:root {
  --bg: #050505;
  --panel: rgba(10, 10, 14, 0.78);
  --panel-border: rgba(255, 255, 255, 0.12);
  --text: #ffffff;
  --muted: rgba(255, 255, 255, 0.72);
  --accent-start: #ff0068;
  --accent-end: #7c3cff;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: var(--text);
}

.language-switch {
  position: fixed;
  top: 18px;
  left: 50%;
  z-index: 10;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px;
  border: 1px solid var(--panel-border);
  border-radius: 999px;
  background: var(--panel);
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow);
  transform: translateX(-50%);
}

.lang-btn {
  appearance: none;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  min-width: 72px;
  padding: 12px 18px;
  transition: background-color 180ms ease, color 180ms ease, transform 180ms ease;
}

.lang-btn:hover {
  color: var(--text);
}

.lang-btn.is-active {
  background: linear-gradient(135deg, var(--accent-start), var(--accent-end));
  color: var(--text);
}

.page-viewer {
  width: 100%;
  min-height: 100svh;
  background: var(--bg);
}

.landing-image {
  display: block;
  width: 100%;
  height: auto;
  min-height: 100svh;
  object-fit: cover;
  object-position: top center;
}

@media (max-width: 768px) {
  .language-switch {
    top: 12px;
    padding: 5px;
  }

  .lang-btn {
    min-width: 64px;
    padding: 10px 14px;
    font-size: 13px;
  }
}