body {
  background: #f3f3f3;
  color: #222;
  font-family: Arial, sans-serif;
}

/* ===================================================== */

/* HERO SECTION */

/* ===================================================== */

.hero-section {
  padding: 40px 0;
}

.hero-box {
  background: white;
  border: 3px solid #111;
  border-radius: 10px;
  min-height: 320px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 30px;
}

.hero-image {
  width: 100%;
  border-radius: 8px;
}

.hero-title {
  font-size: 52px;
  font-weight: 800;
  line-height: 1.2;
}

.hero-subtitle {
  margin-top: 20px;
  font-size: 20px;
  color: #666;
  line-height: 1.8;
}

.hero-buttons {
  margin-top: 30px;
}

/* ===================================================== */

/* MAIN LAYOUT */

/* ===================================================== */

.main-layout {
  padding-bottom: 80px;
}

.sidebar {
  background: #1f2937;
  border: 3px solid #111;
  border-radius: 10px;
  padding: 20px;
  position: sticky;
  top: 20px;
  color: white;
}

.sidebar-title {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 20px;
}

.sidebar a {
  display: block;
  padding: 12px 15px;
  margin-bottom: 8px;
  text-decoration: none;
  color: white;
  border-radius: 8px;
  transition: 0.2s;
}

.sidebar a:hover {
  background: white;
  color: crimson;
}

.content-area {
  background: white;
  border: 3px solid #111;
  border-radius: 10px;
  padding: 50px;
  min-height: 1000px;
}

/* ===================================================== */

/* CONTENT */

/* ===================================================== */

.section {
  margin-bottom: 90px;
}

.section-title {
  font-size: 42px;
  font-weight: 800;
  margin-bottom: 25px;
}

.problem-box {
  background: #f7f7f7;
  border-left: 5px solid #dc3545;
  padding: 20px;
  border-radius: 8px;
  margin-bottom: 30px;
}

.problem-title {
  font-size: 18px;
  font-weight: 700;
}

.step-box {
  background: #f7f7f7;
  border-left: 1px solid #22B14C;
  padding: 10px;
  border-radius: 4px;
  margin-bottom: 10px;
}

.code-block {
  background: #111;
  color: #00ff88;
  border-radius: 10px;
  padding: 25px;
  overflow: auto;
  font-family: Consolas, monospace;
  line-height: 1.8;
  font-size: 15px;
}

.topic-card {
  background: #fafafa;
  border: 1px solid #ddd;
  border-radius: 10px;
  padding: 25px;
  height: 100%;
}

.topic-card h4 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 15px;
}

.architecture-box {
  background: #111;
  color: #00ff88;
  border-radius: 10px;
  padding: 30px;
  font-family: Consolas, monospace;
  line-height: 1.9;
  font-size: 16px;
}

.pipeline-step {
  background: #f5f5f5;
  border: 1px solid #ddd;
  border-radius: 10px;
  padding: 25px;
  text-align: center;
  font-weight: 700;
  height: 100%;
}

/* ===================================================== */

/* RESPONSIVE */

/* ===================================================== */

@media (max-width:992px) {
  .hero-title {
    font-size: 38px;
  }
}

@media (max-width:992px) {
  .content-area {
    margin-top: 30px;
    padding: 30px;
  }
}

@media (max-width:992px) {
  .sidebar {
    position: relative;
    top: auto;
  }
}