/* Dark Theme renk paleti */
:root{
  --bg:       #121212;
  --card:     #1E1E1E;
  --primary:  #90CAF9;  /* Açık mavi ton (accent) */
  --accent:   #42A5F5;  /* Vurgu */
  --text:     #E0E0E0;  /* Açık gri yazı */
  --footer:   #0D47A1;  /* Koyu mavi footer */
}

/* Reset / temel */
* { box-sizing: border-box; }
html,body { 
  height: 100%; 
  margin: 0; 
  padding: 0; 
  font-family: "Segoe UI", Roboto, Arial, sans-serif; 
  color: var(--text); 
  background: var(--bg); 
  scroll-behavior: smooth; 
}

/* Sol üst navigasyon - sabit */
.top-nav {
  position: fixed;
  top: 10px;
  left: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 1000;
}
.top-nav a {
  background: var(--card);
  color: var(--primary);
  padding: 10px 20px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
  transition: background 0.3s;
}
.top-nav a:hover {
  background: var(--accent);
  color: #fff;
}

/* Header */
header{
  text-align: center;
  padding: 2.2rem 1rem;
  background: var(--card);
  color: var(--primary);
  border-bottom: 3px solid var(--accent);
  margin-top: 80px; /* üst navigasyon için boşluk */
}
header h1{ margin: 0; font-size: 2.25rem; }
header .subtitle{ margin: 0.5rem 0 0; opacity: 0.8; color: var(--text); }

/* Main içerik düzeni */
main{
  max-width: 900px;
  margin: 2.5rem auto;
  padding: 0 1rem;
}
section{ 
  margin-bottom: 1.8rem; 
  background: var(--card); 
  border-radius: 10px; 
  padding: 1.4rem; 
  box-shadow: 0 6px 18px rgba(0,0,0,0.4); 
}
h2{
  margin: 0 0 0.6rem 0;
  color: var(--primary);
  font-size: 1.25rem;
  border-left: 4px solid var(--accent);
  padding-left: 0.8rem;
}

/* Link stili */
a{ color: var(--accent); text-decoration: none; }
a:hover{ text-decoration: underline; }

/* Footer */
footer{
  text-align: center;
  padding: 1rem;
  background: var(--card);
  color: var(--primary);
  margin-top: 2rem;
  font-size: 0.95rem;
  border-top-left-radius: 6px;
  border-top-right-radius: 6px;
}

/* Sertifika / Proje kartları hover efekti */
.certificate a h2,
.project a h2 {
  transition: color 0.3s;
}
.certificate a:hover h2,
.project a:hover h2 {
  color: var(--primary);
  text-decoration: underline;
}

/* Responsive küçük ekran düzeltmeleri */
@media (max-width: 480px){
  header h1{ font-size: 1.5rem; }
  main{ margin: 1.2rem auto; padding: 0 0.8rem; }
  section{ padding: 1rem; }
  .top-nav { flex-direction: row; top: 10px; left: 50%; transform: translateX(-50%); }
}
.profile-pic {
  width: 120px;       /* Genişliği küçülttük */
  height: 120px;      /* Yüksekliği küçülttük */
  border-radius: 50%;
  margin-top: 1rem;
  border: 3px solid #42A5F5;
  object-fit: cover;
}