/* ============================================================
   CHEMwithSS — Public Site Design System
   Subject: one instructor's results-driven A/L Chemistry class
   Palette: deep navy + light green glow + warm gold accent
   Style direction: dark futuristic / cyberpunk dashboard,
   sci-fi HUD elements, glowing gradients, premium card UI
   Type: Fraunces (display) / Plus Jakarta Sans (body) / Fira Code (data)
   Signature: molecular bond-line dividers + "Paper Trail" results strip
============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,400;0,9..144,500;0,9..144,600;0,9..144,700;1,9..144,500&family=Plus+Jakarta+Sans:ital,wght@0,400;0,500;0,600;0,700;0,800;1,500&family=Fira+Code:wght@400;500;600&display=swap');

:root{
  /* Color tokens — DARK NAVY + LIGHT GREEN THEME */
  --bg:           #0a0e1a;   /* deep navy-black, primary background */
  --bg-soft:      #0f1424;   /* slightly lifted navy, alt sections */
  --panel:        #141a2e;   /* card / panel surface (navy) */
  --panel-light:  #252e4d;   /* border / divider on navy */
  --paper:        #e8ecf5;   /* cool white — primary text color on dark bg */
  --paper-dim:    #8891ab;   /* muted secondary text on dark */
  --ink:          #141a2e;   /* text on light/white cards */
  --ink-soft:     #5a6280;   /* secondary text on light/white cards */
  --gold:         #4ee08a;   /* PRIMARY ACTION COLOR -- now light green (var name "gold" kept so existing .btn-gold etc keep working without a site-wide rename) */
  --gold-dim:     #3bc575;
  --green-bright: #4ee08a;   /* light green accent — glows, success, badges */
  --green-glow:   #6dffa8;   /* brighter glow variant for shadows */
  --cyan-accent:  #38bdf8;   /* numbered-badge / active-card accent, matches reference image */
  --accent-purple:#7c6ef0;   /* secondary accent — icon badges (matches reference UI) */
  --red-soft:     #ef6f5e;   /* error, on dark bg needs to be brighter to read */
  --line:         rgba(232,236,245,.10);     /* hairline on dark bg */
  --line-onlight: rgba(20,26,46,.10);        /* hairline on light/white cards */

  --font-display: 'Fraunces', Georgia, serif;
  --font-body: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'Fira Code', 'Courier New', monospace;

  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --shadow-card: 0 18px 50px -14px rgba(0,0,0,.55);
  --glow-soft: 0 0 0 rgba(78,224,138,0);
  --glow-gold: 0 0 28px -4px rgba(78,224,138,.55);
  --glow-green: 0 0 28px -4px rgba(78,224,138,.5);
  --glow-purple: 0 0 28px -4px rgba(124,110,240,.5);
  --glow-cyan: 0 0 32px -4px rgba(56,189,248,.5);
  --container: 1180px;
  --transition-fast: .18s cubic-bezier(.4,0,.2,1);
  --transition-med: .32s cubic-bezier(.4,0,.2,1);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font-body);
  background:var(--bg);
  color:var(--paper);
  line-height:1.6;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:none;background:none}
ul{list-style:none}
input,textarea,select{font-family:inherit;font-size:1rem}

@media (prefers-reduced-motion: reduce){
  *{animation-duration:0.001ms !important;animation-iteration-count:1 !important;transition-duration:0.001ms !important;scroll-behavior:auto !important;}
}

/* ---------- Layout helpers ---------- */
.wrap{max-width:var(--container);margin:0 auto;padding:0 24px}
.section{padding:88px 0}
.section-tight{padding:56px 0}
@media (max-width:720px){
  .section{padding:60px 0}
  .section-tight{padding:40px 0}
  .wrap{padding:0 20px}
  body{font-size:14.5px}
  h3{font-size:1.15rem}
  h4{font-size:1.02rem}
  .lede{font-size:1rem}
  p{font-size:.92rem}
  .btn{padding:11px 22px;font-size:.85rem}
  .eyebrow{font-size:.66rem}
  .kicker{font-size:.7rem}
}
@media (max-width:480px){
  body{font-size:13.5px}
  h1{font-size:clamp(1.9rem,7vw,2.6rem)}
  h2{font-size:clamp(1.5rem,5.5vw,1.9rem)}
  h3{font-size:1.05rem}
  .lede{font-size:.92rem}
  .btn{padding:10px 18px;font-size:.8rem}
}

