Intersect Observer: Reveal Cards on Scroll

by Ali Uygur

HTML

<div class="hero-section">
  <h1>Aşağı Kaydırın ve Efekti İnceleyin</h1>
</div>

<div class="card-container">
  <div class="scroll-card purple-gradient">HTML5 & Semantik Yapı</div>
  <div class="scroll-card neon-gradient">CSS3 & Gelişmiş Animasyonlar</div>
  <div class="scroll-card sunset-gradient">Vanilla JavaScript Dücü</div>
</div>

CSS

body {
  background-color: #0b0f19;
  color: #ffffff;
  font-family: 'Poppins', sans-serif;
  margin: 0;
  padding: 0;
  overflow-x: hidden;
}

.hero-section {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: radial-gradient(circle, #1e293b 0%, #0b0f19 100%);
}

.hero-section h1 {
  font-size: 2.5rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  text-shadow: 0 5px 15px rgba(0,0,0,0.5);
}

.card-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 150px;
  padding-bottom: 200px;
}

.scroll-card {
  width: 400px;
  padding: 60px 30px;
  text-align: center;
  border-radius: 24px;
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 1px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
  opacity: 0;
  transform: translateY(100px) scale(0.9);
  transition: opacity 1.2s cubic-bezier(0.25, 1, 0.5, 1), transform 1.2s cubic-bezier(0.25, 1, 0.5, 1);
}

.purple-gradient {
  background: linear-gradient(135deg, #7c3aed, #4f46e5);
}

.neon-gradient {
  background: linear-gradient(135deg, #06b6d4, #0891b2);
}

.sunset-gradient {
  background: linear-gradient(135deg, #f43f5e, #e11d48);
}

.scroll-card.show {
  opacity: 1;
  transform: translateY(0) scale(1);
}

JavaScript

const cards = document.querySelectorAll('.scroll-card');

const observer = new IntersectionObserver((entries) => {
  entries.forEach(entry => {
    if (entry.isIntersecting) {
      entry.target.classList.add('show');
      observer.unobserve(entry.target);
    }
  });
}, {
  threshold: 0.15
});

cards.forEach(card => {
  observer.observe(card);
});