/* General Reset */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Poppins", sans-serif;
  background-color: var(--background-light);
}

:root {
  --primary-color: #4a5568; /* Deep Gray-Blue */
  --secondary-color: #a0aec0; /* Soft Gray */
  --background-light: #f7fafc; /* Soft Gray-White */
  --text-dark: #2d3748; /* Dark Gray */
  --accent-color: #cbd5e0; /* Light Gray */
}

header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  padding: 20px 40px;
  background-color: rgba(247, 250, 252, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 10px rgba(45, 55, 72, 0.1);
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header h1 {
  font-size: 1.5rem;
  white-space: nowrap;
  color: var(--primary-color);
}

.nav {
  display: flex;
  gap: 30px;
  align-items: center;
  list-style: none;
}

.nav-link {
  color: var(--primary-color);
  text-decoration: none;
  font-size: 16px;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
  opacity: 0.8;
}

.nav-link:hover {
  opacity: 1;
  color: var(--secondary-color);
}

.nav-link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -5px;
  left: 0;
  background-color: var(--secondary-color);
  transition: width 0.3s ease;
}

.nav-link:hover::after {
  width: 100%;
}

.home {
  margin-top: 1rem;
}

.main {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.resources-container {
  width: 90rem;
  max-width: 100rem;
  height: auto;
  background-color: white;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
  border-radius: 10px;
  margin-top: 6rem;
}

.portfolio {
  flex: 1;
  background-color: #ffffff;
  color: #2d3748;
  border-radius: 12px;
  margin: 2rem 3rem;
  padding: 3rem;
}

.portfolio h2 {
  color: #2d3748;
  font-size: 2rem;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 3px solid #a0aec0;
}

.books {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.book1 {
  display: flex;
}

.papers {
  display: flex;
  flex-direction: column;
  gap: 30px;
  margin-top: 10px;
}

.paper {
  display: flex;
}

.info {
  padding: 20px;
}

.info h4 {
  margin-bottom: 10px;
}

.portfolio h3 {
  color: #4a5568;
  font-size: 1.5rem;
  margin: 2rem 0 1rem;
  padding-left: 0.5rem;
  border-left: 4px solid #a0aec0;
}

img {
  width: 13rem;
  margin-left: 3rem;
  border: #a0aec0 solid 4px;
}

.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 25px;
  height: 3px;
  margin: 5px 0;
  background-color: var(--primary-color);
  transition: all 0.3s ease;
}


@media (max-width: 768px) {
  .hamburger {
    display: block;
  }

  .nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 250px;
    height: 100vh;
    background-color: var(--background-light);
    flex-direction: column;
    padding-top: 80px;
    transition: right 0.3s ease;
    box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
  }

  .nav.active {
    right: 0;
  }

  .nav li {
    margin: 20px 0;
  }

  /* Hamburger Animation */
  .hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 6px);
  }

  .hamburger.active span:nth-child(2) {
    opacity: 0;
  }

  .hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -6px);
  }

  .resources-container {
    width: 100%;
    margin-top: 5rem;
    padding: 1rem;
  }

  .portfolio {
    margin: 1rem;
    padding: 1.5rem;
  }

  .portfolio h2 {
    font-size: 1.5rem;
  }

  .book1, .paper {
    flex-direction: column;
    align-items: center;
  }

  img {
    width: 80%;
    max-width: 13rem;
    margin: 0;
  }

  .info {
    text-align: center;
  }

  .info a {
    word-break: break-all;
  }
}