/* --- Root Variables & Reset --- */
:root {
  --primary-color: #0047AB; 
  --accent-color: #FF5722;  
  --text-dark: #1A1A1A;
  --text-light: #666666;
  --bg-light: #F4F7FA;
  --white: #FFFFFF;
  --header-height: 70px;
  --mobile-header-height: 60px;
}

body {
  font-family: 'Pretendard', sans-serif;
  color: var(--text-dark);
  margin: 0;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* --- Responsive Layout Container --- */
.container {
  width: 100%;
  padding-right: 20px;
  padding-left: 20px;
  margin-right: auto;
  margin-left: auto;
}

@media (min-width: 1200px) { .container { max-width: 1140px; } }

/* --- Mobile-First Typography --- */
h1, h2, h3 { font-weight: 800; line-height: 1.2; word-break: keep-all; }
h1 { font-size: 1.8rem; }
h2 { font-size: 1.5rem; }

@media (min-width: 768px) {
  h1 { font-size: 3rem; }
  h2 { font-size: 2.5rem; }
}

/* --- Header & Navigation (Responsive) --- */
#site-header {
  height: var(--mobile-header-height);
  background: var(--white);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

@media (min-width: 992px) {
  #site-header { height: var(--header-height); }
}

/* Mobile Menu Overlay */
@media (max-width: 991px) {
  .nav-menu {
    position: fixed;
    top: var(--mobile-header-height);
    left: -100%;
    width: 80%;
    height: 100vh;
    background: var(--white);
    transition: 0.3s ease;
    padding: 30px;
    box-shadow: 5px 0 15px rgba(0,0,0,0.1);
  }
  .nav-menu.active { left: 0; }
  .nav-item { margin-bottom: 20px; border-bottom: 1px solid #eee; padding-bottom: 10px; }
}

/* --- Section Padding --- */
section { padding: 50px 0; }
@media (min-width: 768px) { section { padding: 100px 0; } }

/* --- Footer (Stack on Mobile) --- */
#site-footer {
  background: #111;
  color: #fff;
  padding: 50px 0 20px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}

@media (min-width: 992px) {
  .footer-grid { grid-template-columns: 2fr 1fr 1fr; }
}

/* --- Utility --- */
.m-hide { display: none !important; }
@media (min-width: 768px) { .m-hide { display: block !important; } }
.pc-hide { display: block !important; }
@media (min-width: 992px) { .pc-hide { display: none !important; } }