/* ==========================================================
   Gamma-Style Presentation View
   Full-screen, magazine-layout slides
   ========================================================== */

*,*::before,*::after{box-sizing:border-box}

.gm-present{
  --gm-primary:#6366f1;
  --gm-primary-2:#8b5cf6;
  --gm-ink:#0f172a;
  --gm-ink-2:#334155;
  --gm-muted:#64748b;
  --gm-bg:#0f0f1a;
  --gm-card-bg:#ffffff;
  --gm-border:rgba(255,255,255,.08);
  --gm-radius:16px;

  position:fixed;inset:0;z-index:9999;
  background:var(--gm-bg);
  overflow:hidden;
  font-family:'Inter',-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
  color:#fff;
}

/* ---------- Loading screen ---------- */
.gm-loading{
  position:absolute;inset:0;z-index:10;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  background:var(--gm-bg);
  gap:16px;
  transition:opacity .4s ease;
}
.gm-loading.hidden{opacity:0;pointer-events:none}
.gm-loading-spinner{
  width:48px;height:48px;
  border:3px solid rgba(255,255,255,.1);
  border-top-color:var(--gm-primary);
  border-radius:50%;
  animation:gmSpin .8s linear infinite;
}
@keyframes gmSpin{to{transform:rotate(360deg)}}
.gm-loading-text{font-size:.9rem;color:rgba(255,255,255,.6);font-weight:500}

/* ---------- Top bar ---------- */
.gm-topbar{
  position:absolute;top:0;left:0;right:0;z-index:20;
  display:flex;align-items:center;justify-content:space-between;
  padding:12px 24px;
  background:linear-gradient(180deg,rgba(15,15,26,.95) 0%,transparent 100%);
}
.gm-topbar-left{display:flex;align-items:center;gap:12px}
.gm-topbar-title{
  font-size:.82rem;font-weight:600;color:rgba(255,255,255,.7);
  max-width:300px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;
}
.gm-counter{
  font-size:.78rem;font-weight:700;color:rgba(255,255,255,.5);
  background:rgba(255,255,255,.08);
  padding:4px 12px;border-radius:999px;
}
.gm-exit{
  background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.15);
  color:#fff;border-radius:10px;padding:6px 14px;
  font-size:.78rem;font-weight:600;cursor:pointer;
  transition:all .15s;display:flex;align-items:center;gap:6px;
}
.gm-exit:hover{background:rgba(255,255,255,.2);transform:scale(1.03)}

/* ---------- Progress bar ---------- */
.gm-progress{
  position:absolute;top:0;left:0;right:0;height:3px;z-index:21;
  background:rgba(255,255,255,.06);
}
.gm-progress-fill{
  height:100%;
  background:linear-gradient(90deg,var(--gm-primary),var(--gm-primary-2));
  transition:width .4s ease;
  border-radius:0 3px 3px 0;
}

/* ---------- Slide container ---------- */
.gm-slides{position:absolute;inset:0}
.gm-slide{
  position:absolute;inset:0;
  display:grid;
  grid-template-columns:1fr 1fr;
  opacity:0;pointer-events:none;
  transition:opacity .5s ease,transform .5s ease;
  transform:translateX(40px);
}
.gm-slide.active{opacity:1;pointer-events:auto;transform:translateX(0)}
.gm-slide.prev{transform:translateX(-40px)}

/* ---------- Image side (left) ---------- */
.gm-image{
  position:relative;overflow:hidden;
  background:linear-gradient(135deg,#1e1b4b,#312e81);
}
/* Page display — textbook page centered on gradient */
.gm-page-display{
  position:absolute;inset:0;z-index:2;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  padding:40px 30px;
}
.gm-page-display img{
  max-width:85%;max-height:75%;
  object-fit:contain;
  border-radius:12px;
  box-shadow:0 16px 48px rgba(0,0,0,.5),0 0 0 1px rgba(255,255,255,.08);
  transition:transform .6s ease, opacity .4s ease;
  opacity:0;
}
.gm-page-display img.loaded{opacity:1}
.gm-slide.active .gm-page-display img.loaded{transform:scale(1.02)}
.gm-page-label{
  margin-top:10px;
  font-size:.7rem;font-weight:600;
  color:rgba(255,255,255,.5);
  text-transform:uppercase;letter-spacing:.06em;
}
.gm-page-icon{
  font-size:4rem;opacity:.3;
}
/* Decorative slide number on gradient */
.gm-deco-num{
  position:absolute;bottom:20px;right:20px;z-index:1;
  font-size:6rem;font-weight:900;
  color:rgba(255,255,255,.06);
  line-height:1;letter-spacing:-.05em;
  pointer-events:none;
}
.gm-image .placeholder{
  position:absolute;inset:0;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  color:rgba(255,255,255,.2);font-size:3rem;gap:8px;
}
.gm-image .placeholder span{font-size:.8rem}
.gm-image::after{
  content:"";position:absolute;inset:0;
  background:linear-gradient(90deg,transparent 70%,var(--gm-bg) 100%);
  pointer-events:none;
}

