:root {
  /* PSys design tokens — same as idea2.3 */
  --navy: #0a0e1a;
  --navy-2: #111726;
  --panel-dark: #161d2f;
  --hairline-dark: #1f2942;
  --cream: #f4ede0;
  --cream-soft: #faf6ec;
  --white: #ffffff;
  --hairline: #e8e0cf;
  --ink: #1a1f2e;
  --muted: #6b7280;
  --gold: #c4a661;
  --gold-bright: #dbbf7a;
  --gold-deep: #b8960c;
  --teal: #0d7b8a;  /* secondary accent only */
  --correct: #16a34a;
  --wrong: #dc2626;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--cream-soft);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.7;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ---- SITE NAV (dark — matches idea2.3) ---- */
nav.site {
  padding: 18px 0;
  background: var(--navy);
  border-bottom: 1px solid var(--hairline-dark);
  position: sticky; top: 0; z-index: 100;
}
nav.site .wrap {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 40px;
}
nav.site a { text-decoration: none; color: var(--cream); }
nav.site a:hover { color: var(--gold); }
nav.site .brand {
  display: inline-flex; align-items: center; gap: 14px;
  text-transform: uppercase; text-decoration: none;
}
nav.site .brand .dot {
  width: 10px; height: 10px; background: var(--gold); border-radius: 50%;
  box-shadow: 0 0 0 5px rgba(196, 166, 97, 0.18);
  align-self: center; flex-shrink: 0;
}
nav.site .brand .word {
  display: flex; flex-direction: column; gap: 5px; line-height: 1;
}
nav.site .brand .name {
  font-family: 'Oswald', sans-serif;
  font-weight: 500;
  font-size: 16px;
  color: var(--cream);
  letter-spacing: 0.14em;
}
nav.site .brand .name sup {
  color: var(--gold); font-size: 9px; margin-left: 2px;
}
nav.site .brand .sub {
  font-family: 'Inter', sans-serif;
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--gold);
  font-weight: 600;
}
nav.site ul { list-style: none; display: flex; gap: 26px; align-items: center; }
nav.site ul a {
  font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase;
  font-weight: 500;
}
nav.site ul a.current { color: var(--gold); }
/* Sign In — subtle gold-bordered text link between regular nav and the gold CTA */
nav.site ul a.nav-signin {
  color: var(--gold) !important;
  font-weight: 600;
  padding: 8px 14px;
  border: 1px solid rgba(196,166,97,0.32);
  border-radius: 3px;
  transition: all 0.2s;
}
nav.site ul a.nav-signin:hover {
  background: rgba(196,166,97,0.10);
  border-color: var(--gold);
}
.btn-cta {
  background: var(--gold); color: var(--navy);
  padding: 12px 22px; font-size: 11px; font-weight: 600;
  letter-spacing: 0.16em; text-transform: uppercase;
}

/* ---- LESSON BAR (between site nav and content) ---- */
.lesson-bar {
  background: var(--navy-2);
  padding: 14px 40px;
  display: flex; align-items: center; justify-content: space-between;
  border-bottom: 1px solid var(--hairline-dark);
  flex-wrap: wrap; gap: 12px;
}
.lesson-bar .crumb {
  font-family: 'Oswald', sans-serif;
  font-size: 13px; color: var(--cream);
  letter-spacing: 0.08em;
}
.lesson-bar .crumb em {
  font-family: 'Playfair Display', serif; font-style: italic;
  color: var(--gold-bright); font-weight: 400;
  letter-spacing: 0;
}
.lesson-bar .badge {
  font-size: 10px; font-weight: 600; letter-spacing: 0.16em;
  text-transform: uppercase;
  background: rgba(196,166,97,0.18); color: var(--gold);
  padding: 5px 14px; border-radius: 100px;
  border: 1px solid rgba(196,166,97,0.32);
}

