* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; background: #fff; color: #000; font-family: "Trebuchet MS", "Microsoft YaHei", sans-serif; }
.login-card { width: 90%; max-width: 520px; margin: 12vh auto 0; padding: 28px; border: 2px solid #000; border-radius: 8px; }
h1 { margin: 0; font-size: 36px; }
p { margin: 8px 0 24px; font-weight: bold; }
label { display: block; margin: 16px 0; font-size: 18px; font-weight: bold; }
input { display: block; width: 100%; margin-top: 6px; padding: 10px; border: 2px solid #000; border-radius: 4px; background: #fff; color: #000; font-size: 20px; }
button { width: 100%; margin-top: 12px; padding: 10px; border: 2px solid #000; border-radius: 4px; background: #000; color: #fff; font-size: 20px; font-weight: bold; }
.login-error { margin: 12px 0; color: #900; }