body {
    font-family: Arial, sans-serif;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f7f9fa;
    position: relative;
}

/* Top Bar Styles */
.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #2d3e50;
    color: #fff;
    padding: 15px 30px;
    position: sticky;
    top: 0;
    z-index: 100;
    border-radius: 8px;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(44, 62, 80, 0.07);
    flex-wrap: nowrap; /* default */
}

.top-bar .left,
.top-bar .center,
.top-bar .right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.top-bar select,
.top-bar button {
    padding: 8px 15px;
    border-radius: 6px;
    border: none;
    font-size: 1.1em;
    background: #f7f9fa;
    color: #2d3e50;
    transition: background 0.3s, color 0.3s, transform 0.2s;
}

.top-bar button {
    background: #4caf50;
    color: #fff;
    font-weight: bold;
}

.top-bar button:hover,
.reverse-btn:hover,
#reverseButton:hover {
    background: #388e3c;
    color: #fff;
    transform: scale(1.05);
}

/* Botón de reversear */
.reverse-btn,
#reverseButton {
    background: #4caf50;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 8px 15px;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    margin-left: 10px;
    transition: background 0.3s, color 0.3s, transform 0.2s;
}

/* Sidebar Styles */
.sidebar {
    width: 300px;
    background: #fff;
    padding: 20px;
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    overflow-x: hidden;
    transition: transform 0.3s ease-in-out; /* Cambiado para animación suave */
    z-index: 1;
    box-shadow: 2px 0 8px rgba(44, 62, 80, 0.07);
    border-radius: 0 12px 12px 0;
    transform: translateX(0); /* posición normal */
}

.sidebar #sidebarContent {
    padding: 15px;
}

.sidebar.collapsed {
    transform: translateX(-110%); /* mejor que left para animar */
}

.sidebar.collapsed #sidebarContent {
    display: none;
}

/* Main Content Styles */
main {
    margin-left: 320px;
    padding: 20px;
    transition: margin-left 0.3s ease-in-out;
}

main.sidebar-collapsed {
    margin-left: 20px;
}

/* Practice Area Styles */
.practice-area {
    display: flex;
    justify-content: space-between;
    gap: 40px;
    margin-top: 30px;
}

.word-bank,
.practice-zone {
    flex: 1;
    padding: 30px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(44, 62, 80, 0.07);
    display: flex;
    flex-wrap: wrap;
    align-content: flex-start;
    gap: 15px;
    border: 1.5px solid #e0e0e0;
}

.word-bank {
    background: #f7f9fa;
    border: 1.5px solid #e0e0e0;
}

.draggable {
    padding: 18px 28px;
    background: #5bc0de;
    color: #fff;
    border-radius: 8px;
    cursor: move;
    font-size: 1.2em;
    user-select: none;
    box-shadow: 0 2px 6px rgba(44, 62, 80, 0.10);
    transition: transform 0.2s, background-color 0.2s, box-shadow 0.2s;
    margin: 5px;
    border: none;
}

.draggable:hover,
.draggable.dragging {
    transform: scale(1.05);
    background: #31b0d5;
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.13);
}

.drop-zone {
    width: 100%;
    padding: 30px;
    margin: 10px 0;
    border: 2px dashed #bdbdbd;
    border-radius: 10px;
    font-size: 1.2em;
    text-align: center;
    transition: background-color 0.3s, border-color 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100px;
    background: #f7f9fa;
    color: #2d3e50;
}

.drop-zone.correct {
    background: #e8f5e9;
    border-color: #5cb85c;
    color: #388e3c;
}

.drop-zone.incorrect {
    background: #ffebee;
    border-color: #d9534f;
    color: #a94442;
}

/* Lesson List Styles */
.lesson-list {
    background: #fff;
    border-radius: 8px;
    padding: 40px;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(44, 62, 80, 0.07);
}

.lesson-list h3 {
    margin-top: 0;
    color: #2d3e50;
    border-bottom: 2px solid #eee;
    padding-bottom: 10px;
}

/* Checkbox Styles */
#lessonCheckboxes,
#wordCheckboxes {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

#lessonCheckboxes div,
#wordCheckboxes div {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 5px;
}

/* Utility Classes */
.hidden {
    display: none;
}

#wordBank {
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    pointer-events: auto;
}

