🔲 Modal Dialogs Design Guide

🎨 Modal Demo

Click button to see working modal:

💻 HTML Structure

Complete Modal Markup:

<!-- Modal Overlay -->
<div class="modal-overlay" id="myModal" role="dialog" aria-labelledby="modalTitle" aria-modal="true">
  
  <!-- Modal Dialog -->
  <div class="modal-dialog">
    
    <!-- Header -->
    <div class="modal-header">
      <h2 class="modal-title" id="modalTitle">Modal Title</h2>
      <button class="modal-close" aria-label="Close modal">×</button>
    </div>
    
    <!-- Content -->
    <div class="modal-content">
      <p>Modal content goes here...</p>
    </div>
    
    <!-- Footer (optional) -->
    <div class="modal-footer">
      <button class="btn-secondary">Cancel</button>
      <button class="btn-primary">Confirm</button>
    </div>
    
  </div>
</div>

🎨 CSS Styling

Modal Overlay та Backdrop:

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.6); /* Dark backdrop */
  backdrop-filter: blur(4px); /* Blur background (modern browsers) */
  
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10000; /* Above everything */
  
  /* Hidden by default */
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

/* Active state */
.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

Modal Dialog:

.modal-dialog {
  background: white;
  border-radius: 16px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  
  max-width: 500px; /* Adjustable */
  width: 90%;
  max-height: 90vh; /* Fits viewport */
  
  overflow: hidden;
  
  /* Animation: scale + slide up */
  transform: scale(0.9) translateY(-20px);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.modal-overlay.active .modal-dialog {
  transform: scale(1) translateY(0);
}

Modal Header, Content, Footer:

/* Header */
.modal-header {
  padding: 25px 30px;
  border-bottom: 1px solid #e9ecef;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-size: 1.5em;
  font-weight: 700;
  color: #2c3e50;
  margin: 0;
}

/* Close button */
.modal-close {
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  color: #6c757d;
  font-size: 1.5em;
  cursor: pointer;
  border-radius: 50%;
  transition: all 0.2s;
}

.modal-close:hover {
  background: #f8f9fa;
  color: #2c3e50;
}

/* Content */
.modal-content {
  padding: 30px;
  overflow-y: auto; /* Scrollable if content tall */
  max-height: calc(90vh - 140px); /* Account для header/footer */
}

/* Footer */
.modal-footer {
  padding: 20px 30px;
  border-top: 1px solid #e9ecef;
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

⚙️ JavaScript Implementation

Open/Close Functions:

// Open modal
function openModal(modalId) {
  const modal = document.getElementById(modalId);
  modal.classList.add('active');
  document.body.style.overflow = 'hidden'; // Prevent background scroll
  
  // Focus trap
  trapFocus(modal);
  
  // Store last focused element (для restoration)
  modal.dataset.lastFocus = document.activeElement;
}

// Close modal
function closeModal(modalId) {
  const modal = document.getElementById(modalId);
  modal.classList.remove('active');
  document.body.style.overflow = ''; // Restore scroll
  
  // Restore focus
  const lastFocus = document.querySelector(modal.dataset.lastFocus);
  if (lastFocus) lastFocus.focus();
}

// Close on backdrop click
function closeOnBackdrop(event, modalId) {
  if (event.target.classList.contains('modal-overlay')) {
    closeModal(modalId);
  }
}

// Close on ESC key
document.addEventListener('keydown', (e) => {
  if (e.key === 'Escape') {
    const activeModal = document.querySelector('.modal-overlay.active');
    if (activeModal) {
      closeModal(activeModal.id);
    }
  }
});

Focus Trap (Accessibility):

// Trap focus inside modal
function trapFocus(modal) {
  const focusableElements = modal.querySelectorAll(
    'a[href], button, textarea, input, select, [tabindex]:not([tabindex="-1"])'
  );
  
  const firstFocusable = focusableElements[0];
  const lastFocusable = focusableElements[focusableElements.length - 1];
  
  // Focus first element
  firstFocusable.focus();
  
  modal.addEventListener('keydown', (e) => {
    if (e.key === 'Tab') {
      if (e.shiftKey) {
        // Shift+Tab
        if (document.activeElement === firstFocusable) {
          e.preventDefault();
          lastFocusable.focus();
        }
      } else {
        // Tab
        if (document.activeElement === lastFocusable) {
          e.preventDefault();
          firstFocusable.focus();
        }
      }
    }
  });
}

♿ Accessibility

ARIA Attributes:

<!-- role="dialog" indicates modal purpose -->
<div class="modal-overlay" 
     role="dialog"
     aria-labelledby="modalTitle"
     aria-describedby="modalDescription"
     aria-modal="true">
  
  <div class="modal-dialog">
    <!-- Title для screen readers -->
    <h2 id="modalTitle">Safety Warning</h2>
    
    <!-- Description (if needed) -->
    <p id="modalDescription">Important information about psilocybin legality</p>
  </div>
</div>

Keyboard Navigation:

• ✅ TAB cycles through focusable elements inside modal
• ✅ ESC closes modal
• ✅ Focus trap prevents tabbing outside modal
• ✅ First element focused when modal opens
• ✅ Focus restored до last element after close

✅ Modal Design Checklist