/* ==========================================================================
   HAS SELECTOR CSS - Demo específico
   Colores de brand: #2448A6 (azul) y #F5B841 (dorado)
   ========================================================================== */

/* ==========================================================================
   DEMO HEADER Y NAVEGACIÓN (REUTILIZABLE)
   ========================================================================== */

.demo-header {
  background: var(--background);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  backdrop-filter: blur(10px);
  padding: var(--spacing-lg) 0;
}

.demo-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-lg);
}

.back-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: all var(--transition-fast);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius);
  border: 1px solid transparent;
}

.back-link:hover {
  color: var(--primary-color);
  background: color-mix(in srgb, var(--primary-color) 8%, transparent);
  border-color: var(--primary-color);
  transform: translateX(-2px);
}

.back-link svg {
  transition: transform var(--transition-fast);
}

.back-link:hover svg {
  transform: translateX(-2px);
}

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

.brand-logo-small {
  flex-shrink: 0;
}

.brand-logo-small svg {
  filter: drop-shadow(0 2px 4px color-mix(in srgb, var(--primary-color) 20%, transparent));
  transition: transform var(--transition-normal);
}

.brand-logo-small:hover svg {
  transform: scale(1.05);
}

.brand-name {
  font-weight: 600;
  color: var(--text-primary);
  font-size: var(--font-size-base);
}

/* ==========================================================================
   THEME TOGGLE (REUTILIZABLE)
   ========================================================================== */

.theme-toggle {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--surface);
  border: 2px solid var(--border-color);
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition-normal);
  overflow: hidden;
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--primary-color);
  border-color: var(--primary-color);
  transform: scale(1.05);
  box-shadow: 0 8px 25px color-mix(in srgb, var(--primary-color) 30%, transparent);
}

.theme-toggle:hover .theme-toggle__icon {
  color: var(--brand-white);
}

.theme-toggle:active {
  transform: scale(0.95);
}

.theme-toggle__icon {
  position: absolute;
  width: 18px;
  height: 18px;
  color: var(--text-primary);
  transition: all var(--transition-normal);
  transform-origin: center;
}

/* Estados del tema */
:root[data-theme="light"] .theme-toggle__icon--sun,
:root:not([data-theme]) .theme-toggle__icon--sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

:root[data-theme="light"] .theme-toggle__icon--moon,
:root:not([data-theme]) .theme-toggle__icon--moon {
  opacity: 0;
  transform: rotate(180deg) scale(0.5);
}

:root[data-theme="dark"] .theme-toggle__icon--sun {
  opacity: 0;
  transform: rotate(-180deg) scale(0.5);
}

:root[data-theme="dark"] .theme-toggle__icon--moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.theme-toggle:focus-visible {
  outline: 3px solid var(--primary-color);
  outline-offset: 3px;
}

.theme-toggle[aria-pressed="true"] {
  background: var(--primary-color);
  border-color: var(--primary-color);
}

.theme-toggle[aria-pressed="true"] .theme-toggle__icon {
  color: var(--brand-white);
}

/* ==========================================================================
   MAIN CONTENT
   ========================================================================== */

.demo-main {
  padding: var(--spacing-3xl) 0;
}

/* ==========================================================================
   DEMO HERO SECTION
   ========================================================================== */

.demo-hero {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
  padding: var(--spacing-3xl) 0;
  background: linear-gradient(135deg, 
    color-mix(in srgb, var(--primary-color) 5%, var(--background)) 0%,
    color-mix(in srgb, var(--secondary-color) 3%, var(--background)) 100%
  );
  border-radius: var(--border-radius-large);
  position: relative;
  overflow: hidden;
}

.demo-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 20% 80%, color-mix(in srgb, var(--primary-color) 10%, transparent) 0%, transparent 70%),
    radial-gradient(circle at 80% 20%, color-mix(in srgb, var(--secondary-color) 10%, transparent) 0%, transparent 70%);
  z-index: -1;
}

.demo-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.badge-text {
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 600;
}

.badge-tag {
  background: var(--secondary-color);
  color: var(--text-primary);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.demo-hero__title {
  font-size: var(--font-size-3xl);
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.1;
}