.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:.72rem;font-weight:500;
  letter-spacing:.12em;text-transform:uppercase;color:var(--gold);
  margin-bottom:14px;
}
.eyebrow::before{content:'';width:6px;height:6px;border-radius:50%;background:var(--gold);flex-shrink:0}

h1,h2,h3,h4{font-family:var(--font-display);font-weight:600;letter-spacing:-.01em;line-height:1.12;color:var(--paper)}
.on-light h1,.on-light h2,.on-light h3,.on-light h4{color:var(--ink)}

h1{font-size:clamp(2.4rem,5.2vw,4.2rem);font-weight:600}
h2{font-size:clamp(1.9rem,3.4vw,2.7rem)}
h3{font-size:1.35rem}
p{color:var(--paper-dim)}
.on-light p{color:var(--ink-soft)}
.lede{font-size:1.15rem;line-height:1.65;max-width:640px}

.text-accent{color:var(--gold)}
.text-green{color:var(--green-bright)}

/* ---------- Molecular bond-line divider (signature motif) ---------- */
.bond-divider{
  display:flex;align-items:center;justify-content:center;gap:0;
  margin:0 auto;max-width:100%;height:28px;opacity:.55;
}
.bond-divider svg{width:100%;height:100%;max-width:680px}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:14px 28px;border-radius:999px;font-weight:600;font-size:.92rem;
  letter-spacing:.01em;transition:all var(--transition-fast);white-space:nowrap;
}
.btn-gold{background:var(--gold);color:#04150a;box-shadow:0 8px 22px -6px rgba(78,224,138,.45)}
.btn-gold:hover{background:#5ef09a;transform:translateY(-2px);box-shadow:var(--glow-gold)}
.btn-outline{background:transparent;color:var(--paper);border:1.5px solid var(--line)}
.btn-outline:hover{border-color:var(--gold);color:var(--gold);box-shadow:0 0 0 3px rgba(78,224,138,.08)}
.btn-outline.on-light{color:var(--ink);border-color:var(--line-onlight)}
.btn-outline.on-light:hover{border-color:var(--ink);color:var(--ink)}
.btn-whatsapp{background:#1f9d57;color:#fff;border:1px solid #1a8048}
.btn-whatsapp:hover{background:#1a8048;box-shadow:var(--glow-green);transform:translateY(-2px)}
.btn-block{width:100%}
.btn:active{transform:scale(.97)}
.btn:disabled{opacity:.5;cursor:not-allowed}

/* ---------- Nav ---------- */
#siteNav{
  position:sticky;top:0;z-index:200;
  background:rgba(10,14,26,.82);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid var(--line);
}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:72px}
.nav-logo{display:flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:700;font-size:1.25rem;color:var(--paper)}
.nav-logo .mark{color:var(--gold)}
.nav-links{display:flex;align-items:center;gap:36px}
.nav-links a{font-size:.92rem;font-weight:500;color:var(--paper-dim);position:relative;padding:6px 0;transition:color var(--transition-fast)}
.nav-links a:hover,.nav-links a.active{color:var(--paper)}
.nav-links a.active::after{content:'';position:absolute;left:0;right:0;bottom:0;height:2px;background:var(--gold);box-shadow:0 0 8px rgba(78,224,138,.6)}
.nav-cta{display:flex;align-items:center;gap:14px}
.nav-login-link{font-size:.88rem;font-weight:600;color:var(--paper-dim)}
.nav-login-link:hover{color:var(--gold)}

.hamburger{display:none;flex-direction:column;gap:5px;width:26px;z-index:300}
.hamburger span{height:2px;background:var(--paper);border-radius:2px;transition:all .25s}
.mobile-menu{
  position:fixed;inset:0;background:var(--bg);z-index:250;
  display:flex;flex-direction:column;padding:100px 32px 40px;
  transform:translateX(100%);transition:transform var(--transition-med);
}
.mobile-menu.open{transform:translateX(0)}
.mobile-menu a{font-family:var(--font-display);font-size:1.7rem;padding:14px 0;border-bottom:1px solid var(--line);color:var(--paper)}
.mobile-menu .nav-cta{flex-direction:column;align-items:stretch;margin-top:24px;gap:12px}

