/* Shared by every page (admin, student, exam screen): tokens, reset, buttons, focus. Page rules live in app.css / exam.css. */
:root{--bg:#f5f6f8;--card:#fff;--ink:#16181d;--muted:#626774;--line:#e2e5ea;--line-strong:#cfd4dc;--hover:#f3f4f6;
--accent:#0b6b57;--accent-hover:#095a49;--accent-soft:#e6f3ef;--accent-line:#b6ddd1;
--warn:#a34a14;--warn-soft:#fbeee6;--warn-line:#f0cdb6;--danger:#b42318;--danger-soft:#fdecea;--info:#17607f;--info-soft:#e4f0f6;
--radius:10px;--radius-lg:14px;--shadow:0 1px 2px rgba(16,24,40,.05),0 1px 3px rgba(16,24,40,.08);--ring:0 0 0 3px rgba(11,107,87,.28)}
*{box-sizing:border-box}
body{margin:0;font:16px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:var(--ink)}
[hidden]{display:none!important}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.hint{color:var(--muted);font-size:14px}
a{color:var(--accent)}
:focus-visible{outline:none;box-shadow:var(--ring)}
input:focus-visible,select:focus-visible,textarea:focus-visible{border-color:var(--accent)}
.btn{padding:11px 18px;border:1px solid transparent;border-radius:var(--radius);background:var(--accent);color:#fff;font:inherit;font-weight:600;cursor:pointer;transition:background .15s,border-color .15s,color .15s}
.btn:hover{background:var(--accent-hover)}.btn:active{transform:translateY(1px)}
.btn.ghost{background:#fff;color:var(--ink);border-color:var(--line-strong)}.btn.ghost:hover{background:var(--hover)}
.btn.danger{background:#fff;color:var(--danger);border-color:var(--danger-soft)}.btn.danger:hover{background:var(--danger);border-color:var(--danger);color:#fff}
.btn.small{padding:5px 12px;font-size:14px}
.btn[disabled]{opacity:.45;cursor:not-allowed;transform:none}
.btn[disabled]:hover{background:var(--accent)}.btn.ghost[disabled]:hover{background:#fff}
dialog.confirm{border:0;border-radius:var(--radius-lg);padding:24px;max-width:420px;width:calc(100% - 32px);color:var(--ink);box-shadow:0 10px 30px rgba(16,24,40,.2)}
dialog.confirm::backdrop{background:rgba(20,22,30,.5)}
dialog.confirm p{margin:0 0 20px;overflow-wrap:anywhere}
dialog.confirm .row{display:flex;gap:12px;justify-content:flex-end;flex-wrap:wrap}