.title-highlight {
  display: block;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 900;
  margin-top: var(--spacing-sm);
}

.demo-hero__description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 800px;
  margin: 0 auto var(--spacing-2xl);
}

.demo-hero__features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
  max-width: 600px;
  margin: 0 auto;
}

.feature-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: color-mix(in srgb, var(--surface) 80%, transparent);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
}

.feature-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.feature-text {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  text-align: left;
}

.feature-text strong {
  color: var(--text-primary);
  font-weight: 600;
  font-size: var(--font-size-sm);
}

.feature-text span {
  color: var(--text-muted);
  font-size: var(--font-size-xs);
}

/* ==========================================================================
   INTERACTIVE SECTION
   ========================================================================== */

.interactive-section {
  margin-bottom: var(--spacing-3xl);
}

.section-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  text-align: center;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: -8px;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  border-radius: 2px;
}

.section-subtitle {
  display: block;
  font-size: var(--font-size-base);
  font-weight: 400;
  color: var(--text-secondary);
  margin-top: var(--spacing-sm);
}

/* ==========================================================================
   DEMO INSTRUCTIONS
   ========================================================================== */

.demo-instructions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
  padding: var(--spacing-xl);
  background: color-mix(in srgb, var(--secondary-color) 8%, var(--surface));
  border-radius: var(--border-radius-large);
  border: 1px solid color-mix(in srgb, var(--secondary-color) 20%, var(--border-color));
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition-normal);
}

.demo-instructions.animate-in {
  opacity: 1;
  transform: translateY(0);
}

.instruction-item {
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-start;
}

.instruction-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--primary-color);
  color: var(--brand-white);
  border-radius: 50%;
  font-weight: 700;
  font-size: var(--font-size-sm);
  flex-shrink: 0;
}

.instruction-text {
  margin: 0;
  color: var(--text-secondary);
  line-height: 1.5;
}

.instruction-text strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* ==========================================================================
   SMART FORM - CORAZÓN DEL DEMO
   ========================================================================== */

.demo-showcase {
  background: linear-gradient(135deg, 
    color-mix(in srgb, var(--primary-color) 8%, var(--surface)),
    color-mix(in srgb, var(--secondary-color) 5%, var(--surface))
  );
  padding: var(--spacing-2xl);
  border-radius: var(--border-radius-large);
  border: 1px solid var(--border-color);
  margin: var(--spacing-xl) 0;
  position: relative;
  overflow: hidden;
}

.demo-showcase::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, color-mix(in srgb, var(--primary-color) 5%, transparent) 0%, transparent 70%);
  z-index: -1;
}

.smart-form {
  background: var(--background);
  border-radius: var(--border-radius-large);
  border: 2px solid var(--border-color);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  position: relative;
  max-width: 600px;
  margin: 0 auto var(--spacing-xl);
}

/* ==========================================================================
   :HAS() MAGIC - ESTADOS DEL FORMULARIO
   ========================================================================== */

/* FORMULARIO CON ERRORES */
.smart-form:has(.form-input.error) {
  border-color: var(--error);
  background: color-mix(in srgb, var(--error) 3%, var(--background));
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--error) 15%, transparent);
  transform: scale(1.01);
}

/* Indicador de error */
.smart-form:has(.form-input.error)::before {
  content: '⚠️ Hay errores en el formulario';
  position: absolute;
  top: -50px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--error);
  color: var(--brand-white);
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
  font-weight: 600;
  opacity: 0;
  animation: slideInError 0.4s ease forwards;
  z-index: 10;
}

@keyframes slideInError {
  from {
    opacity: 0;
    transform: translateX(-50%) translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
}

/* FORMULARIO VÁLIDO */
.smart-form:has(.form-input:valid):not(:has(.error)):has(#terms:checked) {
  border-color: var(--success);
  background: color-mix(in srgb, var(--success) 2%, var(--background));
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--success) 12%, transparent);
}

/* Indicador de éxito */
.smart-form:has(.form-input:valid):not(:has(.error)):has(#terms:checked)::after {
  content: '✅ Formulario completo y válido';
  position: absolute;
  top: -50px;
  right: 0;
  background: var(--success);
  color: var(--brand-white);
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
  font-weight: 600;
  animation: slideInSuccess 0.4s ease forwards;
}

