/* ======== Base & Global ======== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --color-primary-light: #00E5FF;
  --color-dark-bg: #121212;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-dark-bg);
  color: #E0E0E0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.5;
}

a {
  color: var(--color-primary-light);
  text-decoration: none;
}

a:hover {
  color: #00838F;
}

/* ======== Header ======== */
header {
  position: relative;
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, #005662, #1F1F1F);
  color: var(--color-primary-light);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 1.5rem 3rem 1.5rem 2rem;
  overflow: hidden;
  user-select: none;
}

header h1 {
  font-size: 3.5rem;
  font-weight: 700;
  margin: 0 0 0.3rem 0;
  line-height: 1.2;
  color: var(--color-primary-light);
  user-select: text;
}

header h2 {
  font-weight: 500;
  margin: 0;
  font-size: 1.25rem;
  color: #a3eefc;
  user-select: text;
}

/* ======== Main Layout ======== */
main {
  display: flex;
  flex-wrap: wrap;
  max-width: 1400px;
  margin: 2rem auto;
  gap: 2rem;
  padding: 0 1rem;
  align-items: flex-start;
  justify-content: center;
}

/* Introduction full width */
#introduction {
  flex-basis: 100%;
  background: #1F1F1F;
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgb(0 0 0 / 0.7), inset 0 0 10px 2px #00E5FF55;
  text-align: center;
}

#introduction h2 {
  color: var(--color-primary-light);
  margin-top: 0;
}

/* Image and Features container */
#img {
  flex: 2 1 600px;
  display: flex;
  justify-content: center;
  align-items: center;
}

#img img {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 229, 255, 0.4);
}

/* Features block beside image */
.features {
  flex: 1 1 500px;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.feature {
  height: 11rem;
  background: linear-gradient(135deg, #00363a, #1E1E1E);
  border-radius: 12px;
  padding: 1rem 1.25rem;
  box-shadow: 0 3px 10px rgb(0 0 0 / 0.75), inset 0 0 10px 2px #00E5FF55;
  transition: box-shadow 0.3s ease, border 0.3s ease;
  border: 2px solid transparent;
  align-content: center;
  text-align: center;
}

.feature strong {
  color: var(--color-primary-light);
  font-size: 1.5rem;
}

.feature:hover {
  border-color: var(--color-primary-light);
  box-shadow: 0 0 12px 3px #00E5FFaa, inset 0 0 15px 3px #00E5FF88;
}

/* ======== Login Button ======== */
#loginButton {
  flex-basis: 100%;
  text-align: center;
}

#loginButton button {
  width: 100%;
  cursor: pointer;
  background: linear-gradient(135deg, #00B8D4, #00838F);
  border: none;
  border-radius: 10px;
  color: #E0E0E0;
  font-weight: 600;
  font-size: 1rem;
  padding: 0.75rem 1.5rem;
  box-shadow: 0 4px 12px -2px #00E5FFcc;
  transition: background 0.3s ease, box-shadow 0.3s ease, transform 0.15s ease;
}

#loginButton button:hover {
  background: linear-gradient(135deg, #00E5FF, #00B8D4);
  box-shadow: 0 0 16px #00E5FFdd;
  transform: translateY(-2px);
}

/* ======== Footer ======== */
footer {
  text-align: center;
  padding: 1rem 0;
  background: #1F1F1F;
  color: #666;
  font-size: 0.9rem;
  user-select: none;
}

footer a {
  color: var(--color-primary-light);
}

footer a:hover {
  color: #00838F;
}

/* ======== Responsive ======== */
@media (max-width: 900px) {
  main {
    flex-direction: column;
    align-items: center;
  }
  #img {
    flex: 1 1 auto; /* Flex basis überschreiben! */
  }

  #introduction { order: 0; }
  .features { order: 2; }
  #img { order: 3; }
  #loginButton { order: 1; }

  .features {
    flex-direction: column;
    align-items: stretch;
  }

  .feature {
    flex: 1 1 auto;
    
  }
}


@media (max-width: 600px) {
  header h1 {
    font-size: 2.5rem;
  }
  header h2 {
    font-size: 1rem;
  }

  .features {
    flex-direction: column;
  }

  .feature {
    flex: 1 1 auto;
  }
}