/* ===============================================
   IA CERTUAP - CSS MODERNO COMPLETO
   Colores oficiales: Azul (#2563eb) y Naranja (#f97316)
   =============================================== */

:root {
    /* Colores CERTUAP oficiales */
    --certuap-blue: #2563eb;
    --certuap-blue-dark: #1d4ed8;
    --certuap-blue-light: #3b82f6;
    --certuap-orange: #f97316;
    --certuap-orange-dark: #ea580c;
    --certuap-orange-light: #fb923c;
    --certuap-cyan: #06b6d4;
    
    /* Sistema de colores */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-quaternary: #e2e8f0;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #64748b;
    --text-quaternary: #94a3b8;
    
    --border-primary: #e2e8f0;
    --border-secondary: #cbd5e1;
    --border-light: #f1f5f9;
    
    /* Sombras */
    --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Radios */
    --radius-xs: 4px;
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 24px;
    
    /* Espaciado */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    
    /* Transiciones */
    --transition-fast: 150ms ease;
    --transition-normal: 200ms ease;
    --transition-slow: 300ms ease;
}

/* Modo oscuro */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-quaternary: #475569;
    
    --text-primary: #f8fafc;
    --text-secondary: #e2e8f0;
    --text-tertiary: #cbd5e1;
    --text-quaternary: #94a3b8;
    
    --border-primary: #334155;
    --border-secondary: #475569;
    --border-light: #64748b;
    
    --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.3), 0 1px 2px -1px rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.3), 0 8px 10px -6px rgb(0 0 0 / 0.3);
}

/* ===============================================
   RESET Y BASE
   =============================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    font-size: 14px;
    transition: background-color var(--transition-slow), color var(--transition-slow);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

button, input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    transition: var(--transition-normal);
}

img {
    max-width: 100%;
    height: auto;
}

/* ===============================================
   LAYOUT PRINCIPAL
   =============================================== */

.app {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* ===============================================
   SIDEBAR
   =============================================== */

.sidebar {
    width: 280px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-primary);
    display: flex;
    flex-direction: column;
    position: relative;
    z-index: 10;
    transition: transform var(--transition-slow);
}

.sidebar-header {
    padding: var(--space-6);
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-primary);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-5);
}

.logo img {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    object-fit: cover;
    box-shadow: var(--shadow-sm);
}

.logo-text h1 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.logo-text p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin: 0;
    font-weight: 500;
}

/* Botón Nueva Conversación */
.new-chat-btn, 
#new-chat-btn {
    width: 100%;
    background: linear-gradient(135deg, var(--certuap-blue) 0%, var(--certuap-cyan) 100%);
    color: white;
    border: none;
    padding: var(--space-4) var(--space-5);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    transition: var(--transition-normal);
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.new-chat-btn:hover,
#new-chat-btn:hover {
    background: linear-gradient(135deg, var(--certuap-blue-dark) 0%, #0891b2 100%);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.new-chat-btn:active,
#new-chat-btn:active {
    transform: translateY(-1px);
}

.new-chat-btn::before,
#new-chat-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.new-chat-btn:hover::before,
#new-chat-btn:hover::before {
    left: 100%;
}

.new-chat-btn i,
#new-chat-btn i {
    font-size: 1rem;
}

/* Contenido del sidebar */
.sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-4);
}

.chat-history {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.empty-state, 
.chat-history .empty-state {
    text-align: center;
    padding: var(--space-8) var(--space-4);
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

/* Footer del sidebar */
.sidebar-footer {
    padding: var(--space-5);
    border-top: 1px solid var(--border-primary);
    background: var(--bg-primary);
}

.user-info {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    border-radius: var(--radius-md);
    transition: var(--transition-normal);
    cursor: pointer;
}

.user-info:hover {
    background: var(--bg-tertiary);
}

.user-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--certuap-orange) 0%, var(--certuap-orange-light) 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
    box-shadow: var(--shadow-sm);
}

.user-info.guest .user-avatar {
    background: linear-gradient(135deg, var(--certuap-blue) 0%, var(--certuap-blue-light) 100%);
}

.user-details {
    flex: 1;
    min-width: 0;
}

.user-name {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.user-status {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.user-menu-btn {
    padding: var(--space-2);
    border-radius: var(--radius-sm);
    color: var(--text-tertiary);
    transition: var(--transition-normal);
}

.user-menu-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

/* ===============================================
   CONTENIDO PRINCIPAL
   =============================================== */

.main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    background: var(--bg-primary);
}

/* Header */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-6);
    border-bottom: 1px solid var(--border-primary);
    background: var(--bg-primary);
    z-index: 5;
    min-height: 64px;
}