/* ---- PROGRESS BAR ---- */
.progress-wrap {
  background: var(--white); padding: 10px 40px;
  border-bottom: 1px solid var(--hairline);
  display: flex; align-items: center; gap: 16px;
}
.progress-bar { flex: 1; height: 5px; background: var(--hairline); border-radius: 100px; overflow: hidden; }
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--gold), var(--gold-bright));
  transition: width .5s ease;
  border-radius: 100px;
}
.progress-text { font-size: 12px; color: var(--muted); white-space: nowrap; }

/* ---- LAYOUT ---- */
.layout { display: grid; grid-template-columns: 240px 1fr; }
.sidebar {
  background: var(--white);
  border-right: 1px solid var(--hairline);
  min-height: calc(100vh - 200px);
  padding: 18px 0;
  position: sticky; top: 144px;
  align-self: start;
  max-height: calc(100vh - 144px);
  overflow-y: auto;
}
.s-section + .s-section { margin-top: 8px; }
.s-head {
  font-size: 9px; font-weight: 700; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--gold-deep); padding: 10px 22px 6px;
  font-family: 'Inter', sans-serif;
}
.s-item {
  display: flex; align-items: center; gap: 11px;
  padding: 10px 22px; cursor: pointer;
  font-size: 12.5px; color: var(--muted);
  transition: all .2s;
  border-left: 3px solid transparent;
  font-family: 'Inter', sans-serif;
}
.s-item:hover { background: var(--cream-soft); color: var(--navy); }
.s-item.active {
  background: rgba(196,166,97,0.10);
  color: var(--navy); font-weight: 600;
  border-left-color: var(--gold);
}
.s-item.done { color: var(--gold-deep); }
.s-num {
  width: 22px; height: 22px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 10px; font-weight: 700; flex-shrink: 0;
  background: var(--hairline); color: var(--muted);
  font-family: 'Oswald', sans-serif;
}
.s-num.a { background: var(--gold); color: var(--navy); }
.s-num.d { background: var(--gold-deep); color: var(--white); }

/* ---- SLIDES ---- */
.content { overflow: hidden; background: var(--cream-soft); }
.slide { display: none; animation: fade-in .35s ease; }
.slide.active {
  display: flex; flex-direction: column;
  min-height: calc(100vh - 200px);
}
@keyframes fade-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

/* ---- HERO (matches idea2.3 hero treatment) ---- */
.hero {
  padding: 56px 56px 44px; position: relative; overflow: hidden;
  background: var(--navy);
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 80% 0%, rgba(196,166,97,0.10), transparent 60%);
  pointer-events: none;
}
.hero.gold-bg {
  background: linear-gradient(135deg, #8a7115 0%, #c4a661 100%);
}
.hero.dark-grad {
  background: linear-gradient(135deg, var(--navy) 0%, var(--panel-dark) 100%);
}
.hero-tag {
  font-size: 10px; font-weight: 700;
  letter-spacing: 0.24em; text-transform: uppercase;
  color: var(--gold); margin-bottom: 14px;
  position: relative; z-index: 1;
  display: inline-flex; align-items: center; gap: 12px;
}
.hero-tag::before { content: ''; width: 28px; height: 1px; background: var(--gold); }
.hero h1 {
  font-family: 'Oswald', sans-serif;
  font-size: clamp(34px, 4.4vw, 52px);
  font-weight: 600; line-height: 1.05;
  color: var(--cream);
  text-transform: uppercase;
  letter-spacing: -0.005em;
  margin-bottom: 16px;
  position: relative; z-index: 1;
}
.hero h1 em {
  font-family: 'Playfair Display', serif;
  font-style: italic; font-weight: 400;
  color: var(--gold-bright);
  text-transform: none;
}
.hero p {
  font-size: 15.5px; line-height: 1.65;
  color: rgba(244, 237, 224, 0.78);
  max-width: 60ch;
  position: relative; z-index: 1;
}

