/* ============================================================
   HEADER — top bar, logo, desktop nav, mobile nav
   ============================================================ */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  height: var(--header-h);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: box-shadow var(--transition), border-color var(--transition);
}
.header.scrolled { box-shadow: var(--shadow-sm); border-bottom-color: var(--border); }
.header-inner {
  max-width: 1400px; margin: 0 auto; padding: 0 32px;
  display: flex; align-items: center; justify-content: space-between; height: 100%;
}

/* Logo (이미지 워드마크 — img/logo-kobra.png, 600×150) */
.logo { display: flex; align-items: center; gap: 2px; text-decoration: none; }
.logo-img { height: 40px; width: auto; display: block; }
.logo-text {
  font-family: var(--font-heading); font-weight: 800; font-size: 24px;
  color: var(--blue); letter-spacing: -0.5px;
}
.logo-text .logo-sub { color: var(--navy); margin-left: 6px; }
.logo-year { font-size: 13px; color: var(--magenta); margin-left: 5px; font-weight: 700; }

/* Desktop nav */
.desktop-nav { display: flex; }
.nav-list { display: flex; gap: 2px; }
.nav-item { position: relative; }
.nav-link {
  display: block; padding: 8px 16px; color: var(--text); font-size: 15px; font-weight: 600;
  border-radius: var(--radius-xs); transition: color var(--transition); position: relative;
}
.nav-link::after {
  content: ''; position: absolute; bottom: 2px; left: 50%; width: 0; height: 2px;
  background: var(--gradient); border-radius: 1px; transition: width var(--transition);
  transform: translateX(-50%);
}
.nav-link:hover, .nav-link.active { color: var(--blue); }
.nav-link:hover::after, .nav-link.active::after { width: 60%; }

/* Dropdown */
.dropdown {
  position: absolute; top: 100%; left: 0; min-width: 220px;
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 8px 0; opacity: 0; visibility: hidden; transform: translateY(8px);
  transition: all var(--transition); box-shadow: var(--shadow);
}
.nav-item:hover .dropdown { opacity: 1; visibility: visible; transform: translateY(0); }
.dropdown li a { display: block; padding: 10px 20px; color: var(--text-muted); font-size: 14px; transition: all var(--transition); }
.dropdown li a:hover { color: var(--blue); background: var(--bg-tint); padding-left: 24px; }

/* Header CTA */
.header-cta {
  padding: 10px 22px; border-radius: 50px;
  background: var(--gradient); color: #fff; font-weight: 700; font-size: 14px;
  transition: all var(--transition); white-space: nowrap; box-shadow: 0 4px 14px rgba(0,108,238,0.25);
}
.header-cta:hover { transform: translateY(-2px); box-shadow: 0 8px 22px rgba(0,108,238,0.35); color: #fff; }

/* Auth links (Login / My Page / Logout) */
.auth-links { display: inline-flex; align-items: center; gap: 14px; }
.auth-link { font-size: 14px; font-weight: 600; color: var(--text); transition: color var(--transition); white-space: nowrap; }
.auth-link:hover { color: var(--blue); }

/* Mobile toggle */
.mobile-toggle {
  display: none; background: none; border: none; cursor: pointer;
  width: 32px; height: 24px; flex-direction: column; justify-content: space-between; padding: 0;
}
.mobile-toggle span { display: block; width: 100%; height: 2px; background: var(--navy); border-radius: 2px; transition: all var(--transition); }

/* Mobile nav sidebar */
.mobile-nav {
  position: fixed; top: 0; right: -320px; width: 320px; height: 100vh;
  background: #fff; z-index: 2000; transition: right 0.4s cubic-bezier(0.4,0,0.2,1);
  overflow-y: auto; padding: 24px; box-shadow: -10px 0 40px rgba(16,40,80,0.12);
}
.mobile-nav.open { right: 0; }
.mobile-nav-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 28px; }
.mobile-close { background: none; border: none; color: var(--text); font-size: 32px; cursor: pointer; line-height: 1; }
.mobile-nav-group { margin-bottom: 18px; border-bottom: 1px solid var(--border); padding-bottom: 14px; }
.mobile-nav-label { font-family: var(--font-heading); font-weight: 700; font-size: 13px; color: var(--blue); text-transform: uppercase; letter-spacing: 1px; display: block; margin-bottom: 8px; }
.mobile-nav-group ul li a { display: block; padding: 9px 0; color: var(--text-muted); font-size: 15px; transition: color var(--transition); }
.mobile-nav-group ul li a:hover { color: var(--blue); }

.mobile-overlay { position: fixed; inset: 0; background: rgba(15,31,46,0.4); z-index: 1999; opacity: 0; visibility: hidden; transition: all var(--transition); }
.mobile-overlay.open { opacity: 1; visibility: visible; }