:root{
    --blueprint: #1B3F6B;
    --blueprint-deep: #122c4d;
    --blueprint-line: #8ECBEE;
    --paper: #F2ECDD;
    --paper-shadow: #e4dcc6;
    --ink: #16233A;
    --ink-soft: #4d5a70;
    --rust: #C1442E;
    --rust-deep: #9c3623;
    --gold: #D9A441;
    --radius-card: 3px;
  }
  
   *{ box-sizing: border-box; }
  html{ scroll-behavior: smooth; }
  body{
    margin:0;
    background: var(--paper);
    color: var(--ink);
    font-family: 'IBM Plex Sans', sans-serif;
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
  }
  
  
  
   h1, h2, h3, .display{
    font-family:'IBM Plex Mono', monospace;
  font-style: italic;
  
    font-weight: 600;
    line-height: 1.08;
    margin: 0;
    color: var(--ink);
  }
  
.tagline{
    font-size: clamp(1.5rem, 5vw, 3rem) ;
    font-family:'IBM Plex Mono', monospace;
    font-style: italic;
    font-weight: 600;
    line-height: 1.08;
    margin: 0;
    color: var(--paper);
}
  
   a{ color: inherit; }
  img, svg{ display:block; }
  
    .wrap{
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 32px;
  }
  
 /* ---------- NAV ---------- */
  .nav{
    background: var(--blueprint);
    color: var(--paper);
  position: fixed;
  width: 100%;
    z-index: 1000;
  
  }
  
   .nav .wrap{
    position: relative;
    display:flex;
    align-items:center;
    justify-content: space-between;
    padding-top: 22px;
    padding-bottom: 22px;
  }
  
  .brand{
    display:flex;
    align-items:baseline;
    gap:10px;
  }
  
    .brand-mark{
    font-family:'IBM Plex Mono', monospace;
  font-style: italic;
  
    font-weight:700;
    font-size: 2rem;
    letter-spacing: 0.01em;
  }
  
    @media (max-width: 800px){
    .brand-mark{ font-size: 1rem; }
  }
  
  
  .brand-sub{
    font-size: 0.75rem;
    color: var(--blueprint-line);
    font-style: italic;
    font-family:'IBM Plex Mono', monospace;
  }
  
   .nav-links{
    display:flex;
    gap:28px;
    font-size: 0.92rem;
  }
  
   .nav-links a{
    text-decoration:none;
    color: #cfe3f5;
    border-bottom: 1px solid transparent;
    padding-bottom:2px;
  }
  .nav-links a:hover, .nav-links a:focus-visible{
    border-bottom-color: var(--gold);
    color: var(--paper);
  }

  /* ---------- DROPDOWN (Subject) ---------- */
  .nav-item{
    position: relative;
  }

  .dropdown-toggle{
    display:flex;
    align-items:center;
    gap:6px;
    background:transparent;
    border:none;
    font-family:inherit;
    font-size: 0.92rem;
    color: #cfe3f5;
    cursor:pointer;
    padding:0 0 2px 0;
    border-bottom: 1px solid transparent;
  }

  .dropdown-toggle:hover,
  .dropdown-toggle:focus-visible,
  .nav-item:hover > .dropdown-toggle,
  .nav-item.open > .dropdown-toggle{
    border-bottom-color: var(--gold);
    color: var(--paper);
  }

  .dropdown-toggle .chevron{
    width: 10px;
    height: 10px;
    stroke: currentColor;
    transition: transform 0.15s ease;
  }

  .nav-item:hover > .dropdown-toggle .chevron,
  .nav-item.open > .dropdown-toggle .chevron{
    transform: rotate(180deg);
  }

  .dropdown-menu{
    display:none;
    position:absolute;
    top: 100%;
    /* right-aligned to the Subject button rather than left-aligned:
       Subject sits near the right edge of the nav, so a menu that
       extends rightward from it would render past the viewport edge
       and effectively be invisible. Opening leftward keeps it on screen. */
    right: 0;
    left: auto;
    /* no margin-top here on purpose: a gap between the button and the
       menu breaks :hover as the cursor crosses it, closing the flyout
       before it's reached. Spacing is added with padding-top instead,
       which stays inside the hoverable box. */
    margin-top: 0;
    min-width: 220px;
    background: var(--blueprint-deep);
    border: 1px solid rgba(142,203,238,0.25);
    border-radius: 4px;
    padding: 14px 0 6px 0;
    box-shadow: 0 12px 24px rgba(0,0,0,0.25);
  }

