/* =============================================
   Base & Typography
   ============================================= */
* {
  font-family: 'Raleway', sans-serif;
  box-sizing: border-box;
}

body {
  max-width: 1400px;
  margin: 0 auto;
  color: #4a4a4a;
  font-family: 'Raleway', sans-serif;
  font-size: 17px;
  line-height: 1.65;
  background-color: #f8f9fb;
  overflow-x: hidden;
}

/* =============================================
   Headings
   ============================================= */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.01em;
  color: #2c3e50;
  margin-top: 0;
}

/* Section title colour */
.text-blue {
  color: #2980b9;
}

/* =============================================
   Links
   ============================================= */
a {
  color: #e8601c;
  text-decoration: none;
  font-weight: 600;
  font-family: inherit;
  transition: color 0.2s ease;
}

a:hover,
a:active {
  color: #2980b9;
}

/* =============================================
   Udemy course images
   ============================================= */
.udemy-img {
  cursor: pointer;
  border-radius: 6px;
  transition: opacity 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.10);
}

.udemy-img:hover {
  opacity: 1;
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}

/* =============================================
   Lists
   ============================================= */
ul,
ol {
  list-style: none;
  padding-left: 0;
}

ol {
  counter-reset: ol-counter;
}

ol > li {
  counter-increment: ol-counter;
  margin-bottom: 12px;
  padding-left: 4px;
}

ol > li::before {
  content: counter(ol-counter) ". ";
  font-weight: 600;
  color: #2980b9;
  margin-right: 6px;
}

ul > li,
li {
  list-style: none;
  margin-bottom: 10px;
  padding-left: 0;
  line-height: 1.7;
}

/* =============================================
   Spacer
   ============================================= */
.spacer {
  height: 24px;
}

/* =============================================
   Footer
   ============================================= */
#site-footer {
  background-color: #2980b9 !important;
  border-radius: 0 0 12px 12px !important;
  box-shadow: none !important;
  border: none !important;
  margin-top: 0 !important;
}

#site-footer p {
  color: #e8f4fd;
  font-size: 18px;
  margin: 0;
  letter-spacing: 0.03em;
}

/* =============================================
   Responsive typography
   ============================================= */

/* Mobile defaults */
h1 { font-size: 24px; }
h2, h3 { font-size: 20px; }
p { font-size: 17px; }

@media only screen and (min-width: 600px) {
  body {
    font-size: 27px;
    line-height: 1.75;
  }

  h1 {
    font-size: 39px;
    font-weight: 700;
  }

  h2, h3 {
    font-size: 33px;
  }

  p {
    font-size: 27px;
  }
}

/* =============================================
   Legacy / utility classes kept
   ============================================= */
#main {
  margin: 30px;
  background: rgba(204, 204, 204, 0.3);
  padding: 20px;
  border-radius: 8px;
}

.wrapper {
  margin: 0 20px;
}

.mainTitle {
  color: white;
}

.card-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around;
}

/* =============================================
   Custom layout (replaces W3.CSS)
   ============================================= */

/* --- Layout & Structure --- */
.sidebar {
  height: 100%;
  width: 300px;
  background: #2196f3;
  color: #fff;
  position: fixed;
  top: 0;
  z-index: 3;
  overflow-x: hidden;
  overflow-y: auto;
  box-shadow: 4px 0 28px rgba(0, 0, 0, 0.18);
  font-weight: bold;
}

.sidebar-logo {
  padding: 8px 16px;
}

.nav {
  width: 100%;
}

.nav-link {
  display: block;
  width: 100%;
  padding: 8px 16px;
  text-align: left;
  border: none;
  background: transparent;
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  border-radius: 8px;
  margin: 2px 4px;
  transition: background-color 0.45s, padding-left 0.45s, letter-spacing 0.45s;
}

.nav-link:hover {
  background: #fff;
  color: #2196f3;
  padding-left: 22px;
  letter-spacing: 0.5px;
}

.sidebar-close-btn {
  display: block;
  width: 100%;
  padding: 8px 16px;
  text-align: left;
  border: none;
  background: transparent;
  cursor: pointer;
  color: #fff;
  font-size: 22px;
  text-decoration: none;
}

.mobile-header {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1;
  background: #2196f3;
  color: #fff;
  padding: 8px 16px;
}

.hamburger-btn {
  display: inline-block;
  padding: 8px 16px;
  border: none;
  background: transparent;
  cursor: pointer;
  color: #fff;
  font-size: 36px;
  line-height: 1;
}

.header-title {
  position: absolute;
  top: 0;
  left: 0;
  padding: 8px 16px;
}

.main {
  margin-left: 340px;
  margin-right: 40px;
  background: #fff;
  border-radius: 0 12px 12px 0;
  box-shadow: 2px 0 24px rgba(0, 0, 0, 0.04);
}

.overlay {
  display: none;
  position: fixed;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 2;
  cursor: pointer;
}

/* --- Section containers --- */
.section-content {
  background: #fff;
  border-radius: 16px;
  margin-bottom: 28px;
  padding: 36px 40px;
  border: 1px solid rgba(0, 0, 0, 0.07);
  box-shadow:
    0 2px 4px rgba(0, 0, 0, 0.05),
    0 6px 18px rgba(0, 0, 0, 0.09),
    0 14px 36px rgba(0, 0, 0, 0.06);
  scroll-margin-top: 24px;
}

.footer-content {
  padding: 8px 16px;
}

/* --- Utility classes --- */
.bg-light    { background: #f4f6f8; }
.avatar      { border-radius: 50%; }

.card {
  background: #fff;
  border-radius: 14px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.04),
    0 4px 12px rgba(0, 0, 0, 0.08),
    0 8px 24px rgba(0, 0, 0, 0.06);
  transition: box-shadow 0.45s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

.card:hover {
  box-shadow:
    0 2px 4px rgba(0, 0, 0, 0.05),
    0 12px 32px rgba(0, 0, 0, 0.13),
    0 20px 48px rgba(0, 0, 0, 0.08);
  transform: translateY(-4px);
}

.mb          { margin-bottom: 16px; }
.text-center { text-align: center; }
.py-16       { padding-top: 16px; padding-bottom: 16px; }
.text-white  { color: #fff; }
.text-xlarge  { font-size: 24px; }
.text-xxlarge { font-size: 36px; }
.text-large   { font-size: 18px; }

/* --- Responsive --- */
@media (min-width: 993px) {
  .hide-desktop { display: none !important; }
}

@media (max-width: 992px) {
  .sidebar { display: none; }
  .main    { margin-left: 8px; margin-right: 8px; margin-top: 60px; }
  .section-content { scroll-margin-top: 80px; }
}