@keyframes slideInSuccess {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* FORMULARIO CON FOCUS */
.smart-form:has(.form-input:focus) {
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--primary-color) 20%, transparent);
}

/* ==========================================================================
   FORM HEADER
   ========================================================================== */

.form-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
}

.form-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.form-description {
  color: var(--text-secondary);
  font-size: var(--font-size-base);
  margin: 0;
}

/* ==========================================================================
   FORM GROUPS CON :HAS()
   ========================================================================== */

.form-group {
  margin-bottom: var(--spacing-lg);
  position: relative;
  transition: all var(--transition-normal);
}

/* Grupo con error */
.form-group:has(.form-input.error) {
  background: color-mix(in srgb, var(--error) 2%, transparent);
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  border-left: 4px solid var(--error);
  margin: var(--spacing-lg) -var(--spacing-md);
  animation: shakeError 0.5s ease;
}

@keyframes shakeError {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-3px); }
  75% { transform: translateX(3px); }
}

/* Grupo con campo enfocado */
.form-group:has(.form-input:focus) {
  transform: scale(1.01);
}

/* ==========================================================================
   LABELS INTELIGENTES
   ========================================================================== */

.form-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
}

.label-icon {
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

/* Label cuando su input tiene error */
.form-group:has(.form-input.error) .form-label {
  color: var(--error);
}

.form-group:has(.form-input.error) .form-label::after {
  content: ' *';
  color: var(--error);
  font-weight: 700;
}

.form-group:has(.form-input.error) .label-icon {
  color: var(--error);
}

/* Label cuando su input está enfocado */
.form-group:has(.form-input:focus) .form-label {
  color: var(--primary-color);
  transform: scale(1.02);
}

.form-group:has(.form-input:focus) .label-icon {
  color: var(--primary-color);
}

/* Label cuando su input es válido */
.form-group:has(.form-input:valid):not(:has(.error)) .form-label {
  color: var(--success);
}

.form-group:has(.form-input:valid):not(:has(.error)) .label-icon {
  color: var(--success);
}

/* ==========================================================================
   INPUTS INTELIGENTES
   ========================================================================== */

.form-input {
  width: 100%;
  padding: var(--spacing-md);
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  font-size: var(--font-size-base);
  background: var(--background);
  color: var(--text-primary);
  transition: all var(--transition-normal);
  position: relative;
}

.form-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary-color) 15%, transparent);
  transform: translateY(-1px);
}

.form-input::placeholder {
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.form-input:focus::placeholder {
  color: transparent;
}

/* Input con error */
.form-input.error {
  border-color: var(--error);
  background: color-mix(in srgb, var(--error) 4%, var(--background));
  color: var(--error);
  animation: inputErrorPulse 0.6s ease;
}

.form-input.error:focus {
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--error) 15%, transparent);
}

@keyframes inputErrorPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.01); }
}

/* Input válido */
.form-input.valid:not(.error) {
  border-color: var(--success);
  background: color-mix(in srgb, var(--success) 2%, var(--background));
}

.form-input.valid:not(.error):focus {
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--success) 15%, transparent);
}

/* ==========================================================================
   PASSWORD FIELD ESPECIAL
   ========================================================================== */

.password-wrapper {
  position: relative;
}

.password-wrapper .form-input {
  padding-right: 50px;
}

.password-toggle {
  position: absolute;
  right: var(--spacing-md);
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  transition: color var(--transition-fast);
  padding: var(--spacing-xs);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
}

.password-toggle:hover {
  color: var(--primary-color);
  background: color-mix(in srgb, var(--primary-color) 8%, transparent);
}

.password-icon {
  position: absolute;
  transition: all var(--transition-fast);
}

.password-icon--hide {
  opacity: 1;
}

.password-icon--show {
  opacity: 0;
}

/* Password strength meter */
.password-strength {
  margin-top: var(--spacing-sm);
}

.strength-bar {
  height: 4px;
  background: var(--border-color);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: var(--spacing-xs);
}

.strength-fill {
  height: 100%;
  width: 0%;
  background: var(--text-muted);
  transition: all var(--transition-normal);
  border-radius: 2px;
}

