:root {
  --primary: #0080ff;
  --background: #ffffff;
  --surface: #f7faff;
  --text: #1c1d1f;
  --footer: #e3e6ea;
  --nav: #f9fbfd;
  --transition: 0.3s;
}
[data-theme="dark"] {
  --primary: #009fff;
  --background: #181a20;
  --surface: #242633;
  --text: #f5f8fb;
  --footer: #232532;
  --nav: #23283b;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  font-family: 'Montserrat', Arial, sans-serif;
  background: var(--background);
  color: var(--text);
  transition: background var(--transition), color var(--transition);
}
/* Header and Navbar */
header {
  background: var(--nav);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 4rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.02);
  position: sticky;
  top: 0;
  z-index: 100;
}
header h1 {
  letter-spacing: 1px;
  font-size: 1.8rem;
  color: var(--primary);
  margin: 0.4rem 0;
  user-select: none;
  transition: opacity var(--transition);
}
nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  align-items: center;
}
nav ul li {
  display: inline;
}
nav a {
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  font-size: 1rem;
  position: relative;
  padding: 0.3rem 0.4rem;
  transition: color var(--transition);
}
nav a:hover, nav a.active {
  color: var(--primary);
  border-bottom: 2px solid var(--primary);
}
.mode-toggle {
  background: var(--surface);
  border: none;
  cursor: pointer;
  padding: 0.5rem 0.8rem;
  border-radius: 20px;
  margin-left: 1rem;
  color: var(--primary);
  transition: background var(--transition);
  font-size: 1.2rem;
  display: flex;
  align-items: center;
}
/* Hamburger Menu for Mobile - Positioned Top Right */
.menu-toggle {
  display: none;
  font-size: 1.8rem;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--primary);
  position: absolute;
  top: 50%;
  right: 1rem;
  transform: translateY(-50%);
  z-index: 101;
}
/* Sections */
section {
  padding: 3.5rem 1.2rem 2rem 1.2rem;
  max-width: 950px;
  margin: 0 auto;
}
/* Home */
#home {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  justify-content: center;
  min-height: 90vh;
  text-align: center;
}
.profile-img {
  width: 200px;
  height: 200px;
  object-fit: cover;
  object-position: center;
  border-radius: 50%;
  border: 4px solid var(--primary);
  box-shadow: 0 4px 24px rgba(0,128,255,0.07);
  margin-bottom: 1rem;
}
.designation {
  color: var(--primary);
  font-size: 1.3rem;
  margin: 0.3rem 0;
  font-weight: 600;
}
/* Boxed Text under Designation */
.welcome-text {
  background: var(--surface);
  padding: 1.5rem 2rem;
  border-radius: 12px;
  border-left: 4px solid var(--primary);
  box-shadow: 0 2px 12px rgba(0,0,0,0.05);
  margin: 1.5rem 0;
  max-width: 500px;
  line-height: 1.6;
}
/* Education */
.edu-timeline {
  margin: 1.5rem auto;
  display: grid;
  row-gap: 2.1rem;
  padding-left: 1rem;
  border-left: 3px solid var(--primary);
  max-width: 500px;
}
.edu-item {
  position: relative;
  margin-left: 0.5rem;
}
.edu-item::before {
  content: '';
  position: absolute;
  left: -1.35rem;
  top: 0.2rem;
  width: 1rem;
  height: 1rem;
  background: var(--primary);
  border-radius: 50%;
  box-shadow: 0 2px 6px rgba(0,128,255,0.2);
}
.edu-degree {
  font-weight: 700;
  font-size: 1.15rem;
}
.edu-institute {
  color: var(--primary);
  font-size: 1rem;
}
.edu-year {
  font-size: 0.90rem;
  color: #888;
}
/* Skills */
.skills-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1.4rem;
  justify-content: center;
  margin-top: 1.8rem;
}
.skill-card {
  background: var(--surface);
  padding: 1.1rem 1.5rem;
  border-radius: 12px;
  font-size: 1.05rem;
  min-width: 100px;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.03);
  letter-spacing: 0.5px;
  transition: transform var(--transition), box-shadow var(--transition);
}
.skill-card:hover {
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 8px 32px -6px var(--primary);
}
/* Projects */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}
.project-card {
