/* ============================================
   ESTILOS COMPARTIDOS T1 - Física 2° Medio
   Los colores se definen con variables CSS en cada HTML
   Variables esperadas: --t1-primario, --t1-secundario, --t1-menu, --t1-primario-rgb, --t1-secundario-rgb
   ============================================ */

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    min-height: 100vh;
    padding: 20px 0;
    color: #333;
}

/* Menú Superior */
.menu-superior {
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    padding: 20px 0;
    border-radius: 0 0 12px 12px;
    margin: 0 auto 30px auto;
    max-width: 1200px;
    width: calc(100% - 40px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-sizing: border-box;
    flex-wrap: wrap;
    gap: 15px;
    transition: transform 0.3s ease, opacity 0.3s ease;
    transform: translateY(0);
    opacity: 1;
}

.menu-superior.oculto {
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
}

.menu-superior .menu-izquierda,
.menu-superior .menu-derecha {
    flex: 1;
    min-width: 0;
    padding: 0 30px;
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.menu-superior .menu-izquierda { justify-content: flex-start; }
.menu-superior .menu-derecha { justify-content: flex-end; }

.menu-izquierda, .menu-derecha {
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.titulo-curso {
    color: white;
    font-weight: 600;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.separador { color: rgba(255, 255, 255, 0.6); font-weight: 400; }

.menu-link {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.95rem;
    background: rgba(255, 255, 255, 0.1);
}

.menu-link:hover {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    transform: translateY(-2px);
}

.nav-boton {
    background: white;
    color: var(--t1-primario);
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.nav-boton:hover {
    background: #f8f9fa;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Contenedor y tarjeta principal */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 30px 20px;
}

.main-card {
    background: white;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    padding: 40px;
    margin-bottom: 30px;
    animation: fadeIn 0.6s ease;
}

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

/* Títulos y texto base */
h1, h2 {
    font-size: 2.2em;
    color: var(--t1-primario);
    text-align: center;
    margin-bottom: 30px;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

h2 {
    font-size: 1.8em;
    color: var(--t1-secundario);
    margin: 40px 0 20px 0;
    text-align: left;
}

p {
    line-height: 1.8;
    margin-bottom: 20px;
    font-size: 1.1em;
    color: #555;
}

strong { color: var(--t1-primario); font-weight: 600; }

img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    margin: 20px 0;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

.content-image { text-align: center; margin: 30px 0; }

.content-image img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    cursor: pointer;
    transition: transform 0.3s ease;
}

.content-image img:hover { transform: scale(1.05); }

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 30px;
    border-radius: 20px;
    width: 90%;
    max-width: 1000px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    animation: slideDown 0.3s ease;
    position: relative;
    max-height: 80vh;
    overflow-y: auto;
    border: 3px solid transparent;
    transition: all 0.3s ease;
}

.modal-content::before {
    content: '';
    position: absolute;
    inset: -3px;
    border-radius: 20px;
    background: linear-gradient(45deg, var(--t1-primario), var(--t1-secundario), var(--t1-primario));
    background-size: 300% 300%;
    animation: rotateBorder 3s linear infinite;
    z-index: -1;
    opacity: 0.8;
}

.modal-content::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 20px;
    background: white;
    z-index: -1;
}

@keyframes rotateBorder {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.modal-content:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 50px rgba(var(--t1-primario-rgb), 0.4);
}

@keyframes slideDown {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.close, .close-btn {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    position: absolute;
    right: 20px;
    top: 15px;
    transition: all 0.3s ease;
    background: none;
    border: none;
    padding: 0;
    line-height: 1;
}

.close:hover, .close-btn:hover {
    color: var(--t1-primario);
    transform: rotate(90deg);
}

.modal h2 {
    color: var(--t1-primario);
    margin-bottom: 20px;
    padding-right: 40px;
}

.modal p { line-height: 1.8; color: #555; margin-bottom: 15px; }
.modal img { width: 100%; margin: 20px 0; border-radius: 10px; }

/* Modal header y body */
.modal-header {
    padding: 25px 30px;
    color: white;
    border-radius: 16px 16px 0 0;
    margin: -30px -30px 20px -30px;
    position: relative;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
}

.modal-header h2 { color: white; margin: 0; font-size: 1.8rem; font-weight: 700; padding-right: 40px; }
.modal-body { padding: 30px; }

.modal-header .close-btn {
    color: white;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.modal-header .close-btn:hover,
.modal-header .close-btn:focus {
    background: rgba(255, 255, 255, 0.3);
    transform: rotate(90deg);
}

