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

a {
  text-decoration: none;
}

a:hover {
  text-decoration: none;
}

:root {
  --bg: #f2f5f9;
  --bg-dark: #111827;
  --bg-deep: #0b1523;
  --bg-section: #e6edf5;
  --surface: #f8fbff;
  --primary: #20314b;
  --primary-light: #5a7ea4;
  --primary-dark: #0d1f33;
  --accent: #8a7a52;
  --accent-light: #b8a775;
  --green: #1e8449;
  --green-light: #27ae60;
  --text: #111827;
  --text-secondary: #4a5e77;
  --text-muted: #6b7485;
  --text-on-dark: #f4f7ff;
  --text-on-dark-muted: rgba(244, 247, 255, 0.72);
  --max-width: 1200px;
  --nav-height: 72px;
  --border: rgba(15, 23, 42, 0.06);
  --radius: 12px;
  --radius-lg: 16px;
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 18px 40px rgba(15, 23, 42, 0.08);
  --font-display: 'Noto Serif SC', serif;
  --font-body: 'Noto Sans SC', sans-serif;
  --font-mono: 'DM Mono', monospace;
}

/* Page container to increase side margins */
body {
  background: var(--bg);
}

.container {
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 0 24px;
}

@media (min-width: 1200px) {
  .container {
    padding: 0 48px;
  }
}

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  transform: translateY(0);
  transition:
    background 0.4s ease,
    box-shadow 0.4s ease,
    backdrop-filter 0.4s ease,
    opacity 0.25s ease;
  will-change: opacity, background;
  /* 与下方 HERO 背景保持一致 */
  background: linear-gradient(135deg, #0f2037 0%, #162d4d 55%, #0d1e33 100%);
}

.nav.nav--scrolled {
  opacity: 1;
  /* 完全不透明 */
  backdrop-filter: none;
  background: linear-gradient(135deg, #0f2037 0%, #162d4d 55%, #0d1e33 100%);
}

/* Keep nav text fully opaque after scrolling */
.nav.nav--scrolled .nav-links a {
  color: rgba(255, 255, 255, 1) !important;
}

.nav.nav--scrolled .nav-links a:hover {
  color: var(--accent-light) !important;
}

.nav.nav--scrolled .nav-logo {
  color: rgba(255, 255, 255, 1) !important;
}

.nav-placeholder {
  height: var(--nav-height);
  background: transparent;
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: #fff;
  transition: color 0.4s;
}

.nav.scrolled .nav-logo {
  color: var(--text);
}

.nav-logo-icon {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  flex-shrink: 0;
  background: transparent;
}

.nav-logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.nav-logo-text {
  white-space: nowrap;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 0.88rem;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.85);
  transition: color 0.3s;
  position: relative;
  letter-spacing: 0.02em;
}

.nav.scrolled .nav-links a {
  color: var(--text-secondary);
}

.nav-links a:hover {
  color: var(--accent-light);
}

.nav.scrolled .nav-links a:hover {
  color: var(--primary);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent-light);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.nav-links a:hover::after {
  transform: scaleX(1);
}

.nav-cta {
  background: var(--primary) !important;
  color: #fff !important;
  padding: 10px 24px;
  border-radius: 8px;
  font-weight: 500 !important;
  transition:
    background 0.3s,
    transform 0.2s !important;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.12);
}

.nav-cta:hover {
  background: var(--primary-dark) !important;
  transform: translateY(-1px);
}

.nav-cta::after {
  display: none !important;
}

.nav-mobile-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.nav-mobile-btn span {
  width: 24px;
  height: 2px;
  background: #fff;
  transition:
    background 0.3s,
    transform 0.3s;
}

.nav.scrolled .nav-mobile-btn span {
  background: var(--text);
}