.strength-text {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  font-weight: 500;
}

/* ==========================================================================
   CHECKBOXES PERSONALIZADOS
   ========================================================================== */

.checkbox-label {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  cursor: pointer;
  line-height: 1.5;
}

.form-checkbox {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.checkbox-custom {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-color);
  border-radius: 4px;
  background: var(--background);
  flex-shrink: 0;
  margin-top: 2px;
  transition: all var(--transition-fast);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.checkbox-custom::after {
  content: '';
  width: 6px;
  height: 10px;
  border: 2px solid var(--brand-white);
  border-top: none;
  border-left: none;
  transform: rotate(45deg) scale(0);
  transition: transform var(--transition-fast);
}

.form-checkbox:checked + .checkbox-custom {
  background: var(--primary-color);
  border-color: var(--primary-color);
}

.form-checkbox:checked + .checkbox-custom::after {
  transform: rotate(45deg) scale(1);
}

.form-checkbox:focus + .checkbox-custom {
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary-color) 15%, transparent);
}

/* Checkbox con error */
.form-group:has(.form-checkbox.error) .checkbox-custom {
  border-color: var(--error);
}

.checkbox-text {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.form-link {
  color: var(--primary-color);
  font-weight: 500;
}

.form-link:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

/* ==========================================================================
   MENSAJES DE ERROR CON :HAS()
   ========================================================================== */

.form-error {
  display: block;
  color: var(--error);
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-sm);
  min-height: 20px;
  opacity: 0;
  transform: translateY(-10px);
  transition: all var(--transition-fast);
  font-weight: 500;
}

/* Error visible cuando el grupo padre tiene input con error */
.form-group:has(.form-input.error) .form-error,
.form-group:has(.form-checkbox.error) .form-error {
  opacity: 1;
  transform: translateY(0);
}

.form-error::before {
  content: '⚠️ ';
  margin-right: var(--spacing-xs);
}

/* ==========================================================================
   FORM ACTIONS
   ========================================================================== */

.form-actions {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
}

.form-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border-radius: var(--border-radius);
  font-weight: 600;
  font-size: var(--font-size-base);
  cursor: pointer;
  transition: all var(--transition-normal);
  border: 2px solid;
  flex: 1;
  position: relative;
  overflow: hidden;
}

.form-button--validate {
  background: var(--secondary-color);
  color: var(--text-primary);
  border-color: var(--secondary-color);
}

.form-button--validate:hover {
  background: color-mix(in srgb, var(--secondary-color) 85%, black);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.form-button--submit {
  background: var(--primary-color);
  color: var(--brand-white);
  border-color: var(--primary-color);
}

.form-button--submit:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.form-button--submit:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.form-button--submit:disabled:hover {
  transform: none;
  box-shadow: none;
}

/* Botón submit habilitado cuando form es válido */
.smart-form:has(#name.valid):has(#email.valid):has(#password.valid):has(#terms:checked):not(:has(.error)) .form-button--submit {
  background: linear-gradient(45deg, var(--success), var(--primary-color));
  background-size: 200% 200%;
  animation: gradientShiftButton 3s ease infinite;
}

@keyframes gradientShiftButton {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* Botón validar pulsante cuando hay errores */
.smart-form:has(.error) .form-button--validate {
  background: var(--warning);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.02); }
}

/* ==========================================================================
   FORM STATUS
   ========================================================================== */

.form-status {
  text-align: center;
  margin-top: var(--spacing-lg);
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  background: var(--surface);
  border: 1px solid var(--border-color);
  transition: all var(--transition-normal);
}

.form-status--info {
  background: color-mix(in srgb, var(--info) 10%, var(--surface));
  border-color: var(--info);
}

.form-status--success {
  background: color-mix(in srgb, var(--success) 10%, var(--surface));
  border-color: var(--success);
}

.form-status--error {
  background: color-mix(in srgb, var(--error) 10%, var(--surface));
  border-color: var(--error);
}

.form-status--warning {
  background: color-mix(in srgb, var(--warning) 10%, var(--surface));
  border-color: var(--warning);
}