@media (max-width:880px){
  .nav-links{display:none}
  .nav-cta .nav-login-link{display:none}
  .hamburger{display:flex}
}

/* ---------- Footer ---------- */
#siteFooter{background:var(--bg-soft);border-top:1px solid var(--line);padding:48px 0 28px}
.footer-top{display:flex;flex-wrap:wrap;gap:40px;justify-content:space-between;margin-bottom:36px}
.footer-brand{max-width:300px}
.footer-brand .nav-logo{margin-bottom:10px}
.footer-brand p{font-size:.88rem}
.footer-col h4{font-family:var(--font-body);font-size:.78rem;letter-spacing:.08em;text-transform:uppercase;color:var(--gold-dim);margin-bottom:14px;font-weight:700}
.footer-col a{display:block;font-size:.9rem;color:var(--paper-dim);margin-bottom:10px;transition:color .15s}
.footer-col a:hover{color:var(--paper)}
.footer-bottom{
  border-top:1px solid var(--line);padding-top:22px;
  display:flex;flex-wrap:wrap;gap:12px;justify-content:space-between;align-items:center;
  font-size:.8rem;color:var(--paper-dim);font-family:var(--font-mono);
}
.footer-bottom a{color:var(--gold-dim);transition:color .15s}
.footer-bottom a:hover{color:var(--gold)}
.social-row{display:flex;gap:14px}
.social-row a{width:34px;height:34px;border-radius:50%;border:1px solid var(--line);display:flex;align-items:center;justify-content:center;transition:all .15s}
.social-row a:hover{border-color:var(--gold);color:var(--gold)}

/* ---------- Cards ---------- */
.card-onpaper{background:#ffffff;color:var(--ink);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);border:1px solid var(--line)}
.card-panel{background:var(--panel);border:1px solid var(--panel-light);border-radius:var(--radius);padding:28px;transition:box-shadow var(--transition-fast),transform var(--transition-fast)}
.card-panel:hover{box-shadow:0 12px 32px -10px rgba(31,157,87,.18);transform:translateY(-2px)}

/* ---------- Stat badges (trust strip) ---------- */
.trust-badges{display:flex;flex-wrap:wrap;gap:10px}
.trust-badge{
  display:inline-flex;align-items:center;gap:7px;
  padding:8px 16px;border-radius:999px;font-size:.82rem;font-weight:600;
  border:1px solid;
}
.tb-check{background:rgba(31,157,87,.08);border-color:rgba(31,157,87,.3);color:var(--green-bright)}
.tb-star{background:rgba(56,189,248,.08);border-color:rgba(56,189,248,.3);color:var(--cyan-accent)}
.tb-trophy{background:rgba(31,157,87,.08);border-color:rgba(31,157,87,.3);color:var(--green-bright)}

/* ---------- Paper Trail strip (signature element) ---------- */
.paper-trail{overflow:hidden;position:relative;-webkit-mask-image:linear-gradient(90deg,transparent,#000 6%,#000 94%,transparent);mask-image:linear-gradient(90deg,transparent,#000 6%,#000 94%,transparent)}
.paper-trail-track{display:flex;gap:18px;width:max-content;animation:trailScroll 38s linear infinite}
.paper-trail:hover .paper-trail-track{animation-play-state:paused}
@keyframes trailScroll{from{transform:translateX(0)}to{transform:translateX(-50%)}}
.paper-chip{
  flex-shrink:0;width:220px;border-radius:var(--radius);overflow:hidden;
  background:var(--panel);border:1px solid var(--panel-light);transition:box-shadow var(--transition-fast),transform var(--transition-fast);
}
.paper-chip:hover{transform:translateY(-3px);box-shadow:var(--glow-gold)}
.paper-chip-head{
  background:linear-gradient(135deg,#3bc575,#1f9d57);
  color:#04150a;padding:16px 16px 14px;position:relative;
}
.paper-chip-num{
  position:absolute;top:10px;right:12px;font-family:var(--font-mono);
  font-size:.68rem;font-weight:700;background:#04150a;color:#6dffa8;
  padding:2px 8px;border-radius:6px;
}
.paper-chip-head .pc-label{font-family:var(--font-mono);font-size:.62rem;letter-spacing:.1em;text-transform:uppercase;opacity:.8}
.paper-chip-head .pc-title{font-family:var(--font-display);font-size:1.05rem;font-weight:700;margin-top:4px}
.paper-chip-body{padding:13px 16px 16px}
.paper-chip-body .pc-meta{font-size:.74rem;color:var(--paper-dim);font-family:var(--font-mono)}
.paper-chip-body .pc-grade{display:inline-flex;align-items:center;gap:6px;margin-top:8px;font-size:.8rem;font-weight:700;color:var(--green-bright)}