/* ---- BODY ---- */
.body { padding: 36px 56px; flex: 1; }

/* ---- CARDS ---- */
.card {
  background: var(--white);
  border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 24px 28px;
  margin-bottom: 16px;
}
.card.gold-l { border-left: 3px solid var(--gold); }
.card.teal-l { border-left: 3px solid var(--teal); }
.card-lbl {
  font-size: 10px; font-weight: 600;
  letter-spacing: 0.20em; text-transform: uppercase;
  color: var(--gold-deep); margin-bottom: 8px;
  font-family: 'Inter', sans-serif;
}
.card h3 {
  font-family: 'Oswald', sans-serif;
  font-size: 22px; font-weight: 600;
  color: var(--navy); margin-bottom: 10px;
  letter-spacing: 0.005em;
}
.card p { font-size: 14.5px; color: var(--ink); line-height: 1.75; }
.card p strong { color: var(--navy); font-weight: 700; }

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.three-col { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 14px; }
.img-col { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; align-items: start; }

.info-box {
  background: var(--white);
  border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 18px 20px;
}
.info-box-title {
  font-size: 10px; font-weight: 700;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--gold-deep); margin-bottom: 8px;
}
.info-box p { font-size: 13.5px; color: var(--ink); line-height: 1.65; }
.info-box p strong { color: var(--navy); }

.tip {
  background: rgba(196,166,97,0.07);
  border: 1px solid rgba(196,166,97,0.22);
  border-radius: 4px;
  padding: 18px 22px; margin-top: 18px;
  display: flex; gap: 14px; align-items: flex-start;
}
.tip-icon { font-size: 22px; flex-shrink: 0; }
.tip-label {
  font-size: 10px; font-weight: 700;
  letter-spacing: 0.20em; text-transform: uppercase;
  color: var(--gold-deep); margin-bottom: 4px;
}
.tip-text {
  font-size: 14px; color: var(--ink);
  line-height: 1.6;
  font-family: 'Playfair Display', serif; font-style: italic;
}

.highlight {
  background: var(--navy);
  border-radius: 4px;
  padding: 24px 28px; margin: 18px 0;
  position: relative;
}
.highlight::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 90% 50%, rgba(196,166,97,0.10), transparent 60%);
  pointer-events: none; border-radius: 4px;
}
.highlight h4 {
  font-family: 'Oswald', sans-serif;
  font-size: 20px; font-weight: 600;
  color: var(--gold); margin-bottom: 10px;
  position: relative; z-index: 1;
}
.highlight p {
  font-size: 14px; color: rgba(244, 237, 224, 0.82);
  line-height: 1.7; position: relative; z-index: 1;
}

/* ---- LEARNING OBJECTIVES ---- */
.obj-list { display: flex; flex-direction: column; gap: 11px; margin-top: 10px; }
.obj {
  display: flex; gap: 14px; align-items: flex-start;
  background: var(--white); border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 16px 20px;
}
.obj-n {
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--navy); color: var(--gold);
  display: flex; align-items: center; justify-content: center;
  font-family: 'Oswald', sans-serif;
  font-weight: 600; font-size: 14px; flex-shrink: 0;
}
.obj strong { color: var(--navy); font-size: 14.5px; }
.obj span { font-size: 13.5px; color: var(--ink); line-height: 1.6; }

/* ---- KEY TERMS GRID ---- */
.terms-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 10px; margin-top: 18px;
}
.term {
  background: var(--white); border: 1px solid var(--hairline);
  border-radius: 4px; padding: 10px 14px;
  font-size: 12.5px; color: var(--navy); font-weight: 500;
  cursor: pointer; transition: all .2s;
  display: flex; align-items: center; gap: 9px;
}
.term:hover { border-color: var(--gold); background: rgba(196,166,97,0.05); }
.term.selected { border-color: var(--gold); background: rgba(196,166,97,0.08); }
.term-dot {
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--gold); flex-shrink: 0;
}
.def-box {
  background: var(--navy); border-radius: 4px;
  padding: 20px 24px; margin-top: 16px; display: none;
  position: relative;
}
.def-box h4 {
  font-family: 'Oswald', sans-serif;
  font-size: 19px; color: var(--gold); margin-bottom: 8px;
}
.def-box p {
  font-size: 14px; color: rgba(244, 237, 224, 0.85);
  line-height: 1.7;
}

