/* Variables globales */
:root {
    --primary-color: #4CAF50;
    --primary-dark: #388E3C;
    --primary-light: #81C784;
    --text-main: #1a1a1a;
    --background-main: #F7F9FC;
    --background-white: #ffffff;
    --shadow-soft: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-medium: 0 4px 6px rgba(0,0,0,0.1);
    --border-radius: 15px;
    --spacing-unit: 1rem;
    --header-height: 60px;
    --bottom-nav-height: 60px;
    --accent-color: #FF5722;
    --text-secondary: #404040;
    --button-color: #388E3C;
    --hover-color: #81C784;
    --overlay-color: rgba(0,0,0,0.5);
    --border-light: #ddd;
    --verb-color: #2196F3;
    --verb-background: #E3F2FD;
    --verb-hover: #1976D2;
    --conjugation-color: #673AB7;
    --conjugation-background: #EDE7F6;
}

/* Reset y estilos base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu, Cantarell, sans-serif;
    line-height: 1.7;
    font-size: 1.05rem;
    color: var(--text-main);
    background-color: var(--background-main);
    overflow-x: hidden;
    padding-bottom: var(--bottom-nav-height);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Header fijo */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--background-white);
    box-shadow: var(--shadow-soft);
    z-index: 1000;
    display: flex;
    align-items: center;
    padding: 0 1rem;
}

.header h1 {
    font-size: 1.25rem;
    margin: 0;
}

/* Contenedor principal */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    padding-top: calc(var(--header-height) + 20px);
}

/* Navegación inferior */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--bottom-nav-height);
    background: var(--background-white);
    box-shadow: 0 -2px 4px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-around;
    align-items: center;
    z-index: 1000;
}

.nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.75rem;
}

.nav-item i {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
}

.nav-item.active {
    color: var(--primary-color);
}

/* Tarjetas */
.card {
    background: var(--background-white);
    border-radius: var(--border-radius);
    padding: 1rem;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-soft);
    transition: transform 0.3s ease;
}

/* Grid responsivo */
.grid {
    display: grid;
    gap: 1rem;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* Botones */
.button, button {
    background-color: var(--button-color);
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.button:hover, button:hover {
    background-color: var(--hover-color);
}

/* Enlaces */
a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--hover-color);
}

/* Títulos */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-main);
    margin-bottom: 1rem;
}

/* Cajas de explicación */
.explanation-box {
    background-color: var(--background-white);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px var(--shadow-color);
}

/* Botones de audio */
.audio-button {
    background-color: var(--button-color);
    color: white;
    border: none;
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.audio-button:hover {
    background-color: var(--hover-color);
}

/* Tablas */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

th {
    background-color: var(--background-main);
    color: var(--text-main);
    padding: 12px;
    text-align: left;
}

td {
    padding: 12px;
    border-bottom: 1px solid var(--border-light);
}

/* Formularios */
input, select, textarea {
    width: 100%;
    padding: 8px;
    margin-bottom: 1rem;
    border: 1px solid var(--border-light);
    border-radius: 4px;
    background-color: var(--background-white);
    color: var(--text-main);
}

/* Modal */
.modal {
    background-color: var(--overlay-color);
}

.modal-content {
    background-color: var(--background-white);
    color: var(--text-main);
}

/* Verbos */
.verb-button {
    background-color: var(--background-white);
    color: var(--text-main);
    border: 1px solid var(--border-light);
    padding: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1rem;
}

.verb-button:hover {
    background-color: var(--background-main);
}

.verb-title {
    color: var(--accent-color);
    font-size: 24px;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.verb-type {
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 20px;
}

.conjugation-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    background: var(--background-white);
}

.conjugation-table th {
    background-color: var(--background-light);
    padding: 12px;
    text-align: left;
    color: var(--primary-color);
    font-weight: 600;
}

.conjugation-table td {
    padding: 12px;
    border-bottom: 1px solid #eee;
}

/* Estilos para verbos y conjugaciones */
.italian {
    color: var(--text-main);
    font-size: 1.2rem;
    font-weight: 500;
    background-color: var(--verb-background);
    padding: 0.3rem 0.6rem;
    border-radius: 4px;
    display: inline-block;
    margin: 0.2rem 0;
    transition: all 0.3s ease;
}

.italian:hover {
    color: var(--verb-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-soft);
}

.conjugation {
    color: var(--conjugation-color);
    background-color: var(--conjugation-background);
    padding: 0.2rem 0.5rem;
    border-radius: 3px;
    font-weight: 500;
    margin: 0.1rem 0;
    display: inline-block;
}

.verb-example {
    border-left: 3px solid var(--verb-color);
    padding-left: 1rem;
    margin: 1rem 0;
    background-color: var(--background-white);
    padding: 1rem;
    border-radius: 0 8px 8px 0;
    box-shadow: var(--shadow-soft);
}

/* Estilos para el alfabeto y botón de escuchar */
.alphabet-container {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin: 1rem 0;
}

.letter-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: var(--background-white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-soft);
    width: 100%;
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.listen-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background-color: var(--accent-color);
    color: white;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    margin-top: 0.5rem;
    transition: all 0.3s ease;
    width: 100%;
}

.listen-button:hover {
    background-color: var(--hover-color);
    transform: translateY(-2px);
}

.listen-button i {
    font-size: 1.1rem;
}

@media (min-width: 769px) {
    .letter-item {
        width: calc(20% - 1rem);
        margin-bottom: 1rem;
    }
    
    .listen-button {
        width: auto;
    }
}

/* Media Queries */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .container {
        padding: 0.75rem;
        padding-top: calc(var(--header-height) + 0.75rem);
    }

    .grid {
        gap: 0.75rem;
    }

    .card {
        padding: 0.75rem;
    }

    .button, button {
        width: 100%;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 12px;
    }

    .container {
        padding: 0.5rem;
        padding-top: calc(var(--header-height) + 0.5rem);
    }

    .grid {
        grid-template-columns: 1fr;
    }

    .header h1 {
        font-size: 1.1rem;
    }

    .nav-item {
        font-size: 0.7rem;
    }
}

/* Mejoras táctiles */
@media (hover: none) {
    .button:active, button:active {
        transform: scale(0.98);
    }
}

/* Modo oscuro */
@media (prefers-color-scheme: dark) {
    :root {
        --background-main: #121212;
        --background-white: #1e1e1e;
        --text-main: #ffffff;
        --text-secondary: #b0b0b0;
        --primary-light: #1b5e20;
    }
}

/* Mejoras de rendimiento */
* {
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

img, video {
    max-width: 100%;
    height: auto;
}

/* Estilos para la página de verbos */
.verbs-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 15px;
}

/* Responsive */
@media (max-width: 768px) {
    .verbs-container {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
        gap: 10px;
        padding: 10px;
    }
    
    .verb-button {
        padding: 10px;
        font-size: 0.9rem;
    }

    .modal-content {
        margin: 0;
        width: 100%;
        height: 100%;
        border-radius: 0;
    }

    .conjugation-table {
        font-size: 14px;
    }

    .conjugation-table th,
    .conjugation-table td {
        padding: 8px;
    }

    .verb-title {
        font-size: 20px;
    }

    .audio-button {
        width: 28px;
        height: 28px;
        font-size: 1em;
    }
}

/* Mejoras de legibilidad */
.dialogue-container {
    font-size: 1.1rem;
    line-height: 1.8;
    padding: 1.5rem;
    background-color: var(--background-white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-soft);
    margin: 1rem 0;
}