/* ---------- Stats counter ---------- */
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
@media (max-width:760px){.stats-grid{grid-template-columns:repeat(2,1fr)}}
.stat-item{text-align:center}
.stat-num{font-family:var(--font-display);font-size:clamp(2.2rem,4vw,3.2rem);font-weight:700;color:var(--gold);line-height:1;text-shadow:0 0 24px rgba(78,224,138,.35)}
.stat-label{font-size:.82rem;color:var(--paper-dim);margin-top:6px;font-weight:500}

/* ---------- Grid layouts ---------- */
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
@media (max-width:880px){
  .grid-2{grid-template-columns:1fr;gap:36px}
  .grid-3{grid-template-columns:1fr}
}

/* ---------- Forms ---------- */
.form-field{margin-bottom:18px}
.form-field label{display:block;font-size:.84rem;font-weight:600;margin-bottom:7px;color:var(--ink)}
.form-field input,.form-field textarea,.form-field select{
  width:100%;padding:13px 16px;border-radius:var(--radius-sm);
  border:1.5px solid var(--line-onlight);background:#fff;color:var(--ink);
  transition:border-color var(--transition-fast),box-shadow var(--transition-fast);
}
.form-field input:focus,.form-field textarea:focus,.form-field select:focus{outline:none;border-color:var(--gold-dim);box-shadow:0 0 0 3px rgba(78,224,138,.12)}
.form-field textarea{resize:vertical;min-height:120px}
.field-error{font-size:.78rem;color:var(--red-soft);margin-top:6px;display:none}
.field-error.show{display:block}
.form-field.invalid input,.form-field.invalid textarea{border-color:var(--red-soft)}

/* ---------- FAQ accordion ---------- */
.faq-item{border-bottom:1px solid var(--line-onlight)}
.faq-q{
  width:100%;display:flex;align-items:center;justify-content:space-between;
  padding:20px 0;font-family:var(--font-body);font-weight:600;font-size:1.02rem;
  color:var(--ink);text-align:left;
}
.faq-q .icon{flex-shrink:0;width:22px;height:22px;position:relative;transition:transform .25s}
.faq-q .icon::before,.faq-q .icon::after{content:'';position:absolute;background:var(--ink-soft);border-radius:2px}
.faq-q .icon::before{width:14px;height:2px;top:10px;left:4px}
.faq-q .icon::after{width:2px;height:14px;top:4px;left:10px;transition:opacity .2s}
.faq-item.open .faq-q .icon::after{opacity:0}
.faq-item.open .faq-q .icon{transform:rotate(180deg)}
.faq-a{max-height:0;overflow:hidden;transition:max-height .3s ease}
.faq-a p{padding-bottom:18px;max-width:680px}

/* ---------- Back to top ---------- */
#backToTop{
  position:fixed;bottom:26px;right:26px;width:46px;height:46px;border-radius:50%;
  background:var(--gold);color:#04150a;display:flex;align-items:center;justify-content:center;
  box-shadow:0 8px 22px -6px rgba(78,224,138,.5);opacity:0;pointer-events:none;
  transition:opacity .25s,transform var(--transition-fast),box-shadow var(--transition-fast);z-index:150;
}
#backToTop.show{opacity:1;pointer-events:auto}
#backToTop:hover{transform:translateY(-3px);box-shadow:var(--glow-gold)}

