:root {
  --bg: #FFFBF5;
  --bg-warm: #FFF5E9;
  --surface: #FFFFFF;
  --primary: #FF6B35;
  --primary-light: #FF8F5E;
  --primary-bg: rgba(255, 107, 53, 0.08);
  --accent: #4ECDC4;
  --accent-bg: rgba(78, 205, 196, 0.1);
  --purple: #7C5CFC;
  --purple-bg: rgba(124, 92, 252, 0.08);
  --text: #2D2A26;
  --text-muted: #6B6560;
  --text-light: #9B9590;
  --border: rgba(0,0,0,0.06);
  --radius: 12px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Noto Sans SC', -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ===== NAV ===== */
.nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 48px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  height: 64px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--text);
}

.nav-logo { font-size: 24px; }

.nav-name {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.nav-links { display: flex; gap: 24px; }

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-link:hover { color: var(--primary); }

/* ===== HERO ===== */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  padding: 80px 48px;
  max-width: 1200px;
  margin: 0 auto;
  align-items: center;
}

.hero-badge {
  display: inline-block;
  background: var(--primary-bg);
  color: var(--primary);
  font-size: 14px;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 20px;
}

.hero-headline {
  font-size: clamp(40px, 5vw, 64px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 16px;
}

.hero-sub {
  font-size: 20px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 12px;
}

.hero-desc {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-cta {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
}

.hero-cta:hover {
  background: var(--primary-light);
  transform: translateY(-1px);
}

.hero-visual {
  display: flex;
  justify-content: center;
}

.hero-img {
  width: 100%;
  max-width: 520px;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  object-fit: cover;
}

/* ===== SECTION SHARED ===== */
.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: clamp(26px, 3vw, 36px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-bottom: 10px;
}

.section-header p {
  color: var(--text-muted);
  font-size: 16px;
}

/* ===== HOW IT WORKS ===== */
.how-it-works {
  background: var(--bg-warm);
  padding: 80px 48px;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1100px;
  margin: 0 auto;
}

.step-card {
  background: var(--surface);
  padding: 32px 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: box-shadow 0.2s, transform 0.2s;
}

.step-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.step-icon { font-size: 36px; margin-bottom: 12px; }

.step-number {
  font-size: 12px;
  font-weight: 600;
  color: var(--primary);
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}

.step-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.step-card p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ===== FEATURES ===== */
.features { padding: 80px 48px; }

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 1100px;
  margin: 0 auto;
}

.feature-item {
  padding: 28px 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: box-shadow 0.2s;
}

.feature-item:hover { box-shadow: var(--shadow-sm); }

.feature-icon { font-size: 28px; margin-bottom: 12px; }

.feature-item h4 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.feature-item p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ===== AUDIENCE ===== */
.audience {
  background: var(--bg-warm);
  padding: 80px 48px;
}

.audience-content {
  max-width: 1000px;
  margin: 0 auto;
  text-align: center;
}

.audience-content h2 {
  font-size: clamp(26px, 3vw, 36px);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 40px;
}

.audience-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.audience-card {
  background: var(--surface);
  padding: 36px 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.audience-icon { font-size: 36px; margin-bottom: 12px; }

.audience-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.audience-card p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ===== CLOSING ===== */
.closing {
  padding: 80px 48px;
  text-align: center;
}

.closing h2 {
  font-size: clamp(26px, 3vw, 36px);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
}

.closing p {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 28px;
}

.closing-cta {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
}

.closing-cta:hover {
  background: var(--primary-light);
  transform: translateY(-1px);
}

/* ===== FOOTER ===== */
.footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 40px 48px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 16px;
  color: var(--text);
  margin-bottom: 8px;
}

.footer-logo { font-size: 20px; }

.footer-tagline {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.footer-copy {
  font-size: 13px;
  color: var(--text-light);
}

/* ===== COURSES HERO ===== */
.courses-hero {
  text-align: center;
  padding: 60px 48px 40px;
  background: var(--bg-warm);
}

.courses-hero h1 {
  font-size: clamp(30px, 4vw, 42px);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
}

.courses-hero > p {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 28px;
}

.courses-filters {
  display: flex;
  justify-content: center;
  gap: 12px;
}

.filter-btn {
  padding: 8px 20px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface);
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.filter-btn:hover { border-color: var(--primary); color: var(--primary); }

.filter-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* ===== COURSES GRID ===== */
.courses-grid-wrap {
  padding: 40px 48px 80px;
  max-width: 1200px;
  margin: 0 auto;
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}