/* Menú Inferior */
.menu-inferior {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    border: 2px solid var(--t1-primario);
    border-radius: 16px 16px 0 0;
    padding: 10px;
    margin: 0;
    max-width: 1200px;
    width: calc(100% - 40px);
    box-shadow: 0 -4px 12px rgba(var(--t1-primario-rgb), 0.1);
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) translateY(150px);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s ease, opacity 0.3s ease;
    z-index: 999;
}

.menu-inferior.visible {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    pointer-events: auto;
}

.subseccion-info {
    text-align: center;
    margin-bottom: 25px;
    padding-bottom: 20px;
    border-bottom: 2px solid rgba(var(--t1-primario-rgb), 0.2);
}

.subseccion-titulo {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--t1-primario);
    margin: 0 0 8px 0;
}

.subseccion-descripcion {
    font-size: 0.95rem;
    color: #475569;
    margin: 0;
    font-style: italic;
}

.navegacion-subsecciones {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.btn-subseccion {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px;
    border-radius: 12px;
    text-decoration: none;
    transition: all 0.3s ease;
    border: 2px solid #dbeafe;
    background: white;
}

.btn-subseccion:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(var(--t1-primario-rgb), 0.2);
    border-color: var(--t1-primario);
}

.btn-anterior { justify-content: flex-start; }
.btn-siguiente { justify-content: flex-end; }

.btn-subseccion .icono {
    font-size: 2rem;
    color: var(--t1-primario);
    transition: transform 0.3s ease;
}

.btn-anterior:hover .icono { transform: translateX(-5px); }
.btn-siguiente:hover .icono { transform: translateX(5px); }

.btn-subseccion .texto {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.btn-subseccion .label {
    font-size: 0.85rem;
    color: #64748b;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.2px;
}

.btn-subseccion .titulo {
    font-size: 1.05rem;
    color: var(--t1-primario);
    font-weight: 600;
}

.btn-anterior .texto { align-items: flex-start; text-align: left; }
.btn-siguiente .texto { align-items: flex-end; text-align: right; }

/* Botones */
.info-btn {
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    margin: 10px 5px;
}

.info-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(var(--t1-primario-rgb), 0.4);
}

.answer-btn {
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    margin: 10px 10px 10px 0;
    box-shadow: 0 2px 8px rgba(var(--t1-primario-rgb), 0.3);
}

.answer-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(var(--t1-primario-rgb), 0.4);
}

.answer-btn.respuestas-bloqueadas,
.btn-ver-desarrollo.respuestas-bloqueadas,
.btn-revisar.respuestas-bloqueadas,
.paes-option.respuestas-bloqueadas,
#paes-revisar-btn.respuestas-bloqueadas {
    opacity: 0.5;
    cursor: not-allowed !important;
    pointer-events: none;
}

/* Cajas genéricas */
.info-box,
.equation-box,
.activities-box,
.features-box,
.freefall-box {
    background: #f8f9fa;
    border-left: 4px solid var(--t1-primario);
    border-radius: 10px;
    padding: 25px;
    margin: 30px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.info-box h2, .equation-box h2, .features-box h3, .freefall-box h3 {
    color: var(--t1-primario);
    margin-bottom: 15px;
}

/* Enlaces y activity-link */
a {
    color: var(--t1-primario);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

a:hover {
    color: var(--t1-secundario);
    text-decoration: underline;
}

.activity-link {
    display: inline-block;
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    color: white;
    padding: 12px 25px;
    border-radius: 25px;
    margin: 10px 10px 10px 0;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(var(--t1-primario-rgb), 0.3);
}

.activity-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(var(--t1-primario-rgb), 0.4);
    text-decoration: none;
    color: white;
}

/* Botón actividad moderna */
.btn-actividad-moderna {
    display: inline-block;
    background: linear-gradient(135deg, var(--t1-primario), var(--t1-secundario));
    color: white;
    padding: 15px 30px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
    transition: all 0.3s ease;
    margin: 10px 5px;
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn-actividad-moderna::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s ease;
}

.btn-actividad-moderna:hover::before { left: 100%; }

.btn-actividad-moderna:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 25px rgba(var(--t1-primario-rgb), 0.4);
    animation: pulseButton 1.5s ease-in-out infinite;
}

@keyframes pulseButton {
    0%, 100% { box-shadow: 0 8px 25px rgba(var(--t1-primario-rgb), 0.4); }
    50% { box-shadow: 0 8px 30px rgba(var(--t1-primario-rgb), 0.6); }
}

