/* =====================================================================
   PEPTIDE REFERENCE — informational site.
   Design tokens, type scale, spacing, buttons, nav, footer and card styles
   are inherited from Subtle Science's "outdoor / aurora" theme so the two
   sites read as one family. Commerce styles were intentionally left out.
   ===================================================================== */

:root {
  --bg:        #05080d;
  --bg-2:      #0a1017;
  --panel:     rgba(255, 255, 255, 0.035);
  --panel-2:   rgba(255, 255, 255, 0.06);
  --border:    rgba(150, 195, 210, 0.14);
  --border-2:  rgba(150, 195, 210, 0.30);
  --text:      #eaf2f4;
  --muted:     #93a7b2;
  --aurora:    #43e08a;   /* signature green */
  --aurora-2:  #5fe6c6;   /* teal */
  --aurora-3:  #8f8bf0;   /* soft indigo, used sparingly */
  --good:      #43e08a;
  --bad:       #ff7a85;
  --warn:      #ffcf6b;

  --r:    16px;
  --r-sm: 11px;
  --maxw: 1180px;

  --s1: 8px; --s2: 16px; --s3: 24px; --s4: 32px; --s5: 48px; --s6: 64px; --s7: 96px;

  --shadow: 0 24px 60px -30px rgba(0, 0, 0, 0.9);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "Jost", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
body::before {
  content: ""; position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(90% 60% at 50% -10%, rgba(67, 224, 138, 0.10), transparent 60%),
    radial-gradient(70% 50% at 85% 8%, rgba(143, 139, 240, 0.08), transparent 55%),
    linear-gradient(180deg, #060b11, #05080d 60%);
}
a { color: var(--aurora-2); text-decoration: none; }
a:hover { opacity: 0.9; }
img { max-width: 100%; display: block; }
em { font-style: normal; color: var(--aurora); }

/* ---------- Type ---------- */
h1, h2, h3, h4 { font-weight: 400; letter-spacing: -0.01em; line-height: 1.2; }
.eyebrow {
  display: inline-block; font-size: 0.72rem; font-weight: 500;
  letter-spacing: 0.34em; text-transform: uppercase; color: var(--aurora-2);
}
.page-title { font-size: clamp(1.9rem, 4vw, 2.6rem); letter-spacing: 0.06em; margin: 12px 0 0; }
.lede { color: var(--muted); font-size: 1.1rem; max-width: 60ch; }

/* ---------- Layout ---------- */
main { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--s3); }
section { padding: var(--s6) 0; }
.wrap-narrow { max-width: 760px; margin: 0 auto; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  padding: 14px 30px; border-radius: 999px; cursor: pointer; border: none;
  font-family: inherit; font-size: 0.82rem; font-weight: 500;
  letter-spacing: 0.16em; text-transform: uppercase; white-space: nowrap;
  transition: transform 0.2s cubic-bezier(.22,1,.36,1), box-shadow 0.2s ease, background 0.2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--aurora), var(--aurora-2)); color: #04160e;
  box-shadow: 0 14px 34px -14px rgba(67, 224, 138, 0.75);
}
.btn-primary:hover { box-shadow: 0 20px 44px -14px rgba(67, 224, 138, 0.9); color: #04160e; }
.btn-ghost { background: rgba(255, 255, 255, 0.04); color: var(--text); border: 1px solid var(--border-2); }
.btn-ghost:hover { border-color: var(--aurora); color: var(--text); background: rgba(67, 224, 138, 0.08); }
.btn-lg { padding: 17px 38px; font-size: 0.86rem; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between; gap: var(--s2);
  padding: 16px clamp(16px, 4vw, 40px);
  background: rgba(6, 10, 15, 0.72); backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand-word { font-size: 1.05rem; letter-spacing: 0.30em; text-transform: uppercase; color: var(--text); font-weight: 400; }
.brand-word b { color: var(--aurora); font-weight: 400; }
.nav-links { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; justify-content: center; }
.nav-links a {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 9px 15px; border-radius: 999px; color: var(--muted);
  font-size: 0.74rem; font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase;
  transition: color 0.18s ease, background 0.18s ease;
}
.nav-links a:hover { color: var(--text); background: rgba(255,255,255,0.05); }
.nav-links a.active { color: var(--aurora); }

/* ---------- Home ---------- */
.intro { padding: var(--s7) 0 var(--s5); border-bottom: 1px solid var(--border); }
.intro h1 { font-size: clamp(2rem, 5vw, 3.2rem); letter-spacing: 0.02em; max-width: 20ch; }
.intro .lede { margin-top: var(--s3); font-size: 1.18rem; }
.intro .cta-row { display: flex; gap: 12px; margin-top: var(--s4); flex-wrap: wrap; }

