/* Base Styles */
:root {
  --primary-color: #4361ee;
  --secondary-color: #3f37c9;
  --accent-color: #4cc9f0;
  --light-color: #f8f9fa;
  --dark-color: #212529;
  --success-color: #4bb543;
  --danger-color: #f94144;
  --warning-color: #f8961e;
  --border-radius: 8px;
  --transition: all 0.3s ease;
  --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --dark-mode-bg: #1a1a2e;
  --dark-mode-text: #e6e6e6;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--dark-color);
  background-color: var(--light-color);
  padding: 2rem;
  max-width: 1200px;
  margin: 0 auto;
  transition: var(--transition);
}

body.dark-mode {
  background-color: var(--dark-mode-bg);
  color: var(--dark-mode-text);
}

h1, h2, h3 {
  margin-bottom: 1rem;
  color: var(--primary-color);
}

h1 {
  font-size: 2.5rem;
  text-align: center;
  margin: 2rem 0;
}

h2 {
  font-size: 1.8rem;
  border-bottom: 2px solid var(--accent-color);
  padding-bottom: 0.5rem;
  margin-top: 2rem;
}

p {
  margin-bottom: 1rem;
}

section {
  padding: 1.5rem;
  margin: 1.5rem 0;
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}

body.dark-mode section {
  background-color: #16213e;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 1rem auto;
  border-radius: var(--border-radius);
}

/* Specific Element Styling */
#element {
  color: var(--secondary-color);
  text-align: center;
  padding: 1rem;
  border: 2px dashed var(--primary-color);
}

#manipulate {
  font-size: 1.2rem;
  font-weight: bold;
  color: var(--danger-color);
}

#manipulate-html {
  padding: 1rem;
  background-color: #f0f0f0;
  border-left: 4px solid var(--warning-color);
}

body.dark-mode #manipulate-html {
  background-color: #2d3748;
}

#style {
  font-style: italic;
  text-decoration: underline;
  color: var(--primary-color);
}

#add-class {
  padding: 0.8rem;
  transition: var(--transition);
}

.highlight {
  background-color: var(--accent-color);
  color: white;
  padding: 0.8rem;
  border-radius: var(--border-radius);
}

#remove-class {
  padding: 0.8rem;
  transition: var(--transition);
}

.ugly {
  font-family: 'Comic Sans MS', cursive;
  background-color: hotpink;
  color: limegreen;
  border: 3px dotted purple;
  transform: rotate(3deg);
}

.basic {
  background-color: var(--light-color);
  padding: 1.5rem;
  border-radius: var(--border-radius);
}

.dark {
  background-color: var(--dark-mode-bg);
  color: var(--dark-mode-text);
}

#color-mode {
  cursor: pointer;
  text-align: center;
  font-weight: bold;
}

/* Form Styles */
form {
  background-color: white;
  padding: 2rem;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  margin: 2rem 0;
}

body.dark-mode form {
  background-color: #16213e;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

input[type="text"] {
  width: 100%;
  padding: 0.8rem;
  border: 2px solid #ddd;
  border-radius: var(--border-radius);
  font-size: 1rem;
  margin-bottom: 1rem;
  transition: var(--transition);
}

input[type="text"]:focus {
  border-color: var(--primary-color);
  outline: none;
  box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

/* Button Styles */
button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 0.8rem 1.5rem;
  border-radius: var(--border-radius);
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  margin: 0.5rem 0;
}

button:hover {
  background-color: var(--secondary-color);
  transform: translateY(-2px);
}

button:active {
  transform: translateY(0);
}

#click, #dbl-click, #fetch-todos {
  display: block;
  margin: 1rem auto;
}

/* Feedback Section */
#feedback-section {
  min-height: 100px;
  border: 2px dashed #ccc;
}

.feedback-item {
  padding: 1rem;
  margin: 0.5rem 0;
  background-color: #f8f9fa;
  border-radius: var(--border-radius);
  border-left: 4px solid var(--success-color);
}

body.dark-mode .feedback-item {
  background-color: #2d3748;
}

/* Todos Section */
#todos-section {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
}

.todo-card {
  background-color: white;
  padding: 1rem;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  border-top: 4px solid var(--primary-color);
}

body.dark-mode .todo-card {
  background-color: #16213e;
}

.todo-card h3 {
  margin-bottom: 0.5rem;
  color: var(--secondary-color);
}

.todo-card.completed {
  opacity: 0.7;
  border-top-color: var(--success-color);
}

/* Mouse Event Section */
#mouse-event {
  text-align: center;
  transition: var(--transition);
}

.hover-effect {
  background-color: var(--accent-color);
  color: white;
  transform: scale(1.02);
}

/* Key Events Section */
#key-down, #key-up, #key-press {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  min-height: 2rem;
}
/* Navigation Styles */
nav {
  background-color: var(--primary-color);
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  padding: 1rem;
  margin: 2rem 0;
  position: sticky;
  top: 1rem;
  z-index: 100;
}

body.dark-mode nav {
  background-color: var(--secondary-color);
}

nav a {
  color: white;
  text-decoration: none;
  padding: 0.75rem 1.25rem;
  margin: 0 0.5rem;
  border-radius: calc(var(--border-radius) - 4px);
  font-weight: 600;
  transition: var(--transition);
  display: inline-block;
  position: relative;
}

nav a:hover {
  background-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

nav a:active {
  transform: translateY(0);
}

/* Active link indicator */
nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 3px;
  background-color: var(--accent-color);
  transition: var(--transition);
  transform: translateX(-50%);
}

nav a:hover::after {
  width: 70%;
}

/* Current section highlight */
nav a.active {
  background-color: rgba(255, 255, 255, 0.3);
}

nav a.active::after {
  width: 70%;
}

/* Responsive navigation */
@media (max-width: 768px) {
  nav {
    position: static;
    text-align: center;
    padding: 0.5rem;
  }
  
  nav a {
    display: block;
    margin: 0.5rem 0;
    padding: 0.5rem;
  }
  
  nav a::after {
    display: none;
  }
}

@media (max-width: 480px) {
  nav a {
    font-size: 0.9rem;
    padding: 0.4rem;
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  body {
    padding: 1rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  section {
    padding: 1rem;
  }
}