.btn-actividad-moderna:active {
    transform: translateY(-1px) scale(1.02);
}

.glow-effect {
    position: relative;
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from { box-shadow: 0 0 5px rgba(var(--t1-primario-rgb), 0.2); }
    to { box-shadow: 0 0 20px rgba(var(--t1-primario-rgb), 0.4); }
}

blockquote {
    background: #f8f9fa;
    border-left: 4px solid var(--t1-primario);
    padding: 15px 20px;
    margin: 20px 0;
    border-radius: 5px;
}

blockquote a { display: block; margin: 8px 0; }

/* Tabla de clases (01) */
.classes-table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    overflow: hidden;
}

.classes-table thead {
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    color: white;
}

.classes-table th {
    padding: 20px;
    text-align: center;
    font-weight: 600;
    font-size: 1.1em;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.classes-table td {
    padding: 20px;
    text-align: center;
    border-bottom: 1px solid #e0e0e0;
    transition: background 0.3s ease;
}

.classes-table tbody tr:hover {
    background: #f5f5f5;
    transform: scale(1.01);
}

.classes-table tbody tr:last-child td { border-bottom: none; }

.class-link {
    color: var(--t1-primario);
    text-decoration: none;
    font-weight: 600;
    padding: 8px 15px;
    border-radius: 8px;
    display: inline-block;
    transition: all 0.3s ease;
}

.class-link:hover {
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(var(--t1-primario-rgb), 0.4);
}

/* Units container y cards */
.units-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-top: 40px;
}

.unit-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
    text-align: center;
}

.unit-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.unit-card h3 { color: var(--t1-primario); font-size: 1.5em; margin-bottom: 15px; }
.unit-card p { color: #666; line-height: 1.6; }

/* Concept list, questions, comparison */
.concept-list {
    background: #f8f9fa;
    border-left: 4px solid var(--t1-primario);
    padding: 20px 30px;
    margin: 25px 0;
    border-radius: 8px;
}

.concept-list li { margin: 15px 0; line-height: 1.8; font-size: 1.05em; }

.questions-box {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 15px;
    padding: 25px;
    margin: 30px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.comparison-box {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 30px 0;
}

.comparison-item {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.comparison-item h3 { color: var(--t1-primario); margin-bottom: 15px; font-size: 1.3em; }

/* Cuestionario selección múltiple */
.pregunta-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
    border-left: 4px solid var(--t1-primario);
}

.pregunta-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.pregunta-header h3 {
    color: var(--t1-primario);
    margin: 0;
    font-size: 1.2em;
}

.alternativas-container { display: flex; flex-direction: column; gap: 10px; }

.alternativa-label {
    display: flex;
    align-items: center;
    padding: 12px 15px;
    background: white;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.alternativa-label:hover {
    background: #e3f2fd;
    border-color: var(--t1-primario);
    transform: translateX(5px);
}

.alternativa-label input[type="radio"] {
    margin-right: 12px;
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.alternativa-letra {
    font-weight: 600;
    color: var(--t1-primario);
    margin-right: 10px;
    min-width: 25px;
}

.alternativa-texto { flex: 1; color: #334155; }

.cuestionario-actions { text-align: center; margin: 30px 0; }

.btn-revisar, .btn-reiniciar {
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    color: white;
    border: none;
    padding: 15px 40px;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(var(--t1-primario-rgb), 0.3);
}

.btn-revisar:hover, .btn-reiniciar:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(var(--t1-primario-rgb), 0.4);
}

.resultados-container { margin-top: 20px; }

.resultado-general {
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
    padding: 25px;
    border-radius: 10px;
    text-align: center;
    margin-bottom: 30px;
    border: 2px solid var(--t1-primario);
}

.resultado-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid var(--t1-primario);
}

.resultado-item.correcta { border-left-color: #28a745; background: #f0f9f4; }
.resultado-item.incorrecta { border-left-color: #dc3545; background: #e3f2fd; }

.btn-ver-desarrollo {
    background: linear-gradient(135deg, var(--t1-primario), var(--t1-secundario));
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(var(--t1-primario-rgb), 0.3);
    white-space: nowrap;
    flex-shrink: 0;
}

.btn-ver-desarrollo:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(var(--t1-primario-rgb), 0.4);
}

/* Título, seccion-card, efectos */
.titulo {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--t1-primario);
    margin: 30px 0 20px 0;
    padding: 20px;
    position: relative;
    display: inline-block;
    transition: color 0.3s ease, transform 0.3s ease, text-shadow 0.3s ease;
}

.titulo::after {
    content: '';
    position: absolute;
    bottom: 10px;
    left: 20px;
    width: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--t1-primario), var(--t1-secundario));
    border-radius: 2px;
    transition: width 0.4s ease;
}

