/* ========== GLOBAL RESET & BASICS ========== */
* {
  box-sizing: border-box;
  max-width: 100%;
}

html {
  scroll-behavior: smooth;
  height: 100%;
}

body {
  font-family: 'Lato', sans-serif;
  font-weight: 400;
  font-size: clamp(16px, 1.1vw, 18px);
  line-height: 1.6;
  margin: 0;
  padding: 0;
  color: #333;
  background-color: #f4f4f9;
  height: 100%;
  overflow-x: hidden;
  opacity: 0;
  transition: opacity 1s ease-in;
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none; /* IE/Edge */
  overflow-y: scroll;
}

body.loaded {
  opacity: 1;
}

/* ========== HEADER ========== */
header {
  background-color: #f4f4f9;
  color: #333;
  display: flex;
  justify-content: space-evenly;
  align-items: center;
  margin-bottom: 1.5vw;
}

#header-link {
  text-decoration: none;
  color: inherit;
}

#header-link h1,
header h1 {
  margin: 0;
  /* font-size: 1.1vw; */
  font-size: clamp(18px, 1.3vw, 22px);
  font-weight: 300;
  cursor: pointer;
}

/* ========== NAVIGATION ========== */
nav ul {
  display: flex;
  justify-content: flex-end;
  margin: clamp(16px, 1.25vw, 20px);
  padding: 0;
}

nav li {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 2.5vw;
  min-width: auto;      /* change this */
  padding: 0 1.2vw;     /* add horizontal padding */
  white-space: nowrap;  /* prevent line breaks */
  background-color: #f4f4f4;
  margin: 0 4vw;
}

nav a {
  text-decoration: none;
  color: #333;
  font-size: clamp(16px, 1.5vw, 20px);
  font-weight: 300;
  display: block;
  width: 100%;
  text-align: center;
  padding: 0.5vw;
}

nav a:hover {
  text-decoration: underline;
}

/* ========== MAIN LAYOUT ========== */
main {
  padding: 0 0.5vw 5vw; /* side padding + breathing room at bottom */
}

section {
  text-align: left;
}

/* ========== ABOUT SECTION ========== */
#about {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  width: 100%;
}

.about-container {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  max-width: 75vw;
  width: 100%;
  height: 100%;
  gap: 5%;
}

#profile-photo {
  max-width: 28%;
  height: auto; /* override the 150% height */
}

/* ========== WORKING PAPERS & WORK IN PROGRESS ========== */
#working_papers,
#work_in_progress {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
}

.working-papers-container,
.work-in-progress-container {
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: 75vw;
  width: 100%;
  height: 100%;
  position: relative;
}

/* ========== PAPER ITEMS ========== */
.paper-item {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  margin-bottom: 2.5vw;
  padding: 1.5vw 1.5vw;
  margin-left: 1vw;

  border: 2px solid transparent;   /* Ensure border is always there */
  border-radius: 0.5vw;

  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease; /* Smooth transition for hover effects */
}

.paper-item:hover {
  cursor: pointer;
  border-color: black;            
  transform: scale(1.02); 
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  border-radius: 0.5vw;
}

.paper-content {
  flex: 1 1 60%;
  padding-right: 1vw;
}

.paper-content h3 {
  margin: 0 0 0.5vw;
}

.paper-content p {
  text-align: justify;
}

.paper-image img {
  width: clamp(320px, 25vw, 420px);  /* min / preferred / max */
  height: auto;
  object-fit: cover;
  border-radius: 0;
  display: block;
}

/* ========== LINKS ========== */
a {
  color: #007BFF;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
  color: #0056b3;
}

.justified {
  text-align: justify;
}


/* ===== RESPONSIVE DESIGN ===== */

/* ===== Tablet ===== */
@media (max-width: 1000px) {
  header {
    flex-direction: column;
    align-items: flex-start;
  }

  nav {
    width: 100%;
    display: flex;
    justify-content: center;
  }

  nav ul {
    justify-content: center;
    width: fit-content;   /* makes centering match the image center */
    margin: 20px auto 32px auto;
  }

  nav li {
    margin: 0 18px;
  }

  .about-container {
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 92vw; /* give content more room */
  }

 #profile-photo {
    width: min(320px, 70vw);
    aspect-ratio: 1 / 1;   /* <-- key: guarantees square */
    height: auto;          /* let aspect-ratio control the height */
    object-fit: cover;
    border-radius: 50%;
    display: block;
    margin-bottom: 24px;
  }

  .about-content {
    width: 100%;
  }
}


/* ===== Mobile phone ===== */
@media (max-width: 600px) {
  main {
    padding: 18px 14px 56px;
  }

  nav {
    width: 100%;
    display: flex;
    justify-content: center;
  }

  nav ul {
    justify-content: center;
    width: fit-content;   /* makes centering match the image center */
    margin: 20px auto 32px auto;
  }

  nav li {
    margin: 0 18px;
  }

  nav a {
    padding: 10px 0;
  }

 #profile-photo {
    width: min(320px, 70vw);
    aspect-ratio: 1 / 1;   /* <-- key: guarantees square */
    height: auto;          /* let aspect-ratio control the height */
    object-fit: cover;
    border-radius: 50%;
    display: block;
    margin-bottom: 24px;
  }

  .paper-item {
    flex-direction: column;
  }

  .paper-image img {
    width: 100%;
    height: auto;
  }
}

/* 
@media (max-width: 700px) {

  header {
    flex-direction: column;
    align-items: flex-start;
    height: auto;
  }

  nav ul {
    justify-content: flex-start;
    margin-top: 10px;
  }

  .paper-item {
    flex-direction: column;
  }

  .paper-image img {
    width: 100%;
    height: auto;
  }

  #profile-photo {
    width: 100%;
    height: auto;
  }

}
 */