/* style.css */

/* 
  1. Base reset: This removes default margins and padding that browsers add, 
  and ensures borders don't increase the total width/height of our elements.
*/
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 
  2. Variables: We define some colors and sizes we'll reuse throughout the app.
  This makes it easy to change the "theme" later. 
*/
:root {
    --bg-color: #f8fafc;        /* A very light, cool gray for the background */
    --panel-bg: #ffffff;        /* Pure white for our sidebar */
    --text-primary: #000000;    /* Black for text */
    --text-secondary: #595959;  /* Secondary text / second accent color */
    --accent-color: #8989eb;    /* Main accent color for buttons and accents */
    --accent-hover: #7575d6;
    --border-color: #f7f7f7;    /* Light border color */
}

/* 3. Global Typography */
body {
    /* Body text updated to Arial or Calibri */
    font-family: Arial, Calibri, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-color);
    line-height: 1.6;
    /* Ensure the body takes up the full height of the screen and hides any overflow */
    height: 100vh;
    overflow: hidden; 
}

/* Add Oswald font for headings */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Oswald', sans-serif;
    font-weight: 500;
}

/* 
  4. Main Layout 
  We use CSS Grid to easily split the screen into two columns.
*/
.app-container {
    display: grid;
    /* 
      This is the magic: 
      - The first column (sidebar) takes up 350px width.
      - The second column (simulation) takes up 1fr (1 fraction = the rest of the available space).
    */
    grid-template-columns: 350px 1fr;
    height: 100vh;
}

/* 5. Tutorial Panel (Sidebar) */
.tutorial-panel {
    background-color: var(--panel-bg);
    border-right: 1px solid var(--border-color);
    /* Flexbox inside the sidebar so we can stack header, main content, and footer vertically */
    display: flex;
    flex-direction: column;
    height: 100%;
}

.tutorial-panel header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

.tutorial-panel header a {
    display: flex;
    align-items: center;
}

.brand-logo {
    width: 85px;
    height: auto;
    object-fit: contain;
}

.tutorial-panel header h1 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin: 0;
    line-height: 1.1;
}

.lesson-content {
    /* 
      flex-grow: 1 means this middle section will expand to fill all available space, 
      pushing the footer to the bottom.
    */
    flex-grow: 1;
    padding: 1.5rem;
    overflow-y: auto; /* Adds a scrollbar if the lesson text gets too long */
}

.lesson-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.lesson-header h2 {
    font-size: 1.25rem;
    margin-bottom: 0;
}

.progress-indicator {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    background-color: var(--border-color);
    padding: 4px 8px;
    border-radius: 12px;
}

.lesson-step {
    background-color: var(--bg-color);
    padding: 1.25rem;
    border-radius: 8px; /* Rounded corners */
    border: 1px solid var(--border-color);
    
    /* Animation defaults */
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

/* When Javascript adds this class, it gracefully fades into view */
.lesson-step.fade-in {
    opacity: 1;
    transform: translateY(0);
}

.lesson-step h3 {
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
}

.lesson-step p {
    color: var(--text-secondary);
    line-height: 1.5;
}

.tutorial-panel footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    background-color: #fbfbfc;
    
    /* Use flexbox to easily align the multiple buttons */
    display: flex;
    gap: 10px;
}

/* 6. Buttons */
.primary-btn {
    flex: 2; /* The primary button gets twice the space of the secondary buttons */
    padding: 0.75rem 1rem;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    /* transition makes the hover effect smooth */
    transition: background-color 0.2s ease, transform 0.1s ease; 
}

.primary-btn:hover:not(:disabled) {
    background-color: var(--accent-hover);
}

.primary-btn:active:not(:disabled) {
    transform: scale(0.98);
}

.secondary-btn {
    flex: 1;
    padding: 0.75rem 1rem;
    background-color: var(--panel-bg);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.secondary-btn:hover:not(:disabled) {
    background-color: var(--border-color);
    color: var(--text-primary);
}

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

/* 7. Simulation Container */
.simulation-container {
    height: 100%;
    width: 100%;
    /* We add a subtle inner shadow so it looks slightly deeper than the sidebar */
    box-shadow: inset 5px 0 10px rgba(0,0,0,0.03); 
}

/* 
  Make the iframe take up the entire container.
  We remove the default border so it looks seamless.
*/
.simulation-container iframe {
    width: 100%;
    height: 100%;
    border: none;
    display: block; 
}