* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}

body {
  background: #0f0f0f;
  color: #fff;
}

/* HEADER */
header {
  position: fixed;
  width: 100%;
  top: 0;
  padding: 15px 20px;
  background: #000;
  z-index: 1000;
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.menu-btn {
  font-size: 22px;
  cursor: pointer;
}

.theme-btn {
  background: #ff7a00;
  border: none;
  padding: 6px 10px;
  border-radius: 8px;
}

/* HERO */
.hero {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 20px;

  background: linear-gradient(135deg, #ff7a00, #000);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,122,0,0.3), transparent);
  animation: move 6s infinite linear;
}

@keyframes move {
  0% { transform: translate(-20%, -20%); }
  50% { transform: translate(20%, 20%); }
  100% { transform: translate(-20%, -20%); }
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 400px;
}

.hero h1 {
  font-size: 30px;
}

.hero p {
  opacity: 0.7;
  margin-top: 10px;
}

/* BUTTON */
.btn {
  margin-top: 20px;
  padding: 12px 28px;
  background: #ff7a00;
  border: none;
  border-radius: 30px;
  color: white;
  font-weight: 500;
  box-shadow: 0 5px 20px rgba(255,122,0,0.4);
  transition: 0.3s;
}

.btn:hover {
  transform: translateY(-3px) scale(1.05);
}

/* SECTION */
.section {
  padding: 70px 20px;
  text-align: center;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.card {
  background: #1a1a1a;
  padding: 25px;
  border-radius: 15px;
  transition: 0.3s;
}

.card:hover {
  transform: translateY(-8px);
}

/* SIDEBAR */
.sidebar {
  position: fixed;
  left: -250px;
  top: 0;
  width: 250px;
  height: 100%;
  background: #111;
  padding: 20px;
  transition: 0.3s;
}

.sidebar.active {
  left: 0;
}

.sidebar a {
  display: block;
  margin: 15px 0;
  color: white;
}

/* FOOTER */
footer {
  text-align: center;
  padding: 20px;
  background: #000;
}
body.light {
  background: #ffffff;
  color: #000;
}

body.light .card {
  background: #f2f2f2;
}

body.light header {
  background: #fff;
  color: #000;
}

body.light .sidebar {
  background: #eee;
}