  background: var(--surface);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  transition: transform var(--transition), box-shadow var(--transition);
  border: 1px solid rgba(0,128,255,0.1);
}
.project-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 40px rgba(0,128,255,0.15);
}
.project-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-bottom: 3px solid var(--primary);
}
.project-content {
  padding: 1.5rem;
}
.project-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.8rem;
}
.project-description {
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 1.5rem;
  color: var(--text);
}
.project-link {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 0.7rem 1.5rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  transition: background var(--transition);
  box-shadow: 0 2px 8px rgba(0,128,255,0.2);
}
.project-link:hover {
  background: #005ecb;
  transform: translateY(-2px);
}
/* Services */
.services-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.7rem;
  margin-top: 1.5rem;
}
.service-card {
  background: var(--surface);
  padding: 1.4rem 1.1rem;
  border-radius: 14px;
  box-shadow: 0 1px 10px rgba(0,0,0,0.03);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  border-left: 5px solid var(--primary);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.service-card:hover {
  border-color: #2cdef3;
  box-shadow: 0 4px 20px -4px var(--primary);
}
.service-card i {
  font-size: 2.1rem;
  color: var(--primary);
  margin-bottom: 0.7rem;
}
/* About */
#about {
  max-width: 700px;
}
.about-content {
  font-size: 1.1rem;
  line-height: 1.7;
  margin: 1rem 0 0.5rem 0;
}
/* Contact */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  max-width: 450px;
  margin: 2.2rem auto 1rem auto;
  background: var(--surface);
  padding: 2rem 1.3rem 1.3rem 1.3rem;
  border-radius: 14px;
  box-shadow: 0 2px 14px rgba(0,0,0,0.04);
}
.contact-form input,
.contact-form textarea {
  padding: 0.7rem 0.8rem;
  border: 1px solid #dbe1ea;
  border-radius: 7px;
  font-size: 1rem;
  background: #f9fafb;
  transition: border var(--transition);
  resize: none;
  font-family: inherit;
}
.contact-form input:focus,
.contact-form textarea:focus {
  border: 1.7px solid var(--primary);
  outline: none;
  background: #fff;
}
.contact-form button {
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 0.85rem;
  border-radius: 8px;
  font-size: 1.09rem;
  font-weight: bold;
  letter-spacing: 0.6px;
  cursor: pointer;
  transition: background var(--transition);
  margin-top: 0.4rem;
  box-shadow: 0 2px 10px rgba(0,128,255,0.07);
}
.contact-form button:hover {
  background: #005ecb;
}
.contact-info {
  text-align: center;
  margin-top: 2rem;
  color: var(--primary);
  font-weight: 500;
  font-size: 1rem;
}
/* Footer */
footer {
  background: var(--footer);
  text-align: center;
  color: #888e9b;
  font-size: 0.98rem;
  padding: 1.1rem 0;
  margin-top: 2rem;
  letter-spacing: 0.02em;
  box-shadow: 0 0px 7px rgba(0,0,0,0.033);
}
/* Responsive Design */
@media (max-width: 680px) {
  header {
    flex-direction: row;
    justify-content: space-between;
    padding: 1rem 1rem;
  }
  nav ul {
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--nav);
    padding: 1rem;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  }
  nav ul.show {
    display: flex;
  }
  .menu-toggle {
    display: block;
  }
  .welcome-text {
    padding: 1.2rem 1.5rem;
  }
  .projects-grid {
    grid-template-columns: 1fr;
  }
}
@media (max-width: 800px) {
  header {
    flex-direction: row;
    justify-content: space-between;
    padding: 1rem 1rem;
  }
  nav ul {
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--nav);
    padding: 1rem;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  }
  nav ul.show {
    display: flex;
  }
  .menu-toggle {
    display: block;
  }
  section {
    padding: 2.5rem 0.4rem 1.3rem 0.4rem;
  }
  .contact-form {
    padding: 1.3rem 0.5rem;
  }
}
/* Utilities */
.sr-only {
  position:absolute;
  width:1px;
  height:1px;
  margin:-1px;
  padding:0;
  overflow:hidden;
  border:0;
  clip:rect(0,0,0,0);
}