:root {
  --bg: #0a0a0f;
  --surface: #12121a;
  --surface2: #1a1a26;
  --border: #ffffff12;
  --border2: #ffffff22;
  --text: #f0f0f8;
  --muted: #8888aa;
  --accent: #7c6af7;
  --accent2: #a594fa;
  --green: #22d3a0;
  --blue: #4facfe;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  min-height: 100vh;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(124,106,247,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(124,106,247,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(10,10,15,0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 56px;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.back-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--muted);
  text-decoration: none;
  font-family: 'DM Mono', monospace;
  font-size: 0.8rem;
  transition: color 0.15s;
}
.back-link:hover { color: var(--accent2); }
.topbar-sep { color: var(--border2); font-size: 1.2rem; }
.topbar-title {
  font-family: 'Syne', sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
}
.lang-toggle {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-family: 'DM Mono', monospace;
  font-size: 0.72rem;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--border2);
  padding: 0.25rem 0.65rem;
  border-radius: 6px;
  transition: color 0.15s, border-color 0.15s;
}
.lang-toggle:hover { color: var(--accent2); border-color: var(--accent2); }
.content {
  max-width: 800px;
  margin: 0 auto;
  padding: 4rem 2rem;
  position: relative;
}
.hero {
  text-align: center;
  margin-bottom: 3.5rem;
}
.badge {
  display: inline-block;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: white;
  font-family: 'DM Mono', monospace;
  font-size: 0.75rem;
  padding: 0.3rem 0.9rem;
  border-radius: 999px;
  letter-spacing: 0.08em;
  margin-bottom: 1.2rem;
}
h1 {
  font-family: 'Syne', sans-serif;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  background: linear-gradient(135deg, var(--text), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.8rem;
}
.subtitle {
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.6;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: 20px;
  padding: 2rem;
  text-decoration: none;
  color: var(--text);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  opacity: 0;
  transition: opacity 0.2s;
}
.card.excel::before { background: linear-gradient(90deg, #22d3a0, #4facfe); }
.card.ppt::before { background: linear-gradient(90deg, var(--accent), var(--accent2)); }
.card:hover { transform: translateY(-4px); border-color: var(--accent); box-shadow: 0 8px 32px rgba(124,106,247,0.18); }
.card:hover::before { opacity: 1; }
.card-header {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.card-icon {
  width: 52px; height: 52px;
  border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.6rem;
  flex-shrink: 0;
}
.icon-excel { background: rgba(34,211,160,0.12); }
.icon-ppt { background: rgba(124,106,247,0.12); }
.card-title {
  font-family: 'Syne', sans-serif;
  font-size: 1.3rem;
  font-weight: 700;
}
.card-desc {
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.6;
  flex: 1;
}
.card-modules {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.module-pill {
  font-family: 'DM Mono', monospace;
  font-size: 0.75rem;
  padding: 0.25rem 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--border2);
  color: var(--muted);
}
.card-cta {
  font-family: 'DM Mono', monospace;
  font-size: 0.8rem;
  color: var(--accent2);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: auto;
}
.info-banner {
  margin-top: 2.5rem;
  background: rgba(124,106,247,0.06);
  border: 1px solid rgba(124,106,247,0.2);
  border-radius: 14px;
  padding: 1.2rem 1.5rem;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.info-banner-icon { font-size: 1.2rem; flex-shrink: 0; margin-top: 0.1rem; }
.info-banner-text { font-size: 0.88rem; color: var(--muted); line-height: 1.6; }
.info-banner-text strong { color: var(--text); }