:root {
  --bg: #0a0d12;
  --bg2: #131820;
  --felt: #1c6433;
  --felt-bright: #2a8a4a;
  --accent: #4fb3ff;
  --accent2: #ffd166;
  --good: #6ddc9b;
  --text: #e6ebf2;
  --muted: #9aa3af;
}
* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0;
  background: var(--bg); color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }

/* ----- Hero ----- */
.hero {
  background:
    radial-gradient(circle at 25% 30%, rgba(28, 100, 51, 0.35) 0%, transparent 50%),
    radial-gradient(circle at 80% 60%, rgba(79, 179, 255, 0.10) 0%, transparent 60%),
    linear-gradient(180deg, #0a0d12 0%, #0e1116 100%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  position: relative;
  overflow: hidden;
}
.nav {
  display: flex; justify-content: space-between; align-items: center;
  padding: 18px 32px;
  max-width: 1200px;
  margin: 0 auto;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text);
}
.brand-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px;
  background: #000;
  color: #fff; font-weight: 900;
  border-radius: 50%;
  border: 2px solid var(--felt);
}
.brand-name { font-size: 16px; }
.nav-cta {
  background: linear-gradient(180deg, #ff8a3c 0%, #e63946 100%);
  color: #fff;
  padding: 10px 22px;
  border-radius: 24px;
  font-weight: 600;
  font-size: 14px;
  box-shadow: 0 4px 14px rgba(230, 57, 70, 0.3);
  transition: transform 0.15s, box-shadow 0.15s;
}
.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(230, 57, 70, 0.5);
}

.hero-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 32px 96px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 60px;
  align-items: center;
}
.hero-text h1 {
  font-size: 48px;
  line-height: 1.15;
  margin: 0 0 20px;
  font-weight: 800;
  letter-spacing: -0.5px;
}
.hero-accent {
  background: linear-gradient(90deg, var(--accent2), #ff9a4d);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-sub {
  font-size: 18px;
  color: #cfd6df;
  max-width: 520px;
  margin: 0 0 32px;
}
.hero-sub b { color: var(--accent2); }
.hero-cta {
  display: flex; gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}
.cta-primary {
  background: linear-gradient(180deg, #4fb3ff 0%, #2d80c7 100%);
  color: #fff;
  padding: 14px 30px;
  border-radius: 28px;
  font-size: 15px;
  font-weight: 600;
  box-shadow: 0 6px 22px rgba(79, 179, 255, 0.3);
  transition: transform 0.15s, box-shadow 0.15s;
}
.cta-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(79, 179, 255, 0.5);
}
.cta-secondary {
  padding: 14px 24px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 28px;
  color: var(--text);
  font-size: 15px;
}
.cta-secondary:hover { background: rgba(255, 255, 255, 0.05); }
.hero-meta {
  display: flex; gap: 20px;
  color: var(--muted);
  font-size: 13px;
}
.hero-meta span { display: inline-flex; gap: 6px; }

/* Hero visual — mock pool table */
.hero-visual {
  display: flex; justify-content: center; align-items: center;
}
.hero-table {
  width: 100%;
  max-width: 480px;
  aspect-ratio: 2 / 1.2;
  background: #14171d;
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.06);
  position: relative;
}
.hero-felt {
  width: 100%; height: 100%;
  background: var(--felt);
  background:
    radial-gradient(circle at 50% 50%, var(--felt-bright) 0%, var(--felt) 80%);
  border-radius: 6px;
  position: relative;
  overflow: hidden;
}
.hero-pocket {
  position: absolute;
  width: 26px; height: 26px;
  background: #000;
  border-radius: 50%;
  border: 3px solid #c8b489;
}
.hero-pocket.tl { top: -10px; left: -10px; }
.hero-pocket.tr { top: -10px; right: -10px; }
.hero-pocket.bl { bottom: -10px; left: -10px; }
.hero-pocket.br { bottom: -10px; right: -10px; }
.hero-aim-line {
  position: absolute;
  height: 4px;
  background: linear-gradient(90deg, transparent, #46d4ff 30%, #6fe8ff 70%, transparent);
  top: 60%;
  left: 18%;
  right: 18%;
  transform: rotate(-15deg);
  box-shadow: 0 0 14px rgba(70, 212, 255, 0.7);
  animation: aim-pulse 2s ease-in-out infinite;
}
@keyframes aim-pulse {
  0%, 100% { opacity: 0.7; }
  50% { opacity: 1; }
}
.hero-ball-cue {
  position: absolute;
  width: 32px; height: 32px;
  background: radial-gradient(circle at 35% 30%, #fff, #e8e0d0 70%, #b0a890);
  border-radius: 50%;
  bottom: 30%;
  left: 18%;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.35);
}
.hero-ball-obj {
  position: absolute;
  width: 32px; height: 32px;
  background: radial-gradient(circle at 35% 30%, #ff8a8a, #e63946 70%, #a02838);
  border-radius: 50%;
  top: 30%;
  right: 30%;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.35);
}
.hero-ghost {
  position: absolute;
  width: 32px; height: 32px;
  border-radius: 50%;
  border: 2px dashed rgba(255, 255, 255, 0.7);
  top: 38%;
  right: 38%;
}

/* ----- Features ----- */
.features {
  max-width: 1200px;
  margin: 0 auto;
  padding: 80px 32px;
  text-align: center;
}
.features h2 {
  font-size: 32px;
  margin: 0 0 50px;
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.feature-card {
  background: var(--bg2);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 12px;
  padding: 32px 28px;
  text-align: left;
  transition: transform 0.2s, border-color 0.2s;
}
.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(79, 179, 255, 0.3);
}
.feature-icon {
  font-size: 36px;
  margin-bottom: 16px;
}
.feature-card h3 {
  font-size: 19px;
  margin: 0 0 10px;
}
.feature-card p {
  color: var(--muted);
  font-size: 14px;
  margin: 0;
}
.feature-card b { color: var(--accent2); }

