:root {
  --bg: #0a0f16;
  --card-bg: rgba(22, 27, 34, 0.75);
  --text: #e6edf3;
  --accent: #4ea1f3;
  --border: #2d3748;
  --shadow: rgba(0, 0, 0, 0.45);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  user-select: none;
}

body {
  font-family: "Inter", "Segoe UI", Arial, sans-serif;
  background: radial-gradient(circle at top left, #0d1117, #080c12);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  backdrop-filter: blur(12px);
  background: rgba(13, 17, 23, 0.85);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  text-align: center;
  padding: 1.5rem 1rem;
  box-shadow: 0 2px 10px var(--shadow);
  z-index: 100;
}

header h1 {
  font-size: 2rem;
  font-weight: 600;
  color: var(--accent);
}

header p {
  font-size: 0.95rem;
  color: #9ba6b3;
  margin-top: 0.3rem;
}

/* -------------------------------------- */
/* 🔹 Navigation mit animierter Linie */
/* -------------------------------------- */
nav {
  margin-top: 1rem;
  position: relative;
  display: inline-block;
}

nav a {
  color: var(--text);
  text-decoration: none;
  margin: 0 1.2rem;
  font-weight: 500;
  cursor: pointer;
  position: relative;
  transition: color 0.3s ease;
}

nav a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s ease;
}

nav a:hover {
  color: var(--accent);
}

nav a:hover::after {
  width: 100%;
}

nav a.active {
  color: var(--accent);
}

nav a.active::after {
  width: 100%;
}

/* kleine bewegliche Linie unter dem aktiven Menüpunkt */
nav .indicator {
  position: absolute;
  bottom: -4px;
  height: 2px;
  background: var(--accent);
  transition: all 0.35s ease;
  border-radius: 2px;
}

/* -------------------------------------- */

section {
  display: none;
  opacity: 0;
  transition: opacity 0.4s ease;
  padding: 3rem 2rem;
  max-width: 1000px;
  margin: 0 auto;
  flex-grow: 1;
}

section.active {
  display: block;
  opacity: 1;
}

h2 {
  font-size: 1.6rem;
  border-bottom: 2px solid var(--accent);
  display: inline-block;
  padding-bottom: 0.4rem;
  margin-bottom: 2rem;
}

.about-card {
  display: flex;
  align-items: center;
  gap: 2rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: 0 4px 20px var(--shadow);
  backdrop-filter: blur(15px);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.about-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(78, 161, 243, 0.2);
}

.profile-pic {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  border: 3px solid var(--accent);
  box-shadow: 0 0 20px rgba(78, 161, 243, 0.3);
}

.about-content p {
  font-size: 1.1rem;
  line-height: 1.8;
  color: #b8c1cc;
}

.skills {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.skill-tag {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 1.2rem;
  font-weight: 600;
  color: var(--accent);
  box-shadow: 0 2px 6px var(--shadow);
  transition: transform 0.2s ease;
}

.skill-tag:hover {
  transform: translateY(-3px);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: 0 3px 12px var(--shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  text-decoration: none;
  color: inherit;
  display: block;
  cursor: pointer;
}

.project-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 6px 18px rgba(78, 161, 243, 0.25);
  border-color: var(--accent);
}

.project-card:active {
  transform: scale(1);
}

.project-card h3 {
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.project-card p {
  color: #b3bcc9;
  font-size: 0.95rem;
  line-height: 1.5;
}

.stars {
  margin-top: 0.8rem;
  color: #f1c40f;
  font-size: 0.9rem;
}

.skills-cards {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
  margin-top: 20px;
}

.skill-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
  width: 120px;
  box-shadow: 0 4px 20px var(--shadow);
  backdrop-filter: blur(15px);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.skill-card img {
  width: 60px;
  height: 60px;
  object-fit: contain;
  margin-bottom: 10px;
}

.skill-card span {
  color: var(--accent);
  font-weight: 600;
  text-align: center;
}

.skill-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(78, 161, 243, 0.2);
  border-color: var(--accent);
}

footer {
  text-align: center;
  padding: 1.5rem;
  font-size: 0.9rem;
  color: #7b8694;
  border-top: 1px solid var(--border);
  background: rgba(13, 17, 23, 0.8);
  backdrop-filter: blur(10px);
  margin-top: auto;
}


@media (max-width: 700px) {
  .about-card {
    flex-direction: column;
    text-align: center;
  }

  .profile-pic {
    width: 100px;
    height: 100px;
  }

  nav a {
    margin: 0 0.6rem;
    font-size: 1.1rem;
  }

  section {
    padding: 2rem 1.2rem;
  }

  * {
    -webkit-tap-highlight-color: transparent;
    outline: none;
    color-scheme: dark;
    --system-bar: #0a0f16;
  }

  a, button {
    -webkit-tap-highlight-color: transparent;
    outline: none;
  }

  .about-card:hover,
  .skill-card:hover,
  .project-card:hover {
    transform: none;
    box-shadow: 0 4px 20px var(--shadow);
    border-color: var(--border);
  }

  .project-card:active {
    transform: scale(0.95);
}
}