@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,wght@0,300;0,400;0,500;1,300&family=DM+Serif+Display:ital@0;1&display=swap');

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

:root {
  --bg:        #080c12;
  --bg-2:      #0e1520;
  --bg-3:      #131c28;
  --border:    rgba(255,255,255,0.07);
  --border-md: rgba(255,255,255,0.12);
  --text:      #e8ecf0;
  --text-2:    rgba(232,236,240,0.5);
  --text-3:    rgba(232,236,240,0.3);
  --teal:      #4fc3a1;
  --teal-2:    #6dd4b5;
  --teal-dim:  rgba(79,195,161,0.15);
  --blue:      #5b9bd5;
  --amber:     #d4954a;
  --radius:    6px;
  --nav-h:     62px;
}

html { scroll-behavior: smooth; }
body { font-family: 'DM Sans', sans-serif; background: var(--bg); color: var(--text); font-size: 15px; line-height: 1.6; -webkit-font-smoothing: antialiased; }

.nav { position: sticky; top: 0; z-index: 200; height: var(--nav-h); display: flex; align-items: center; justify-content: space-between; padding: 0 48px; background: rgba(8,12,18,0.88); backdrop-filter: blur(14px); border-bottom: 0.5px solid var(--border); }
.nav-logo { font-family: 'DM Serif Display', serif; font-size: 17px; letter-spacing: 0.04em; color: var(--text); text-decoration: none; }
.nav-logo span { color: var(--teal); }
.nav-links { display: flex; gap: 32px; list-style: none; }
.nav-links a { font-size: 12px; letter-spacing: 0.07em; text-transform: uppercase; color: var(--text-3); text-decoration: none; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.nav-cta { font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--teal); border: 0.5px solid var(--teal); padding: 8px 20px; border-radius: 2px; background: transparent; cursor: pointer; transition: background .2s, color .2s; font-family: 'DM Sans', sans-serif; text-decoration: none; display: inline-flex; align-items: center; gap: 6px; }
.nav-cta:hover { background: var(--teal); color: var(--bg); }

.hero { min-height: calc(100vh - var(--nav-h)); display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 80px 48px 64px; position: relative; overflow: hidden; }
.hero-glow { position: absolute; inset: 0; pointer-events: none; background: radial-gradient(ellipse 70% 55% at 50% 60%, rgba(79,195,161,0.07) 0%, transparent 70%); }
.hero-grid { position: absolute; inset: 0; pointer-events: none; background-image: linear-gradient(rgba(79,195,161,0.035) 1px, transparent 1px), linear-gradient(90deg, rgba(79,195,161,0.035) 1px, transparent 1px); background-size: 60px 60px; }
.eyebrow { font-size: 11px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--teal); margin-bottom: 22px; position: relative; }
.hero h1 { font-family: 'DM Serif Display', serif; font-size: clamp(40px, 6vw, 70px); line-height: 1.08; letter-spacing: -0.01em; color: #f0f4f7; max-width: 800px; margin-bottom: 22px; position: relative; }
.hero h1 em { font-style: italic; color: var(--teal); }
.hero-sub { font-size: 17px; color: var(--text-2); max-width: 500px; line-height: 1.75; margin-bottom: 44px; position: relative; font-weight: 300; }
.btn-row { display: flex; gap: 14px; position: relative; flex-wrap: wrap; justify-content: center; }
.btn-primary { font-family: 'DM Sans', sans-serif; font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; font-weight: 500; background: var(--teal); color: var(--bg); border: none; padding: 14px 32px; border-radius: 2px; cursor: pointer; transition: background .2s; text-decoration: none; display: inline-flex; align-items: center; gap: 8px; }
.btn-primary:hover { background: var(--teal-2); }
.btn-ghost { font-family: 'DM Sans', sans-serif; font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; background: transparent; color: var(--text-2); border: 0.5px solid var(--border-md); padding: 14px 32px; border-radius: 2px; cursor: pointer; transition: border-color .2s, color .2s; text-decoration: none; display: inline-flex; align-items: center; }
.btn-ghost:hover { border-color: rgba(255,255,255,0.35); color: var(--text); }

