:root {
  --bg: #f4f6f8;
  --card: #ffffff;
  --ink: #1f2933;
  --muted: #6b7280;
  --brand: #1d4ed8;
  --ok: #047857;
  --err: #b91c1c;
  --border: #d7dde3;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
}

a { color: var(--brand); }
h1 { font-size: 1.5rem; }
h2 { font-size: 1.15rem; margin-top: 2rem; }
code { background: #eef2f7; padding: 0.1em 0.35em; border-radius: 4px; }

.muted { color: var(--muted); }
.small { font-size: 0.85rem; }

/* ---- layout admin ---- */
.admin-header {
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 0.5rem;
  background: var(--card); border-bottom: 1px solid var(--border);
  padding: 0.6rem 1rem;
}
.admin-nav { display: flex; flex-wrap: wrap; gap: 0.9rem; align-items: center; }
.admin-nav .brand { font-weight: 700; color: var(--ink); text-decoration: none; }
.admin-nav a { text-decoration: none; }
.admin-user { display: flex; align-items: center; gap: 0.75rem; font-size: 0.9rem; }
.admin-main { max-width: 1000px; margin: 1.5rem auto; padding: 0 1rem; }

/* ---- tablas / formularios ---- */
table { width: 100%; border-collapse: collapse; margin: 0.75rem 0; background: var(--card); }
th, td { text-align: left; padding: 0.5rem 0.6rem; border-bottom: 1px solid var(--border); font-size: 0.92rem; }
th { background: #f0f3f6; }

form label { display: block; margin: 0.5rem 0; font-size: 0.9rem; }
input, select, button {
  font: inherit; padding: 0.5rem 0.6rem; border: 1px solid var(--border);
  border-radius: 6px; background: #fff;
}
button {
  background: var(--brand); color: #fff; border-color: var(--brand);
  cursor: pointer;
}
button:disabled { opacity: 0.5; cursor: default; }

.button-link {
  display: inline-block; text-decoration: none;
  background: var(--brand); color: #fff; border: 1px solid var(--brand);
  border-radius: 6px; padding: 0.5rem 0.8rem;
}
.button-link.secondary { background: #fff; color: var(--brand); }

.form-inline { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; margin: 0.75rem 0; }
.form-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 0.5rem 1rem; max-width: 720px; }
.form-grid button { grid-column: 1 / -1; justify-self: start; }
.check { display: inline-flex; align-items: center; gap: 0.35rem; }

.cards { display: flex; flex-wrap: wrap; gap: 0.75rem; margin: 1rem 0; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 8px; padding: 0.9rem 1.2rem; min-width: 120px; }
.card .num { display: block; font-size: 1.6rem; font-weight: 700; }

.tabs { display: flex; gap: 1rem; margin: 1rem 0; border-bottom: 1px solid var(--border); }
.tabs a { padding: 0.4rem 0; text-decoration: none; }
.tabs a.active { border-bottom: 2px solid var(--brand); font-weight: 600; }

section { margin-bottom: 1.5rem; }

/* ---- pantallas centradas (login / celular / display) ---- */
.centered-card, .mobile-card {
  max-width: 420px; margin: 3rem auto; background: var(--card);
  border: 1px solid var(--border); border-radius: 12px; padding: 1.5rem;
}
.mobile-card { margin: 1.5rem auto; }
.mobile-card button, .centered-card button { width: 100%; margin-top: 0.75rem; padding: 0.8rem; font-size: 1.05rem; }

.alert { padding: 0.6rem 0.8rem; border-radius: 6px; }
.alert.error, .status.error { background: #fde8e8; color: var(--err); }
.status { padding: 0.8rem; border-radius: 6px; background: #eef2f7; margin: 1rem 0; text-align: center; }
.status.ok { background: #dcfce7; color: var(--ok); }

.display { text-align: center; padding: 2rem 1rem; }
.display img { width: min(70vw, 480px); height: auto; image-rendering: pixelated; background: #fff; }
.display .countdown { font-size: 1.25rem; margin-top: 1rem; }

.site-footer { text-align: center; color: var(--muted); font-size: 0.8rem; padding: 2rem 0 1rem; }