body {
      margin: 0;
      font-family: 'Inter', sans-serif;
      background: linear-gradient(to bottom, rgba(0,0,0,0.1) 0%, rgba(0,0,0,0.1) 50%, white 50%, white 100%),
                  url('img/background-tech-highres.webp') no-repeat center top fixed;
      background-size: cover;
      color: white;
      padding-top: 100px;
    }

    header {
      position: fixed;
      top: 0;
      left: 0;
      width: 90%;
      background: rgba(0, 0, 0, 0.0);
      color: white;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 20px 20px;
      z-index: 1000;
    }

    header nav a {
      margin-left: 20px;
      text-decoration: none;
      color: white;
      font-weight: 500;
    }

    .logo {
      height: 45px;
    }

    nav ul {
      list-style: none;
      display: flex;
      gap: 30px;
      margin: 0;
      padding: 0;
    }

    nav a {
      color: white;
      text-decoration: none;
      font-weight: bold;
    }

    .hero {
      padding: 140px 40px 160px;
      max-width: 800px;
    }

    .hero h1 {
      font-size: 40px;
      margin: 0;
    }

    .hero p {
      font-size: 18px;
      margin: 20px 0;
    }

    .buttons a {
      display: inline-block;
      padding: 12px 20px;
      margin: 10px 10px 0 0;
      text-decoration: none;
      border-radius: 6px;
      font-weight: 600;
    }

    .btn-blue { background-color: #004B8D; color: white; }
    .btn-orange { background-color: #F57C00; color: white; }

    .features {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 30px;
      padding: 80px 40px;
      background-color: transparent;
      position: relative;
    }

    .features::after {
      content: "";
      position: absolute;
      bottom: -80px;
      left: 0;
      width: 100%;
      height: 120px;
      background: linear-gradient(rgba(255,255,255,0) 0%, white 100%);
      z-index: -1;
    }

    .feature-box {
      width: 200px;
      padding: 30px;
      background-color: rgba(255,255,255,0.9);
      border-radius: 10px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.1);
      text-align: center;
      transition: all 0.3s ease-in-out;
      color: #003366;
    }

    .feature-box:hover {
      transform: translateY(-5px);
      box-shadow: 0 8px 16px rgba(0,0,0,0.2);
    }

    .feature-box img {
      width: 50px;
      height: auto;
      margin-bottom: 10px;
    }

    .feature-box .label {
      font-weight: 700;
      margin-bottom: 6px;
      color: #001f3f;
    }

.footer-modern {
  background: #002147;
  color: #ccc;
  padding: 60px 20px 100px;
  font-size: 14px;
  position: relative;
}

.footer-container {
  max-width: 1200px;
  margin: auto;
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  justify-content: space-between;
}

.footer-brand img {
  height: 45px;
  margin-bottom: 10px;
}
.footer-brand p {
  margin: 10px 0;
}
.btk-badge {
  width: 100px;
  margin-top: 10px;
  opacity: 0.8;
}

.footer-section h4 {
  color: #fff;
  margin-bottom: 12px;
  cursor: pointer;
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section ul li a {
  color: #ccc;
  text-decoration: none;
  display: block;
  margin-bottom: 6px;
}

.newsletter-form {
  display: flex;
  flex-direction: column;
}
.newsletter-form input {
  padding: 8px;
  border: none;
  border-radius: 4px;
  margin-bottom: 10px;
}
.newsletter-form button {
  padding: 10px;
  background-color: #F57C00;
  border: none;
  color: white;
  border-radius: 4px;
  cursor: pointer;
}
.newsletter-form button:hover {
  background-color: #d96c00;
}

.footer-bottom {
  text-align: center;
  margin-top: 40px;
  border-top: 1px solid #333;
  padding-top: 20px;
  color: #999;
  font-size: 13px;
}

.chat-button {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background-color: #004B8D;
  color: white;
  border: none;
  border-radius: 30px;
  padding: 14px 20px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  box-shadow: 0 4px 10px rgba(0,0,0,0.3);
  z-index: 1000;
}
.chat-button:hover {
  background-color: #003766;
}

@media (max-width: 768px) {
  .accordion .accordion-content {
    display: none;
  }

  .accordion.open .accordion-content {
    display: block;
    margin-top: 8px;
  }
}
.footer-link-group {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
}

.social-icons {
  display: flex;
  gap: 16px; /* ikonlar arasında boşluk */
  margin-top: 10px;
}

.social-icons a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: rgba(255,255,255,0.1); /* opsiyonel hover efekti için */
  transition: background 0.3s;
}

.social-icons a:hover {
  background-color: rgba(255,255,255,0.25);
}

.social-icons img {
  width: 20px;
  height: 20px;
  filter: brightness(0) invert(1); /* beyaz ikon efekti */
}