:root {
    --usa-blue: #0A3161;
    --usa-red: #B31942;
    --usa-white: #FFFFFF;
    --light-gray: #F3F4F6;
    --dark-gray: #1F2937;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--light-gray);
    color: var(--dark-gray);
    overflow-x: hidden;
}

.app-content {
    display: none;
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
}

.app-content.visible {
    opacity: 1;
}

.section-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.section-animate.visible {
    opacity: 1;
    transform: translateY(0);
}

/* New American-themed animations and styles */
.star {
    position: absolute;
    background-color: white;
    clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
    animation: twinkle 3s infinite alternate;
}

@keyframes twinkle {
    0% {
        opacity: 0.7;
    }

    100% {
        opacity: 1;
    }
}

@keyframes wave {
    0% {
        transform: rotate(0deg);
    }

    25% {
        transform: rotate(5deg);
    }

    50% {
        transform: rotate(0deg);
    }

    75% {
        transform: rotate(-5deg);
    }

    100% {
        transform: rotate(0deg);
    }
}

.flag-wave {
    animation: wave 3s infinite;
    transform-origin: top left;
}

.firework {
    position: absolute;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    animation: explode 1.5s forwards;
    opacity: 0;
}

@keyframes explode {
    0% {
        transform: translate(0, 0) scale(0.1);
        opacity: 1;
    }

    100% {
        transform: translate(var(--tx), var(--ty)) scale(2);
        opacity: 0;
    }
}

/* --- BOTÓN PATRIÓTICO (NUEVO EFECTO GLOW) --- */
.button-patriotic {
    background-color: var(--usa-blue); /* Fondo azul sólido */
    transition: all 0.3s ease; /* Transición rápida */
    position: relative;
    overflow: hidden;
    /* El texto blanco ya se aplica en el HTML */
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2); /* Sombra inicial */
}

.button-patriotic:hover {
    transform: translateY(-3px);
    /* Aplicamos la animación de resplandor patriótico */
    animation: patriotic-glow 1.5s infinite alternate;
}

.button-patriotic:active {
    transform: translateY(-1px);
}

/* Keyframes para el resplandor del botón */
@keyframes patriotic-glow {
    0% {
        /* Sombra sutil azul */
        box-shadow: 0 0 15px 5px rgba(10, 49, 97, 0.4); 
    }
    50% {
        /* Sombra sutil blanca */
        box-shadow: 0 0 20px 8px rgba(255, 255, 255, 0.7);
    }
    100% {
        /* Sombra sutil roja */
        box-shadow: 0 0 15px 5px rgba(179, 25, 66, 0.4);
    }
}
/* --- FIN SECCIÓN BOTÓN --- */


.stripes-bg {
    background: repeating-linear-gradient(0deg,
            var(--usa-red),
            var(--usa-red) 8px,
            var(--usa-white) 8px,
            var(--usa-white) 16px);
}

.patriotic-border {
    border: 3px solid;
    border-image: linear-gradient(45deg, var(--usa-blue), var(--usa-white), var(--usa-red)) 1;
}

.header-glow {
    box-shadow: 0 4px 20px rgba(179, 25, 66, 0.3);
}


/* --- SECCIÓN DE EFECTOS DE TARJETAS (MODIFICADA) --- */

.card-hover {
    transition: all 0.3s ease;
    position: relative; /* Necesario para efectos */
    overflow: hidden;   /* Esconde el brillo fuera del card */
}

/* Hover "por defecto" (lift + shadow) para las info-cards */
.feature-card.card-hover:hover,
.method-card.card-hover:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 20px 30px rgba(0, 0, 0, 0.15);
}

/* --- Efecto "Glass Shimmer" (SOLO para tarjetas de info blancas) --- */
.feature-card::before,
.method-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%; 
    width: 100%;
    height: 100%;
    
    /* MODIFICADO: Onda de luz "oscura" (tipo vidrio) para que se vea en fondo blanco */
    background: linear-gradient(
        110deg, 
        transparent 30%, 
        rgba(0, 0, 0, 0.05) 50%, 
        transparent 70%
    );

    transform: skewX(-25deg);
    transition: left 0.85s cubic-bezier(0.23, 1, 0.32, 1);
    z-index: 1; /* Detrás del texto */
    pointer-events: none; 
}

.feature-card:hover::before,
.method-card:hover::before {
    left: 100%;
}

/* FIX DE Z-INDEX (SOLO para tarjetas de info) */
/* Asegura que el texto y los iconos estén encima del shimmer */
.feature-card > *,
.method-card > * {
    position: relative;
    z-index: 2;
}
/* --- Fin Efecto Shimmer (Info Cards) --- */


/* --- Efecto "Sliding Gradient" (SOLO para tarjetas de lección) --- */

/* 1. Aplicamos el fondo de botón al link <a> interno */
.lesson-card .lesson-link {
    /* MODIFICADO: Gradientes más pronunciados para azul y rojo */
    background: linear-gradient(45deg, #07244B 0%, var(--usa-blue) 25%, var(--usa-white) 50%, var(--usa-red) 35%, #D43A5F 100%);
    background-size: 300% 100%; 
    
    background-position: 0% 0; /* POSICIÓN INICIAL: Mostrar el AZUL */

    color: var(--usa-white); 
    transition: all 0.5s ease; 
    display: block;
    height: 100%;
    position: relative;
    z-index: 1;
}

/* 2. Arreglar el footer de la card */
.lesson-card .lesson-link div[class*="bg-gray-50"] {
    background-color: transparent; 
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--usa-white); 
}
.lesson-card .lesson-link div[class*="bg-gray-50"] * {
     color: var(--usa-white); 
}


/* 3. Definimos el hover para la TARJETA PADRE */
.lesson-card.card-hover:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* 4. Al hacer hover, deslizamos el fondo del LINK HIJO */
.lesson-card.card-hover:hover .lesson-link {
    background-position: 100% 0; /* POSICIÓN FINAL: Mostrar el ROJO */
}
/* --- Fin Efecto "Sliding Gradient" --- */


.progress-bar {
    height: 6px;
    background: repeating-linear-gradient(90deg,
            var(--usa-blue),
            var(--usa-blue) 15px,
            var(--usa-white) 15px,
            var(--usa-white) 30px,
            var(--usa-red) 30px,
            var(--usa-red) 45px);
    background-size: 200% 100%;
    animation: progress-animation 20s linear infinite;
}

@keyframes progress-animation {
    0% {
        background-position: 100% 0;
    }

    100% {
        background-position: 0% 0;
    }
}

.confetti {
    position: absolute;
    width: 10px;
    height: 10px;
    opacity: 0;
    animation: confetti-fall 5s linear forwards;
}

@keyframes confetti-fall {
    0% {
        transform: translateY(-100px) rotate(0deg);
        opacity: 1;
    }

    100% {
        transform: translateY(100vh) rotate(720deg);
        opacity: 0;
    }
}

.modal-content {
    background: linear-gradient(135deg, var(--usa-blue) 0%, var(--usa-red) 100%);
    border-radius: 15px;
    overflow: hidden;
    position: relative;
}

.modal-content::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 10px;
    background: repeating-linear-gradient(90deg,
            var(--usa-white),
            var(--usa-white) 20px,
            transparent 20px,
            transparent 40px);
}

/* Login modal animations */
#login-modal {
    display: flex;
    opacity: 1;
    transition: opacity 0.5s ease-in-out;
}

#login-modal.hidden {
    opacity: 0;
    pointer-events: none;
}