problem{margin:16px 0 0;padding:11px 12px;border-radius:8px;background:#fdecec;color:#9b1c1c;font-size:.875rem}
.note{margin:18px 0 0;font-size:.8125rem;color:var(--muted);text-align:center}
.about{margin:0 0 14px;line-height:1.5}.check{margin:0;padding:12px 14px;border-radius:8px;background:#f3f6ff;font-size:.875rem;line-height:1.55}.check strong{font-family:ui-monospace,Menlo,monospace;letter-spacing:2px;font-size:1rem}
.choices{display:flex;gap:10px}.choices button{flex:1}button.plain{background:white;color:inherit;border:1px solid #cfd6e2}