/* --- Variables de Tema y Estilos Globales --- */
:root {
    --bg-color: #1a1a1a;
    --surface-color: #2c2c2c;
    --primary-color: #00e676;
    --text-color: #f0f0f0;
    --border-color: #444;
    --text-color-light: #1a1a1a;

    --font-family: 'Poppins', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --border-radius: 6px;
    --box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* --- Cabecera y Título de Página --- */
header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 2rem;
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--box-shadow);
}

.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    transition: opacity 0.2s ease;
}

.logo-link:hover {
    opacity: 0.8;
}

.logo { max-height: 45px; }

.header-nav {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-button {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    background-color: var(--primary-color);
    color: #ffffff;
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--border-radius);
    transition: all 0.2s ease;
}

.nav-button i {
    font-size: 0.9rem;
    color: #ffffff;
    transition: transform 0.2s ease;
}

.nav-button:hover {
    background-color: #00ff88;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 230, 118, 0.3);
}

.nav-button:hover i {
    transform: scale(1.1);
}

.page-title-container {
    text-align: center;
    margin-bottom: 3rem;
}
.page-title-container h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}
.page-title-container p {
    font-size: 1.1rem;
    color: #a0a0a0;
    margin: 0;
}
.page-title-container h1::after {
    content: '';
    display: block;
    width: 80px;
    height: 3px;
    background-color: var(--primary-color);
    margin: 0.75rem auto 0;
    border-radius: 2px;
}

/* --- Contenedor Principal --- */
.main-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem;
    width: 100%;
    flex: 1;
}

.qr-layout {
    width: 100%;
    max-width: 600px;
}

.info-card {
    background-color: var(--surface-color);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    border: 1px solid var(--border-color);
}

/* --- Pestañas --- */
.tab-container {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.tab-button {
    padding: 0.75rem 0.5rem;
    cursor: pointer;
    background: none;
    border: none;
    color: var(--text-color);
    opacity: 0.6;
    font-size: 0.9rem;
    font-weight: 600;
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.3rem;
}

.tab-button i {
    font-size: 1.2rem;
}

.tab-button:hover {
    opacity: 1;
    background-color: var(--bg-color);
}

.tab-button.active {
    opacity: 1;
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* --- Formularios --- */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: bold;
    font-size: 0.95rem;
}

.qr-card input,
.qr-card select,
.qr-card textarea {
    width: 100%;
    padding: 0.75rem;
    font-size: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: var(--bg-color);
    color: var(--text-color);
    box-sizing: border-box;
    transition: all 0.2s ease;
}

.qr-card input:focus,
.qr-card select:focus,
.qr-card textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 230, 118, 0.25);
}

.qr-card textarea {
    resize: vertical;
    font-family: var(--font-family);
}

/* --- Botones --- */
.generate-button {
    width: 100%;
    padding: 0.85rem;
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--text-color-light);
    background-color: var(--primary-color);
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.generate-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 230, 118, 0.25);
}

/* --- Resultado del QR --- */
.qr-result-container {
    display: none;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
}

#qr-canvas-wrapper {
    background-color: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

#qr-canvas {
    display: block;
    border-radius: 4px;
}

#download-qr-link {
    width: auto;
    padding: 0.7rem 2rem;
    display: inline-flex;
}

/* --- Footer --- */
footer {
    text-align: center;
    padding: 1rem;
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
    width: 100%;
    margin-top: auto;
}

/* --- Media Queries --- */
@media (max-width: 768px) {
    .tab-container {
        grid-template-columns: repeat(3, 1fr);
    }

    .tab-button {
        font-size: 0.85rem;
        padding: 0.6rem 0.3rem;
    }

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

@media (max-width: 550px) {
    .page-title-container h1 {
        font-size: 1.8rem;
    }
    
    .page-title-container p {
        font-size: 1rem;
    }

    .main-container {
        padding: 1.5rem 1rem;
    }

    header {
        display: flex;
        justify-content: space-between;
        padding: 0.75rem 1rem;
    }

    .logo {
        max-height: 40px;
    }

    .header-nav {
        gap: 1rem;
    }

    .nav-button {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }

    .nav-button i {
        font-size: 0.8rem;
    }

    .info-card, .qr-card {
        padding: 1.5rem;
    }

    .tab-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.25rem;
    }

    .tab-button {
        font-size: 0.75rem;
        padding: 0.5rem 0.25rem;
    }

    #qr-canvas-wrapper {
        padding: 0.75rem;
    }
}