:root {
  --primary: #0d6efd;
  --hover: #0b5ed7;
  --text: #2d3436;
  --l-gray: #f8f9fa;
  --m-gray: #6c757d;
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --trans: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

section {
  padding: 100px 0;
  position: relative;
}

section::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: var(--primary);
  border-radius: 2px;
}

.skill-card,
.project-card {
  border-radius: 12px;
  transition: var(--trans);
  overflow: hidden;
}

.skill-card {
  border: 1px solid rgba(0, 0, 0, 0.08);
}

.skill-card:hover,
.project-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow);
}

.skill-card:hover {
  border-color: var(--primary);
}

.skill-card i {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  transition: transform var(--trans);
}

.skill-card:hover i {
  transform: scale(1.1);
}

.project-card .card-body {
  padding: 2rem;
  background-color: var(--l-gray);
}

.nav-link {
  position: relative;
  padding: 0.5rem 1rem;
  font-weight: 500;
  color: var(--text);
}

.nav-link::after {
  content: "";
  position: absolute;
  width: 0;
  height: 2px;
  bottom: 0;
  left: 50%;
  background: var(--primary);
  transition: all var(--trans);
  transform: translateX(-50%);
}

.nav-link:hover {
  color: var(--primary);
}

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

.social-icon {
  font-size: 1.75rem;
  color: var(--m-gray);
  transition: all var(--trans);
  padding: 0.5rem;
  border-radius: 50%;
}

.social-icon:hover {
  color: var(--primary);
  background: var(--l-gray);
  transform: translateY(-3px);
}

.tech-stack {
  display: inline-block;
  padding: 0.5em 1em;
  font-size: 0.85em;
  font-weight: 600;
  color: var(--primary);
  background: rgba(13, 110, 253, 0.1);
  border-radius: 20px;
  margin: 0.3rem;
  transition: all var(--trans);
}

.tech-stack:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-2px);
}

.btn {
  padding: 0.6rem 1.5rem;
  border-radius: 8px;
  font-weight: 500;
  transition: all var(--trans);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.card {
  border: 0;
  transition: var(--trans);
}

.card:hover {
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}