:root {
  --ink: #151719;
  --muted: #697078;
  --line: #dfe3e8;
  --paper: #f4f6f9;
  --blue: #1558e8;
  --blue-soft: #eef4ff;
  --red: #b53f38;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --serif: "Songti SC", "Noto Serif SC", STSong, SimSun, serif;
}

* { box-sizing: border-box; }
body { margin: 0; min-width: 320px; color: var(--ink); background: radial-gradient(circle at 50% 0, #fff 0, var(--paper) 62%); font-family: var(--sans); }
.auth-shell { min-height: 100vh; display: grid; place-items: center; padding: 28px; }
.auth-card { width: min(420px, 100%); padding: 34px; border: 1px solid var(--line); border-radius: 16px; background: rgba(255,255,255,.96); box-shadow: 0 22px 60px rgba(23,31,44,.09); }
.auth-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 34px; font: 800 24px/1 var(--serif); }
.auth-brand img { width: 34px; height: 34px; border-radius: 9px; box-shadow: 0 4px 14px rgba(21,88,232,.18); }
.eyebrow { margin: 0 0 9px; color: var(--blue); font-size: 10px; font-weight: 800; letter-spacing: 1.6px; }
h1 { margin: 0; font: 750 30px/1.25 var(--serif); }
.description { margin: 12px 0 24px; color: var(--muted); font-size: 13px; line-height: 1.75; }
.auth-error { margin: 0 0 16px; padding: 10px 12px; color: var(--red); background: #fff3f2; border: 1px solid #f0cbc8; border-radius: 8px; font-size: 12px; }
.hidden { display: none; }
form { display: grid; gap: 10px; }
label { color: #41474e; font-size: 12px; font-weight: 700; }
input { width: 100%; height: 46px; padding: 0 13px; border: 1px solid #cfd5dc; border-radius: 9px; outline: 0; font: inherit; }
input:focus { border-color: var(--blue); box-shadow: 0 0 0 4px var(--blue-soft); }
button { height: 46px; margin-top: 5px; border: 0; border-radius: 9px; color: #fff; background: var(--blue); font: 700 14px var(--sans); cursor: pointer; }
button:hover { background: #104bc8; }
.security-note { margin: 17px 0 0; color: #8a9199; font-size: 10px; line-height: 1.6; }

@media (max-width: 520px) {
  .auth-shell { padding: 16px; }
  .auth-card { padding: 28px 22px; }
}