/* ========================================
   DOPIAS ONBOARDING MODAL - OPTIMIZED CSS
   Zero dependencies | GPU accelerated | Mobile-first
   ======================================== */

:root {
  --modal-primary: #0D9488;
  --modal-primary-hover: #0F766E;
  --modal-primary-light: #5EEAD4;
  --modal-bg: #FFFFFF;
  --modal-overlay: rgba(0, 0, 0, 0.5);
  --modal-text: #374151;
  --modal-text-light: #6B7280;
  --modal-border: #E5E7EB;
  --modal-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --modal-radius: 16px;
  --modal-radius-sm: 8px;
  --modal-transition: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   MODAL OVERLAY & CONTAINER
   ======================================== */

.howtouse-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--modal-overlay);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 9998;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s var(--modal-transition), 
              visibility 0.3s var(--modal-transition);
  /* Performance optimization */
  will-change: opacity;
}

.howtouse-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* ========================================
   MODAL CONTENT
   ======================================== */

.howtouse-modal {
  background: var(--modal-bg);
  border-radius: var(--modal-radius);
  box-shadow: var(--modal-shadow);
  width: 100%;
  max-width: 600px;
  max-height: 90vh;
  position: relative;
  overflow: hidden;
  transform: scale(0.95);
  transition: transform 0.3s var(--modal-transition);
  /* Performance optimization */
  contain: layout style paint;
  will-change: transform;
  transform: translateZ(0);
}

.howtouse-overlay.active .howtouse-modal {
  transform: scale(1);
}

/* ========================================
   CLOSE BUTTON
   ======================================== */

.howtouse-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 40px;
  height: 40px;
  border: none;
  background: rgba(255, 255, 255, 0.9);
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.howtouse-close:hover {
  background: #fff;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  transform: scale(1.05);
}

.howtouse-close:focus {
  outline: 2px solid var(--modal-primary);
  outline-offset: 2px;
}

.howtouse-close::before,
.howtouse-close::after {
  content: '';
  position: absolute;
  width: 18px;
  height: 2px;
  background: var(--modal-text);
  border-radius: 1px;
}

.howtouse-close::before {
  transform: rotate(45deg);
}

.howtouse-close::after {
  transform: rotate(-45deg);
}

/* ========================================
   SLIDER CONTAINER
   ======================================== */

.howtouse-slider {
  overflow: hidden;
  position: relative;
  width: 100%;
}

.howtouse-slides {
  display: flex;
  transition: transform 0.4s var(--modal-transition);
  /* Performance optimization */
  will-change: transform;
}

.howtouse-slide {
  min-width: 100%;
  padding: 3rem 2rem 2rem;
  box-sizing: border-box;
}

/* ========================================
   SLIDE CONTENT
   ======================================== */

.howtouse-slide h2 {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--modal-text);
  margin: 0 0 1rem;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.2;
}

.howtouse-slide p {
  font-size: 1.125rem;
  color: var(--modal-text-light);
  margin: 0 0 2rem;
  line-height: 1.6;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

/* Steps list for slide 4 */
.howtouse-steps {
  list-style: none;
  padding: 0;
  margin: 0 0 2rem;
  counter-reset: step-counter;
}

.howtouse-steps li {
  position: relative;
  padding: 0.75rem 0 0.75rem 3rem;
  font-size: 1.125rem;
  color: var(--modal-text);
  counter-increment: step-counter;
}

.howtouse-steps li::before {
  content: counter(step-counter);
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: 2rem;
  height: 2rem;
  background: var(--modal-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
}

/* ========================================
   CTA BUTTON
   ======================================== */

.howtouse-cta {
  display: inline-block;
  background: var(--modal-primary);
  color: white;
  padding: 0.875rem 2rem;
  border-radius: var(--modal-radius-sm);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  box-shadow: 0 4px 6px -1px rgba(13, 148, 136, 0.3);
}

.howtouse-cta:hover {
  background: var(--modal-primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 12px -2px rgba(13, 148, 136, 0.4);
}

.howtouse-cta:focus {
  outline: 2px solid var(--modal-primary);
  outline-offset: 2px;
}

.howtouse-cta:active {
  transform: translateY(0);
}

/* ========================================
   SVG AGENT
   ======================================== */

.howtouse-agent {
  width: 120px;
  margin: 1.5rem auto 0;
  display: block;
  transition: opacity 0.5s ease;
}