/* ----- Curriculum ----- */
.curriculum-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 32px;
}
.curriculum-section h2 {
  font-size: 32px;
  margin: 0 0 12px;
  text-align: center;
}
.curriculum-intro {
  text-align: center;
  color: var(--muted);
  margin: 0 0 32px;
  font-size: 16px;
}
.chapter-heading {
  margin: 32px 0 14px;
  padding: 0 4px 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 1.5px;
}
.chapter-heading:first-of-type { margin-top: 8px; }
.course-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}
.course-card {
  background: var(--bg2);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 10px;
  padding: 22px 24px;
  color: var(--text);
  transition: transform 0.15s, border-color 0.15s, box-shadow 0.15s;
  position: relative;
  overflow: hidden;
}
.course-card:hover {
  transform: translateY(-3px);
  border-color: rgba(79, 179, 255, 0.4);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.3);
}
.course-chip {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 1.5px;
  padding: 3px 10px;
  background: rgba(79, 179, 255, 0.12);
  color: var(--accent);
  border-radius: 3px;
  margin-bottom: 12px;
  text-transform: uppercase;
}
.course-card h3 {
  font-size: 18px;
  margin: 0 0 10px;
}
.course-card p {
  font-size: 14px;
  color: var(--muted);
  margin: 0 0 14px;
}
.course-stats {
  font-size: 12px;
  color: var(--accent2);
  font-family: "Menlo", "Consolas", monospace;
}

/* ----- How it works ----- */
.how-it-works {
  background: var(--bg2);
  padding: 80px 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.how-it-works h2 {
  text-align: center;
  font-size: 32px;
  margin: 0 0 50px;
}
.how-steps {
  list-style: none;
  padding: 0;
  margin: 0 auto;
  max-width: 1200px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}
.how-steps li {
  text-align: center;
}
.step-num {
  width: 48px; height: 48px;
  background: linear-gradient(180deg, var(--accent), #2d80c7);
  border-radius: 50%;
  margin: 0 auto 18px;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
  font-weight: 700;
  color: #fff;
  box-shadow: 0 6px 18px rgba(79, 179, 255, 0.35);
}
.how-steps h3 {
  font-size: 17px;
  margin: 0 0 8px;
}
.how-steps p {
  color: var(--muted);
  font-size: 13px;
  margin: 0;
}

/* ----- FAQ ----- */
.faq {
  max-width: 720px;
  margin: 0 auto;
  padding: 80px 32px;
}
.faq h2 {
  text-align: center;
  font-size: 32px;
  margin: 0 0 40px;
}
.faq details {
  background: var(--bg2);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 8px;
  padding: 14px 20px;
  margin-bottom: 12px;
  cursor: pointer;
}
.faq details[open] {
  border-color: rgba(79, 179, 255, 0.3);
}
.faq summary {
  font-size: 15px;
  font-weight: 600;
  list-style: none;
  position: relative;
  padding-right: 30px;
}
.faq summary::after {
  content: '+';
  position: absolute;
  right: 0;
  font-size: 22px;
  color: var(--muted);
  transition: transform 0.2s;
}
.faq details[open] summary::after {
  transform: rotate(45deg);
}
.faq p {
  color: var(--muted);
  font-size: 14px;
  margin: 12px 0 0;
}
.faq b { color: var(--accent2); }

/* ----- Footer ----- */
.site-footer {
  background: #07090c;
  text-align: center;
  padding: 32px;
  color: var(--muted);
}
.site-footer p { margin: 4px 0; }
.site-footer .small {
  font-size: 12px;
  color: rgba(255, 255, 255, 0.3);
}

/* ----- Responsive ----- */
@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
    padding: 40px 24px 60px;
    gap: 40px;
  }
  .hero-text h1 { font-size: 36px; }
  .hero-sub { font-size: 16px; }
  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .how-steps {
    grid-template-columns: repeat(2, 1fr);
  }
  .features h2,
  .curriculum-section h2,
  .how-it-works h2,
  .faq h2 { font-size: 26px; }
  .hero-table { max-width: 100%; }
}

@media (max-width: 560px) {
  .hero-text h1 { font-size: 28px; }
  .hero-cta { flex-direction: column; align-items: stretch; }
  .cta-primary, .cta-secondary { text-align: center; }
  .how-steps { grid-template-columns: 1fr; }
}

/* ----- Ad slots ----- */
/* DISABLED until real AdSense account is set up. To re-enable, delete this
   `display: none` rule (the rest of the styling below stays correct). */
.ad-slot { display: none; }

/* Visual style + placeholder text live on the wrapper, NOT the <ins>, because
   AdSense's push() script mutates the <ins> (adds data-adsbygoogle-status),
   so :empty no longer matches it. The <ins> sits transparent on top; when a
   real ad fills, its iframe visually covers the placeholder. */
.ad-slot {
  position: relative;
  max-width: 1100px;
  margin: 28px auto;
  min-height: 110px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px dashed rgba(255, 255, 255, 0.14);
  border-radius: 10px;
  overflow: hidden;
}
.ad-slot::before {
  content: "广告位 · Ad Slot";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 2px;
  pointer-events: none;
}
.ad-slot ins.adsbygoogle {
  display: block;
  position: relative;
  z-index: 1;
  min-height: 110px;
  background: transparent;
  border: none;
}
@media (max-width: 720px) {
  .ad-slot { margin: 20px 16px; }
}