:root {
  --color-primary: #c00;
  --color-bg: rgba(255,255,255,0.6);
  --color-bg-light: rgba(255,255,255,0.2);
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-nav-gap: 20px;
  --logo-size: 100px;
  --logo-size-mobile: 100px;
  --font-zh: "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-id: "Segoe UI", sans-serif;
  --font-brand: 'Great Vibes', cursive;
  --font-size-sm: 0.8125rem;
  --font-size-base: 0.875rem;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-id);
  scroll-behavior: smooth;
  background: url('../images/pzxp-a.png') center/cover fixed no-repeat;
}

body[lang="zh"] {
  font-family: var(--font-zh);
}

.logo {
  width: var(--logo-size);
  height: var(--logo-size);
  z-index: 10;
}

.logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

header {
  background: var(--color-bg-light);
  backdrop-filter: blur(4px);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: var(--space-1) var(--space-2);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.title-and-nav {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
}

.brand-line {
  font-family: var(--font-brand);
  font-size: 1.25rem;
  color: #000(--color-primary);
  color: #000;
  font-weight: bold;
  text-shadow: 0 1px 1px rgba(0,0,0,0.1);

}

.brand-phone-lang {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-size: 0.85rem;
  color: #700000;
  margin-top: 4px;
}

.nav-lang-group {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.nav {
  display: flex;
  gap: var(--space-nav-gap);
  justify-content: center;
  flex-wrap: wrap;
}

.nav a,
.lang-toggle button {
  padding: 8px 32px;
  font-size: var(--font-size-sm);
  font-weight: 900;
  background: var(--color-bg-light);
  color: var(--color-primary);
  text-decoration: none;
  border-radius: 4px;
  white-space: nowrap;
  transition: background 0.3s;
  border: none;
  cursor: pointer;
}

.nav a[aria-current="page"] {
  background: rgba(255,255,255,0.5);
}

.nav a:hover,
.lang-toggle button:hover {
  background: rgba(255,255,255,0.8);
}

.lang-toggle {
  display: flex;
}

main, .welcome-section {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: var(--space-3);
  min-height: 50vh;
}

.welcome-section h1 {
  font-size: 2.5rem;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
  font-weight: 700;
  text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
}

.welcome-section p {
  font-size: 1.5rem;
  color: #a00000;
  font-weight: bold;
  text-shadow: 1px 1px 1px rgba(0,0,0,0.08);
}

footer {
  text-align: center;
  padding: var(--space-2);
  font-size: var(--font-size-sm);
  color: var(--color-primary);
  background: var(--color-bg);
  margin-top: auto;
}

footer p {
  margin: 0 auto;
  text-align: center;
}

@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    align-items: center;
  }

  .nav-lang-group {
    flex-direction: column;
    gap: var(--space-2);
  }

  .nav a,
  .lang-toggle button {
    padding: 6px 20px;
  }

  .logo {
    width: var(--logo-size-mobile);
    height: var(--logo-size-mobile);
  }

  .welcome-section {
    padding: var(--space-2);
    min-height: 40vh;
  }

  .welcome-section h1 {
    font-size: 1.8rem;
  }

  .welcome-section p {
    font-size: 1.2rem;
  }
}