  .nav-item:hover > .dropdown-menu,
  .nav-item.open > .dropdown-menu{
    display:block;
  }

  .dropdown-link{
    display:flex;
    align-items:center;
    justify-content:space-between;
    gap:8px;
    width:100%;
    text-align:left;
    background:transparent;
    border:none;
    font-family:inherit;
    text-decoration:none;
    color: #cfe3f5;
    font-size: 0.9rem;
    padding: 10px 18px;
    cursor:pointer;
  }

  .dropdown-link:hover, .dropdown-link:focus-visible{
    color: var(--paper);
    background: rgba(142,203,238,0.12);
  }

  .dropdown-item{
    position: relative;
  }

  .submenu-toggle .chevron{
    width: 9px;
    height: 9px;
    stroke: currentColor;
    transform: rotate(90deg);
    transition: transform 0.15s ease;
  }

  .dropdown-item:hover > .submenu-toggle .chevron,
  .dropdown-item.open > .submenu-toggle .chevron{
    transform: rotate(0deg);
  }

  .submenu{
    display:none;
    position:absolute;
    top: -6px;
    /* opens to the left of the Astronomy row, same direction as the
       parent menu, so it stays within the viewport rather than
       extending further toward the right edge */
    right: 100%;
    left: auto;
    /* touches the dropdown-item's left edge with no horizontal gap,
       so hover doesn't drop out crossing the seam */
    margin-right: 0;
    min-width: 200px;
    background: var(--blueprint-deep);
    border: 1px solid rgba(142,203,238,0.25);
    border-radius: 4px;
    padding: 6px 0;
    box-shadow: 0 12px 24px rgba(0,0,0,0.25);
  }

  .dropdown-item:hover > .submenu,
  .dropdown-item.open > .submenu{
    display:block;
  }

  .submenu-link{
    display:block;
    text-decoration:none;
    color: #cfe3f5;
    font-size: 0.9rem;
    padding: 10px 18px;
  }

  .submenu-link:hover, .submenu-link:focus-visible{
    color: var(--paper);
    background: rgba(142,203,238,0.12);
  }

   .nav-toggle{
    display:none;
    align-items:center;
    justify-content:center;
    background:transparent;
    border:1.5px solid rgba(142,203,238,0.55);
    border-radius: 3px;
    width: 40px;
    height: 40px;
    padding: 0;
    cursor:pointer;
  }

  .nav-toggle svg{
    width: 22px;
    height: 22px;
    stroke: var(--paper);
  }

  .nav-toggle .icon-close{ display:none; }

  .nav-toggle[aria-expanded="true"] .icon-open{ display:none; }
  .nav-toggle[aria-expanded="true"] .icon-close{ display:block; }

   @media (max-width: 640px){
    .nav-links{
      display:none;
      position: absolute;
      top: 100%;
      left: 0;
      right: 0;
      flex-direction: column;
      gap: 0;
      background: var(--blueprint-deep);
      border-top: 1px solid rgba(142,203,238,0.25);
    }

    .nav-links.open{ display:flex; }

    .nav-links a{
      padding: 16px 32px;
      border-bottom: 1px solid rgba(142,203,238,0.15);
    }

    .nav-toggle{ display:flex; }

    /* Dropdown becomes an inline accordion on mobile */
    .dropdown-toggle{
      width:100%;
      justify-content:space-between;
      padding: 16px 32px;
      border-bottom: 1px solid rgba(142,203,238,0.15);
      font-size: inherit;
    }

    .dropdown-menu{
      display:none;
      position:static;
      margin-top:0;
      min-width:0;
      background: rgba(0,0,0,0.15);
      border:none;
      border-radius:0;
      padding:0;
      box-shadow:none;
    }

