:root {
  --ink: #0f172a; --muted: #475569; --line: #e2e8f0; --bg: #f1f5f9; --card: #ffffff;
  --accent: #0f766e; --accent-dark: #0c5d57; --bad: #b91c1c; --bad-bg: #fef2f2; --ok-bg: #f0fdfa;
}
@media (prefers-color-scheme: dark) {
  :root { --ink: #e2e8f0; --muted: #94a3b8; --line: #334155; --bg: #0b1220; --card: #111a2c;
          --accent: #2dd4bf; --accent-dark: #5eead4; --bad: #fca5a5; --bad-bg: #2a1215; --ok-bg: #0f2a28; }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; }
body { min-height: 100vh; display: grid; place-items: center; padding: 24px 16px; background: var(--bg);
       color: var(--ink); font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
.card { width: 100%; max-width: 520px; background: var(--card); border: 1px solid var(--line); border-radius: 16px;
        padding: 28px; box-shadow: 0 10px 30px rgba(15, 23, 42, .08); }
.brand { display: flex; align-items: center; gap: 8px; font-size: .8rem; font-weight: 700; letter-spacing: .08em;
         text-transform: uppercase; color: var(--muted); margin-bottom: 18px; }
.lock { width: 14px; height: 14px; border: 2px solid var(--accent); border-radius: 3px; position: relative; margin-top: 4px; }
.lock::before { content: ""; position: absolute; left: 1px; top: -8px; width: 8px; height: 8px; border: 2px solid var(--accent);
                border-bottom: 0; border-radius: 6px 6px 0 0; }
h1 { font-size: 1.4rem; line-height: 1.25; margin: 0 0 14px; }
p { margin: 0 0 14px; }
.note { font-size: .88rem; color: var(--muted); }
.status { padding: 12px 14px; border-radius: 10px; background: var(--ok-bg); margin-bottom: 14px; }
.status--bad { background: var(--bad-bg); color: var(--bad); }
.status[hidden] { display: none; }
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 11px 20px;
       border-radius: 10px; border: 2px solid var(--accent); background: var(--accent); color: #fff; font: inherit;
       font-weight: 700; cursor: pointer; text-decoration: none; }
@media (prefers-color-scheme: dark) { .btn { color: #042f2e; } }
.btn:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
.btn:disabled { opacity: .6; cursor: wait; }
.btn:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.btn--ghost { background: transparent; color: var(--accent); }
.btn--ghost:hover { background: transparent; color: var(--accent-dark); }
#reveal, #enroll { width: 100%; }
label { display: block; font-weight: 700; font-size: .85rem; margin-bottom: 6px; }
textarea { width: 100%; font: 15px/1.5 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; padding: 12px;
           border: 1px solid var(--line); border-radius: 10px; background: var(--bg); color: var(--ink); resize: vertical;
           word-break: break-all; }
.actions { display: flex; gap: 10px; flex-wrap: wrap; margin: 12px 0 14px; }