*{
  margin: 0;
  padding: 0;
  font-family: 'Poppins', sans-serif;
  box-sizing: border-box;
}
:root {
  --highlight-color: #e09f7c; /* color for highlight */
  --gradient_up: rgba(143, 127, 90, 0.7);
  --gradient_dwn: rgba(188, 93, 164, 0.269);
  --default-color: #fff;
  --col-1-width: 35%;
  --col-2-width: calc(100% - var(--col-1-width) - var(--gap));
  --gap: 5%;

}
body{
  background: #080808;
  color: var(--default-color);
}
#header{
  width: 100%;
  height: 100vh;
  background-image: url(images_portfol/Christian_Fernandez_page.JPG);
  background-size: cover;
  background-position: center;
}

@media (max-width: 1500px) {
  #header {
    background-position: 80% center; /* Shift left slightly on smaller screens */
  }
}

.container{
  padding: 10px 10%;
  
}

nav{
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}
.logo{
  width: 140px;
}

nav ul li{
  display: inline-block;
  list-style: none;
  margin: 10px 20px;
}

nav ul li a{
  color: var(--default-color);
  text-decoration: none;
  font-size: 18px;
  position: relative;
}

nav ul li a::after{
  content: '';
  width: 0;
  height: 3px;
  background: var(--highlight-color);
  position: absolute;
  left: 0;
  bottom: -6px;
  transition: 0.5s;

}
nav ul li a:hover::after{
  width: 100%;
}

.header-text{
  margin-top: 20%;
  font-size: 30px;
}

.header-text h1{
  font-size: 60px;
  margin-top: 20px
}
.header-text h1 span{
  color: var(--highlight-color);
}

/*--------------about-----------------*/
#about{
  padding: 80px 0;
  color: #ababab;
  text-align: justify;

}
.row{
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
}
.about-col-1{
  flex-basis: var(--col-1-width);
}

.about-col-1 img{
  width: 100%;
  border-radius: 15px;
}

.about-col-2{
  flex-basis: var(--col-2-width);
}

.sub-title{
  font-size: 60px;
  font-weight: 600;
  color: #fff;
}

.tab-titles{
  display: flex;
  margin: 20px 0 40px;
}

.tab-links{
  margin-right: 50px;
  font-size: 18px;
  font-weight: 500;
  cursor: pointer;
  position: relative;
}

.tab-links::after{
  content: '';
  width: 0;
  height: 3px;
  background: var(--highlight-color);
  position: absolute;
  left: 0;
  bottom: -8px;
  transition: 0.5s;
}

.tab-links.active-link::after{
  width: 50%;
}

.tab-contents ul li{
  list-style: none;
  margin: 10px 0;
}

.tab-contents ul li span{
  color: var(--highlight-color);
  font-size: 14px;
}

.tab-contents{
  display: none;
}

.tab-contents.active-tab{
  display: block;
}

/* -----------services----------- */
#services{
  padding: 30px 0;
}

.services-list{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  grid-gap: 40px;
  margin-top: 50px;
  /* text-align: justify; */
}

.services-list div{
  background: #262626;
  padding: 40px;
  font-size: 13px;
  font-weight: 300;
  border-radius: 10px;
  transition: background 0.5s, transform 0.5s;
}

.services-list div i { /*#this will modifi the icon*/
  font-size: 50px;
  margin-bottom: 30px;
}

.services-list div h2{
  font-size: 30px;
  font-weight: 500;
  margin-bottom: 15px;
}

.services-list div a{
  text-decoration: none;
  color: #fff;
  font-size: 12px;
  margin-top: 20px;
  display: inline-block;
}

.services-list div:hover{
  background: var(--highlight-color);
  transform: translateY(-10px);

}
/* ------Portfolio---- */
#portfolio{
  padding: 50px 0;
}

.work-list{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  grid-gap: 40px;
  margin-top: 50px;
}

.work{
  border-radius: 30px;
  position: relative;
  overflow: hidden;
}

.work img{
  width: 100%;
  border-radius: 10px;
  display: block;
  transition: transform 0.5s
}

.layer{ 
  width: 100%;
  height: 0%;
  transition: height 0.5s;
  background: linear-gradient(rgba(0,0,0,0.6), var(--highlight-color));
  border-radius: 10px;
  position: absolute;
  left: 0;
  bottom: 0; 
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  padding: 0 40 40px;
  text-align: center;
  font-size: 14px

}

.layer h3{
  font-weight: 700; 
  margin-bottom: 20px; 
} 

.layer a{
  margin-top: 20px;
  color: var(--highlight-color);
  text-decoration: none;
  font-size: 18px;
  line-height: 60px;
  background: #fff;
  width: 60px;
  height: 60px;
  border-radius: 50%;
  text-align: center;

}

.work:hover img{
  transform: scale(1.1)