.sidebar-toggle {
    display: none;
    padding: var(--space-3);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: var(--transition-normal);
}

.sidebar-toggle:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* Selector de modelo */
.model-selector {
    position: relative;
    z-index: 20;
    flex: 1;
    max-width: 320px;
}

.model-current,
#model-current {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    transition: var(--transition-normal);
    cursor: pointer;
    width: 100%;
}

.model-current:hover,
#model-current:hover {
    background: var(--bg-tertiary);
    border-color: var(--certuap-blue);
    box-shadow: var(--shadow-sm);
}

.model-icon {
    width: 28px;
    height: 28px;
    background: linear-gradient(135deg, var(--certuap-blue) 0%, var(--certuap-cyan) 100%);
    color: white;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    flex-shrink: 0;
}

.model-info {
    flex: 1;
    text-align: left;
    min-width: 0;
}

.model-name {
    display: block;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.model-desc {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.model-current .fa-chevron-down {
    color: var(--text-tertiary);
    font-size: 0.75rem;
    transition: var(--transition-normal);
    flex-shrink: 0;
}

.model-dropdown {
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    display: none;
    z-index: 21;
    overflow: hidden;
    max-height: 300px;
    overflow-y: auto;
}

.model-option {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4);
    transition: var(--transition-normal);
    cursor: pointer;
    position: relative;
}

.model-option:hover:not(.disabled) {
    background: var(--bg-secondary);
}

.model-option.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.premium-badge {
    background: linear-gradient(135deg, var(--certuap-orange) 0%, var(--certuap-orange-light) 100%);
    color: white;
    font-size: 0.625rem;
    font-weight: 700;
    padding: 2px 6px;
    border-radius: var(--radius-xs);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    flex-shrink: 0;
}

/* Header actions */
.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.credits-display {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: linear-gradient(135deg, var(--certuap-orange) 0%, var(--certuap-orange-light) 100%);
    color: white;
    border-radius: var(--radius-2xl);
    font-weight: 600;
    font-size: 0.875rem;
    box-shadow: var(--shadow-sm);
}

.theme-toggle,
#theme-toggle {
    padding: var(--space-3);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: var(--transition-normal);
}

.theme-toggle:hover,
#theme-toggle:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* ===============================================
   ÁREA DE CHAT
   =============================================== */

.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Pantalla de bienvenida */
.welcome-screen,
.welcome,
#welcome {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-8);
    background: var(--bg-primary);
}

.welcome-content {
    text-align: center;
    max-width: 600px;
    width: 100%;
}

.welcome-logo {
    margin-bottom: var(--space-8);
}

.welcome-logo img {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-xl);
    object-fit: cover;
    box-shadow: var(--shadow-lg);
}

.welcome-content h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-4);
    line-height: 1.2;
}

.welcome-content p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-8);
    line-height: 1.5;
}

.quick-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-4);
}

.quick-action,
.suggestion {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-6);
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-xl);
    transition: var(--transition-normal);
    text-align: center;
    cursor: pointer;
}

.quick-action:hover,
.suggestion:hover {
    background: var(--bg-tertiary);
    border-color: var(--certuap-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.quick-action i {
    font-size: 1.5rem;
    color: var(--certuap-blue);
}

.quick-action span {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
}

/* Mensajes del chat */
.chat-messages,
.messages,
#messages {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-6);
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
    background: var(--bg-primary);
}

.message {
    display: flex;
    gap: var(--space-3);
    max-width: 768px;
    margin: 0 auto;
    width: 100%;
    animation: fadeInUp 0.3s ease;
}

.message.user {
    flex-direction: row-reverse;
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    overflow: hidden;
    flex-shrink: 0;
    box-shadow: var(--shadow-sm);
}

.message-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.message.user .message-avatar {
    background: linear-gradient(135deg, var(--certuap-orange) 0%, var(--certuap-orange-light) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 600;
    font-size: 0.875rem;
}

.message-content {
    flex: 1;
    min-width: 0;
}

.message.user .message-content {
    display: flex;
    justify-content: flex-end;
}

.message-text {
    padding: var(--space-4) var(--space-5);
    border-radius: var(--radius-xl);
    color: var(--text-primary);
    line-height: 1.6;
    max-width: 100%;
    word-wrap: break-word;
}

.message.user .message-text {
    background: linear-gradient(135deg, var(--certuap-blue) 0%, var(--certuap-cyan) 100%);
    color: white;
    border-radius: var(--radius-xl) var(--radius-xl) var(--radius-xs) var(--radius-xl);
    box-shadow: var(--shadow-sm);
}

.message.ai .message-text {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-xs) var(--radius-xl) var(--radius-xl) var(--radius-xl);
    box-shadow: var(--shadow-xs);
}

