/* --- Main Stylesheet for Professor Messer Notes (Plain Version) --- */

/* Modern CSS Reset */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* Root Variables for easy theme changes */
:root {
  --bg-color: #ffffff;
  --text-color: #212529;
  --heading-color: #343a40;
  --accent-color: #007bff;
  --subtle-border-color: #dee2e6;
  --highlight-bg-color: #f1f3f5;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
  color: var(--text-color);
  background-color: var(--bg-color);
}

.container {
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
}

h1,
h2 {
  color: var(--heading-color);
  line-height: 1.3;
}

h1 {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 10px;
  font-weight: 700;
}

h2 {
  font-size: 1.75rem;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--subtle-border-color);
  font-weight: 600;
}

.section {
  margin-bottom: 40px;
}

ul {
  list-style-position: outside;
  padding-left: 20px;
}

li {
  margin-bottom: 12px;
}

li ul {
  margin-top: 12px;
}

strong {
  color: var(--accent-color);
  font-weight: 600;
}

code {
  background-color: var(--highlight-bg-color);
  padding: 3px 6px;
  border-radius: 4px;
  font-family: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;
  font-size: 0.9em;
  color: #d6336c;
}

.header,
.footer {
  text-align: center;
  color: #6c757d;
}

.header {
  margin-bottom: 40px;
}

.footer {
  margin-top: 40px;
  border-top: 1px solid var(--subtle-border-color);
  padding-top: 20px;
}

.footer p {
  margin-bottom: 20px;
}

/* Button Styling */
.nav-button {
  display: inline-block;
  padding: 12px 20px;
  background-color: #ffffff;
  color: #000000;
  text-decoration: none;
  font-size: 1.1rem;
  font-weight: 800;
  border: 3px solid #000000;
  cursor: pointer;
  margin: 0 10px;
  transition: all 0.2s ease;
  text-transform: uppercase;
  letter-spacing: 1px;
  box-shadow: 4px 4px 0px #000000;
  position: relative;
  overflow: hidden;
  border-radius: 0;
}

.nav-button::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background-color: rgb(0, 119, 255);
  transition: left 0.3s ease;
  z-index: -1;
}

.nav-button:hover {
  color: #ffffff;
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0px #000000;
}

.nav-button:hover::before {
  left: 0;
}

/* Responsive Design */
@media (max-width: 600px) {
  h1 {
    font-size: 2rem;
  }
  h2 {
    font-size: 1.5rem;
  }
  .container {
    margin: 20px auto;
  }
}