/* ---- IMAGE FRAME ---- */
.img-frame {
  background: var(--white);
  border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 18px;
  text-align: center;
}
.wb-img {
  width: 100%; border-radius: 3px;
}
.img-caption {
  font-size: 12px; color: var(--muted);
  text-align: center; margin-top: 10px;
  font-family: 'Playfair Display', serif; font-style: italic;
}

/* ---- LIGHTNING ROUND ---- */
.lg-game { max-width: 560px; margin: 0 auto; text-align: center; }
.lg-timer {
  font-family: 'Oswald', sans-serif;
  font-size: 56px; font-weight: 600;
  color: var(--navy); line-height: 1;
  margin-bottom: 6px;
}
.lg-timer.red { color: var(--wrong); }
.lg-tbar-bg {
  height: 5px; background: var(--hairline); border-radius: 100px;
  margin-bottom: 26px; overflow: hidden;
}
.lg-tbar {
  height: 100%; background: var(--gold);
  transition: width .1s linear;
}
.lg-score { display: flex; justify-content: center; gap: 28px; margin-bottom: 20px; }
.lg-s-num {
  font-family: 'Oswald', sans-serif;
  font-size: 32px; font-weight: 600;
}
.lg-s-lbl {
  font-size: 10px; text-transform: uppercase; letter-spacing: 0.16em;
  color: var(--muted);
}
.lg-q {
  font-family: 'Oswald', sans-serif;
  font-size: 22px; font-weight: 500;
  color: var(--navy); line-height: 1.35;
  padding: 22px 26px;
  background: var(--white); border: 1px solid var(--hairline);
  border-radius: 4px; margin-bottom: 24px;
}
.lg-btns { display: flex; gap: 14px; justify-content: center; }
.lg-t, .lg-f {
  color: var(--white); font-size: 13px; font-weight: 700;
  letter-spacing: 0.12em; text-transform: uppercase;
  padding: 14px 36px;
  border: none; border-radius: 3px; cursor: pointer;
  transition: all .2s;
  font-family: 'Inter', sans-serif;
}
.lg-t { background: var(--correct); }
.lg-f { background: var(--wrong); }
.lg-t:hover, .lg-f:hover { filter: brightness(1.1); }
.lg-fb {
  font-size: 14px; font-weight: 600;
  padding: 14px 18px; border-radius: 4px;
  margin-bottom: 16px;
  font-family: 'Inter', sans-serif;
}
.lg-fb.cf { background: rgba(22,163,74,0.10); color: var(--correct); }
.lg-fb.wf { background: rgba(220,38,38,0.10); color: var(--wrong); }

/* ---- MULTIPLE CHOICE ---- */
.mc-game { max-width: 700px; margin: 0 auto; }
.mc-q {
  font-family: 'Oswald', sans-serif;
  font-size: 21px; font-weight: 500;
  color: var(--navy); line-height: 1.35;
  padding: 22px 26px;
  background: var(--white); border: 1px solid var(--hairline);
  border-radius: 4px; margin-bottom: 16px;
}
.mc-opts { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 16px; }
.mc-opt {
  background: var(--white); border: 2px solid var(--hairline);
  border-radius: 4px; padding: 14px 18px;
  cursor: pointer; font-size: 13.5px;
  color: var(--navy); font-weight: 500;
  transition: all .2s; text-align: left;
  font-family: 'Inter', sans-serif;
}
.mc-opt:hover { border-color: var(--gold); }
.mc-opt.correct { border-color: var(--correct); background: rgba(22,163,74,0.07); color: var(--correct); }
.mc-opt.wrong   { border-color: var(--wrong);   background: rgba(220,38,38,0.06); color: var(--wrong); }
.mc-fb {
  font-size: 13px; font-weight: 600;
  padding: 14px 18px; border-radius: 4px;
  margin-bottom: 14px; display: none;
}
.mc-fb.cf { background: rgba(22,163,74,0.10); color: var(--correct); }
.mc-fb.wf { background: rgba(220,38,38,0.10); color: var(--wrong); }
.mc-score { font-size: 12px; color: var(--muted); text-align: center; margin-bottom: 14px;
            letter-spacing: 0.08em; text-transform: uppercase; }