/* ===============================================
   IMÁGENES EN MENSAJES - MEJORADO
   =============================================== */

.message-image {
    margin-top: var(--space-3);
    border-radius: var(--radius-lg);
    overflow: hidden;
    cursor: pointer;
    max-width: 400px;
    box-shadow: var(--shadow-md);
    transition: var(--transition-normal);
    position: relative;
    background: var(--bg-tertiary);
}

.message-image:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-lg);
}

.message-image img {
    width: 100%;
    height: auto;
    display: block;
    transition: var(--transition-normal);
}

.message-image:hover img {
    filter: brightness(0.9);
}

/* Overlay de hover para las imágenes */
.image-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition-normal);
    color: white;
    font-size: 1.5rem;
    backdrop-filter: blur(2px);
}

.message-image:hover .image-overlay {
    opacity: 1;
}

.image-overlay i {
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { 
        opacity: 1; 
        transform: scale(1); 
    }
    50% { 
        opacity: 0.7; 
        transform: scale(1.1); 
    }
}

/* ===============================================
   MODAL DE IMAGEN - NUEVO
   =============================================== */

.image-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-slow);
}

.image-modal.show {
    opacity: 1;
    visibility: visible;
}

.image-modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(8px);
    cursor: pointer;
}

.image-modal-content {
    position: relative;
    width: 90vw;
    height: 90vh;
    max-width: 1200px;
    max-height: 800px;
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-primary);
    transform: scale(0.9);
    transition: transform var(--transition-slow);
}

.image-modal.show .image-modal-content {
    transform: scale(1);
}

.image-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-6);
    border-bottom: 1px solid var(--border-primary);
    background: var(--bg-secondary);
    flex-shrink: 0;
}

.image-modal-info {
    flex: 1;
    min-width: 0;
}

.image-modal-title {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.image-modal-actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.image-modal-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-lg);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-normal);
    cursor: pointer;
}

.image-modal-btn:hover {
    background: var(--certuap-blue);
    color: white;
    border-color: var(--certuap-blue);
    transform: scale(1.05);
}

.image-modal-btn:active {
    transform: scale(0.95);
}

.image-modal-body {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: var(--bg-secondary);
    overflow: hidden;
}

#modal-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    transition: var(--transition-normal);
}

.image-modal-loading {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-4);
    color: var(--text-secondary);
    font-weight: 500;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-primary);
    border-top: 3px solid var(--certuap-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Typing indicator */
.typing-indicator,
.typing,
#typing {
    padding: var(--space-6);
}

.typing-animation,
.typing-bubble {
    display: flex;
    gap: 4px;
    padding: var(--space-4) var(--space-5);
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-xl);
    width: fit-content;
}

.typing-animation span {
    width: 8px;
    height: 8px;
    background: var(--text-tertiary);
    border-radius: 50%;
    animation: typing 1.5s ease-in-out infinite;
}

.typing-animation span:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-animation span:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {
    0%, 80%, 100% {
        opacity: 0.3;
        transform: scale(0.8);
    }
    40% {
        opacity: 1;
        transform: scale(1);
    }
}

/* ===============================================
   INPUT DE CHAT
   =============================================== */

.chat-input-container,
.input-section {
    padding: var(--space-6);
    border-top: 1px solid var(--border-primary);
    background: var(--bg-primary);
}

.no-credits-message {
    text-align: center;
    padding: var(--space-8);
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-xl);
    max-width: 600px;
    margin: 0 auto;
}

.no-credits-message p {
    color: var(--text-secondary);
    margin-bottom: var(--space-4);
    font-size: 1rem;
}

.credit-actions {
    display: flex;
    gap: var(--space-3);
    justify-content: center;
    flex-wrap: wrap;
}

.btn-primary, .btn-secondary {
    padding: var(--space-3) var(--space-5);
    border-radius: var(--radius-lg);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.875rem;
    transition: var(--transition-normal);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--certuap-blue) 0%, var(--certuap-cyan) 100%);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--certuap-blue-dark) 0%, #0891b2 100%);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-primary);
}

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--certuap-blue);
}

.chat-form,
#chat-form {
    max-width: 768px;
    margin: 0 auto;
}

.input-group,
.input-container {
    display: flex;
    align-items: flex-end;
    gap: var(--space-3);
    background: var(--bg-secondary);
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-2xl);
    padding: var(--space-3);
    transition: var(--transition-normal);
}

.input-group:focus-within,
.input-container:focus-within {
    border-color: var(--certuap-blue);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.input-action,
.btn-image,
#btn-image {
    padding: var(--space-3);
    border-radius: var(--radius-lg);
    color: var(--text-secondary);
    transition: var(--transition-normal);
    flex-shrink: 0;
    background: var(--bg-tertiary);
}