.form-status--loading {
  background: color-mix(in srgb, var(--primary-color) 10%, var(--surface));
  border-color: var(--primary-color);
}

.status-text {
  color: var(--text-primary);
  font-weight: 500;
  font-size: var(--font-size-sm);
  margin: 0;
}

/* ==========================================================================
   HAS() EXPLANATION
   ========================================================================== */

.has-explanation {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-xl);
  background: color-mix(in srgb, var(--primary-color) 5%, var(--background));
  border-radius: var(--border-radius-large);
  border: 1px solid color-mix(in srgb, var(--primary-color) 20%, var(--border-color));
}

.explanation-title {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  text-align: center;
}

.explanation-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.explanation-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: var(--background);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
}

.explanation-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.explanation-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.explanation-content strong {
  color: var(--primary-color);
  font-weight: 600;
  font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
  font-size: var(--font-size-sm);
}

.explanation-content span {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

/* ==========================================================================
   CODE SECTION
   ========================================================================== */

.code-section {
  margin-bottom: var(--spacing-3xl);
}

.code-examples {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.code-block {
  background: var(--surface);
  border-radius: var(--border-radius-large);
  border: 1px solid var(--border-color);
  overflow: hidden;
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition-normal);
}

.code-block.animate-in {
  opacity: 1;
  transform: translateY(0);
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg) var(--spacing-xl);
  background: color-mix(in srgb, var(--primary-color) 8%, var(--surface));
  border-bottom: 1px solid var(--border-color);
}

.code-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.code-lang {
  background: var(--primary-color);
  color: var(--brand-white);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
}

.code-content {
  font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
  font-size: var(--font-size-sm);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--background);
  padding: var(--spacing-xl);
  margin: 0;
  overflow-x: auto;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.code-content:hover {
  background: color-mix(in srgb, var(--secondary-color) 5%, var(--background));
}

/* ==========================================================================
   USE CASES SECTION
   ========================================================================== */

.use-cases-section {
  margin-bottom: var(--spacing-3xl);
}

.use-cases-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
}

.use-case-card {
  background: var(--surface);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-large);
  border: 1px solid var(--border-color);
  text-align: center;
  transition: all var(--transition-normal);
  opacity: 0;
  transform: translateY(20px);
}

.use-case-card.animate-in {
  opacity: 1;
  transform: translateY(0);
}

.use-case-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

.use-case-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-lg);
  display: block;
}

.use-case-title {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.use-case-description {
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--spacing-lg);
}

.use-case-code {
  background: var(--background);
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
}

.use-case-code code {
  font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
  font-size: var(--font-size-sm);
  color: var(--primary-color);
  background: none;
  padding: 0;
}

/* ==========================================================================
   BROWSER SUPPORT SECTION
   ========================================================================== */

.support-section {
  margin-bottom: var(--spacing-3xl);
}

.browser-support {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.browser-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: var(--surface);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
}

.browser-item--supported {
  border-left: 4px solid var(--success);
}

.browser-item--limited {
  border-left: 4px solid var(--warning);
}

.browser-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.browser-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.browser-info strong {
  color: var(--text-primary);
  font-weight: 600;
}

.browser-info span {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.support-fallback {
  background: color-mix(in srgb, var(--warning) 10%, var(--surface));
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-large);
  border: 1px solid color-mix(in srgb, var(--warning) 30%, var(--border-color));
}

.support-fallback h3 {
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-base);
}

/* ==========================================================================
   FOOTER (REUTILIZABLE)
   ========================================================================== */

.footer {
  background: var(--surface);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-2xl) 0;
  margin-top: var(--spacing-3xl);
}

.footer__content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-lg);
}

.footer__brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.footer__logo svg {
  filter: drop-shadow(0 2px 4px color-mix(in srgb, var(--primary-color) 15%, transparent));
}

.footer__info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.footer__text {
  color: var(--text-secondary);
  margin: 0;
  font-size: var(--font-size-sm);
}

.footer__author {
  color: var(--primary-color);
  font-weight: 600;
}

.footer__subtitle {
  color: var(--text-muted);
  font-size: var(--font-size-xs);
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.footer__links {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.footer__link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--primary-color);
}