    .nav-item:hover > .dropdown-menu{
      display:none;
    }

    .nav-item.open > .dropdown-menu{
      display:block;
    }

    .dropdown-link{
      padding: 14px 32px 14px 44px;
      border-bottom: 1px solid rgba(142,203,238,0.1);
    }

    .submenu{
      display:none;
      position:static;
      min-width:0;
      background: rgba(0,0,0,0.15);
      border:none;
      border-radius:0;
      padding:0;
      box-shadow:none;
    }

    .dropdown-item:hover > .submenu{
      display:none;
    }

    .dropdown-item.open > .submenu{
      display:block;
    }

    .submenu-link{
      padding: 12px 32px 12px 58px;
      border-bottom: 1px solid rgba(142,203,238,0.08);
    }
  }
  
  /* ---------- HERO ---------- */
  .hero{
    position: relative;
    background: var(--blueprint);
    color: var(--paper);
    overflow: hidden;
    background-image:
      linear-gradient(rgba(142,203,238,0.16) 1px, transparent 1px),
      linear-gradient(90deg, rgba(142,203,238,0.16) 1px, transparent 1px);
    background-size: 44px 44px;
    border-bottom: 6px solid var(--blueprint-deep);
  }
  
    .hero::after{
    content:"";
    position:absolute;
    inset:0;
    background: radial-gradient(ellipse at 78% 20%, rgba(217,164,65,0.16), transparent 55%),
                radial-gradient(ellipse at 10% 90%, rgba(193,68,46,0.14), transparent 50%);
    pointer-events:none;
  }
  
    .hero .wrap{
    position:relative;
    padding-top: 92px;
    padding-bottom: 96px;
    display:grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 48px;
    align-items:center;
  }
  
   @media (max-width: 860px){
    .hero .wrap{ grid-template-columns: 1fr; padding-top:64px; padding-bottom:64px; }
  }
  
  .eyebrow-tag{
    display:inline-flex;
    align-items:center;
    gap:8px;
    font-size: 0.8rem;
    color: var(--blueprint);
    background: var(--gold);
    padding: 5px 12px 5px 10px;
    border-radius: 2px;
    font-family: 'IBM Plex Sans', sans-serif;
    font-weight:600;
    margin-bottom: 22px;
  }
  
    .eyebrow-tag svg{ width:14px; height:14px; }
  
   .hero h1{
    font-size: clamp(2.4rem, 4.4vw, 3.6rem);
    max-width: 14ch;
    color: var(--paper);
  }
  
  .hero-sub{
    margin-top: 22px;
    font-size: 1.08rem;
    color: #d7e6f4;
    max-width: 46ch;
  }
  
    @media (max-width: 800px){
    .tagline{ font-size: 1.2 rem; }
  }
 
   .hero-form{
    margin-top: 34px;
    display:flex;
    gap:0;
    max-width: 420px;
    border: 1.5px solid rgba(142,203,238,0.55);
    border-radius: 3px;
    overflow:hidden;
    background: rgba(255,255,255,0.03);
  }
  
    .hero-form input{
    flex:1;
    border:none;
    background: transparent;
    padding: 14px 16px;
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.95rem;
    color: var(--paper);
    min-width: 0;
  }
  
    .hero-form input::placeholder{ color: #9db6cc; }
  .hero-form input:focus{ outline: none; background: rgba(142,203,238,0.08); }
  .hero-form button{
    border:none;
    background: var(--gold);
    color: var(--blueprint);
    font-family: 'IBM Plex Sans', sans-serif;
    font-weight:600;
    font-size: 0.95rem;
    padding: 14px 20px;
    cursor:pointer;
    transition: background 0.15s ease;
    white-space: nowrap;
  }
  .hero-form button:hover{ background: var(--rust-deep); }
  .hero-form button:focus-visible, .hero-form input:focus-visible{
    outline: 2px solid var(--gold);
    outline-offset: -2px;
  }
  
   .hero-note{
    margin-top: 12px;
    font-size: 0.82rem;
    color: #9db6cc;
  }
  
