:root {
  --gh-primary: #ef4444;
  --gh-primary-hover: #dc2626;
  --gh-primary-light: #fee2e2;
  --gh-accent: #f59e0b;
  --gh-success: #10b981;
  --gh-ink: #0f172a;
  --gh-muted: #64748b;
  --gh-card: #ffffff;
  --gh-line: #e2e8f0;
  --gh-soft: #f8fafc;
}

body {
  font-family: "Noto Sans", "Noto Sans CJK SC", "Noto Sans Vietnamese", "Segoe UI", sans-serif;
  background-color: var(--gh-soft);
  color: var(--gh-ink);
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
}

.gh-extra-mode {
  display: none !important;
}

.gh-extra-mode.active {
  display: block !important;
}

/* Youthful Hero Card */
.gh-hero {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 32px;
  border: 1.5px solid var(--gh-line);
  border-radius: 28px;
  background: linear-gradient(135deg, #ffffff 0%, #f1f5f9 100%);
  box-shadow: 0 16px 40px rgba(15, 23, 42, 0.06);
  position: relative;
  overflow: hidden;
}

.gh-hero::after {
  content: "🀄";
  position: absolute;
  right: -10px;
  bottom: -20px;
  font-size: 7.5rem;
  opacity: 0.05;
  pointer-events: none;
}

.gh-kicker,
.gh-section-head span,
.gh-review small,
.gh-goal small {
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gh-primary);
}

.gh-hero h2 {
  margin: 8px 0 6px;
  font-size: clamp(1.8rem, 4.2vw, 2.8rem);
  letter-spacing: -0.03em;
  font-weight: 900;
  line-height: 1.2;
}

.gh-hero p {
  margin: 0;
  color: var(--gh-muted);
  font-size: 1rem;
}

.gh-xp {
  min-width: 130px;
  align-self: flex-start;
  padding: 16px;
  border-radius: 20px;
  background: #ffffff;
  border: 1.5px solid var(--gh-line);
  display: flex;
  flex-direction: column;
  gap: 4px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.03);
}

.gh-xp b {
  font-size: 1.45rem;
  font-weight: 900;
  color: #f59e0b;
}

.gh-xp span {
  color: var(--gh-muted);
  font-size: 0.85rem;
  font-weight: 700;
}

/* Daily Goal Bar */
.gh-goal {
  margin: 20px 0;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 16px;
  align-items: center;
  padding: 18px 24px;
  background: var(--gh-card);
  border: 1.5px solid var(--gh-line);
  border-radius: 22px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.03);
}

.gh-goal strong {
  display: block;
  margin-top: 4px;
  font-size: 1.05rem;
}

.gh-progress {
  height: 12px;
  border-radius: 99px;
  background: #e2e8f0;
  overflow: hidden;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.06);
}

.gh-progress i {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, #ef4444 0%, #f97316 100%);
  border-radius: inherit;
  transition: width 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Quick Mode Buttons Grid */
.gh-quick {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 14px;
}

.gh-quick button {
  border: 1.5px solid var(--gh-line);
  background: var(--gh-card);
  border-radius: 20px;
  padding: 18px 14px;
  text-align: left;
  cursor: pointer;
  transition: transform 0.18s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.18s ease, border-color 0.18s ease;
  display: flex;
  flex-direction: column;
  gap: 6px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.03);
  touch-action: manipulation;
}

.gh-quick button:hover {
  transform: translateY(-3px);
  border-color: #cbd5e1;
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.08);
}

.gh-quick button:active {
  transform: scale(0.96) !important;
}

.gh-quick b {
  font-size: 1rem;
  font-weight: 800;
  color: var(--gh-ink);
}

.gh-quick small {
  color: var(--gh-muted);
  font-size: 0.78rem;
  font-weight: 600;
}

/* Gamified Stats Grid */
.gh-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin: 20px 0;
}

.gh-stats article {
  padding: 18px 20px;
  border: 1.5px solid var(--gh-line);
  border-radius: 20px;
  background: var(--gh-card);
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 14px;
  align-items: center;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.03);
  transition: transform 0.15s ease;
}

.gh-stats article:hover {
  transform: translateY(-2px);
}

.gh-stats span {
  grid-row: span 2;
  font-size: 1.8rem;
}

.gh-stats b {
  font-size: 1.4rem;
  font-weight: 900;
  color: var(--gh-ink);
}

.gh-stats small {
  color: var(--gh-muted);
  font-size: 0.8rem;
  font-weight: 600;
}

/* Smart Review Banner */
.gh-review {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  padding: 24px 28px;
  border-radius: 24px;
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  color: #ffffff;
  box-shadow: 0 14px 34px rgba(15, 23, 42, 0.18);
}

.gh-review h3 {
  margin: 6px 0;
  font-size: 1.25rem;
  font-weight: 800;
}

.gh-review p {
  margin: 0;
  color: #94a3b8;
  font-size: 0.9rem;
}

.gh-primary,
.gh-secondary {
  border: 0;
  border-radius: 14px;
  padding: 12px 20px;
  font-weight: 800;
  cursor: pointer;
  transition: all 0.18s cubic-bezier(0.34, 1.56, 0.64, 1);
  touch-action: manipulation;
}

.gh-primary {
  background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(239, 68, 68, 0.35);
}

.gh-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(239, 68, 68, 0.45);
}

.gh-primary:active {
  transform: scale(0.96);
}

.gh-secondary {
  background: #ffffff;
  color: #0f172a;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.gh-secondary:hover {
  transform: translateY(-2px);
  background: #f8fafc;
}

.gh-secondary:active {
  transform: scale(0.96);
}

.gh-section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.gh-section-head h2 {
  margin: 4px 0 6px;
  font-weight: 900;
}

.gh-section-head p {
  color: var(--gh-muted);
  margin: 0;
}

.gh-toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translate(-50%, 20px);
  opacity: 0;
  z-index: 100000;
  background: #0f172a;
  color: #ffffff;
  padding: 12px 20px;
  border-radius: 14px;
  transition: all 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  pointer-events: none;
  font-weight: 700;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.2);
}

.gh-toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* Floating Bottom Dock on Mobile */
#gh-mobile-nav { display: none !important; }

@media (max-width: 1000px) {
  .gh-quick {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 650px) {
  main {
    padding-bottom: 24px;
  }
  .gh-hero {
    padding: 24px;
    flex-direction: column;
  }
  .gh-xp {
    align-self: stretch;
  }
  .gh-goal {
    grid-template-columns: 1fr auto;
  }
  .gh-progress {
    grid-column: 1 / -1;
    grid-row: 2;
  }
  .gh-quick {
    grid-template-columns: repeat(2, 1fr);
  }
  .gh-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .gh-review {
    align-items: flex-start;
    flex-direction: column;
  }
  .gh-section-head {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  #gh-mobile-nav { display: none !important; }
}

/* Dark Mode Theme */
body.dark-mode {
  --gh-card: #1e293b;
  --gh-line: #334155;
  --gh-soft: #0f172a;
  --gh-ink: #f8fafc;
  --gh-muted: #94a3b8;
  background-color: var(--gh-soft);
  color: var(--gh-ink);
}

body.dark-mode .gh-hero {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
}

body.dark-mode .gh-xp {
  background: #243448;
}

body.dark-mode .gh-review {
  background: linear-gradient(135deg, #020617 0%, #0f172a 100%);
}