/* ==========================================================================
   i-Vana Practice Speaking - Main Stylesheet
   Following Atomic Design Principles: Atoms, Molecules, Organisms, Templates, Pages
   Mobile-first approach with responsive enhancements
   ========================================================================== */

/* ==========================================================================
   ATOMS - Base, fundamental building blocks
   ========================================================================== */

/* --- Typography --- */
:root {
  --primary-blue: #0033A0;
  --primary-dark: #002266;
  --text-dark: #1A1A1A;
  --text-medium: #495057;
  --text-light: #6C757D;
  --bg-light: #F0F4F8;
  --bg-panel: #FFFFFF;
  --bg-accent: #E8EDF2;
  --accent-light: #D6E4FF;
  --accent-medium: #A0B3D9;
  --border-color: #CED4DA;
  --success: #28a745;
  --warning: #ffc107;
  --danger: #D9534F;
  
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 12px;
  
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 0.75rem;
  --spacing-base: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.9rem;
  --font-size-base: 1rem;
  --font-size-md: 1.1rem;
  --font-size-lg: 1.4rem;
  --font-size-xl: 1.6rem;
}

/* Basic Reset & Defaults */
*, *::before, *::after { 
  box-sizing: border-box; 
  margin: 0; 
  padding: 0; 
}

html { 
  font-size: 100%; 
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--bg-light);
  padding: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3 { 
  margin-bottom: var(--spacing-md); 
  line-height: 1.2; 
  font-weight: 700; 
}

h1 {
  color: var(--primary-blue);
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin: 0;
}

h2 {
  border-bottom: none;
  padding-bottom: var(--spacing-sm);
  color: var(--primary-blue);
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-base);
}

h3 {
  color: var(--text-dark);
  font-size: var(--font-size-md);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

p {
  margin-bottom: var(--spacing-base);
}

/* Form Elements */
label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
  color: var(--text-dark);
  font-size: var(--font-size-sm);
}

textarea, input {
  width: 100%;
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-base);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  font-family: inherit;
  font-size: var(--font-size-sm);
  background-color: var(--bg-panel);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

textarea:focus, input:focus {
  outline: none;
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 3px rgba(0, 51, 160, 0.1);
}

textarea {
  min-height: 120px;
  resize: vertical;
}

/* Buttons & Interactive Elements */
button, select, a.button-link {
  display: inline-block;
  padding: var(--spacing-md) var(--spacing-lg);
  font-size: var(--font-size-sm);
  border-radius: var(--border-radius-md);
  border: none;
  background-color: var(--primary-blue);
  color: white;
  cursor: pointer;
  transition: background-color 0.2s ease, opacity 0.2s ease, transform 0.2s ease;
  margin: 0;
  vertical-align: middle;
  font-weight: 500;
  text-decoration: none;
  text-align: center;
  user-select: none;
}

button:hover, select:hover, a.button-link:hover {
  background-color: var(--primary-dark);
  color: white;
  transform: translateY(-1px);
}

button:focus, select:focus, a.button-link:focus {
  outline: 3px solid var(--accent-medium);
  outline-offset: 1px;
}

button:active, a.button-link:active {
  transform: translateY(1px);
}

button:disabled, select:disabled, a.button-link:disabled {
  background-color: var(--accent-medium);
  border-color: var(--accent-medium);
  color: var(--bg-accent);
  cursor: not-allowed;
  opacity: 0.8;
  transform: none;
}

/* Select Dropdown Styling */
select {
  background-color: white;
  color: var(--text-dark);
  border: 1px solid var(--border-color);
  padding-right: 2.5rem;
  background-image: url('data:image/svg+xml;utf8,<svg fill="%230033A0" height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg"><path d="M7 10l5 5 5-5z"/><path d="M0 0h24v24H0z" fill="none"/></svg>');
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1.5em;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
}

select:hover {
  border-color: var(--text-light);
  background-color: var(--bg-accent);
}

/* Icons & Visual Elements */
.icon {
  display: inline-block;
  vertical-align: middle;
  margin-right: var(--spacing-xs);
}

/* ==========================================================================
   MOLECULES - Groups of atoms bonded together
   ========================================================================== */

/* --- Navigation & Controls --- */
.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-base);
}

.navigation-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-base);
  margin-bottom: var(--spacing-lg);
}

.playback-controls {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  align-items: center;
}

/* Error & Loading Messages */
.message-area { 
  min-height: 1.2em; 
  margin-top: var(--spacing-md); 
  font-size: var(--font-size-sm); 
}

