:root {
  --primary-color: #007bff;
  --secondary-color: #6c757d;
  --dark-color: #343a40;
  --light-color: #f8f9fa;
  --white-color: #fff;
  --body-font: 'Roboto', sans-serif;
  --heading-font: 'Montserrat', sans-serif;
}

body {
  font-family: var(--body-font);
  color: var(--dark-color);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-image: url('images/kalli-linux.jpg');
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  background-attachment: fixed;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: -1;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--heading-font);
  font-weight: 700;
  color: var(--dark-color);
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: 3rem;
  position: relative;
  display: inline-block;
  color: var(--dark-color);
}

.section-title::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: -10px;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background-color: var(--primary-color);
  border-radius: 2px;
}

#main-content {
  display: block;
  flex-grow: 1;
  padding-top: 70px;
}

#mobile-under-construction {
  display: none;
  background-image: url('images/kalli-linux.jpg');
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  background-attachment: fixed;
  color: var(--white-color);
  min-height: 100vh;
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 999;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

#mobile-under-construction::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.7);
  z-index: 1;
}

#mobile-under-construction .mobile-construction-content {
  position: relative;
  z-index: 2;
  padding: 20px;
  max-width: 90%;
  margin: auto;
}

#mobile-under-construction h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--white-color);
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

#mobile-under-construction p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.5);
}

@media (max-width: 767px) {
  body {
    display: block;
    min-height: auto;
    overflow-y: hidden;
    background-image: none;
  }
  body::before {
    content: none;
  }

  #main-content {
    display: none; 
    flex-grow: 0; 
    padding-top: 0;
  }

  #mobile-under-construction {
    display: flex;
  }

  #backToTopBtn {
    display: none !important;
  }
}

.navbar {
  box-shadow: 0 2px 4px rgba(0, 0, 0, .08);
  background-color: rgba(52, 58, 64, 0.95);
}

.navbar-brand {
  font-weight: 700;
  font-size: 1.5rem;
}

.navbar-dark .navbar-nav .nav-link {
  color: rgba(255, 255, 255, 0.8);
  transition: color 0.3s ease;
}

.navbar-dark .navbar-nav .nav-link:hover,
.navbar-dark .navbar-nav .nav-link.active {
  color: var(--primary-color);
}

#inicio {
  background: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('images/background-inicio.jpg') no-repeat center center/cover;
  color: var(--white-color);
  min-height: 100vh;
  padding: 100px 0;
  position: relative;
  overflow: hidden;
  z-index: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

#inicio .container {
  z-index: 1;
}

#inicio h1 {
  font-size: 3.5rem;
  margin-bottom: 10px;
  color: var(--white-color);
  text-shadow: 2px 2px 6px rgba(0, 0, 0, 0.7);
}

#inicio .lead {
  font-size: 1.5rem;
  margin-bottom: 30px;
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 1px 1px 4px rgba(0, 0, 0, 0.6);
}

.profile-img {
  width: 180px;
  height: 180px;
  object-fit: cover;
  border: 5px solid var(--primary-color);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

#sobre, #habilidades, #projetos, #contato {
  padding: 80px 0;
  background-color: rgba(255, 255, 255, 0.9);
}

.about-image {
  max-width: 100%;
  height: auto;
  max-height: 500px;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

#habilidades .card {
  border: none;
  transition: transform 0.3s ease;
  box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.05);
}

#habilidades .card:hover {
  transform: translateY(-10px);
  box-shadow: 0 1rem 2rem rgba(0, 0, 0, 0.1);
}

#habilidades .card i {
  color: var(--primary-color);
}

.project-card {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 1rem 2rem rgba(0, 0, 0, 0.15) !important;
}

.project-card img {
  height: 200px;
  object-fit: cover;
}

#backToTopBtn {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 1000;
  width: 50px;
  height: 50px;
  font-size: 1.2rem;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

footer {
  background-color: var(--dark-color);
  color: rgba(255, 255, 255, 0.7);
  margin-top: auto;
}

footer a {
  color: rgba(255, 255, 255, 0.7);
  transition: color 0.3s ease;
  text-decoration: none; 
}

footer a:hover {
  color: var(--primary-color);
}

.tech-icons i {
  transition: color 0.3s ease, transform 0.3s ease, filter 0.3s ease;
}

.tech-icons i:hover {
  transform: scale(1.2);
  filter: brightness(1.2);
  cursor: pointer;
}

.tech-icons .fa-html5 { color: #e34f26; }
.tech-icons .fa-css3-alt { color: #1572b6; }
.tech-icons .fa-sass { color: #cc6699; }
.tech-icons .fa-bootstrap { color: #7952b3; }
.tech-icons .fa-js { color: #f7df1e; }
.tech-icons .fa-react { color: #61dafb; }
.tech-icons .fa-git-alt { color: #f05030; }
.tech-icons .fa-github { color: #181717; }
.tech-icons .fa-php { color: #777bb3; }
.tech-icons .fa-node { color: #339933; }
.tech-icons .fa-python { color: #3776ab; }
.tech-icons .fa-database { color: #4db33d; }
.tech-icons .fa-aws { color: #ff9900; }
.tech-icons .fa-docker { color: #2496ed; }

.project-detail-section {
  padding: 100px 0 60px 0;
  background-color: rgba(255, 255, 255, 0.9);
}

.project-detail-section h1 {
  font-size: 3rem;
  margin-bottom: 20px;
}

.project-detail-section .lead {
  font-size: 1.25rem;
  margin-bottom: 30px;
}

.project-detail-img {
  max-width: 100%;
  height: auto;
  margin-bottom: 20px;
  border-radius: 8px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.technologies-list .badge {
  font-size: 1em;
  margin: 0 5px 5px 0;
  padding: 8px 12px;
}

.project-links a {
  margin-right: 15px;
  margin-bottom: 10px;
}

.project-links i {
  margin-right: 5px;
}