/* ---- SCORE BOARD ---- */
.sb { text-align: center; padding: 40px 24px; }
.sb h2 {
  font-family: 'Oswald', sans-serif;
  font-size: 34px; font-weight: 600;
  color: var(--navy); margin-bottom: 8px;
  text-transform: uppercase;
}
.sb-stars { font-size: 32px; margin-bottom: 12px; }
.sb-big {
  font-family: 'Oswald', sans-serif;
  font-size: 64px; font-weight: 600;
  color: var(--gold); line-height: 1; margin: 12px 0;
}
.sb-msg { font-size: 15px; color: var(--muted); margin-bottom: 22px; max-width: 44ch; margin-left: auto; margin-right: auto; }

/* ---- FOOTER NAV (lesson controls) ---- */
.lesson-foot {
  padding: 18px 56px; border-top: 1px solid var(--hairline);
  background: var(--white);
  display: flex; justify-content: space-between; align-items: center;
  margin-top: auto;
}
.slide-ctr {
  font-size: 12px; color: var(--muted);
  letter-spacing: 0.06em;
  font-family: 'Oswald', sans-serif;
}
.btn {
  font-size: 12px; font-weight: 700;
  letter-spacing: 0.14em; text-transform: uppercase;
  padding: 12px 24px;
  border-radius: 3px; border: none; cursor: pointer;
  transition: all .2s;
  font-family: 'Inter', sans-serif;
}
.btn-n { background: var(--navy); color: var(--cream); }
.btn-n:hover { background: var(--gold); color: var(--navy); }
.btn-p { background: transparent; color: var(--navy); border: 1.5px solid var(--navy); }
.btn-p:hover { background: var(--navy); color: var(--cream); }
.btn-g { background: var(--gold); color: var(--navy); }
.btn-g:hover { background: var(--gold-bright); }
.btn-gold { background: var(--gold); color: var(--navy);
            font-size: 12px; font-weight: 700; letter-spacing: 0.14em;
            text-transform: uppercase; padding: 13px 26px;
            border-radius: 3px; border: none; cursor: pointer; }
.btn-outline-w {
  background: transparent; color: var(--cream);
  border: 1.5px solid rgba(244,237,224,0.35);
  font-size: 12px; font-weight: 700; letter-spacing: 0.14em;
  text-transform: uppercase; padding: 13px 26px;
  border-radius: 3px; cursor: pointer;
}

/* ---- LESSON COMPLETE ---- */
.comp-hero {
  background: var(--navy); text-align: center;
  padding: 56px 32px; position: relative;
}
.comp-hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(196,166,97,0.14), transparent 60%);
}
.comp-badge {
  width: 110px; height: 110px; border-radius: 50%;
  background: var(--gold);
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 20px; font-size: 44px;
  position: relative; z-index: 1;
}
.comp-title {
  font-family: 'Oswald', sans-serif;
  font-size: 36px; font-weight: 600;
  color: var(--cream); margin-bottom: 12px;
  text-transform: uppercase; position: relative; z-index: 1;
}
.comp-sub {
  font-size: 14.5px; color: rgba(244,237,224,0.72);
  max-width: 48ch; margin: 0 auto 28px;
  line-height: 1.7; position: relative; z-index: 1;
}
.comp-btns { display: flex; gap: 12px; justify-content: center;
             flex-wrap: wrap; position: relative; z-index: 1; }

/* ---- RESPONSIVE ---- */
@media (max-width: 880px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .hero { padding: 36px 24px; }
  .body { padding: 24px; }
  .lesson-foot { padding: 16px 24px; }
  .two-col, .three-col, .img-col { grid-template-columns: 1fr; }
  .mc-opts { grid-template-columns: 1fr; }
  nav.site ul { display: none; }
}