/* ===== Fixed Navbar ===== */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--nav-h, 76px);
  display: flex;
  align-items: center;
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  background: rgba(255, 255, 255, 0.72);
  border-bottom: 1px solid rgba(0, 0, 0, 0.04);
  transition: box-shadow .25s, background .25s;
}
.site-nav.scrolled {
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 6px 24px -12px rgba(30, 30, 60, .15);
}
.site-nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

/* Logo */
.nav-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 1px;
  text-decoration: none;
}
.nav-logo .brand-logo img { height: var(--nav-logo-h, 40px); width: auto; }
/* 长 logo 样式（长图更高） */
.nav-logo.nav-style-logo_only .brand-logo-long img { height: calc(var(--nav-logo-h, 40px) + 8px); }
.nav-logo.nav-style-logo_only .brand-logo-long { --logo-h: calc(var(--nav-logo-h, 40px) + 8px); }

/* Desktop Menu */
.nav-menu {
  display: flex;
  gap: 6px;
  align-items: center;
}
.nav-menu a {
  position: relative;
  padding: 10px 16px;
  font-weight: 500;
  color: #444a5b;
  border-radius: 999px;
  transition: color .2s, background .2s;
}
.nav-menu a::after {
  content: "";
  position: absolute;
  left: 50%; bottom: 4px;
  width: 0; height: 2px;
  background: linear-gradient(90deg, var(--c-primary), var(--c-secondary));
  border-radius: 2px;
  transform: translateX(-50%);
  transition: width .3s;
}
.nav-menu a:hover { color: var(--c-primary); }
.nav-menu a:hover::after { width: 40%; }

/* Mobile toggle */
.nav-toggle {
  display: none;
  width: 42px; height: 42px;
  border: none;
  background: transparent;
  border-radius: 12px;
  padding: 0;
  position: relative;
  z-index: 110;
}
.nav-toggle span {
  display: block;
  width: 22px; height: 2px;
  background: #333;
  margin: 5px auto;
  border-radius: 2px;
  transition: .3s;
}
.nav-toggle.open span { background: #fff; }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Spacer */
.nav-spacer { height: var(--nav-h, 76px); }

/* ============ Mobile 全屏抽屉 ============ */
@media (max-width: 768px) {
  .nav-toggle { display: block; }

  .nav-menu {
    position: fixed;
    inset: 0;
    z-index: 105;
    background:
      radial-gradient(circle at 30% 25%, rgba(79,195,247,.55), transparent 55%),
      radial-gradient(circle at 75% 75%, rgba(255,128,171,.55), transparent 55%),
      linear-gradient(135deg, #1a1c2b, #2a1d40);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 40px 24px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-12px);
    transition: opacity .35s ease, transform .35s ease, visibility 0s linear .35s;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
  }
  .nav-menu.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    transition: opacity .35s ease, transform .35s ease, visibility 0s;
  }

  .nav-menu li {
    width: 100%;
    max-width: 320px;
    text-align: center;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity .5s, transform .5s;
  }
  .nav-menu.open li { opacity: 1; transform: translateY(0); }
  /* 逐个渐入 */
  .nav-menu.open li:nth-child(1) { transition-delay: .05s; }
  .nav-menu.open li:nth-child(2) { transition-delay: .10s; }
  .nav-menu.open li:nth-child(3) { transition-delay: .15s; }
  .nav-menu.open li:nth-child(4) { transition-delay: .20s; }
  .nav-menu.open li:nth-child(5) { transition-delay: .25s; }
  .nav-menu.open li:nth-child(6) { transition-delay: .30s; }
  .nav-menu.open li:nth-child(7) { transition-delay: .35s; }

  .nav-menu a {
    display: block;
    padding: 16px 28px;
    font-size: 1.2rem;
    color: #fff;
    font-weight: 600;
    border-radius: 14px;
    letter-spacing: 2px;
    margin: 4px auto;
    transition: background .25s, transform .2s;
  }
  .nav-menu a:hover,
  .nav-menu a:active {
    color: #fff;
    background: rgba(255,255,255,.10);
    transform: scale(1.02);
  }
  .nav-menu a::after { display: none; }

  /* 抽屉底部装饰 */
  .nav-menu::after {
    content: "Hangx · 让每一个想法闪闪发光";
    position: absolute;
    bottom: 30px;
    left: 0; right: 0;
    text-align: center;
    color: rgba(255,255,255,.35);
    font-size: .8rem;
    letter-spacing: 3px;
    opacity: 0;
    transition: opacity .5s .5s;
  }
  .nav-menu.open::after { opacity: 1; }

  /* 打开时锁定滚动条 */
  body.nav-open { overflow: hidden; }

  /* 让打开时的导航栏底部透明 */
  .site-nav.mobile-open {
    background: transparent;
    border-bottom-color: transparent;
    box-shadow: none;
  }
}