/* -------------------------------
   RESET
--------------------------------*/
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
  transition: background 0.4s, color 0.4s;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }

/* -------------------------------
   THEME COLORS
--------------------------------*/
:root {
  --bg: #f9f9f9;
  --text: #222;
  --card-bg: rgba(255,255,255,0.6);
  --accent: #00d4ff;
  --accent-gradient: linear-gradient(90deg,#00d4ff,#0078ff);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f19;
    --text: #e5e5e5;
    --card-bg: rgba(25,25,35,0.6);
    --accent: #00f7ff;
    --accent-gradient: linear-gradient(90deg,#00f7ff,#4facfe);
  }
}

/* -------------------------------
   HEADER
--------------------------------*/
header {
  position: fixed;
  top: 0; left: 0; width: 100%;
  padding: 15px 40px;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.2);
  z-index: 100;
}
header nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
header nav a {
  margin-left: 20px;
  font-weight: 600;
  position: relative;
}
header nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: -4px;
  width: 0; height: 2px;
  background: var(--accent);
  transition: .3s;
}
header nav a:hover::after { width: 100%; }

/* -------------------------------
   SECTIONS
--------------------------------*/
section { padding: 100px 10%; }
h1, h2, h3 { margin-bottom: 15px; font-weight: 700; }

/* -------------------------------
   HERO
--------------------------------*/
#hero {
  height: 100vh;
  display: flex; flex-direction: column;
  justify-content: center; align-items: center;
  text-align: center;
  color: white;
  background: var(--accent-gradient);
  position: relative; overflow: hidden;
}
#hero::after {
  content: "";
  position: absolute; inset: 0;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,0.2), transparent 60%),
              radial-gradient(circle at 70% 70%, rgba(255,255,255,0.1), transparent 60%);
  animation: floatGlow 8s infinite alternate ease-in-out;
}
#hero h1 { font-size: 3rem; z-index: 1; }
#hero p { font-size: 1.2rem; margin-top: 10px; z-index: 1; }

/* -------------------------------
   ABOUT
--------------------------------*/
#about {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}

/* -------------------------------
   SKILLS
--------------------------------*/
#skills .skill { margin: 20px 0; }
.skill-bar {
  background: #3333;
  border-radius: 20px;
  overflow: hidden;
}
.skill-fill {
  height: 12px;
  width: 0;
  border-radius: 20px;
  background: var(--accent-gradient);
  transition: width 2s;
}

/* -------------------------------
   CERTIFICATES (Swiper)
--------------------------------*/
#certificates { margin-top: 40px; }
.swiper {
  width: 100%; max-width: 700px;
  margin: auto;
  padding-bottom: 40px;
}
.swiper-slide {
  background: var(--card-bg);
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  display: flex; justify-content: center; align-items: center;
}
.swiper-slide img {
  width: 100%; height: auto; border-radius: 15px;
}
.swiper-button-next, .swiper-button-prev { color: var(--accent); }
.swiper-pagination-bullet { background: var(--accent); }

/* -------------------------------
   PROJECTS
--------------------------------*/
#projects .grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
}
.project-card {
  background: var(--card-bg);
  padding: 20px;
  border-radius: 15px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.2);
  transition: transform .3s, box-shadow .3s;
}
.project-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.4);
}

/* -------------------------------
   ANIMATIONS
--------------------------------*/
@keyframes floatGlow {
  from { transform: scale(1); }
  to { transform: scale(1.05); }
}