/* Textbook page thumbnail overlay */
.gm-page-thumb{
  position:absolute;bottom:16px;left:16px;z-index:5;
  background:rgba(15,15,26,.8);
  backdrop-filter:blur(8px);
  border:1px solid rgba(255,255,255,.12);
  border-radius:10px;
  padding:6px;
  display:flex;flex-direction:column;align-items:center;gap:4px;
  cursor:pointer;
  transition:all .2s ease;
  box-shadow:0 4px 16px rgba(0,0,0,.4);
}
.gm-page-thumb:hover{
  transform:scale(1.6);
  transform-origin:bottom left;
  z-index:10;
  box-shadow:0 8px 30px rgba(0,0,0,.6);
}
.gm-page-thumb img{
  width:64px;height:auto;
  border-radius:6px;
  object-fit:contain;
  box-shadow:0 2px 8px rgba(0,0,0,.3);
}
.gm-page-thumb span{
  font-size:.58rem;font-weight:600;
  color:rgba(255,255,255,.6);
  text-transform:uppercase;
  letter-spacing:.04em;
}

/* ---------- Content side (right) ---------- */
.gm-content{
  padding:80px 48px 80px 32px;
  overflow-y:auto;
  display:flex;flex-direction:column;
  scrollbar-width:thin;
  scrollbar-color:rgba(255,255,255,.15) transparent;
}
.gm-content::-webkit-scrollbar{width:5px}
.gm-content::-webkit-scrollbar-thumb{background:rgba(255,255,255,.15);border-radius:5px}

.gm-slide-num{
  font-size:5rem;font-weight:900;
  color:rgba(255,255,255,.04);
  position:absolute;top:60px;right:40px;
  line-height:1;letter-spacing:-.05em;
  pointer-events:none;
}

.gm-title{
  font-size:clamp(1.6rem,3vw,2.4rem);
  font-weight:800;
  color:#fff;
  line-height:1.15;
  margin:0 0 8px;
  letter-spacing:-.02em;
}
.gm-title-bar{
  width:60px;height:4px;
  background:linear-gradient(90deg,var(--gm-primary),var(--gm-primary-2));
  border-radius:4px;
  margin-bottom:28px;
}

/* ---------- Card grid ---------- */
.gm-cards{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:14px;
  margin-bottom:24px;
}
.gm-card{
  background:rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.08);
  border-radius:14px;
  padding:18px 16px;
  transition:all .25s ease;
  position:relative;overflow:hidden;
}
.gm-card::before{
  content:"";position:absolute;top:0;left:0;right:0;height:3px;
  background:var(--card-color,var(--gm-primary));
  border-radius:14px 14px 0 0;
}
.gm-card:hover{
  background:rgba(255,255,255,.1);
  border-color:rgba(255,255,255,.15);
  transform:translateY(-2px);
}
.gm-card-title{
  font-size:.92rem;font-weight:700;color:#fff;
  margin:0 0 8px;line-height:1.3;
}
.gm-card-text{
  font-size:.82rem;color:rgba(255,255,255,.65);
  line-height:1.55;margin:0;
}

/* ---------- Paragraph / body text ---------- */
.gm-body-text{
  font-size:1rem;
  color:rgba(255,255,255,.75);
  line-height:1.7;
  margin-top:auto;
  padding-top:16px;
  border-top:1px solid rgba(255,255,255,.06);
}

/* ---------- Keywords ---------- */
.gm-keywords{
  display:flex;flex-wrap:wrap;gap:6px;
  margin-top:16px;
}
.gm-kw{
  font-size:.68rem;font-weight:600;
  padding:4px 10px;border-radius:999px;
  background:rgba(99,102,241,.15);
  color:rgba(167,139,250,.9);
  border:1px solid rgba(99,102,241,.2);
}