  .hero-note a{ text-decoration: underline; color: #cfe3f5; }
 
   /* orrery diagram */
  .orrery{ width: 100%; height: auto; }
  .orrery-label{
    font-family:'IBM Plex Sans', sans-serif;
    font-size: 9px;
    fill: #9db6cc;
    letter-spacing: 0.04em;
  }
  
   /* ---------- FACT OF THE DAY ---------- */
  .fact-of-day{
    background: var(--paper);
    border-bottom: 1px solid var(--paper-shadow);
  }
  .fact-of-day .wrap{
    padding-top: 64px;
    padding-bottom: 68px;
    display:grid;
    grid-template-columns: 0.62fr 1fr;
    gap: 56px;
    align-items:center;
  }
  @media (max-width: 800px){
    .fact-of-day .wrap{ grid-template-columns: 1fr; gap:28px; padding-top:48px; padding-bottom:48px; }
  }
  
    .fact-label{
    font-size: 0.82rem;
    color: var(--blueprint);
    font-weight:600;
    margin-bottom: 10px;
  }
  
   .fact-number{
    font-family:'IBM Plex Mono', monospace;
  font-style: italic;
    font-weight: 700;
    font-size: clamp(3rem, 8vw, 5.2rem);
    color: var(--gold);
    line-height: 1;
    letter-spacing: -0.01em;
  }
  
    .fact-number-caption{
    margin-top: 10px;
    font-size: 0.95rem;
    color: var(--ink-soft);
    max-width: 22ch;
  }
  
    .fact-text{
    font-family:'IBM Plex Mono', monospace;
    font-size: clamp(1.3rem, 2.4vw, 1.7rem);
    font-weight: 500;
    color: var(--ink);
    max-width: 34ch;
  }
  
    .fact-source{
    margin-top: 18px;
    font-size: 0.85rem;
    color: var(--ink-soft);
    border-left: 2px solid var(--gold);
    padding-left: 12px;
  }
  
   /* ---------- TRIVIA GRID ---------- */
  .trivia{
    background: var(--blueprint);
    padding-top: 76px;
    padding-bottom: 84px;
  }
  
.trivia-head{
    color: var(--paper);
    max-width: 52ch;
    margin-bottom: 44px;
  }
  
.trivia-head h2{
    font-size: clamp(1.7rem, 3vw, 2.3rem);
    color: var(--paper);
  }
  
.trivia-head p{
    margin-top: 14px;
    color: #b9cee2;
    font-size: 1rem;
  }
  
.card-grid{
    display:grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
  }
  
@media (max-width: 900px){
    .card-grid{ grid-template-columns: repeat(2, 1fr); }
  }
@media (max-width: 620px){
    .card-grid{ grid-template-columns: 1fr; }
  }
  
.card-grid a{
    text-decoration: none;
  }

.card{
    background: var(--paper);
    border: 1px solid var(--paper-shadow);
    border-radius: var(--radius-card);
    position: relative;
    box-shadow: 0 1px 0 rgba(0,0,0,0.04);
   transition: transform 0.3s ease;
  }
  
  .card:hover {
    transform: scale(0.96);}
  

  
.card-cat{
    font-size: 1.37rem;
    font-weight: 600;
    margin: 20px 0 20px 0;
    text-transform: uppercase;
    letter-spacing: 0.06em;
   
  }
  
.card-box {
    text-align:center;
    color:black;
  width: 100%
    padding:20px;
    margin:10px;
    border:2px solid black;
  }
  
  .card p.card-fact{
    font-size: 0.97rem;
    color: var(--ink);
    margin: 20px;
  }
  
.card-tag{
    margin-top: 16px;
    font-size: 0.78rem;
    color: var(--ink-soft);
    font-style: italic;
    font-family: 'Fraunces', serif;
  }
  
.physics{
    background: #704a21;
    color: var(--paper);
  }
  
.astronomy{
    background: #ff7f00;
  }
  
.chemistry{
    background: #ee2b2a;
  }
  
.dataVisual{
    background: #66318f;
    color: var(--paper);
  }
  
.geography{
    background: #1e5aa8;
    color: var(--paper);
  }
  
  
.mathematics{
    background: #009447;
  } 
  
  
   /* ---------- QUIZ STRIP ---------- */
.quiz{
    background: var(--paper);
    border-bottom: 1px solid var(--paper-shadow);
  }
  