.titulo:hover::after {
    width: calc(100% - 40px);
    box-shadow: 0 0 10px rgba(var(--t1-primario-rgb), 0.6);
}

.titulo:hover {
    color: var(--t1-secundario);
    transform: translateX(8px);
    text-shadow: 0 2px 12px rgba(var(--t1-primario-rgb), 0.5);
}

.subtitulo {
    font-size: 1.3em;
    color: var(--t1-secundario);
    text-align: center;
    margin-bottom: 40px;
    font-weight: 500;
}

.seccion-card {
    background: white;
    border-radius: 16px;
    padding: 30px;
    margin: 30px 0;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(var(--t1-primario-rgb), 0.1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.seccion-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--t1-primario), var(--t1-secundario));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s ease;
}

.seccion-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(var(--t1-primario-rgb), 0.2);
    border-color: var(--t1-primario);
}

.seccion-card:hover::before { transform: scaleX(1); }

.parrafo, p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #1e293b;
    margin: 15px 0;
    padding: 10px 20px;
    transition: all 0.3s ease;
}

p:hover {
    background: rgba(var(--t1-primario-rgb), 0.05);
    border-radius: 8px;
    transform: translateX(5px);
}

.animate-fade { animation: fadeIn 0.6s ease-out; }

.glow-effect:hover {
    box-shadow: 0 0 20px rgba(var(--t1-primario-rgb), 0.6),
                0 0 40px rgba(var(--t1-secundario-rgb), 0.4);
    transition: box-shadow 0.3s ease;
}

/* Pregunta actividad, desarrollo */
.pregunta-actividad {
    background: white;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    border-left: 4px solid var(--t1-primario);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
    transition: all 0.3s ease;
}

.pregunta-actividad:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(var(--t1-primario-rgb), 0.15);
}

.pregunta-texto-act {
    flex: 1;
    font-size: 1.05rem;
    color: #1e293b;
    line-height: 1.6;
    font-weight: 500;
}

.desarrollo-contenido {
    font-size: 1.05rem;
    line-height: 1.8;
    color: #334155;
}

.desarrollo-contenido h4 {
    color: var(--t1-primario);
    margin-top: 20px;
    margin-bottom: 12px;
    font-size: 1.2rem;
}

.paso-calculo {
    background: linear-gradient(135deg, rgba(var(--t1-primario-rgb), 0.1), rgba(var(--t1-secundario-rgb), 0.1));
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid var(--t1-primario);
    margin: 20px 0;
}

.formula {
    background: white;
    padding: 15px 20px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 1.1rem;
    border: 2px solid rgba(var(--t1-primario-rgb), 0.2);
    margin: 15px 0;
    text-align: center;
}

.resultado-final {
    background: linear-gradient(135deg, rgba(var(--t1-primario-rgb), 0.1), rgba(var(--t1-secundario-rgb), 0.1));
    padding: 20px;
    border-radius: 12px;
    border: 2px solid var(--t1-primario);
    margin: 20px 0;
    text-align: center;
}

.nota-importante {
    background: rgba(var(--t1-primario-rgb), 0.1);
    padding: 15px 20px;
    border-radius: 10px;
    border-left: 4px solid var(--t1-primario);
    margin: 15px 0;
    font-size: 0.95rem;
}

.grid-enunciado {
    background: #f8fafc;
    padding: 15px;
    border-radius: 8px;
    border: 2px dashed #cbd5e0;
    margin: 15px 0;
}

.btn-modal {
    background: white;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    padding: 25px;
    margin: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.btn-modal:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.click-hint {
    color: var(--t1-primario);
    font-weight: 600;
    margin-top: 15px;
    font-size: 0.95rem;
}

/* Responsive */
@media (max-width: 768px) {
    .titulo, h1, h2 { font-size: 1.6em; }
    .main-card { padding: 20px; }
    .comparison-box { grid-template-columns: 1fr; }
    .menu-superior {
        flex-direction: column;
        align-items: flex-start;
        padding: 15px 20px;
        width: calc(100% - 20px);
        max-width: 100%;
    }
    .menu-inferior { width: calc(100% - 20px); max-width: 100%; }
    .menu-izquierda, .menu-derecha { width: 100%; justify-content: flex-start; }
    .titulo-curso { font-size: 1rem; flex-wrap: wrap; }
    .menu-link, .nav-boton { font-size: 0.9rem; padding: 8px 14px; }
    .navegacion-subsecciones { grid-template-columns: 1fr; }
    .modal-content { width: 95%; margin: 10% auto; padding: 20px; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: #f1f1f1; }
::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, var(--t1-primario) 0%, var(--t1-secundario) 100%);
    border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover { background: var(--t1-secundario); }