:root {
  --zen-bamboo: #1a4d3a;
  --zen-bamboo-light: #2a5d4a;
  --zen-ceramic: #5b8a9a;
  --zen-sandalwood: #8b6f47;
  --zen-rice-paper: #f5f1e8;
  --zen-rice-paper-dark: #e8e3d5;
  --zen-ink: #1a1a1a;
  --zen-ink-light: #4a4a4a;
  --zen-mist: rgba(245, 241, 232, 0.8);
  --zen-shadow: rgba(26, 77, 58, 0.1);
  --zen-shadow-strong: rgba(26, 77, 58, 0.2);

  --font-zh: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "WenQuanYi Micro Hei", sans-serif;
  --font-en: "Georgia", "Times New Roman", serif;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-xxl: 4rem;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

html, body {
  height: 100%;
  font-family: var(--font-zh);
  background: var(--zen-rice-paper);
  color: var(--zen-ink);
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  overflow-x: hidden;
}

.app-container {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.ink-background {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg,
    var(--zen-rice-paper) 0%,
    var(--zen-mist) 50%,
    var(--zen-rice-paper) 100%);
  z-index: -1;
}

.ink-background::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(91, 138, 154, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(139, 111, 71, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--zen-shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.logo-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: var(--zen-bamboo);
  color: var(--zen-rice-paper);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 500;
  box-shadow: 0 4px 12px var(--zen-shadow-strong);
}

.app-title {
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--zen-bamboo);
  letter-spacing: 0.1em;
}

.main-nav {
  display: flex;
  gap: var(--space-md);
}

.nav-item {
  color: var(--zen-ink-light);
  text-decoration: none;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  position: relative;
}

.nav-item:hover {
  color: var(--zen-bamboo);
  background: rgba(26, 77, 58, 0.05);
}

.nav-item.active {
  color: var(--zen-bamboo);
  font-weight: 500;
}

.nav-item.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background: var(--zen-bamboo);
  border-radius: var(--radius-full);
}

.app-main {
  flex: 1;
  padding: var(--space-lg);
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.page-content {
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.app-footer {
  text-align: center;
  padding: var(--space-md);
  color: var(--zen-ink-light);
  font-size: 0.9rem;
  border-top: 1px solid var(--zen-shadow);
  background: rgba(255, 255, 255, 0.5);
}

@keyframes breathing {
  0%, 100% {
    transform: scale(1);
    opacity: 0.8;
  }
  50% {
    transform: scale(1.05);
    opacity: 1;
  }
}

.breathing-circle {
  animation: breathing 4s ease-in-out infinite;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.6s ease;
}

@media (max-width: 768px) {
  .app-header {
    flex-direction: column;
    gap: var(--space-sm);
  }

  .main-nav {
    flex-wrap: wrap;
    justify-content: center;
  }

  .app-main {
    padding: var(--space-md);
  }
}