.error { 
  color: var(--danger); 
  font-weight: 500; 
}

.loading { 
  color: var(--primary-blue); 
  font-weight: 500; 
}

.success {
  color: var(--success);
  font-weight: 500;
}

/* --- Lesson Item --- */
.lesson-btn {
  width: 100%;
  text-align: left;
  margin-bottom: var(--spacing-sm);
  padding: var(--spacing-md);
  background-color: var(--bg-accent);
  color: var(--text-dark);
  border-left: 3px solid var(--primary-blue);
  transition: all 0.2s ease;
}

.lesson-btn:hover {
  background-color: var(--accent-light);
  border-left-width: 5px;
}

/* --- Pronunciation Help --- */
.ipa-result {
  margin-bottom: var(--spacing-md);
  padding: var(--spacing-md);
  background-color: var(--bg-accent);
  border-radius: var(--border-radius-md);
  border-left: 3px solid var(--primary-blue);
}

.ipa-result strong {
  display: block;
  margin-bottom: var(--spacing-xs);
  color: var(--primary-blue);
}

/* --- Word Highlighting --- */
.word {
  cursor: pointer;
  transition: background-color 0.15s ease-out, color 0.15s ease-out;
  padding: 0.1em 0.05em;
  margin: 0;
  display: inline-block;
  border-radius: var(--border-radius-sm);
}

.word:hover {
  background-color: var(--accent-light);
}

.highlighted-word {
  background-color: var(--accent-medium);
  color: var(--primary-dark);
  border-radius: var(--border-radius-sm);
}

/* ==========================================================================
   ORGANISMS - Groups of molecules joined together as distinct sections
   ========================================================================== */

/* --- App Header --- */
.app-header {
  background-color: var(--bg-panel);
  padding: var(--spacing-base);
  box-shadow: var(--shadow-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-base);
}

.header-actions {
  display: flex;
  gap: var(--spacing-sm);
}

/* Add styles for the new logo */
#app-logo {
  height: 100px; /* Adjust as needed */
  vertical-align: middle; /* Align logo vertically with other header elements */
}

/* --- Courses Section --- */
.courses-section {
  padding: 0 var(--spacing-base);
  margin-bottom: var(--spacing-base);
}

.courses-container {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.course-panel {
  background-color: var(--bg-panel);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
}

.lesson-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

/* --- Main Content Panels --- */
.panel {
  background-color: var(--bg-panel);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  min-width: 300px;
}

#sentence-display {
  font-size: var(--font-size-lg);
  line-height: 1.7;
  margin-top: var(--spacing-base);
  padding: var(--spacing-lg);
  background-color: var(--bg-accent);
  border-radius: var(--border-radius-md);
  min-height: 8em;
  transition: background-color 0.3s ease;
  color: var(--text-dark);
}

#sentence-display p {
  font-size: var(--font-size-sm);
  color: var(--text-light);
  font-style: italic;
}

#pronunciation-display-area {
  padding: var(--spacing-md);
  background-color: var(--bg-accent);
  border-radius: var(--border-radius-md);
  min-height: 150px;
}

/* --- Modal --- */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.modal-content {
  background-color: var(--bg-panel);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-lg);
  max-width: 600px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  padding: var(--spacing-xl);
  position: relative;
}

.close-modal {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-light);
  cursor: pointer;
  padding: var(--spacing-xs);
}

.modal-body {
  margin-top: var(--spacing-lg);
}

.modal-body ol {
  padding-left: 1.5rem;
}

.modal-body li {
  margin-bottom: var(--spacing-sm);
}

/* --- Loader --- */
.loader-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(255, 255, 255, 0.8);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 2000;
}

.loader-spinner {
  width: 50px;
  height: 50px;
  border: 5px solid var(--bg-accent);
  border-radius: 50%;
  border-top-color: var(--primary-blue);
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ==========================================================================
   TEMPLATES - Page-level layout structures
   ========================================================================== */

.page-section {
  padding: 0 var(--spacing-base) var(--spacing-base);
}

.container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  max-width: 1400px;
  margin: 0 auto;
}

/* ==========================================================================
   PAGES - Specific instances of templates
   ========================================================================== */

/* --- Responsiveness --- */
/* Default is mobile-first */

/* Tablet and larger */
@media (min-width: 768px) {
  .courses-container {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .container {
    flex-direction: row;
    flex-wrap: wrap;
  }
  
  #controls-panel, #pronunciation-panel {
    flex-basis: 100%;
  }
  
  #main-content {
    flex-basis: 100%;
  }
}

/* Desktop and larger */
@media (min-width: 1024px) {
  .courses-container {
    grid-template-columns: repeat(3, 1fr);
  }
  
  #controls-panel, #pronunciation-panel {
    flex-basis: 25%;
    flex-grow: 0;
    flex-shrink: 0;
  }
  
  #main-content {
    flex-basis: 50%;
    flex-grow: 1;
  }
}