:root {
  --bg: #f3f4f6;
  --card: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --primary: #0f766e;
  --primary-dark: #115e59;
  --border: #e5e7eb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}

.brand {
  font-size: 20px;
  font-weight: 700;
}

nav a {
  margin-left: 16px;
  text-decoration: none;
  color: var(--primary);
  font-weight: 600;
}

.container {
  max-width: 1100px;
  margin: 24px auto 60px;
  padding: 0 16px;
}

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

.card.narrow {
  max-width: 420px;
  margin: 40px auto;
}

h1, h2 {
  margin-top: 0;
}

label {
  display: block;
  margin-top: 12px;
  font-size: 14px;
  color: var(--muted);
}

input, select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-top: 6px;
}

button {
  margin-top: 14px;
  padding: 10px 16px;
  border: none;
  background: var(--primary);
  color: #fff;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
}

button.secondary {
  background: #374151;
}

.alert {
  background: #fef3c7;
  border: 1px solid #f59e0b;
  color: #92400e;
  padding: 10px 12px;
  border-radius: 6px;
  margin-bottom: 16px;
}

.alert.success {
  background: #dcfce7;
  border-color: #22c55e;
  color: #166534;
}

.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.stat {
  background: var(--card);
  border: 1px solid var(--border);
  padding: 18px;
  border-radius: 8px;
}

.stat-label {
  color: var(--muted);
  font-size: 14px;
}

.stat-value {
  font-size: 28px;
  font-weight: 700;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

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

.inline-form {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.grid-form {
  display: grid;
  grid-template-columns: 1fr;
}

@media (max-width: 720px) {
  nav a {
    margin-left: 8px;
  }

  .inline-form {
    flex-direction: column;
    align-items: stretch;
  }
}