.artist-card {
  display: block;
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  text-decoration: none;
  color: var(--text);
  transition: box-shadow 0.25s, transform 0.25s;
}

.artist-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

/* Artist info header — portrait circle + name side by side */
.artist-info-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}

.artist-portrait {
  width: 64px;
  min-width: 64px;
  height: 64px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--bg-warm);
  flex-shrink: 0;
}

.artist-portrait img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.artist-portrait-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #e0e0e0;
  border-radius: 50%;
}

.artist-portrait-placeholder span {
  font-size: 24px;
  font-weight: 700;
  color: #888;
}

.artist-name-group {
  flex: 1;
  min-width: 0;
}

/* Artwork thumbnail on course card — hero image at top of card */
.artist-artwork-thumb {
  position: relative;
  width: 100%;
  height: 160px;
  overflow: hidden;
  background: var(--bg-warm);
}
.artist-artwork-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s;
}
.artist-card:hover .artist-artwork-thumb img {
  transform: scale(1.05);
}
.artwork-thumb-label {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 4px 10px;
  font-size: 11px;
  color: #fff;
  background: linear-gradient(transparent, rgba(0,0,0,0.55));
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.artist-info { padding: 16px 18px 20px; }

.artist-name {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 2px;
}

.artist-name-en {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 0;
}

.artist-name-group .artist-name { margin-bottom: 0; }
.artist-name-group .artist-name-en { margin-top: 2px; }

.artist-style-tag {
  display: inline-block;
  background: var(--purple-bg);
  color: var(--purple);
  font-size: 12px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 10px;
}

.artist-ages {
  display: flex;
  gap: 6px;
}

.age-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 4px;
}

.age-young {
  background: var(--accent-bg);
  color: #2BA89D;
}

.age-older {
  background: var(--primary-bg);
  color: var(--primary);
}

.age-link {
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
}

.age-link:hover {
  transform: translateY(-1px);
  box-shadow: 0 2px 6px rgba(0,0,0,0.12);
}

.courses-empty {
  text-align: center;
  padding: 60px 24px;
  color: var(--text-muted);
  font-size: 18px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 960px) {
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav { padding: 0 20px; }
  .hero {
    grid-template-columns: 1fr;
    gap: 40px;
    padding: 48px 24px 60px;
  }
  .hero-visual { order: -1; }
  .hero-img { max-width: 100%; }
  .how-it-works, .features, .audience, .closing { padding: 60px 24px; }
  .steps-grid { grid-template-columns: 1fr 1fr; }
  .features-grid { grid-template-columns: 1fr; }
  .audience-grid { grid-template-columns: 1fr; }
  .courses-hero { padding: 40px 24px 32px; }
  .courses-grid-wrap { padding: 24px 20px 60px; }
  .courses-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 16px; }
  .footer { padding: 32px 24px; }
}

/* ===== PDF DOWNLOAD BUTTONS ===== */
.artist-pdf-links {
  display: flex;
  gap: 6px;
  margin-top: 10px;
  flex-wrap: wrap;
}

.pdf-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s;
  border: 1px solid var(--border);
  color: var(--text-muted);
  background: var(--surface);
}

.pdf-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
  transform: translateY(-1px);
}

.pdf-btn svg {
  flex-shrink: 0;
}

@media (max-width: 480px) {
  .steps-grid { grid-template-columns: 1fr; }
  .hero-headline { font-size: 36px; }
}

/* ===== LESSON DETAIL (ld-*) ===== */
.ld-header {
  background: var(--bg-warm);
  padding: 20px 48px;
  border-bottom: 1px solid var(--border);
}

.ld-header-inner {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.ld-back {
  font-size: 14px;
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}

.ld-back:hover { color: var(--primary); }

.ld-section {
  padding: 48px 48px;
}

.ld-section:nth-child(odd) { background: var(--bg); }
.ld-section:nth-child(even) { background: var(--bg-warm); }

.ld-section-inner {
  max-width: 860px;
  margin: 0 auto;
}

.ld-step-badge {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  padding: 5px 16px;
  border-radius: 20px;
  margin-bottom: 24px;
  letter-spacing: 0.02em;
}

/* Artist card — portrait + meta side by side */
.ld-artist-card {
  display: flex;
  gap: 32px;
  align-items: flex-start;
  margin-bottom: 28px;
}

.ld-artist-portrait {
  width: 140px;
  min-width: 140px;
  height: 140px;
  border-radius: 16px;
  overflow: hidden;
  background: var(--bg-warm);
  box-shadow: var(--shadow-md);
}

