:root {
  --primary: #2c3e50;
  --secondary: #c0392b;
  --accent: #2980b9;
  --bg: #f4f7f6;
  --text: #333;
  --white: #ffffff;
  --border: #dee2e6;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Open Sans', sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

header {
  background: var(--primary);
  color: var(--white);
  padding: 1.5rem 1rem;
  text-align: center;
  border-bottom: 5px solid var(--secondary);
}

.container {
  display: grid;
  grid-template-columns: 250px 1fr 180px;
  gap: 20px;
  max-width: 1300px;
  margin: 20px auto;
  padding: 0 15px;
}

/* Menú Lateral */

nav {
  background: var(--white);
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  height: fit-content;
}

nav h3 {
  font-size: 1.1rem;
  margin-bottom: 1rem;
  color: var(--primary);
  border-bottom: 2px solid var(--bg);
  padding-bottom: 5px;
}

nav ul {
  list-style: none;
}

nav ul li {
  margin-bottom: 12px;
}

nav ul li a {
  text-decoration: none;
  color: var(--text);
  font-size: 0.9rem;
  transition: 0.3s;
}

nav ul li a:hover {
  color: var(--secondary);
  font-weight: bold;
}

/* Contenido Principal */

main {
  background: var(--white);
  padding: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

h1 {
  color: var(--secondary);
  margin-bottom: 1rem;
  font-size: 1.4rem;
  text-transform: uppercase;
}

.intro-text {
  font-size: 0.9rem;
  color: #666;
  border-bottom: 1px solid var(--border);
  padding-bottom: 20px;
  margin-bottom: 25px;
}

/* Agrupación por Años */

.year-section {
  margin-bottom: 40px;
}

.year-title {
  background: #eee;
  padding: 5px 15px;
  font-size: 1.1rem;
  font-weight: bold;
  color: var(--primary);
  border-radius: 4px;
  margin-bottom: 15px;
  display: flex;
  align-items: center;
}

.year-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: #ccc;
  margin-left: 15px;
}

/* Estilo de los Registros (Compacto para mucho texto) */

.record {
  padding: 15px;
  border-bottom: 1px solid #f0f0f0;
  transition: background 0.2s;
}

.record:hover {
  background: #fdfdfd;
}

.record-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 5px;
}

.exp-number {
  font-weight: 700;
  color: var(--secondary);
  font-size: 0.95rem;
}

.date-label {
  font-size: 0.8rem;
  color: #888;
}

.record-body {
  font-size: 0.9rem;
  color: #444;
}

.record-detail {
  margin-top: 5px;
  font-size: 0.85rem;
  background: #f9f9f9;
  padding: 8px;
  border-radius: 4px;
}

.record-detail strong {
  color: var(--primary);
}

/* Sidebar Derecha */

.sidebar-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.sidebar-links img {
  width: 100%;
  border-radius: 4px;
  opacity: 0.9;
}

@media (max-width: 1000px) {
  .container {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 1000px) {
  .sidebar-links {
    display: none;
  }
}