/* Variables y estilos base (Herencia) */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #34495e;
    --animation-duration: 0.3s;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

/* Selectores de elemento */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--dark-color));
    color: white;
    padding: 1rem 0;
    position: relative;
}

/* Selector de clase */
.header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 1rem 5%;
}

/* Selector de ID */
#resultados {
    margin-top: 2rem;
    padding: 1.5rem;
    border-radius: 8px;
    background-color: white;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

/* Pseudoclase */
.search-button:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
}

/* Pseudoelemento */
.search-input::placeholder {
    color: #95a5a6;
    font-style: italic;
}

/* Posicionamiento */
.logo {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    height: 50px;
    width: auto;
}

.footer {
    position: fixed;
    bottom: 0;
    width: 100%;
    background-color: var(--dark-color);
    color: white;
    text-align: center;
    padding: 0.5rem 0;
}

/* Animaciones */
@keyframes pulse {
    0% {
        transform: scale(1);
        opacity: 0.7;
    }

    50% {
        transform: scale(1.05);
        opacity: 1;
    }

    100% {
        transform: scale(1);
        opacity: 0.7;
    }
}

.animated-circle {
    width: 20px;
    height: 20px;
    background-color: var(--secondary-color);
    border-radius: 50%;
    animation: pulse 1.5s infinite ease-in-out;
    display: none;
    /* Solo visible durante búsqueda */
}

.search-button {
    transition: all var(--animation-duration) ease;
}

/* Diseño de la sección de búsqueda */
.search-controls {
    display: flex;
    gap: 10px;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.search-select,
.search-input,
.search-button {
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

.search-input {
    flex-grow: 1;
    min-width: 200px;
}

.search-button {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Estilos para resultados */
.student-card {
    background-color: var(--light-color);
    border-left: 4px solid var(--secondary-color);
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 4px;
    transition: transform var(--animation-duration);
}

.student-card:hover {
    transform: translateX(5px);
}

.student-card h3 {
    color: var(--primary-color);
    margin-top: 0;
}

.student-info {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 10px;
}

/* Responsive */
@media (max-width: 768px) {
    .search-controls {
        flex-direction: column;
    }

    .logo {
        position: static;
        transform: none;
        margin: 0 auto;
    }

    .header {
        flex-direction: column;
        text-align: center;
    }
}