/* ---------- Navigation ---------- */
.gm-nav{
  position:absolute;bottom:0;left:0;right:0;z-index:20;
  display:flex;align-items:center;justify-content:center;gap:12px;
  padding:16px 24px;
  background:linear-gradient(0deg,rgba(15,15,26,.95) 0%,transparent 100%);
}
.gm-nav-btn{
  background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.12);
  color:#fff;border-radius:12px;
  padding:10px 20px;font-size:.82rem;font-weight:600;
  cursor:pointer;transition:all .15s;
  display:flex;align-items:center;gap:6px;
}
.gm-nav-btn:hover{background:rgba(255,255,255,.18);transform:translateY(-1px)}
.gm-nav-btn:disabled{opacity:.3;cursor:not-allowed;transform:none}
.gm-nav-btn.primary{
  background:linear-gradient(135deg,var(--gm-primary),var(--gm-primary-2));
  border-color:transparent;
  box-shadow:0 4px 16px rgba(99,102,241,.4);
}
.gm-nav-btn.primary:hover{box-shadow:0 8px 24px rgba(99,102,241,.5)}
.gm-nav-dots{display:flex;gap:5px;align-items:center}
.gm-dot{
  width:8px;height:8px;border-radius:50%;
  background:rgba(255,255,255,.15);
  transition:all .3s;cursor:pointer;
}
.gm-dot.active{
  background:var(--gm-primary);
  width:24px;border-radius:4px;
  box-shadow:0 0 10px rgba(99,102,241,.5);
}

/* ---------- Quiz overlay ---------- */
.gm-quiz-overlay{
  position:absolute;inset:0;z-index:30;
  background:rgba(15,15,26,.92);
  backdrop-filter:blur(12px);
  display:flex;align-items:center;justify-content:center;
  animation:gmFadeIn .3s ease;
}
@keyframes gmFadeIn{from{opacity:0}to{opacity:1}}
.gm-quiz-box{
  background:#fff;border-radius:20px;
  padding:36px 32px;max-width:520px;width:90%;
  color:var(--gm-ink);
  box-shadow:0 24px 60px rgba(0,0,0,.4);
}
.gm-quiz-badge{
  display:inline-flex;align-items:center;gap:6px;
  background:linear-gradient(135deg,#6366f1,#8b5cf6);
  color:#fff;border-radius:999px;
  padding:6px 14px;font-size:.74rem;font-weight:700;
  text-transform:uppercase;letter-spacing:.05em;
  margin-bottom:16px;
}
.gm-quiz-q{
  font-size:1.1rem;font-weight:700;color:var(--gm-ink);
  line-height:1.4;margin-bottom:20px;
}
.gm-quiz-opt{
  display:block;width:100%;text-align:left;
  background:#f8fafc;border:2px solid #e2e8f0;
  border-radius:12px;padding:14px 16px;
  font-size:.9rem;font-weight:500;color:var(--gm-ink);
  cursor:pointer;transition:all .15s;
  margin-bottom:8px;
}
.gm-quiz-opt:hover{border-color:#c7d2fe;background:#eef2ff}
.gm-quiz-opt.correct{border-color:#10b981;background:#d1fae5;color:#065f46}
.gm-quiz-opt.wrong{border-color:#ef4444;background:#fef2f2;color:#991b1b}
.gm-quiz-skip{
  background:none;border:none;color:var(--gm-muted);
  font-size:.82rem;font-weight:600;cursor:pointer;
  margin-top:12px;padding:6px 0;
}
.gm-quiz-skip:hover{color:var(--gm-ink)}

/* ---------- Mobile ---------- */
@media (max-width:768px){
  .gm-slide{grid-template-columns:1fr;grid-template-rows:35vh 1fr}
  .gm-image::after{
    background:linear-gradient(180deg,transparent 60%,var(--gm-bg) 100%);
  }
  .gm-content{padding:24px 20px 100px}
  .gm-title{font-size:1.5rem}
  .gm-cards{grid-template-columns:1fr}
  .gm-slide-num{display:none}
  .gm-topbar{padding:8px 14px}
  .gm-nav{padding:12px 14px}
}