* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: 'Inter', sans-serif;
  background-color: #0d1117;
  color: #c9d1d9;
  overflow-x: hidden;
}

/* Smooth fade-in animation */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  animation: fadeIn 1s ease-in;
}

/* Header */
header {
  background-color: #161b22;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #30363d;
  animation: fadeIn 1s ease-in 0.2s both;
  position: relative;
  z-index: 10;
}

header h2 {
  color: #58a6ff;
  font-size: 1.5rem;
  margin: 0;
}

/* Hamburger icon */
.menu-toggle {
  display: none;
  font-size: 1.8rem;
  color: #c9d1d9;
  background: none;
  border: none;
  cursor: pointer;
}

/* Nav (desktop) */
nav {
  display: flex;
  gap: 1rem;
}

nav a {
  color: #8b949e;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s;
}

nav a:hover {
  color: #58a6ff;
}

/* Main content */
main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1rem;
}

/* APOD content box */
.content {
  background-color: #161b22;
  border: 1px solid #30363d;
  border-radius: 12px;
  padding: 2rem;
  max-width: 800px;
  width: 100%;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  margin-bottom: 2rem;
  animation: fadeIn 1s ease-in 0.4s both;
}

h1 {
  color: #58a6ff;
  font-size: 2rem;
  text-align: center;
  margin-bottom: 0.5rem;
}

.date {
  text-align: center;
  color: #8b949e;
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

img {
  width: 100%;
  height: auto;
  border-radius: 10px;
  margin-bottom: 1.5rem;
}

p {
  font-size: 1rem;
  line-height: 1.6;
  text-align: justify;
  color: #d1d5da;
}

.video-link {
  display: inline-block;
  text-align: center;
  margin-top: 0.8rem;
  color: #58a6ff;
  font-weight: 600;
  text-decoration: none;
}

.video-link:hover {
  text-decoration: underline;
}

/* Form */
form {
  background-color: #161b22;
  border: 1px solid #30363d;
  padding: 1.5rem;
  border-radius: 12px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  max-width: 800px;
  width: 100%;
  animation: fadeIn 1s ease-in 0.6s both;
}

input, select {
  padding: 0.75rem;
  background-color: #0d1117;
  border: 1px solid #30363d;
  border-radius: 6px;
  color: #c9d1d9;
  font-size: 1rem;
  width: 120px;
  transition: border-color 0.3s;
}

input:focus {
  border-color: #58a6ff;
  outline: none;
}

button {
  padding: 0.75rem 1.5rem;
  background-color: #238636;
  border: none;
  border-radius: 6px;
  color: white;
  font-size: 1rem;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
}

button:hover {
  background-color: #2ea043;
  transform: translateY(-2px);
}

/* Footer */
footer {
  background-color: #161b22;
  text-align: center;
  padding: 1rem;
  color: #8b949e;
  font-size: 0.9rem;
  border-top: 1px solid #30363d;
  animation: fadeIn 1s ease-in 0.8s both;
  margin-top: auto;
}

/* Responsive styles */
@media (max-width: 600px) {
  .menu-toggle {
    display: block;
  }

  nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    background-color: #161b22;
    flex-direction: column;
    display: none;
    padding: 1rem 2rem;
    border-top: 1px solid #30363d;
  }

  nav.show {
    display: flex;
  }

  nav a {
    margin: 0.5rem 0;
  }

  input, button {
    width: 100%;
  }

  .content, form {
    padding: 1rem;
  }

  h1 {
    font-size: 1.3rem;
  }

  .date {
    font-size: 0.85rem;
  }
}

.video-wrapper {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 aspect ratio */
  margin-bottom: 1.5rem;
}

.video-wrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 10px;
  border: none;
}