:root {
  --tcc-navy: #0f2540;
  --tcc-navy-dark: #081627;
  --border: #d8dde3;
  --bg: #f5f6f8;
  --text: #1c2733;
  --muted: #5b6b7b;
  --ok: #1e7d3c;
  --warn: #b8860b;
  --err: #b3261e;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

header {
  background: var(--tcc-navy);
  color: #fff;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header h1 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
}

header .who {
  font-size: 13px;
  color: #cfd9e3;
}

header a {
  color: #cfd9e3;
  text-decoration: underline;
  font-size: 13px;
}

main {
  max-width: 1000px;
  margin: 0 auto;
  padding: 24px;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 20px;
}

.card h2 {
  margin-top: 0;
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.signin-box {
  text-align: center;
  padding: 60px 20px;
}

.signin-box h2 {
  font-size: 20px;
  color: var(--text);
  text-transform: none;
  letter-spacing: normal;
}

.btn {
  display: inline-block;
  background: var(--tcc-navy);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 8px 16px;
  font-size: 14px;
  cursor: pointer;
  text-decoration: none;
}

.btn:hover {
  background: var(--tcc-navy-dark);
}

.btn.secondary {
  background: #fff;
  color: var(--tcc-navy);
  border: 1px solid var(--tcc-navy);
}

.btn.danger {
  background: #fff;
  color: var(--err);
  border: 1px solid var(--err);
}

.btn.small {
  padding: 4px 10px;
  font-size: 12px;
}

input, select {
  font-size: 14px;
  padding: 7px 9px;
  border: 1px solid var(--border);
  border-radius: 5px;
}

.form-row {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 10px;
}

.form-row label {
  font-size: 13px;
  color: var(--muted);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

th, td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  color: var(--muted);
  font-weight: 600;
}

.tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
}

.tab {
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-bottom: none;
  border-radius: 6px 6px 0 0;
  background: #eceff2;
  cursor: pointer;
  font-size: 13px;
  color: var(--muted);
}

.tab.active {
  background: #fff;
  color: var(--text);
  font-weight: 600;
}

.hint {
  color: var(--muted);
  font-size: 13px;
}

.error-banner {
  background: #fdecea;
  border: 1px solid #f5c6c0;
  color: var(--err);
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 13px;
  margin-bottom: 16px;
}

.ok-banner {
  background: #eaf6ee;
  border: 1px solid #bfe6cb;
  color: var(--ok);
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 13px;
  margin-bottom: 16px;
}

.assignment-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #eef1f4;
  border-radius: 14px;
  padding: 3px 6px 3px 10px;
  font-size: 12px;
  margin: 2px 4px 2px 0;
}

.assignment-tag button {
  border: none;
  background: none;
  color: var(--err);
  cursor: pointer;
  font-size: 13px;
  line-height: 1;
  padding: 2px;
}

.remaining-neg { color: var(--err); font-weight: 600; }
.remaining-ok { color: var(--ok); font-weight: 600; }