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

body {
  background: #0a0a0a;
  color: white;
  font-family: Arial, sans-serif;

  /* 🔥 핵심 수정 */
  min-height: 100vh;
  display: flex;
  flex-direction: column;

  padding-top: 80px; /* fixed header 공간 확보 */
}

a {
  color: inherit;
  text-decoration: none;
}

/* HEADER */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: 20px 40px;

  display: flex;
  justify-content: space-between;
  align-items: center;

  backdrop-filter: blur(10px);
  background: rgba(0,0,0,0.4);
  z-index: 100;
}

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

/* NAV */
.nav {
  display: flex;
  gap: 20px;
  align-items: center;
}

.nav a {
  opacity: 0.6;
  transition: 0.3s;
}

.nav a:hover {
  opacity: 1;
  transform: translateY(-1px);
}

/* HAMBURGER */
.hamburger {
  display: none;
  font-size: 28px;
  cursor: pointer;
}

/* HERO */
.hero {
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
}

.title {
  font-size: 10vw;
}

.sub {
  opacity: 0.6;
}

/* ABOUT */
.about {
  padding: 120px 40px;
  max-width: 800px;
  margin: 0 auto;
}

.about h2 {
  font-size: 2.2rem;
  margin-bottom: 30px;
}

.about p {
  line-height: 1.8;
  margin-bottom: 18px;
  opacity: 0.9;
}

/* FOOTER */
.footer {
  margin-top: auto; /* 🔥 핵심 */
  width: 100%;
  padding: 24px 16px;

  display: flex;
  justify-content: center;
  align-items: center;

  border-top: 1px solid rgba(255,255,255,0.08);
  background: rgba(0,0,0,0.2);
  backdrop-filter: blur(10px);

  color: rgba(255,255,255,0.6);
  font-size: 13px;
}

/* MOBILE */
@media (max-width: 768px) {

  .header {
    padding: 15px 20px;
  }

  .hamburger {
    display: block;
  }

  .nav {
    position: absolute;
    top: 70px;
    right: 20px;

    background: rgba(0,0,0,0.9);
    flex-direction: column;

    padding: 15px 20px;
    border-radius: 10px;

    display: none;
  }

  .nav.active {
    display: flex;
  }

  .title {
    font-size: 14vw;
  }

  .about {
    padding: 80px 20px;
  }
}