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

:root {
  /* Light Mode Variables */
  --bg-color: #f3f4f6;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --card-bg: rgba(255, 255, 255, 0.7);
  --card-border: rgba(255, 255, 255, 0.8);
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --card-hover-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --primary-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --bg-gradient: radial-gradient(
      circle at top left,
      rgba(99, 102, 241, 0.15),
      transparent 40%
    ),
    radial-gradient(
      circle at bottom right,
      rgba(168, 85, 247, 0.15),
      transparent 40%
    );
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Dark Mode Variables */
    --bg-color: #111827;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --card-bg: rgba(31, 41, 55, 0.7);
    --card-border: rgba(255, 255, 255, 0.1);
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
    --card-hover-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --bg-gradient: radial-gradient(
        circle at top left,
        rgba(99, 102, 241, 0.1),
        transparent 40%
      ),
      radial-gradient(
        circle at bottom right,
        rgba(168, 85, 247, 0.1),
        transparent 40%
      );
  }
}

body {
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Background Effect */
.page-background {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-gradient);
  z-index: -1;
  pointer-events: none;
}

/* Utilities */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */
header {
  padding: 2rem 0;
  margin-bottom: 2rem;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  letter-spacing: -0.025em;
}

/* Language Switcher */
.lang-toggle-input {
  display: none;
}

.lang-switch {
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: 9999px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  transition: all 0.2s ease;
}

.lang-switch:hover {
  color: var(--text-primary);
  border-color: var(--text-secondary);
}

/* Main Grid */
main {
  flex: 1;
}

.grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: 1fr; /* Mobile: 1 card per row */
}

@media (min-width: 1024px) {
  .grid {
    grid-template-columns: repeat(2, 1fr); /* Desktop: 2 cards per row */
  }
}

/* Card Component */
.card {
  display: flex;
  align-items: center;
  padding: 1.5rem;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--card-border);
  border-radius: 1rem;
  text-decoration: none;
  box-shadow: var(--card-shadow);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  gap: 1.5rem;
  overflow: hidden;
  position: relative;
}

/* Glass shine effect on hover */
.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.1),
    transparent
  );
  transition: 0.5s;
}

.card:hover::before {
  left: 100%;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
  border-color: rgba(99, 102, 241, 0.3); /* Subtle primary color tint */
}

.card-icon {
  flex-shrink: 0;
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 0.75rem;
  overflow: hidden;
  background: var(--bg-color); /* Fallback */
  display: flex; /* Centering for SVG */
  align-items: center;
  justify-content: center;
  color: var(--text-primary); /* SVG currentColor */
}

.card-icon img,
.card-icon svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-icon svg {
  padding: 0.5rem; /* Optional: SVGs often look better with some padding if they touch edges */
}

.card-content {
  flex: 1;
  min-width: 0; /* Text truncation support */
}

.card-content h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.card-content p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Footer */
footer {
  padding: 2rem 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Language Switching Logic */
/* Default State: Show English, Hide Chinese */
.lang-zh {
  display: none !important;
}

/* Checked State: Hide English, Show Chinese */
/* We use the sibling selector because the checkbox is at the top of body */
#lang-toggle:checked ~ header .lang-en,
#lang-toggle:checked ~ main .lang-en,
#lang-toggle:checked ~ footer .lang-en {
  display: none;
}

#lang-toggle:checked ~ header .lang-zh,
#lang-toggle:checked ~ main .lang-zh,
#lang-toggle:checked ~ footer .lang-zh {
  display: block !important; /* Force display block to override display:none */
}