/* Reset y configuración base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colores principales - diseño educativo con colores vivos */
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --danger-color: #ef4444;
    
    /* Colores de fondo */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #e2e8f0;
    --bg-chat: #f1f5f9;
    
    /* Colores de texto - alto contraste */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    
    /* Sombras */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    
    /* Bordes */
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-color: #e2e8f0;
    
    /* Fuentes - tamaño grande para accesibilidad */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-size-xs: 0.875rem;
    --font-size-sm: 1rem;
    --font-size-base: 1.125rem;
    --font-size-lg: 1.25rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background: var(--bg-primary);
    box-shadow: var(--shadow-lg);
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo i {
    font-size: var(--font-size-xl);
    color: var(--accent-color);
}

.logo h1 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    margin: 0;
}

.subject-selector {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: var(--font-size-base);
}

.subject-dropdown {
    padding: 0.5rem 1rem;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-sm);
    background: rgba(255, 255, 255, 0.1);
    color: white;
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.subject-dropdown:focus {
    outline: none;
    border-color: var(--accent-color);
    background: rgba(255, 255, 255, 0.2);
}

.subject-dropdown option {
    background: var(--primary-color);
    color: white;
}

/* Chat Container */
.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg-chat);
}

/* Welcome Message */
.welcome-message {
    padding: 2rem;
    text-align: center;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
}

.welcome-content {
    max-width: 600px;
    margin: 0 auto;
}

.welcome-icon {
    font-size: 3rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.welcome-message h2 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.welcome-message p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

#currentSubject {
    font-weight: 600;
    color: var(--primary-color);
}

.quick-questions h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.question-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.quick-question {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: var(--font-size-base);
    font-weight: 500;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
}

.quick-question:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.quick-question i {
    font-size: var(--font-size-lg);
    color: var(--secondary-color);
    transition: color 0.3s ease;
}

.quick-question:hover i {
    color: var(--accent-color);
}

/* Chat Messages */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.message {
    display: flex;
    gap: 1rem;
    max-width: 85%;
    animation: fadeInUp 0.3s ease;
}

.message.user {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.message-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-lg);
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: var(--primary-color);
    color: white;
}

.message.bot .message-avatar {
    background: var(--secondary-color);
    color: white;
}

.message-content {
    background: var(--bg-primary);
    padding: 1.25rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    font-size: var(--font-size-base);
    line-height: 1.7;
}

.message.user .message-content {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.message-content pre {
    background: var(--bg-tertiary);
    padding: 1rem;
    border-radius: var(--border-radius-sm);
    overflow-x: auto;
    margin: 1rem 0;
    font-size: var(--font-size-sm);
}

.message.user .message-content pre {
    background: rgba(255, 255, 255, 0.1);
}

.message-content code {
    background: var(--bg-tertiary);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: var(--font-size-sm);
}

.message.user .message-content code {
    background: rgba(255, 255, 255, 0.2);
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.5rem;
    color: var(--text-secondary);
    font-size: var(--font-size-base);
}

.typing-dots {
    display: flex;
    gap: 0.25rem;
}

.typing-dots span {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--secondary-color);
    animation: typing 1.4s infinite ease-in-out;
}

.typing-dots span:nth-child(1) { animation-delay: -0.32s; }
.typing-dots span:nth-child(2) { animation-delay: -0.16s; }

@keyframes typing {
    0%, 80%, 100% { transform: scale(0.8); opacity: 0.5; }
    40% { transform: scale(1); opacity: 1; }
}

/* Input Container */
.input-container {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 2rem;
}

.input-wrapper {
    display: flex;
    gap: 1rem;
    align-items: flex-end;
    max-width: 100%;
}

#messageInput {
    flex: 1;
    min-height: 50px;
    max-height: 120px;
    padding: 1rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.5;
    resize: none;
    transition: all 0.3s ease;
    background: var(--bg-secondary);
}

#messageInput:focus {
    outline: none;
    border-color: var(--primary-color);
    background: var(--bg-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

#messageInput::placeholder {
    color: var(--text-light);
    font-size: var(--font-size-base);
}

.send-button {
    width: 50px;
    height: 50px;
    border: none;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    font-size: var(--font-size-lg);
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.send-button:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.send-button:disabled {
    background: var(--text-light);
    cursor: not-allowed;
    transform: none;
}

.input-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.75rem;
    font-size: var(--font-size-xs);
    color: var(--text-light);
}

.character-count {
    font-weight: 500;
}

.powered-by {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.loading-spinner {
    background: var(--bg-primary);
    padding: 2rem;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.loading-spinner i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.loading-spinner p {
    font-size: var(--font-size-lg);
    color: var(--text-primary);
    font-weight: 500;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1001;
}

.modal-content {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow: hidden;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-secondary);
}

.modal-header h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--danger-color);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: var(--font-size-xl);
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.modal-close:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.modal-body {
    padding: 2rem;
}

.modal-body p {
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
}

.modal-footer {
    padding: 1.5rem 2rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    background: var(--bg-secondary);
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        height: 100vh;
    }
    
    .header {
        padding: 1rem;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .logo h1 {
        font-size: var(--font-size-lg);
    }
    
    .welcome-message {
        padding: 1.5rem 1rem;
    }
    
    .welcome-message h2 {
        font-size: var(--font-size-xl);
    }
    
    .welcome-message p {
        font-size: var(--font-size-base);
    }
    
    .question-buttons {
        grid-template-columns: 1fr;
    }
    
    .chat-messages {
        padding: 1rem;
    }
    
    .message {
        max-width: 95%;
    }
    
    .input-container {
        padding: 1rem;
    }
    
    .modal-content {
        margin: 1rem;
        width: calc(100% - 2rem);
    }
}

@media (max-width: 480px) {
    :root {
        --font-size-base: 1rem;
        --font-size-lg: 1.125rem;
        --font-size-xl: 1.25rem;
        --font-size-2xl: 1.5rem;
    }
    
    .input-wrapper {
        gap: 0.75rem;
    }
    
    .send-button {
        width: 44px;
        height: 44px;
    }
}