.hero-stats { display: flex; margin-top: 64px; position: relative; border: 0.5px solid var(--border); border-radius: 4px; overflow: hidden; max-width: 720px; width: 100%; }
.hero-stat { flex: 1; padding: 18px 20px; text-align: center; border-right: 0.5px solid var(--border); }
.hero-stat:last-child { border-right: none; }
.hero-stat-num { font-family: 'DM Serif Display', serif; font-size: 26px; color: var(--teal); display: block; margin-bottom: 3px; }
.hero-stat-label { font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-3); }

.section { padding: 88px 48px; max-width: 1100px; margin: 0 auto; }
.section-label { font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--teal); margin-bottom: 10px; }
.section-title { font-family: 'DM Serif Display', serif; font-size: clamp(26px, 3.5vw, 40px); color: #f0f4f7; line-height: 1.15; }
.section-header { display: flex; justify-content: space-between; align-items: flex-end; margin-bottom: 36px; }
.link-quiet { font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; color: rgba(79,195,161,0.6); background: transparent; border: none; cursor: pointer; font-family: 'DM Sans', sans-serif; text-decoration: none; transition: color .2s; }
.link-quiet:hover { color: var(--teal); }

hr.divider { border: none; border-top: 0.5px solid var(--border); margin: 0 48px; }

.featured-card { display: grid; grid-template-columns: 1fr 1fr; border: 0.5px solid var(--border); border-radius: var(--radius); overflow: hidden; background: var(--bg-2); margin-bottom: 24px; }
.featured-thumb { aspect-ratio: 16/9; background: var(--bg-3); display: flex; align-items: center; justify-content: center; position: relative; }
.badge-new { position: absolute; top: 14px; left: 14px; font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; background: var(--teal); color: var(--bg); padding: 4px 10px; border-radius: 2px; font-weight: 500; z-index: 2; }
.play-btn { width: 52px; height: 52px; border-radius: 50%; border: 1px solid rgba(79,195,161,0.5); display: flex; align-items: center; justify-content: center; transition: border-color .2s, background .2s; cursor: pointer; position: relative; z-index: 2; }
.play-btn:hover { background: var(--teal-dim); border-color: var(--teal); }
.play-icon { width: 0; height: 0; border-top: 10px solid transparent; border-bottom: 10px solid transparent; border-left: 16px solid var(--teal); margin-left: 4px; }
.duration-badge { position: absolute; bottom: 12px; right: 12px; font-size: 11px; color: #e8ecf0; letter-spacing: 0.04em; background: rgba(8,12,18,0.8); padding: 2px 8px; border-radius: 2px; z-index: 2; }
.featured-meta { padding: 32px 30px; display: flex; flex-direction: column; justify-content: center; }
.video-tag { font-size: 10px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--teal); margin-bottom: 8px; display: block; }
.featured-meta .video-title { font-size: 19px; font-weight: 400; color: var(--text); line-height: 1.35; margin-bottom: 12px; }
.featured-meta .video-desc { font-size: 13px; color: var(--text-2); line-height: 1.65; }
.watch-link { margin-top: 22px; display: inline-flex; align-items: center; gap: 8px; font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--teal); cursor: pointer; border: none; background: transparent; font-family: 'DM Sans', sans-serif; padding: 0; text-decoration: none; transition: gap .2s; }
.watch-link:hover { gap: 14px; }

