/* === Reset === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, "Segoe UI", "Microsoft YaHei", Helvetica, Arial, sans-serif; color: #333; background: #fff; line-height: 1.6; }
a { color: #3dc9b3; text-decoration: none; }
a:hover { color: #2fa894; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* === Navbar === */
.navbar {
  background: #1a1a2e; padding: 0 40px; display: flex; justify-content: flex-end; align-items: center; height: 50px;
}
.navbar ul { display: flex; gap: 0; }
.navbar li a {
  display: block; padding: 14px 18px; color: rgba(255,255,255,0.7); font-size: 13px;
  text-transform: uppercase; letter-spacing: 0.5px; transition: color 0.2s;
}
.navbar li a:hover { color: #fff; }

/* === Hero Slider === */
.hero-slider {
  position: relative; width: 100%; height: 100vh; overflow: hidden; background: #111;
}
.hero-slide {
  position: absolute; inset: 0; opacity: 0;
  animation: heroFade 6s infinite;
}
.hero-slide:first-child { opacity: 1; }
.hero-slide:nth-child(2) { animation-delay: 3s; }
@keyframes heroFade {
  0%   { opacity: 0; z-index: 0; }
  10%  { opacity: 1; z-index: 1; }
  45%  { opacity: 1; z-index: 1; }
  55%  { opacity: 0; z-index: 0; }
  100% { opacity: 0; z-index: 0; }
}
.hero-slide img {
  width: 100%; height: 100%; object-fit: cover;
}
.hero-overlay {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
  background: rgba(0,0,0,0.25);
}
.hero-title {
  color: #fff; font-size: 36px; font-weight: 300; letter-spacing: 2px;
  text-shadow: 0 2px 8px rgba(0,0,0,0.5);
  opacity: 0; animation: heroTextIn 1s 0.5s forwards;
}
.hero-subtitle {
  color: rgba(255,255,255,0.85); font-size: 16px; margin-top: 12px;
  text-shadow: 0 1px 4px rgba(0,0,0,0.5);
  opacity: 0; animation: heroTextIn 1s 1.2s forwards;
}
.hero-btn {
  display: inline-block; margin-top: 24px; padding: 10px 28px;
  border: 2px solid #fff; color: #fff; border-radius: 4px; font-size: 14px;
  letter-spacing: 1px; transition: all 0.3s;
  opacity: 0; animation: heroTextIn 1s 1.8s forwards;
}
.hero-btn:hover { background: #fff; color: #222; }
@keyframes heroTextIn {
  from { opacity: 0; transform: translateY(15px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* === Section layout === */
.section { padding: 50px 0; }
.container { max-width: 85%; width: 85%; margin: 0 auto; }
.section-title {
  text-align: center; font-size: 15px; color: #222; text-transform: uppercase;
  font-weight: bold; margin-bottom: 20px;
  font-family: -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
}
#portfolio { background: #f5f5f5; }

/* === Footer === */
.footer {
  background: #1a1a2e; padding: 20px 0; text-align: center;
  color: rgba(255,255,255,0.6); font-size: 13px;
}
.footer a { color: #3dc9b3; }
.footer a:hover { color: #fff; }

/* === Responsive === */
@media (max-width: 768px) {
  .navbar { padding: 0 12px; height: auto; flex-wrap: wrap; justify-content: center; }
  .navbar li a { padding: 10px 12px; font-size: 12px; }
  .hero-slider { height: 100vh; }
  .hero-title { font-size: 24px; }
  .hero-subtitle { font-size: 13px; }
  .container { max-width: 95%; width: 95%; }
}