@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;700&family=Teko:wght@400;600&display=swap');

:root {
    --primary-color: #0d6efd;
    --secondary-color: #6c757d;
    --background-color: #f0f2f5;
    --surface-color: #ffffff;
    --text-color: #212529;
    --heading-font: 'Teko', sans-serif;
    --body-font: 'Roboto', sans-serif;
    --border-radius: 8px;
}

body {
    font-family: var(--body-font);
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    line-height: 1.7;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

header {
    background: linear-gradient(45deg, #0052D4, #4364F7, #6FB1FC);
    color: white;
    padding: 3rem 0;
    text-align: center;
    border-bottom: 5px solid var(--primary-color);
}

header h1 {
    font-family: var(--heading-font);
    font-size: 3.8rem;
    font-weight: 600;
    margin: 0;
    letter-spacing: 1px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

header .subtitle {
    font-size: 1.2rem;
    font-weight: 300;
    opacity: 0.9;
    max-width: 700px;
    margin: 0.5rem auto 0;
}

nav {
    background-color: var(--surface-color);
    border-bottom: 1px solid #dee2e6;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(0,0,0,0.07);
}

nav .container {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.nav-link {
    font-family: var(--heading-font);
    font-size: 1.6rem;
    color: var(--secondary-color);
    text-decoration: none;
    padding: 0.5rem 1.5rem;
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.nav-link:hover {
    color: var(--primary-color);
    background-color: #e9ecef;
}

.nav-link.active {
    color: var(--primary-color);
    border-color: var(--primary-color);
    font-weight: 600;
}

main {
    padding: 3rem 0;
    min-height: 60vh;
}

.content-section {
    background-color: var(--surface-color);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    animation: fadeIn 0.8s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

h2 {
    font-family: var(--heading-font);
    font-size: 3rem;
    color: var(--primary-color);
    border-bottom: 4px solid var(--primary-color);
    padding-bottom: 0.5rem;
    margin-top: 0;
    margin-bottom: 2rem;
}

h3 {
    font-family: var(--heading-font);
    font-size: 2.2rem;
    color: var(--text-color);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
}

.chart-container {
    max-width: 700px;
    margin: 2.5rem auto;
    padding: 1.5rem;
    border: 1px solid #e0e0e0;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.chart-caption {
    text-align: center;
    font-size: 0.9rem;
    color: var(--secondary-color);
    margin-top: 0.5rem;
    margin-bottom: 2.5rem;
}

.dual-column, .dual-column-strategy {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
    margin-top: 2rem;
}

.strategy-box {
    background-color: #f8f9fa;
    padding: 2rem;
    border-radius: var(--border-radius);
    border-left: 5px solid var(--primary-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.strategy-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}
.strategy-box:last-child {
    border-left-color: #28a745; /* Verde para la segunda estrategia */
}
.strategy-box h4 {
    font-family: var(--heading-font);
    font-size: 1.8rem;
    margin-top: 0;
}
.strategy-goal {
    font-weight: bold;
    color: var(--primary-color);
    margin-top: 1.5rem;
    border-top: 1px solid #ddd;
    padding-top: 1rem;
}
.strategy-box:last-child .strategy-goal {
    color: #28a745;
}

ul {
    padding-left: 20px;
}
li {
    margin-bottom: 1rem;
}

.loader {
    border: 8px solid #f3f3f3;
    border-radius: 50%;
    border-top: 8px solid var(--primary-color);
    width: 60px;
    height: 60px;
    animation: spin 1s linear infinite;
    margin: 5rem auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

footer {
    text-align: center;
    padding: 2.5rem 0;
    margin-top: 3rem;
    background-color: #343a40;
    color: white;
}
footer p {
    margin: 0;
    opacity: 0.8;
}

/* Responsive */
@media (max-width: 820px) {
    header h1 { font-size: 2.8rem; }
    .dual-column, .dual-column-strategy { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
    nav .container {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
    .nav-link { font-size: 1.4rem; }
    .content-section { padding: 1.5rem; }
    h2 { font-size: 2.4rem; }
    h3 { font-size: 1.8rem; }
}