* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Poppins', 'Segoe UI', sans-serif;
  background: #0e1117;
  color: #f2f2f2;
  line-height: 1.6;
  scroll-behavior: smooth;
}

header {
  background: rgba(25, 30, 40, 0.95);
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 0.8rem 0;
  box-shadow: 0 1px 6px rgba(0,0,0,0.5);
}

.container { width: 90%; max-width: 1000px; margin: auto; }

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: bold;
  font-size: 1.4rem;
  color: #00bcd4;
}

.main-nav a {
  color: #ddd;
  text-decoration: none;
  margin-left: 1.2rem;
  transition: color 0.3s;
}

.main-nav a:hover {
  color: #00bcd4;
}

.lang-flags {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-left: 10px;
}

.flag-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 20px;
  transition: transform 0.2s ease;
}

.flag-btn:hover {
  transform: scale(1.25);
}

.hero {
  text-align: center;
  padding: 4rem 1rem;
  background: radial-gradient(circle at top, #1b2735, #090a0f);
}

.hero h1 {
  font-size: 2.3rem;
  margin-top: 1rem;
  color: #00bcd4;
}

.hero h2 {
  font-size: 1.1rem;
  font-weight: 400;
  margin-top: 0.5rem;
  color: #bbb;
  min-height: 1.2em;
}

.avatar {
  width: 120px;
  border-radius: 50%;
  background: #222;
  padding: 4px;
  border: 2px solid #00bcd4;
}

.section {
  padding: 3rem 1rem;
}

.section h2 {
  font-size: 1.8rem;
  color: #00bcd4;
  margin-bottom: 1rem;
  text-align: center;
}

.about p {
  text-align: center;
  max-width: 700px;
  margin: auto;
  color: #ccc;
}

.timeline {
  position: relative;
  margin: 2rem auto;
  padding-left: 30px;
  border-left: 2px solid #00bcd4;
  max-width: 600px;
}

.timeline-item {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.6s ease;
  margin-bottom: 1.5rem;
}

.timeline-item.visible {
  opacity: 1;
  transform: translateY(0);
}

.timeline-item .year {
  font-weight: bold;
  color: #00bcd4;
  display: block;
}

.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
}

.cert-card {
  background: #151a22;
  border: 1px solid #00bcd420;
  border-radius: 10px;
  padding: 1rem;
  text-align: center;
  box-shadow: 0 2px 5px rgba(0,0,0,0.4);
  transition: transform 0.3s;
}

.cert-card:hover {
  transform: translateY(-5px);
  border-color: #00bcd4;
}

.contact {
  text-align: center;
}

.contact-links a {
  display: block;
  color: #00bcd4;
  text-decoration: none;
  margin: 0.4rem 0;
  font-size: 1.05rem;
}

.contact-links a:hover {
  text-decoration: underline;
}

footer {
  background: #11141a;
  text-align: center;
  padding: 1rem;
  color: #777;
  font-size: 0.9rem;
}