/* ---------- Scroll fade-in ---------- */
.fade-up{opacity:0;transform:translateY(22px);transition:opacity .6s ease,transform .6s ease}
.fade-up.visible{opacity:1;transform:none}

/* ---------- Page hero shared ---------- */
.page-hero{padding:64px 0 48px;border-bottom:1px solid var(--line)}
.page-hero .eyebrow{margin-bottom:12px}
.page-hero p.lede{margin-top:14px}

/* ---------- Breadcrumb-ish small label ---------- */
.kicker{font-family:var(--font-mono);font-size:.75rem;color:var(--paper-dim);letter-spacing:.05em}

/* ---------- Toast (contact form success) ---------- */
.form-success{
  display:none;background:rgba(31,157,87,.08);border:1px solid rgba(31,157,87,.3);
  border-radius:var(--radius);padding:18px 20px;color:var(--ink);align-items:flex-start;gap:12px;
}
.form-success.show{display:flex}
.form-success .ic{flex-shrink:0;width:24px;height:24px;border-radius:50%;background:var(--green-bright);color:#fff;display:flex;align-items:center;justify-content:center;font-size:.8rem;font-weight:700}

/* ---------- Glow & transition utilities (shared across whole site) ---------- */
.glow-on-hover{transition:box-shadow var(--transition-fast),transform var(--transition-fast)}
.glow-on-hover:hover{box-shadow:var(--glow-green);transform:translateY(-2px)}
.pulse-dot-green{display:inline-block;width:7px;height:7px;border-radius:50%;background:var(--green-bright);box-shadow:0 0 0 0 rgba(31,157,87,.6);animation:pulseRing 1.8s ease-out infinite}
@keyframes pulseRing{0%{box-shadow:0 0 0 0 rgba(31,157,87,.55)}70%{box-shadow:0 0 0 8px rgba(31,157,87,0)}100%{box-shadow:0 0 0 0 rgba(31,157,87,0)}}

/* ---------- Numbered card badge + active/featured card glow ----------
   Matches the reference design: a small "01/02/03" cyan number above
   the card title, with the first/active card getting a persistent
   green glow border instead of only a hover effect. Reusable anywhere
   a numbered card grid is needed (e.g. resource tiers, step lists). */
.numbered-card{
  background:var(--panel);border:1.5px solid var(--panel-light);border-radius:var(--radius-lg);
  padding:28px 26px;position:relative;transition:border-color var(--transition-fast),box-shadow var(--transition-fast),transform var(--transition-fast);
}
.numbered-card:hover{transform:translateY(-3px);box-shadow:0 0 30px -8px rgba(78,224,138,.35)}
.numbered-card.active{
  border-color:var(--cyan-accent);
  box-shadow:var(--glow-cyan),0 0 60px -20px rgba(56,189,248,.4) inset;
  background:linear-gradient(160deg,rgba(56,189,248,.06),var(--panel) 60%);
}
.numbered-card .nc-num{
  font-family:var(--font-mono);font-size:.82rem;font-weight:700;
  color:var(--cyan-accent);letter-spacing:.04em;margin-bottom:10px;display:block;
}
.numbered-card .nc-title{font-size:1.3rem;font-weight:700;color:var(--paper);margin-bottom:10px}
.numbered-card .nc-desc{font-size:.88rem;color:var(--paper-dim);line-height:1.55;margin-bottom:18px}
.numbered-card .nc-pill{
  display:inline-flex;align-items:center;gap:6px;font-size:.76rem;font-weight:600;
  padding:6px 14px;border-radius:999px;background:rgba(78,224,138,.1);
  border:1px solid rgba(78,224,138,.3);color:var(--green-bright);
}
.numbered-card .nc-pill.cyan{background:rgba(56,189,248,.1);border-color:rgba(56,189,248,.3);color:var(--cyan-accent)}
.numbered-card .nc-pill.muted{background:rgba(136,145,171,.08);border-color:var(--line);color:var(--paper-dim)}