.howtouse-agent svg {
  width: 100%;
  height: auto;
  display: block;
}

/* ========================================
   INFO BLOCK
   ======================================== */

.howtouse-info {
  background: #F3F4F6;
  border-left: 3px solid var(--modal-primary-light);
  padding: 1rem 1.25rem;
  margin: 2rem 0 0;
  border-radius: var(--modal-radius-sm);
}

.howtouse-info p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--modal-text-light);
  line-height: 1.5;
}

/* Typewriter text */
.typewriter-text {
  display: inline-block;
}

/* ========================================
   NAVIGATION
   ======================================== */

.howtouse-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem 2rem;
  margin-top: 1rem;
}

.howtouse-nav-btn {
  background: none;
  border: 2px solid var(--modal-border);
  padding: 0.625rem 1.5rem;
  border-radius: var(--modal-radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  color: var(--modal-text);
  transition: all 0.2s ease;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

.howtouse-nav-btn:hover:not(:disabled) {
  border-color: var(--modal-primary);
  color: var(--modal-primary);
  background: rgba(13, 148, 136, 0.05);
}

.howtouse-nav-btn:focus {
  outline: 2px solid var(--modal-primary);
  outline-offset: 2px;
}

.howtouse-nav-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

/* ========================================
   DOTS INDICATORS
   ======================================== */

.howtouse-dots {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  justify-content: center;
}

.howtouse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--modal-border);
  border: none;
  padding: 0;
  cursor: pointer;
  transition: all 0.3s ease;
}

.howtouse-dot:hover {
  background: var(--modal-text-light);
  transform: scale(1.2);
}

.howtouse-dot.active {
  background: var(--modal-primary);
  width: 24px;
  border-radius: 4px;
}

.howtouse-dot:focus {
  outline: 2px solid var(--modal-primary);
  outline-offset: 2px;
}

/* ========================================
   RESPONSIVE DESIGN - MOBILE FIRST
   ======================================== */

@media (max-width: 640px) {
  .howtouse-overlay {
    padding: 0.5rem;
  }

  .howtouse-modal {
    max-height: 95vh;
    border-radius: 12px;
  }

  .howtouse-slide {
    padding: 2.5rem 1.5rem 1.5rem;
  }

  .howtouse-slide h2 {
    font-size: 1.5rem;
  }

  .howtouse-slide p {
    font-size: 1rem;
  }

  .howtouse-steps li {
    font-size: 1rem;
    padding-left: 2.5rem;
  }

  .howtouse-steps li::before {
    width: 1.75rem;
    height: 1.75rem;
    font-size: 0.75rem;
  }

  .howtouse-nav {
    padding: 0 1.5rem 1.5rem;
  }

  .howtouse-nav-btn {
    padding: 0.5rem 1rem;
    font-size: 0.813rem;
  }

  .howtouse-cta {
    padding: 0.75rem 1.5rem;
    font-size: 0.938rem;
  }

  .howtouse-close {
    width: 36px;
    height: 36px;
    top: 0.75rem;
    right: 0.75rem;
  }

  .howtouse-close::before,
  .howtouse-close::after {
    width: 16px;
  }
}

/* ========================================
   TABLET & DESKTOP
   ======================================== */

@media (min-width: 768px) {
  .howtouse-slide {
    padding: 3.5rem 3rem 2.5rem;
  }

  .howtouse-nav {
    padding: 0 3rem 2.5rem;
  }
}

/* ========================================
   REDUCED MOTION ACCESSIBILITY
   ======================================== */

@media (prefers-reduced-motion: reduce) {
  .howtouse-overlay,
  .howtouse-modal,
  .howtouse-slides,
  .howtouse-close,
  .howtouse-nav-btn,
  .howtouse-cta,
  .howtouse-dot {
    transition: none !important;
    animation: none !important;
  }
}

/* ========================================
   PRINT STYLES
   ======================================== */

@media print {
  .howtouse-overlay {
    display: none !important;
  }
}

/* ========================================
   HIGH CONTRAST MODE
   ======================================== */

@media (prefers-contrast: high) {
  .howtouse-modal {
    border: 2px solid currentColor;
  }

  .howtouse-cta {
    border: 2px solid transparent;
  }
}