.input-action:hover,
.btn-image:hover,
#btn-image:hover {
    background: var(--certuap-orange);
    color: white;
    transform: scale(1.05);
}

.chat-input,
#chat-input {
    flex: 1;
    border: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 1rem;
    line-height: 1.5;
    resize: none;
    outline: none;
    min-height: 24px;
    max-height: 120px;
    padding: var(--space-2) 0;
}

.chat-input::placeholder,
#chat-input::placeholder {
    color: var(--text-tertiary);
}

.send-btn,
.btn-send,
#send-btn,
#btn-send {
    padding: var(--space-3);
    background: linear-gradient(135deg, var(--certuap-blue) 0%, var(--certuap-cyan) 100%);
    color: white;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-normal);
    cursor: pointer;
    flex-shrink: 0;
    box-shadow: var(--shadow-sm);
}

.send-btn:not(:disabled):hover,
.btn-send:not(:disabled):hover,
#send-btn:not(:disabled):hover,
#btn-send:not(:disabled):hover {
    background: linear-gradient(135deg, var(--certuap-blue-dark) 0%, #0891b2 100%);
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.send-btn:disabled,
.btn-send:disabled,
#send-btn:disabled,
#btn-send:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

/* ===============================================
   MODAL
   =============================================== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-6);
}

.modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    width: 100%;
    max-width: 400px;
    overflow: hidden;
    border: 1px solid var(--border-primary);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-6);
    border-bottom: 1px solid var(--border-primary);
}

.modal-header h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.modal-close {
    padding: var(--space-2);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: var(--transition-normal);
}

.modal-close:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.modal-body {
    padding: var(--space-4);
}

.modal-link {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: var(--radius-lg);
    transition: var(--transition-normal);
}

.modal-link:hover {
    background: var(--bg-secondary);
}

.modal-link.logout {
    color: #ef4444;
}

.modal-link.logout:hover {
    background: rgba(239, 68, 68, 0.1);
}

/* ===============================================
   RESPONSIVE - MODAL DE IMAGEN
   =============================================== */

@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        z-index: 40;
        transform: translateX(-100%);
        transition: transform var(--transition-slow);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .sidebar-toggle {
        display: block;
    }
    
    .header {
        padding: var(--space-4);
    }
    
    .model-selector {
        max-width: none;
        flex: 1;
    }
    
    .model-info {
        display: none;
    }
    
    .welcome-content h2 {
        font-size: 1.5rem;
    }
    
    .welcome-content p {
        font-size: 1rem;
    }
    
    .quick-actions {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-3);
    }
    
    .quick-action {
        padding: var(--space-4);
    }
    
    .quick-action i {
        font-size: 1.25rem;
    }
    
    .chat-messages,
    .messages,
    #messages {
        padding: var(--space-4);
    }
    
    .message {
        gap: var(--space-2);
    }
    
    .message-avatar {
        width: 32px;
        height: 32px;
    }
    
    .chat-input-container,
    .input-section {
        padding: var(--space-4);
    }
    
    .modal {
        padding: var(--space-4);
    }
    
    /* Modal de imagen en móvil */
    .image-modal-content {
        width: 95vw;
        height: 90vh;
    }
    
    .image-modal-header {
        padding: var(--space-3) var(--space-4);
    }
    
    .image-modal-title {
        font-size: 0.875rem;
    }
    
    .image-modal-btn {
        width: 36px;
        height: 36px;
    }
    
    #modal-image {
        padding: var(--space-2);
    }
}

@media (max-width: 480px) {
    .quick-actions {
        grid-template-columns: 1fr;
    }
    
    .credit-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .header-actions .credits-display {
        padding: var(--space-2);
        font-size: 0.75rem;
    }
    
    /* Modal de imagen en pantallas muy pequeñas */
    .image-modal-content {
        width: 100vw;
        height: 100vh;
        border-radius: 0;
    }
    
    .image-modal-actions {
        gap: var(--space-1);
    }
    
    .image-modal-btn {
        width: 32px;
        height: 32px;
        font-size: 0.875rem;
    }
}

/* ===============================================
   UTILIDADES
   =============================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Scrollbar personalizado */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-secondary);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

/* Animaciones */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Estados de focus mejorados */
button:focus-visible,
.chat-input:focus,
.model-current:focus {
    outline: 2px solid var(--certuap-blue);
    outline-offset: 2px;
}

/* Mejoras de accesibilidad */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms;
        animation-iteration-count: 1;
        transition-duration: 0.01ms;
    }
    
    .image-overlay i {
        animation: none;
    }
    
    .spinner {
        animation: none;
    }
}