:root {
  --primary: #1f7a3e;
  --primary-dark: #15542b;
  --secondary: #2f5f98;
  --bg: #f4f6f8;
  --card: #ffffff;
  --text: #1f2937;
  --error: #b91c1c;
  --success: #166534;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.navbar {
  background: var(--primary);
  color: #fff;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.2rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.navbar nav {
  display: flex;
  gap: 0.6rem;
}

.navbar a {
  color: #e8f5ec;
  text-decoration: none;
  padding: 0.4rem 0.7rem;
  border-radius: 6px;
}

.navbar a.active,
.navbar a:hover {
  background: rgba(255, 255, 255, 0.2);
}

.container {
  width: min(900px, 92%);
  margin: 1.5rem auto;
  flex: 1;
}

.hero {
  display: grid;
  place-items: center;
  text-align: center;
}

.card {
  background: var(--card);
  border-radius: 12px;
  padding: 1.2rem;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.08);
}

.form-grid {
  display: grid;
  gap: 1rem;
}

label {
  display: grid;
  gap: 0.5rem;
  font-weight: 600;
}

input,
select,
button {
  font: inherit;
  border-radius: 8px;
}

input,
select {
  border: 1px solid #c7ced8;
  padding: 0.65rem;
}

.btn {
  display: inline-block;
  width: fit-content;
  padding: 0.7rem 1rem;
  border: none;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
}

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

.btn-secondary {
  background: var(--secondary);
}

.message {
  display: none;
  margin-bottom: 1rem;
  padding: 0.8rem;
  border-radius: 8px;
  font-weight: 600;
}

.message.error {
  display: block;
  background: #fee2e2;
  color: var(--error);
}

.message.success {
  display: block;
  background: #dcfce7;
  color: var(--success);
}

.hidden {
  display: none;
}

.loading-screen {
  min-height: 70vh;
  display: grid;
  place-items: center;
}

.centered {
  text-align: center;
}

.spinner {
  width: 50px;
  height: 50px;
  border: 6px solid #d1d5db;
  border-top-color: var(--primary);
  border-radius: 50%;
  margin: 1rem auto;
  animation: spin 0.9s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.result-list {
  line-height: 1.8;
}

.button-row {
  margin-top: 1.2rem;
}

footer {
  text-align: center;
  padding: 1rem;
}

@media (max-width: 640px) {
  .navbar {
    justify-content: center;
    text-align: center;
  }

  .btn {
    width: 100%;
    text-align: center;
  }
}