/* Estilos para el acordeón */
.lesson-accordion {
    border: 1px solid #eee;
    border-radius: 8px;
    margin-bottom: 15px;
    background: #fafbfc;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.lesson-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 15px;
    cursor: pointer;
    background: #f0f4f8;
    border-radius: 8px 8px 0 0;
    user-select: none;
}

.toggle-words-btn {
    background: none;
    border: none;
    font-size: 1.2em;
    cursor: pointer;
    margin-right: 5px;
}

.words-list {
    padding: 10px 25px 10px 35px;
    display: block;
    transition: max-height 0.3s;
}

.words-list.collapsed {
    display: none;
}

.word-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 3px 0;
}

.word-item label {
    cursor: pointer;
}

/* Estilos para mejorar la experiencia táctil */
.draggable {
    touch-action: none;
    transition: transform 0.2s, opacity 0.2s;
}

.draggable.dragging {
    opacity: 0.7;
    transform: scale(1.05);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

/* Responsive: Móvil y tablet (vertical) */
@media (max-width: 900px), (orientation: portrait) {
    /* Flex-wrap en top-bar para que los botones no se amontonen */
    .top-bar {
        flex-wrap: wrap;
        gap: 10px;
        padding: 12px 20px;
    }
    .top-bar .left,
    .top-bar .center,
    .top-bar .right {
        flex: 1 1 100%;
        justify-content: center;
        gap: 10px;
    }

    .sidebar {
        width: 85vw;
        max-width: 320px;
        height: 100vh;
        box-shadow: 2px 0 12px rgba(44, 62, 80, 0.12);
        border-radius: 0 0 16px 16px;
        position: fixed;
        top: 0;
        left: 0;
        transform: translateX(0);
        z-index: 20;
        transition: transform 0.3s ease-in-out;
    }
    .sidebar.collapsed {
        transform: translateX(-110%);
    }

    main {
        margin-left: 0;
        padding: 15px 10px;
        transition: margin-left 0.3s ease-in-out;
    }

    .practice-area {
        flex-direction: column;
        gap: 20px;
        align-items: stretch;
    }

    .practice-zone,
    .word-bank {
        padding: 25px 20px;
        font-size: 1.1em;
    }

    .draggable {
        padding: 16px 28px;
        margin: 8px 5px;
        font-size: 1.15em;
        border-radius: 10px;
    }

    .drop-zone {
        padding: 30px 25px;
        font-size: 1.15em;
        min-height: 120px;
        border-radius: 12px;
    }

    .top-bar select,
    .top-bar button {
        width: 100%;
        max-width: 300px;
        padding: 10px 20px;
        font-size: 1.15em;
    }
}

/* Extra responsive para pantallas muy pequeñas */
@media (max-width: 400px) {
    body {
        font-size: 17px;
    }
    .top-bar {
        padding: 10px 12px;
    }
    .top-bar select,
    .top-bar button {
        padding: 8px 15px;
        font-size: 1.05em;
    }
    #toggleSidebar {
        font-size: 1.3em;
    }
    main {
        padding: 10px 8px;
    }
    .practice-area {
        gap: 12px;
    }
    .word-bank,
    .practice-zone {
        padding: 18px 15px;
        font-size: 1.05em;
    }
    .draggable {
        padding: 14px 22px;
        font-size: 1.1em;
    }
    .drop-zone {
        padding: 22px 18px;
        font-size: 1.1em;
    }
    .lesson-list {
        padding: 25px 20px;
    }
}
/* INVERSIÓN del orden en móvil: Drop Zone arriba, Word Bank abajo */
@media (max-width: 900px), (orientation: portrait) {
    .practice-area {
        display: flex;
        flex-direction: column-reverse; /* <- Aquí la magia */
    }

    /* Ajustes para que el header esté fijo arriba del todo y el sidebar debajo */
    .top-bar {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        z-index: 1000;
        border-radius: 0;
        padding: 12px 20px;
    }

    body {
        padding-top: 80px; /* Empujar contenido hacia abajo para dejar espacio al header fijo */
    }

    .sidebar {
        top: 80px; /* Para que empiece debajo del header fijo */
        z-index: 999; /* Justo debajo del top-bar */
        height: calc(100% - 80px); /* Ajuste para que sidebar no tape el top-bar */
    }
}
.top-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: #2d3e50;
    color: #fff;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: top 0.3s ease-in-out;
}

/* Esta clase se agregará/quitara dinámicamente con JS */
.top-bar.hidden-on-scroll {
    top: -200px; /* Oculta el top-bar al deslizar hacia arriba */
}