:root {
  --gradient-start: #000000;
  --gradient-end: #1a1a1a;
  --circle-color: rgba(255, 255, 255, 0.1);
  --button-gradient-start: #222222;
  --button-gradient-end: #444444;
  --button-text-color: #ffffff;
  --font: 'Kanit', sans-serif;
  --text-color: #ffffff;
}

/* 🌞 Light Theme Variables */
.light-theme {
  --gradient-start: #f0f0f0;
  --gradient-end: #d9d9d9;
  --circle-color: rgba(0, 0, 0, 0.05);
  --button-gradient-start: #ffffff;
  --button-gradient-end: #e0e0e0;
  --button-text-color: #000000;
  --text-color: #000000;
}

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

html, body {
  height: 100%;
  overflow: hidden;
  font-family: var(--font);
  color: var(--text-color);
  position: relative;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
}

/* Background Image (with low opacity) */
body::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: url("https://i.ibb.co/YTQQBTBr/image.png") center/cover no-repeat;
  opacity: 0.12;
  z-index: 0;
}

/* Light Glow Bottom */
body::after {
  content: "";
  position: absolute;
  bottom: 0; left: 50%;
  transform: translateX(-50%);
  width: 100%;
  height: 300px;
  background: radial-gradient(circle at center top, rgba(255,255,255,0.12) 0%, rgba(255,255,255,0) 70%);
  filter: blur(80px);
  z-index: 1;
}

/* Theme Toggle */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 25px;
  background: rgba(255, 255, 255, 0.07);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 50px;
  width: 50px;
  height: 50px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 20;
  transition: all 0.3s ease;
}
.theme-toggle:hover {
  background: rgba(255,255,255,0.15);
  transform: scale(1.05);
}
.theme-toggle svg {
  color: var(--text-color);
  position: absolute;
  transition: opacity 0.3s ease;
}
#sunIcon { opacity: 0; }
.light-theme #moonIcon { opacity: 0; }
.light-theme #sunIcon { opacity: 1; }

/* Loading screen */
#loading-screen {
  position: fixed;
  width: 100%;
  height: 100%;
  background: #000;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 999;
  transition: opacity 1s ease;
}
#loading-screen.hidden { opacity: 0; pointer-events: none; }

.loader {
  border: 4px solid rgba(255,255,255,0.1);
  border-top: 4px solid #888;
  border-radius: 50%;
  width: 60px;
  height: 60px;
  animation: spin 1s linear infinite;
}
@keyframes spin { 100% { transform: rotate(360deg); } }

/* Center content - shifted higher for focus */
.center-container {
  position: absolute;
  top: 40%;  /* 👈 เดิม 50% ปรับขึ้น */
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  z-index: 5;
}

/* Gradient Text Animation */
.gradient-text {
  background: linear-gradient(270deg, #ffffff, #999, #ffffff);
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: moveGradient 4s ease infinite;
}
@keyframes moveGradient {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.title h2 {
  font-size: 2.8rem;
  font-weight: 700;
}
.title p {
  margin-top: 8px;
  font-size: 1.2rem;
  opacity: 0.85;
}

/* Button */
button {
  margin-top: 40px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 40px;
  font-size: 1.2rem;
  background: linear-gradient(135deg, var(--button-gradient-start), var(--button-gradient-end));
  color: var(--button-text-color);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 40px;
  cursor: pointer;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.15), 0 0 20px rgba(0,0,0,0.7);
  transition: all 0.3s ease;
  backdrop-filter: blur(6px);
}
button:hover {
  transform: translateY(-2px);
  background: linear-gradient(135deg, #333, #555);
  box-shadow: 0 0 25px rgba(255,255,255,0.1);
}
button svg {
  stroke: var(--button-text-color);
  transition: transform 0.3s ease;
}
button:hover svg { transform: rotate(90deg); }

/* Circle Follow */
#circle {
  position: fixed;
  top: 0; left: 0;
  width: 250px;
  height: 250px;
  border-radius: 50%;
  background: var(--circle-color);
  pointer-events: none;
  filter: blur(80px);
  transform: translate(-50%, -50%);
  z-index: 2;
}

/* Footer */
footer {
  position: absolute;
  bottom: 15px;
  width: 100%;
  text-align: center;
  color: rgba(255,255,255,0.5);
  font-size: 0.9rem;
  z-index: 5;
}

/* Responsive */
@media (max-width: 600px) {
  .title h2 { font-size: 1.8rem; }
  button { padding: 14px 28px; font-size: 1rem; }
  #circle { width: 180px; height: 180px; filter: blur(50px); }
}