.index-title {
  color: rgba(0, 0, 0, 0.84);
  margin-top: 20px;
}
.index-sub {
  color: rgba(0, 0, 0, 0.54);
}
.index-text {
  margin-top: 20px;
  color: rgba(0, 0, 0, 0.44);
}
.index-image {
  width: 400px;
}


.social-icon {
  color: rgba(0, 0, 0, 0.44);
  font-size: 1.5rem;
}
.clock {
  margin-left: 25px;
}
.jumbotron.fortags a {
  background: #a7de72 !important;
}
.error {
  text-align: center !important;
}
@media (min-width: 769px) {
  .md-nopad-right {
    padding-right: 0px !important;
  }
  .md-nopad-left {
    padding-left: 0px !important;
  }
}

/* Educational Content Structure & Typography */
.lesson-content h1, 
.lesson-content h2, 
.lesson-content h3, 
.lesson-content h4, 
.lesson-content h5, 
.lesson-content h6 {
  font-weight: 700;
  color: #2b2b2b;
  margin-top: 2.5rem;
  margin-bottom: 1.25rem;
  line-height: 1.3;
}

.lesson-content h1 { font-size: 2.5rem; letter-spacing: -0.02em; }
.lesson-content h2 { 
  font-size: 2.0rem; 
  letter-spacing: -0.01em;
  padding-bottom: 0.5rem;
  border-bottom: 3px solid var(--brand-accent-color, #007bff);
  display: inline-block;
}
.lesson-content h3 { font-size: 1.5rem; }
.lesson-content h4 { font-size: 1.25rem; }
.lesson-content h5 { font-size: 1.1rem; }
.lesson-content h6 { font-size: 1rem; text-transform: uppercase; letter-spacing: 0.05em; color: #555; }

.lesson-content p {
  font-size: 1.15rem;
  line-height: 1.8;
  color: #444;
  margin-bottom: 1.5rem;
}

.lesson-content strong {
  color: #000;
}

/* Inline code in lessons (vocabulary words in backticks) */
.lesson-content code {
  font-family: inherit;
  font-size: inherit;
  color: var(--brand-accent-color, #d32f2f);
  background: rgba(0, 0, 0, 0.04);
  padding: 0.1em 0.35em;
  border-radius: 4px;
  font-weight: 600;
}

html.dark-mode .lesson-content code {
  color: var(--brand-accent-color, #ff6b6b);
  background: rgba(255, 255, 255, 0.08);
}

.lesson-content blockquote {
  border-left: 4px solid #02843A;
  padding-left: 1rem;
  color: #555;
  font-style: italic;
  background-color: #fcfcfc;
  padding: 1rem;
  margin-top: 1.5rem;
  margin-bottom: 1.5rem;
}

.lesson-content .youtube {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 */
  height: 0;
  margin-bottom: 2rem;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.lesson-content .youtube iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}