.video-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 18px; }
.video-card { background: var(--bg-2); border: 0.5px solid var(--border); border-radius: var(--radius); overflow: hidden; cursor: pointer; transition: border-color .2s, transform .2s; text-decoration: none; display: block; }
.video-card:hover { border-color: rgba(79,195,161,0.3); transform: translateY(-2px); }
.video-thumb { width: 100%; aspect-ratio: 16/9; background: var(--bg-3); display: flex; align-items: center; justify-content: center; position: relative; }
.play-btn-sm { width: 36px; height: 36px; border-radius: 50%; border: 1px solid rgba(79,195,161,0.4); display: flex; align-items: center; justify-content: center; position: relative; z-index: 2; }
.play-icon-sm { width: 0; height: 0; border-top: 7px solid transparent; border-bottom: 7px solid transparent; border-left: 11px solid var(--teal); margin-left: 3px; }
.series-label { position: absolute; top: 10px; right: 10px; font-size: 10px; letter-spacing: 0.1em; text-transform: uppercase; background: rgba(8,12,18,0.85); color: var(--teal); padding: 3px 8px; border-radius: 2px; z-index: 2; }
.video-meta { padding: 14px 16px; }
.video-title { font-size: 13px; font-weight: 500; color: var(--text); line-height: 1.45; margin-bottom: 8px; }
.tag-row { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 8px; }
.tag { font-size: 10px; letter-spacing: 0.06em; background: var(--bg-3); border: 0.5px solid var(--border-md); color: var(--text-3); padding: 3px 9px; border-radius: 2px; }
.meta-row { display: flex; align-items: center; gap: 10px; margin-top: 8px; }
.meta-pill { font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; padding: 3px 8px; border-radius: 2px; }
.pill-essential  { background: rgba(79,195,161,0.1); color: var(--teal); }
.pill-advanced   { background: rgba(91,155,213,0.12); color: var(--blue); }
.pill-challenging{ background: rgba(212,149,74,0.12); color: var(--amber); }
.pill-standard   { background: rgba(255,255,255,0.05); color: var(--text-3); }
.meta-duration   { font-size: 11px; color: var(--text-3); margin-left: auto; }

.about-grid { display: grid; grid-template-columns: 1fr 1.3fr; gap: 80px; align-items: center; }
.about-portrait { aspect-ratio: 3/4; background: var(--bg-2); border: 0.5px solid var(--border); border-radius: var(--radius); display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; color: var(--text-3); font-size: 12px; letter-spacing: 0.06em; }
.about-portrait svg { opacity: 0.18; }
.about-text h2 { font-family: 'DM Serif Display', serif; font-size: 36px; color: #f0f4f7; line-height: 1.2; margin-bottom: 18px; }
.about-text p { font-size: 15px; color: var(--text-2); line-height: 1.8; margin-bottom: 14px; font-weight: 300; }
.about-pills { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.about-pill { font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; padding: 5px 14px; border: 0.5px solid rgba(79,195,161,0.25); border-radius: 2px; color: rgba(79,195,161,0.7); }

.newsletter-band { background: var(--bg-2); border-top: 0.5px solid var(--border); border-bottom: 0.5px solid var(--border); padding: 80px 48px; text-align: center; }
.newsletter-band h2 { font-family: 'DM Serif Display', serif; font-size: 30px; color: #f0f4f7; margin-bottom: 8px; }
.newsletter-band p { font-size: 15px; color: var(--text-2); margin-bottom: 30px; font-weight: 300; }

footer { padding: 36px 48px; display: flex; align-items: center; justify-content: space-between; border-top: 0.5px solid var(--border); flex-wrap: wrap; gap: 12px; }
.footer-logo { font-family: 'DM Serif Display', serif; font-size: 15px; color: var(--text-3); }
.footer-copy { font-size: 12px; color: var(--text-3); letter-spacing: 0.04em; }
.footer-links { display: flex; gap: 24px; }
.footer-links a { font-size: 12px; color: var(--text-3); text-decoration: none; letter-spacing: 0.05em; text-transform: uppercase; transition: color .2s; }
.footer-links a:hover { color: var(--teal); }

.library-hero { padding: 64px 48px 48px; max-width: 1100px; margin: 0 auto; }
.library-hero h1 { font-family: 'DM Serif Display', serif; font-size: clamp(30px, 4vw, 50px); color: #f0f4f7; margin-bottom: 10px; }
.library-hero p { font-size: 16px; color: var(--text-2); font-weight: 300; max-width: 560px; }