}

.work:hover .layer{
  height: 100%
}

.btn{
  display:  block;
  margin: 50px auto;
  width: fit-content;
  border: 1px solid var(--highlight-color);
  padding: 14px 50px;
  border-radius: 6px;
  text-decoration: None;
  color: var(--col-1-width);
  transition: background 0.5s;
}

.btn:hover{
  background: var(--highlight-color) ;
}


/* ------ Contact ------ */

.contact-left{
  flex-basis: 35%;
}

.contact-right{
  flex-basis: 60%;
}

.contact-left p{
  margin-top: 30px; 
}

.contact-left p i{
  color: var(--highlight-color);
  margin-left: 15px;
  font-size: 25px;
}

.social-icons{
  margin-top: 30px;
}

.social-icons a{
  text-decoration: none;
  font-size: 30px;
  margin-right: 15px;
  color: var(--default-color);
  display: inline-block;
  transition: transform 0.5s;
}

.social-icons a:hover{
  color: var(--highlight-color);
  transform: translateY(-5px);
}

.btn.btn2{
  display: inline-block;
  background: var(--highlight-color);
}

.contact-right form{
  width: 100%;
}

form input, form textarea{
  width: 100%;
  border: 0;
  outline: none;
  background: #262626;
  padding: 15px;
  margin: 15px 0;
  color: #fff;
  font-size: 18px;
  border-radius: 10px;
}

form .btn2{
  padding: 14px 60px;
  font-size: 18px;
  margin-top: 20px;
  cursor: pointer; 
}

.copyright{
  width: 100;
  text-align: center;
  padding: 25px 0;
  background: #262626;
  font-weight: 200;
  margin-top: 20px;
}
/* 
.copyright i{
  color: ;

} */
html{
  scroll-behavior: smooth;
}


/* --------------- css for small screen -------- */
nav .fa{
  display: none;
}

@media only screen and (max-width: 900px){
  .header-text{
    margin-top: 80%;
    font-size: 16px;
  }

  .header-text h1{
    font-size: 30px;
  }

  nav .fa{
    display: block;
    font-size: 25px;
  }

  nav ul{
    background: var(--highlight-color);
    position: fixed;
    top: 0;
    right: -200px;
    width: 200px;
    height: 100vh;
    padding-top: 50px;
    z-index: 2;
    transition: right 0.5s;

  }

  nav ul li{
    display: block;
    margin: 25px;
  }

  nav ul .fa{
    position: absolute;
    top: 25px;
    left: 25px;
    cursor: pointer;
  }

  .contact-left, .contact-right{
    flex-basis: 100%;
  }

  .copyright{
    font-size: 14px;
  }

}

#msg{
  color: var(--highlight-color);
  margin-top: -40px;
  display: block

}

/* ------------  My Work ------------ */
/* ---------- upper part (butons) -------- */
#sub-header{
  height:  80vh;
  width: 100%;
  background-image: linear-gradient(var(--gradient_up),var(--gradient_dwn)),url(images_portfol/myWork/corrected_voltage_charge_electric_field_with_colorbars.png);
  background-position: center;
  background-size: cover;
  text-align: center;
  color: #fff;

}

.background-wrapper {
  background: black; /* Black background spanning the full width */
  width: 100%; /* Full width */
  height:  8vh;
}


/* ---------- sections ---------- */

.simulations{
  width: 80%;
  margin: auto;
  padding-top: 80px;
  padding-bottom: 50px;
}

.row {
  display: flex; /* Enable Flexbox for horizontal alignment */
  align-items: top; /* Vertically center the content */
}

.sim-col {
  flex-basis: 30%; /* Default width is 30% for text column */
  padding: 30px 10px; /* Add padding */
}

.sim-col img {
  width: 100%; /* Ensure the image fills its column */
}

.sim-col:last-child {
  flex-basis: 70%; /* Set the image column to 70% */
}

.sim-col h1{
  padding-top: 0;
}

.sim-col p{
  padding: 15px 0 25px;
}

/* ------------  Resume  ------------ */

#sub-header-resume{
  height:  30vh;
  width: 100%;
  background-image: linear-gradient(var(--gradient_up),var(--gradient_dwn));
  background-position: center;
  background-size: cover;
  text-align: center;
  color: #fff;
}
/* --------- I added this part because no image --------- */
#resume-title {
  margin-top: -200px; /* Move the text up */
  font-size: 50px; /* Optional: Adjust font size if needed */ /* Optional: Change the color */
  text-align: center; /* Optional: Align it to the center */
}

.iframe-wrapper {
  display: flex; /* Flex container for additional flexibility */
  align-items: center; /* Center content within the wrapper */
  justify-content: center; /* Center horizontally */
  padding-top: 80px;
  padding-bottom: 50px;
}

iframe#myPDF {
  width: 70%;
  height:  100vh;
}