:root { --blu: #1f4a8a; --blu2: #2d5fa8; --ink: #14202e; --bg: #e9eef5; --card: #fff; --line: #c9d3e0; --red: #c62828; }
@media (prefers-color-scheme: dark) { :root { --ink: #e8eef5; --bg: #0f1722; --card: #182231; --line: #2b3a4e; } }
* { box-sizing: border-box; } body { margin: 0; min-height: 100vh; display: flex; align-items: center; justify-content: center; background: var(--bg); color: var(--ink); font: 15px/1.4 system-ui, "Segoe UI", sans-serif; }
.box { width: min(420px, 92vw); background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 26px 28px; box-shadow: 0 10px 30px rgba(0,0,0,.12); }
.logo { font-size: 30px; font-weight: 800; color: var(--blu2); letter-spacing: 1px; text-align: center; } .logo small { display: block; font-size: 13px; letter-spacing: 0; color: #6b7a8c; font-weight: 600; }
h1 { font-size: 19px; margin: 14px 0 4px; } .hint { color: #6b7a8c; font-size: 13px; }
label { display: block; font-weight: 600; font-size: 13px; margin: 12px 0 4px; } input { width: 100%; font: inherit; padding: 10px; border: 1px solid var(--line); border-radius: 8px; background: transparent; color: inherit; }
button { width: 100%; margin-top: 16px; padding: 12px; border: 0; border-radius: 8px; background: linear-gradient(var(--blu2), var(--blu)); color: #fff; font: inherit; font-weight: 700; cursor: pointer; } button[disabled] { opacity: .6; }
.err { color: var(--red); font-weight: 600; min-height: 1.3em; margin-top: 8px; }