.quiz .wrap{
    padding-top: 64px;
    padding-bottom: 64px;
  }
  
.quiz-card{
    border: 1.5px solid var(--blueprint);
    border-radius: 4px;
    padding: 36px 38px;
    display:grid;
    grid-template-columns: 1fr auto;
    gap: 24px;
    align-items:center;
    background: repeating-linear-gradient(0deg, transparent, transparent 27px, rgba(27,63,107,0.05) 28px);
  }
  
   @media (max-width: 700px){
    .quiz-card{ grid-template-columns: 1fr; }
  }
.quiz-eyebrow{
    font-size: 0.78rem;
    font-weight:600;
    color: var(--blueprint);
    margin-bottom:10px;
  }
  
 #quiz-question{
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--ink);
    max-width: 42ch;
  }
  #quiz-answer{
    margin-top: 12px;
    font-size: 0.94rem;
    color: var(--ink-soft);
    display:none;
  }
  
    #quiz-answer.show{ display:block; }
  .quiz-btns{
    display:flex;
    flex-direction: column;
    gap: 10px;
  }
  .btn{
    font-family: 'IBM Plex Sans', sans-serif;
    font-weight: 600;
    font-size: 0.9rem;
    padding: 12px 20px;
    border-radius: 3px;
    border: none;
    cursor: pointer;
    text-align:center;
    white-space:nowrap;
  }
  .btn-primary{
    background: var(--gold);
    color: var(--paper);
  }
  .btn-primary:hover{ background: var(--rust); }
  .btn-ghost{
    background: transparent;
    color: var(--blueprint);
    border: 1.5px solid var(--blueprint);
  }
  .btn-ghost:hover{ background: rgba(27,63,107,0.06); }
  .btn:focus-visible{ outline: 2px solid var(--gold); outline-offset: 2px; }
  
   /* ---------- CTA BANNER ---------- */
   
   .cta-caption{
     color: var(--ink);
   }
   
  .cta-banner{
    background: var(--gold);
    color: var(--ink);
  }
  
   .cta-banner .wrap{
    padding-top: 68px;
    padding-bottom: 68px;
    display:grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 40px;
    align-items:center;
  }
  @media (max-width: 760px){
    .cta-banner .wrap{ grid-template-columns: 1fr; }
  }
  .cta-banner h2{
    color: var(--ink);
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    max-width: 16ch;
  }
  .cta-banner p{
    margin-top: 14px;
    color: var(--ink);
    max-width: 40ch;
  }
  .cta-form{
    display:flex;
    max-width: 420px;
    margin-left:auto;
    border: 1.5px solid rgba(255,255,255,0.55);
    border-radius: 3px;
    overflow: hidden;
  }
  @media (max-width: 760px){ .cta-form{ margin-left:0; } }
  .cta-form input{
    flex:1;
    border:none;
    background: rgba(255,255,255,0.06);
    padding: 14px 16px;
    color: var(--ink);
    font-family:'IBM Plex Sans', sans-serif;
    font-size: 0.95rem;
    min-width: 0;
  }
  .cta-form input::placeholder{ color: (--ink); }
  .cta-form button{
    border:none;
    background: var(--blueprint);
    color: var(--paper);
    font-weight: 600;
    padding: 14px 20px;
    cursor:pointer;
    font-family:'IBM Plex Sans', sans-serif;
  }
  .cta-form button:hover{ background: var(--blueprint-deep); }

  /* ---------- FOOTER ---------- */
  footer{
    background: var(--blueprint-deep);
    color: #8ea6bf;
  }
  footer .wrap{
    padding-top: 36px;
    padding-bottom: 36px;
    display:flex;
    justify-content: space-between;
    align-items:center;
    flex-wrap: wrap;
    gap: 16px;
    font-size: 0.85rem;
  }
  footer a{ text-decoration:none; color:#b9cee2; }
  footer a:hover{ color: var(--paper); }
  .footer-links{ display:flex; gap:20px; }

  .sr-only{
    position:absolute; width:1px; height:1px; padding:0; margin:-1px;
    overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0;
  }