:root {
  --bg: #ffffff;
  --fg: #111827;
  --muted: #6b7280;
  --border: #d1d5db;
  --accent: #2563eb;
  --ok-bg: #eaffea;
  --ok-br: #aaffaa;
  --err-bg: #ffeaea;
  --err-br: #ffabab;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

html, body { background: var(--bg); color: var(--fg); margin: 0; }
body { padding: 2rem; }

h1 { font-size: 1.6rem; margin: 0 0 1rem 0; }
h2 { font-size: 1.25rem; margin-top: 2rem; }
h4 { margin: .2rem 0 .6rem 0; }

fieldset {
  border: 1px solid var(--border);
  padding: 1rem;
  margin-bottom: 1rem;
  border-radius: .5rem;
}
legend { font-weight: 600; padding: 0 .3rem; }

.row { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 1rem; }
.row3 { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 1rem; }

label { display: block; margin: .4rem 0 .2rem; font-weight: 600; }
input[type="text"], input[type="date"], input[type="time"], input[type="datetime-local"], select {
  width: 100%; padding: .45rem; border: 1px solid var(--border); border-radius: .375rem;
}
input[type="text"]:focus, input[type="date"]:focus, input[type="time"]:focus, input[type="datetime-local"]:focus, select:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px rgba(37,99,235,.15);
}

button {
  padding: .6rem 1rem; font-weight: 600; background: var(--accent); color: #fff;
  border: none; border-radius: .5rem; cursor: pointer;
}
button:hover { filter: brightness(1.05); }

.actions { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: 1rem; }
.inline { display: flex; gap: 1rem; align-items: center; margin-top: .5rem; }

.errors { background: var(--err-bg); border: 1px solid var(--err-br); padding: .75rem; border-radius: .375rem; }
.ok     { background: var(--ok-bg);  border: 1px solid var(--ok-br);  padding: .75rem; border-radius: .375rem; }
.muted  { color: var(--muted); }
ul { padding-left: 1.1rem; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }