/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: 'Segoe UI', sans-serif;
  line-height: 1.6;
  color: #333;
  background: linear-gradient(135deg, #e0e1dd 25%, #f9f9f9 25%, #f9f9f9 50%, #e0e1dd 50%, #e0e1dd 75%, #f9f9f9 75%, #f9f9f9);
  background-size: 20px 20px;
  animation: backgroundAnimation 10s linear infinite;
}
@keyframes backgroundAnimation {
  0% { background-position: 0 0; }
  100% { background-position: 20px 20px; }
}

/* Navbar */
.navbar {
  background-color: rgba(13, 27, 42, 0.9);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  inset-block-start: 0;
  z-index: 1000;
}
.logo {
  color: #e0e1dd;
  font-size: 1.2rem;
  font-weight: bold;
  transition: transform 0.3s;
}
.back-btn {
  background: #4d77ff;
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  text-decoration: none;
  font-weight: 500;
  transition: background 0.3s;
}
.back-btn:hover {
  background: #2b5797;
}

/* Hero Section */
.hero {
  background: linear-gradient(to right, #1b263b, #0f1a2c);
  color: white;
  text-align: center;
  padding: 4rem 2rem;
}
.hero h1 {
  font-size: 2.5rem;
  margin-block-end: 1rem;
}

/* Skill Details */
.skill-details {
  max-inline-size: 800px;
  margin: 2rem auto;
  padding: 2rem;
  background: white;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}
.skill-details h2 {
  margin-block-end: 1rem;
  color: #1b263b;
}
.skill-details ul {
  list-style: disc inside;
  margin-block-end: 1rem;
}
.skill-details li {
  margin-block-end: 0.5rem;
}

/* Demo Box */
.demo-box {
  inline-size: 100%;
  padding: 2rem;
  background: #4d77ff;
  color: #fff;
  font-size: 2rem;
  text-align: center;
  border-radius: 4px;
  margin-block-end: 1rem;
  transition: transform 0.2s ease;
}

/* Buttons */
button {
  margin: 0.5rem 0.5rem 0 0;
  padding: 0.5rem 1rem;
  background: #254e70;
  color: #fff;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.3s ease;
}
button:hover {
  background: #1b3a58;
}

/* Footer */
.contact-footer {
  text-align: center;
  margin: 4rem 0;
}

/* Responsif */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .skill-details { padding: 1.5rem; }
  .demo-box {
    font-size: 1.5rem;
  }
  button {
    inline-size: 100%;
    margin-block-end: 0.5rem;
  }
}