.ld-artist-portrait img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.ld-portrait-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-bg), var(--accent-bg));
}

.ld-portrait-placeholder span {
  font-size: 48px;
  font-weight: 700;
  color: var(--primary);
}

.ld-artist-meta { flex: 1; }

.ld-artist-name {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 4px;
}

.ld-artist-name-en {
  font-size: 15px;
  color: var(--text-light);
  margin-bottom: 12px;
}

.ld-artist-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.ld-tag {
  display: inline-block;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 13px;
  padding: 4px 12px;
  border-radius: 6px;
  color: var(--text-muted);
}

.ld-tag-style {
  background: var(--purple-bg);
  border-color: transparent;
  color: var(--purple);
}

.ld-artist-bio {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.7;
}

/* Step content blocks */
.ld-step-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin-top: 16px;
}

.ld-step-content h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}

.ld-step-content p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
  white-space: pre-line;
}

/* Style keywords */
.ld-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 20px;
}

.ld-keyword {
  display: inline-block;
  background: var(--accent-bg);
  color: #2BA89D;
  font-size: 14px;
  font-weight: 500;
  padding: 6px 16px;
  border-radius: 20px;
}

/* Artwork showcase */
.ld-artwork-card {
  background: var(--surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-bottom: 20px;
}

.ld-artwork-img-wrap {
  width: 100%;
  max-height: 400px;
  overflow: hidden;
  background: #f0ebe4;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ld-artwork-img {
  width: 100%;
  height: auto;
  object-fit: contain;
  max-height: 400px;
}

.ld-artwork-placeholder {
  text-align: center;
  padding: 60px 24px;
  background: var(--surface);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  margin-bottom: 20px;
}

.ld-artwork-placeholder span { font-size: 48px; display: block; margin-bottom: 8px; }
.ld-artwork-placeholder p { color: var(--text-light); font-size: 14px; }

.ld-artwork-info { padding: 24px 28px; }

.ld-artwork-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 4px;
}

.ld-artwork-title-en {
  font-size: 14px;
  color: var(--text-light);
  margin-bottom: 12px;
}

.ld-artwork-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
}

/* Creation section: meta row, materials, tips */
.ld-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 20px;
}

.ld-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--text-muted);
}

.ld-meta-item strong {
  color: var(--text);
  font-weight: 600;
  margin-left: 4px;
}

.ld-materials,
.ld-tips,
.ld-activity-pages {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin-top: 16px;
}

.ld-materials h3,
.ld-tips h3,
.ld-activity-pages h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 12px;
}

.ld-materials ul {
  list-style: none;
  padding: 0;
}

.ld-materials li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
}

.ld-materials li::before {
  content: '•';
  position: absolute;
  left: 4px;
  color: var(--primary);
  font-weight: 700;
}

.ld-tips p,
.ld-activity-pages p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
}

/* Bottom section: PDF button + navigation */
.ld-bottom {
  text-align: center;
  padding-bottom: 64px;
}

.ld-pdf-btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
  margin-bottom: 32px;
}

.ld-pdf-btn:hover {
  background: var(--primary-light);
  transform: translateY(-1px);
}

.ld-nav-row {
  display: flex;
  justify-content: center;
  align-items: stretch;
  gap: 16px;
  flex-wrap: wrap;
}

.ld-nav-link {
  display: inline-block;
  padding: 14px 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  text-decoration: none;
  color: var(--text);
  font-size: 14px;
  font-weight: 500;
  transition: box-shadow 0.2s, border-color 0.2s;
  min-width: 160px;
}

.ld-nav-link:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.ld-nav-link span {
  display: block;
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 400;
  margin-top: 4px;
}

.ld-nav-disabled {
  color: var(--text-light);
  cursor: default;
  opacity: 0.5;
}

.ld-nav-disabled:hover {
  border-color: var(--border);
  box-shadow: none;
}

.ld-nav-all {
  background: var(--bg-warm);
  font-weight: 600;
}

/* Responsive — lesson detail */
@media (max-width: 768px) {
  .ld-header { padding: 16px 20px; }
  .ld-section { padding: 32px 20px; }

  .ld-artist-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .ld-artist-portrait { width: 110px; min-width: 110px; height: 110px; }
  .ld-artist-tags { justify-content: center; }

  .ld-step-content,
  .ld-materials,
  .ld-tips,
  .ld-activity-pages { padding: 20px; }

  .ld-nav-row { flex-direction: column; align-items: center; }
  .ld-nav-link { min-width: 200px; text-align: center; }
}