/* --- Neo-Brutalism Stylesheet for Main Index Page --- */
/* Modern CSS Reset */
*,
::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* Root Variables - Neo-Brutalism Color Palette */
:root {
  --bg-color: #f5f3f0;
  --text-color: #000000;
  --heading-color: #000000;
  --accent-color:rgb(0, 119, 255);
  --subtle-border-color: #000000;
  --highlight-bg-color: #ffffff;
  --shadow-offset: 4px;
  --border-width: 3px;
}

body {
  font-family: "Inter", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.5;
  color: var(--text-color);
  background-color: var(--bg-color);
  font-weight: 500;
}

.container {
  max-width: 800px;
  margin: 50px auto;
  padding: 0 20px;
}

h1 {
  text-align: center;
  font-size: 3rem;
  margin-bottom: 50px;
  color: var(--heading-color);
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: -1px;
  border: var(--border-width) solid var(--subtle-border-color);
  padding: 20px;
  background-color: var(--highlight-bg-color);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0px #000,
    inset 0 0 0 2px #000;
  transform: rotate(-1deg);
  position: relative;
}

/* Styling for each major topic section */
.topic-section {
  margin-bottom: 50px;
  position: relative;
}

.topic-section h2 {
  font-size: 2rem;
  color: var(--heading-color);
  margin-bottom: 25px;
  padding: 15px 20px;
  font-weight: 800;
  text-transform: uppercase;
  background-color: var(--highlight-bg-color);
  border: var(--border-width) solid var(--subtle-border-color);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0px #000;
  display: inline-block;
  transform: translateX(-10px);
}

/* Styling for the list of subtopics */
.subtopic-list {
  list-style: none;
  padding-left: 0;
  background-color: var(--highlight-bg-color);
  border: var(--border-width) solid var(--subtle-border-color);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0px #000;
  padding: 10px;
}

.subtopic-list li {
  margin-bottom: 10px;
}

.subtopic-list li:last-child {
  margin-bottom: 0;
}

.subtopic-list li a {
  display: block;
  padding: 15px 20px;
  text-decoration: none;
  color: var(--text-color);
  font-size: 1.1rem;
  font-weight: 700;
  border: 2px solid var(--subtle-border-color);
  background-color: var(--bg-color);
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

.subtopic-list li a::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background-color: var(--accent-color);
  transition: left 0.3s ease;
  z-index: -1;
}

.subtopic-list li a:hover {
  color: #ffffff;
  transform: translate(-2px, -2px);
  box-shadow: 4px 4px 0px #000;
}

.subtopic-list li a:hover::before {
  left: 0;
}

/* Footer styling */
footer {
  text-align: center;
  margin-top: 60px;
  padding: 20px;
  color: var(--text-color);
  font-weight: 700;
  font-size: 1rem;
  border: var(--border-width) solid var(--subtle-border-color);
  background-color: var(--highlight-bg-color);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0px #000;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Responsive Design */
@media (max-width: 600px) {
  h1 {
    font-size: 2rem;
    transform: rotate(-0.5deg);
  }
  h2 {
    font-size: 1.5rem;
    transform: translateX(-5px);
  }
  .container {
    margin: 30px auto;
  }
  .subtopic-list li a {
    padding: 12px 15px;
    font-size: 1rem;
  }
}