:root {
  --navy: #1C4056; --navy-d: #12293a; --maroon: #852110; --bg: #f3f5f7; --card: #fff;
  --line: #d9dee3; --muted: #667784; --ok: #1f7a3d; --warn: #b45309; --err: #b42318;
  color-scheme: light;
}
* { box-sizing: border-box; }
body { margin: 0; font: 15px/1.45 -apple-system, "Segoe UI", Roboto, Arial, "Noto Sans Tamil", sans-serif; background: var(--bg); color: #1b2a35; }
.muted { color: var(--muted); }
header.top { background: var(--navy); color: #fff; display: flex; align-items: center; gap: 12px; padding: 10px 20px; }
header.top h1 { font-size: 18px; margin: 0; font-weight: 700; }
header.top .school { opacity: .8; font-size: 13px; }
header.top .sp { flex: 1; }
header.top a { color: #fff; opacity: .85; font-size: 13px; text-decoration: none; }
main { display: grid; grid-template-columns: minmax(380px, 520px) 1fr; gap: 16px; padding: 16px 20px 40px; max-width: 1500px; margin: 0 auto; align-items: start; }
@media (max-width: 900px) { main { grid-template-columns: 1fr; padding: 12px; } .preview { position: static !important; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; margin-bottom: 14px; }
.card h2 { font-size: 15px; margin: 0 0 10px; color: var(--navy); }
.row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin-bottom: 10px; }
.btn { border: 1px solid var(--line); background: #fff; border-radius: 8px; padding: 7px 12px; font: inherit; cursor: pointer; color: #1b2a35; }
.btn:hover { background: #eef2f5; }
.btn.primary { background: var(--navy); color: #fff; border-color: var(--navy); font-weight: 600; }
.btn.primary:hover { background: var(--navy-d); }
.btn.big { padding: 10px 18px; font-size: 16px; }
.btn.sm { padding: 4px 9px; font-size: 13px; }
.btn.danger { color: var(--err); }
select, input[type=text], input[type=number], textarea { font: inherit; border: 1px solid var(--line); border-radius: 8px; padding: 7px 9px; background: #fff; width: 100%; }
textarea { min-height: 330px; font-family: ui-monospace, Menlo, Consolas, "Noto Sans Tamil", monospace; font-size: 13.5px; line-height: 1.5; resize: vertical; }
label { display: block; font-size: 13px; color: var(--muted); margin: 0 0 3px; }
.field { margin-bottom: 10px; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 8px; }
.tab { border: 1px solid var(--line); background: #fff; border-radius: 8px 8px 0 0; padding: 6px 12px; cursor: pointer; font-size: 13.5px; border-bottom: 3px solid transparent; }
.tab.active { border-bottom-color: var(--navy); font-weight: 700; background: #f3f8fb; }
.swatches { display: flex; gap: 6px; align-items: center; }
.sw { width: 22px; height: 22px; border-radius: 50%; border: 2px solid #fff; box-shadow: 0 0 0 1px var(--line); cursor: pointer; padding: 0; }
.sw.active { box-shadow: 0 0 0 2px var(--navy); }
.toolbar { display: flex; gap: 5px; flex-wrap: wrap; margin-bottom: 6px; }
details { font-size: 13px; color: var(--muted); margin-top: 8px; }
details pre { background: #f3f5f7; padding: 8px 10px; border-radius: 8px; white-space: pre-wrap; color: #1b2a35; font-size: 12.5px; }
.preview { position: sticky; top: 12px; }
.summary { background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 12px 16px; margin-bottom: 12px; }
.summary .big { font-size: 20px; font-weight: 800; color: var(--navy); }
.summary .small { font-size: 13.5px; margin-top: 4px; }
.summary .warn { color: var(--warn); font-weight: 600; margin-top: 6px; }
.summary .err { color: var(--err); font-weight: 600; }
.frame-wrap { position: relative; background: #8895a0; border-radius: 10px; overflow: hidden; border: 1px solid var(--line); }
#pdfImg { width: 100%; display: block; background: #fff; }
.frame-wrap { padding: 10px; }
.empty { color: #fff; text-align: center; padding: 60px 0; }
.busy { position: absolute; inset: 0; background: rgba(255,255,255,.65); display: none; align-items: center; justify-content: center; font-weight: 700; color: var(--navy); }
.busy.on { display: flex; }
.modal { position: fixed; inset: 0; background: rgba(15,30,40,.5); display: none; align-items: center; justify-content: center; z-index: 10; padding: 16px; }
.modal.on { display: flex; }
.modal .box { background: #fff; border-radius: 12px; padding: 18px; width: min(720px, 100%); max-height: 90vh; overflow: auto; }
.modal textarea { min-height: 260px; }
.login-body { display: flex; align-items: center; justify-content: center; min-height: 100vh; }
.login-card { background: #fff; padding: 28px; border-radius: 14px; border: 1px solid var(--line); width: 320px; text-align: center; display: flex; flex-direction: column; gap: 12px; }
.login-card h1 { margin: 0; font-size: 22px; color: var(--navy); }
.login-logo { font-size: 38px; }
.err { color: var(--err); }