/* --------------------------------------------------
   Fonts: Importing local Poppins font
-------------------------------------------------- */
@font-face {
  font-family: 'Poppins';
  src: url('../fonts/Poppins-Regular.ttf') format('truetype');
  font-weight: 400;
}
@font-face {
  font-family: 'Poppins';
  src: url('../fonts/Poppins-Bold.ttf') format('truetype');
  font-weight: 600;
}

/* --------------------------------------------------
   Global Reset and Base Styles
-------------------------------------------------- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Apply Poppins to typical text elements */
body, p, h1, h2, h3, h4, h5, h6, a, span, div {
  font-family: 'Poppins', sans-serif;
}

/* --------------------------------------------------
   Theme Definitions
-------------------------------------------------- */
[data-theme="matthias"] {
  --gradient: linear-gradient(315deg, #6a1b9a, #283593, #1565c0, #00838f, #00695c, #204d3a, #6c3c81);
}

[data-theme="jin"] {
  --gradient: linear-gradient(315deg, #6a1b9a, #bf07e9, #d7329d, #a767de, #5351dd, #212487, #580bb6);
}

/* --------------------------------------------------
   Body Layout and Background
-------------------------------------------------- */
body {
  /* Support mobile browser height correctly */
  min-height: 100vh;
  height: calc(var(--vh, 1vh) * 100);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  scroll-behavior: smooth;
  text-align: center;
  color: #ffffff;

  /* Background gradient animation */
  background-image: var(--gradient);
  background-size: 400% 400%;
  animation: gradientBG 120s ease infinite;
}

@keyframes gradientBG {
  0% { background-position: 100% 100%; }
  50% { background-position: 0% 0%; }
  100% { background-position: 100% 100%; }
}

/* --------------------------------------------------
   Logo (top left corner)
-------------------------------------------------- */
.logo {
  position: absolute;
  top: 15px;
  left: 15px;
  font-size: 2rem;
  font-weight: 200;
  opacity: 0.4;
  color: #ffffff;
}

.logo-link {
  text-decoration: none;
  color: inherit;
  opacity: inherit;
  transition: opacity 0.3s ease;
}

.logo-link:hover {
  opacity: 1;
}

/* --------------------------------------------------
   Header / Main Content
-------------------------------------------------- */
header {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 20px;
  animation: fadeIn 2s ease-in-out;
}

@keyframes fadeIn {
  0% { opacity: 0; transform: translateY(-20px); }
  100% { opacity: 1; transform: translateY(0); }
}

h1 {
  font-size: 3rem;
  letter-spacing: 0.15em;
  text-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
}

p {
  font-size: 1.2rem;
  margin-top: 10px;
  opacity: 0.9;
  letter-spacing: 0.15em;
  text-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
}

/* --------------------------------------------------
   Social Links
-------------------------------------------------- */
.social-links {
  margin-top: 20px;
}

.social-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  margin: 0 10px;
  color: #ffffff;
  text-decoration: none;
  transition: color 0.3s ease;
}

.social-links a:hover {
  color: #00adb5;
}

.social-links svg {
  width: 1.8rem;
  height: 1.8rem;
  fill: currentColor;
}

/* --------------------------------------------------
   Footer
-------------------------------------------------- */
.footer {
  padding: 10px 0;
  text-align: center;
  width: 100%;
}

.footer-link {
  color: #ffffff;
  text-decoration: none;
  font-size: 1rem;
  margin: 0 10px;
  opacity: 0.4;
  transition: opacity 0.3s ease;
}

.footer-link:hover {
  opacity: 1;
}

.footer-separator {
  margin: 0 5px;
  pointer-events: none;
}

/* --------------------------------------------------
   Bubbles Animation (Background Effect)
-------------------------------------------------- */
.bubble {
  position: absolute;
  bottom: -10px;
  background-color: rgba(255, 255, 255, 0.7);
  border-radius: 50%;
  opacity: 0;
  animation: bubbles 10s infinite ease-in;
}

@keyframes bubbles {
  0% { transform: translateY(100vh) scale(0.5); opacity: 0; }
  30% { opacity: 1; }
  100% { transform: translateY(-110vh) scale(1.2); opacity: 0; }
}