.search-bar-wrap { padding: 0 48px 40px; max-width: 1100px; margin: 0 auto; display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.search-input-wrap { flex: 1; position: relative; min-width: 240px; }
.search-input-wrap svg { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); opacity: 0.3; pointer-events: none; }
#search-input { width: 100%; background: var(--bg-2); border: 0.5px solid var(--border-md); border-radius: 3px; padding: 11px 14px 11px 42px; font-family: 'DM Sans', sans-serif; font-size: 14px; color: var(--text); outline: none; transition: border-color .2s; }
#search-input:focus { border-color: rgba(79,195,161,0.4); }
#search-input::placeholder { color: var(--text-3); }
.filter-btn { font-family: 'DM Sans', sans-serif; font-size: 12px; letter-spacing: 0.07em; text-transform: uppercase; background: var(--bg-2); border: 0.5px solid var(--border-md); color: var(--text-3); padding: 10px 18px; border-radius: 3px; cursor: pointer; transition: all .2s; }
.filter-btn:hover, .filter-btn.active { border-color: rgba(79,195,161,0.4); color: var(--teal); background: rgba(79,195,161,0.06); }
.filter-sep { width: 0.5px; height: 32px; background: var(--border); align-self: center; }

.proc-tabs { padding: 0 48px 32px; max-width: 1100px; margin: 0 auto; display: flex; gap: 0; border-bottom: 0.5px solid var(--border); }
.proc-tab { font-family: 'DM Sans', sans-serif; font-size: 13px; letter-spacing: 0.05em; text-transform: uppercase; background: transparent; border: none; color: var(--text-3); cursor: pointer; padding: 0 24px 14px; border-bottom: 2px solid transparent; margin-bottom: -0.5px; transition: color .2s, border-color .2s; }
.proc-tab:first-child { padding-left: 0; }
.proc-tab:hover { color: var(--text-2); }
.proc-tab.active { color: var(--teal); border-bottom-color: var(--teal); }

.library-body { padding: 48px; max-width: 1100px; margin: 0 auto; }
.chapter-group { margin-bottom: 56px; }
.chapter-header { display: flex; align-items: center; gap: 14px; margin-bottom: 20px; }
.chapter-num { font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--teal); border: 0.5px solid rgba(79,195,161,0.3); padding: 4px 10px; border-radius: 2px; white-space: nowrap; }
.chapter-title { font-family: 'DM Serif Display', serif; font-size: 20px; color: #f0f4f7; }
.chapter-count { font-size: 12px; color: var(--text-3); margin-left: auto; }

.curriculum-path { display: flex; align-items: center; background: var(--bg-2); border: 0.5px solid var(--border); border-radius: 4px; overflow-x: auto; padding: 16px 20px; margin-bottom: 40px; scrollbar-width: none; }
.curriculum-path::-webkit-scrollbar { display: none; }
.path-step { display: flex; align-items: center; flex-shrink: 0; cursor: pointer; }
.path-node { font-size: 11px; letter-spacing: 0.06em; text-transform: uppercase; padding: 6px 14px; border-radius: 2px; white-space: nowrap; color: var(--text-3); transition: all .2s; border: 0.5px solid transparent; }
.path-step:hover .path-node { color: var(--text); border-color: var(--border-md); }
.path-arrow { width: 0; height: 0; border-top: 5px solid transparent; border-bottom: 5px solid transparent; border-left: 7px solid var(--border); margin: 0 4px; flex-shrink: 0; }

.no-results { text-align: center; padding: 80px 20px; color: var(--text-3); font-size: 14px; }

@media (max-width: 900px) {
  .nav { padding: 0 24px; }
  .nav-links { display: none; }
  .section, .library-hero, .search-bar-wrap, .proc-tabs, .library-body { padding-left: 24px; padding-right: 24px; }
  hr.divider { margin: 0 24px; }
  .hero { padding: 60px 24px 48px; }
  .video-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .featured-card { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; }
  footer { padding: 28px 24px; }
}
@media (max-width: 600px) {
  .video-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 34px; }
}