.footer__separator {
  color: var(--text-muted);
  font-size: var(--font-size-xs);
}

/* ==========================================================================
   RESPONSIVE DESIGN
   ========================================================================== */

@media (max-width: 768px) {
  .demo-nav {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .header-brand {
    position: static;
    transform: none;
  }
  
  .demo-hero {
    padding: var(--spacing-xl) var(--spacing-lg);
  }
  
  .demo-hero__title {
    font-size: var(--font-size-2xl);
  }
  
  .demo-hero__features {
    grid-template-columns: 1fr;
  }
  
  .feature-item {
    flex-direction: column;
    text-align: center;
  }
  
  .demo-instructions {
    grid-template-columns: 1fr;
  }
  
  .form-actions {
    flex-direction: column;
  }
  
  .explanation-grid {
    grid-template-columns: 1fr;
  }
  
  .use-cases-grid {
    grid-template-columns: 1fr;
  }
  
  .browser-support {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer__content {
    flex-direction: column;
    text-align: center;
  }
  
  .footer__brand {
    flex-direction: column;
  }
}

@media (max-width: 576px) {
  .demo-header {
    padding: var(--spacing-md) 0;
  }
  
  .demo-showcase {
    padding: var(--spacing-lg);
  }
  
  .smart-form {
    padding: var(--spacing-lg);
  }
  
  .code-header {
    flex-direction: column;
    gap: var(--spacing-sm);
    align-items: flex-start;
  }
  
  .code-content {
    padding: var(--spacing-lg);
    font-size: var(--font-size-xs);
  }
  
  .browser-support {
    grid-template-columns: 1fr;
  }
  
  .instruction-item {
    flex-direction: column;
    text-align: center;
  }
  
  .checkbox-label {
    align-items: center;
  }
}

/* ==========================================================================
   ACCESIBILIDAD Y PREFERENCIAS
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  .smart-form,
  .form-input,
  .form-button,
  .code-block,
  .use-case-card,
  .demo-instructions {
    animation: none;
    transition: none;
  }
  
  .smart-form:hover,
  .use-case-card:hover {
    transform: none;
  }
  
  .form-group:has(.form-input.error) {
    animation: none;
  }
  
  .form-button--submit {
    animation: none;
    background: var(--primary-color);
  }
  
  .form-button--validate {
    animation: none;
  }
}

@media (prefers-contrast: high) {
  .smart-form,
  .code-block,
  .use-case-card,
  .demo-instructions {
    border-width: 2px;
  }
  
  .form-input,
  .checkbox-custom {
    border-width: 2px;
  }
  
  .badge-tag,
  .code-lang,
  .instruction-number {
    border: 2px solid var(--text-primary);
  }
}

/* ==========================================================================
   FALLBACK PARA NAVEGADORES SIN :HAS()
   ========================================================================== */

@supports not selector(:has(*)) {
  .demo-showcase::after {
    content: '⚠️ Tu navegador no soporta el selector :has(). Funcionalidad limitada.';
    display: block;
    background: var(--warning);
    color: var(--background);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    text-align: center;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    font-size: var(--font-size-sm);
  }
  
  /* Fallback usando clases añadidas via JavaScript */
  .smart-form.has-errors {
    border-color: var(--error);
    background: color-mix(in srgb, var(--error) 3%, var(--background));
  }
  
  .smart-form.all-valid {
    border-color: var(--success);
    background: color-mix(in srgb, var(--success) 2%, var(--background));
  }
  
  .form-group.field-error {
    background: color-mix(in srgb, var(--error) 2%, transparent);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--error);
  }
  
  .form-group.field-error .form-label {
    color: var(--error);
  }
  
  .form-group.field-error .form-error {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==========================================================================
   ANIMACIONES DE ENTRADA
   ========================================================================== */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Aplicar animaciones de entrada */
.demo-hero {
  animation: fadeInUp 0.8s ease-out;
}

.smart-form {
  animation: slideInLeft 0.8s ease-out 0.3s both;
}

.has-explanation {
  animation: slideInRight 0.8s ease-out 0.5s both;
}

.back-link {
  animation: slideInRight 0.6s ease-out 0.1s both;
}

/* Utility class para screen readers */
.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;
}