:root {
  --bg-dark: #0f0e17;
  --bg-card: #1a1926;
  --accent: #e94560;
  --accent-soft: #ff6b6b;
  --text: #eaeaea;
  --text-muted: #a0a0a0;
  --border: #2d2a3e;
  --success: #00d9a5;
  --error: #e94560;
}

* {
  box-sizing: border-box;
}

body {
  font-family: Georgia, 'Times New Roman', Times, serif;
  background: var(--bg-dark);
  color: var(--text);
  margin: 0;
  min-height: 100vh;
  line-height: 1.6;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

header {
  text-align: center;
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

h1 {
  font-size: 2rem;
  font-weight: 400;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-soft);
  margin: 0;
}

nav {
  margin-top: 1rem;
}

nav a {
  color: var(--text-muted);
  text-decoration: none;
  margin: 0 0.75rem;
  font-size: 0.95rem;
  transition: color 0.2s;
}

nav a:hover {
  color: var(--accent-soft);
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.75rem;
  margin-bottom: 1.5rem;
}

.card h2 {
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--accent-soft);
  margin: 0 0 1.25rem 0;
  letter-spacing: 0.08em;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.form-group input {
  width: 100%;
  padding: 0.6rem 0.85rem;
  background: var(--bg-dark);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text);
  font-size: 1rem;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--accent);
}

.form-group select {
  padding: 0.6rem 0.85rem;
  background: var(--bg-dark);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text);
  font-size: 1rem;
  font-family: inherit;
  cursor: pointer;
}

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

.form-group--utc input,
.form-group--utc select {
  width: auto;
  min-width: 12rem;
}

.form-group--coordinates {
  margin-bottom: 1.25rem;
}

.form-group--coordinates .form-row {
  margin-top: 0.4rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.2s;
}

.btn:hover {
  background: var(--accent-soft);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0;
}
.btn-group .btn {
  flex: 1 1 auto;
  min-width: 0;
}
@media (max-width: 520px) {
  .btn-group {
    flex-direction: column;
  }
  .btn-group .btn {
    width: 100%;
    text-align: center;
  }
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.alert {
  padding: 1rem 1.25rem;
  border-radius: 4px;
  margin-bottom: 1.5rem;
}

.alert-error {
  background: rgba(233, 69, 96, 0.15);
  border: 1px solid var(--error);
  color: var(--error);
}

.chart-result {
  margin-top: 2rem;
}

.result-actions {
  margin-bottom: 1rem;
}

.chart-result h3 {
  font-size: 1.1rem;
  color: var(--accent-soft);
  margin: 1.5rem 0 0.75rem 0;
  letter-spacing: 0.05em;
}

.chart-result h3:first-child {
  margin-top: 0;
}

.chart-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.5rem 0 1.25rem 0;
}

.chart-table th,
.chart-table td {
  padding: 0.6rem 0.85rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.chart-table th {
  color: var(--text-muted);
  font-weight: 400;
  font-size: 0.85rem;
}

.chart-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.chart-result ul {
  padding-left: 1.5rem;
  margin: 0.5rem 0 1.25rem 0;
}

.chart-result li {
  margin-bottom: 0.4rem;
}

.chart-result p {
  margin: 0.5rem 0 1rem 0;
  color: var(--text-muted);
}

@media (max-width: 520px) {
  .form-row {
    grid-template-columns: 1fr;
  }
}