.section-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--s3); padding: var(--s6) 0; }
.section-card {
  display: block; background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--r); padding: var(--s4); color: var(--text);
  transition: border-color 0.2s ease, transform 0.2s ease, background 0.2s ease;
}
.section-card:hover { border-color: var(--border-2); transform: translateY(-3px); background: var(--panel-2); opacity: 1; }
.section-card .num { font-size: 0.72rem; letter-spacing: 0.2em; color: var(--aurora); text-transform: uppercase; }
.section-card h3 { font-size: 1.4rem; margin: 10px 0 8px; }
.section-card p { color: var(--muted); font-size: 0.98rem; }
.section-card .go { margin-top: var(--s2); color: var(--aurora-2); font-size: 0.8rem; letter-spacing: 0.12em; text-transform: uppercase; }

/* ---------- Article + sidebar TOC ---------- */
.article-head { padding: var(--s6) 0 var(--s4); border-bottom: 1px solid var(--border); }
.article-layout { display: grid; grid-template-columns: 220px 1fr; gap: var(--s6); padding: var(--s5) 0 var(--s7); align-items: start; }
.toc { position: sticky; top: 92px; font-size: 0.86rem; }
.toc-title { font-size: 0.68rem; letter-spacing: 0.2em; text-transform: uppercase; color: var(--muted); margin-bottom: var(--s2); }
.toc a { display: block; color: var(--muted); padding: 6px 0; border-left: 1px solid var(--border); padding-left: 14px; margin-left: -1px; transition: color 0.15s ease, border-color 0.15s ease; }
.toc a:hover, .toc a.active { color: var(--aurora); border-color: var(--aurora); opacity: 1; }

.prose { max-width: 68ch; }
.prose h2 { font-size: 1.5rem; letter-spacing: 0.02em; margin: var(--s6) 0 var(--s2); scroll-margin-top: 90px; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 1.12rem; color: var(--aurora-2); margin: var(--s4) 0 var(--s1); }
.prose p { color: #d3dee2; margin-bottom: var(--s2); }
.prose ul, .prose ol { color: #d3dee2; margin: 0 0 var(--s2) 1.2em; }
.prose li { margin-bottom: 8px; }
.prose strong { color: var(--text); font-weight: 500; }
.prose a { text-decoration: underline; text-underline-offset: 3px; }

/* Step list for the walkthrough */
.steps { list-style: none; margin: var(--s3) 0; counter-reset: step; }
.steps > li {
  position: relative; padding: var(--s3) var(--s3) var(--s3) 68px; margin-bottom: var(--s2);
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--r); counter-increment: step;
}
.steps > li::before {
  content: counter(step); position: absolute; left: var(--s3); top: var(--s3);
  width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  background: rgba(67,224,138,0.14); color: var(--aurora); border: 1px solid rgba(67,224,138,0.4);
  font-size: 0.9rem;
}
.steps h3 { margin: 0 0 4px; color: var(--text); font-size: 1.1rem; }
.steps p { margin: 0; color: var(--muted); }

/* ---------- Interactive stepper (replaces the wordy step list) ---------- */
.stepper { max-width: 720px; margin: var(--s4) 0 var(--s5); }
.stepper-rail { position: relative; display: flex; justify-content: space-between; margin: 0 6px var(--s4); }
.stepper-rail::before { content: ""; position: absolute; left: 19px; right: 19px; top: 19px; height: 2px; background: var(--border); }
.rail-fill { position: absolute; left: 19px; top: 19px; height: 2px; width: 0; background: linear-gradient(90deg, var(--aurora), var(--aurora-2)); transition: width 0.45s cubic-bezier(.22,1,.36,1); }
.step-dot {
  position: relative; z-index: 1; width: 38px; height: 38px; border-radius: 50%;
  border: 1px solid var(--border-2); background: var(--bg-2); color: var(--muted);
  cursor: pointer; font-family: inherit; font-size: 0.9rem;
  display: grid; place-items: center; transition: transform 0.25s ease, color 0.25s ease, border-color 0.25s ease, background 0.25s ease, box-shadow 0.25s ease;
}
.step-dot:hover { transform: translateY(-2px); }
.step-dot.active { border-color: var(--aurora); color: var(--aurora); box-shadow: 0 0 0 4px rgba(67,224,138,0.12); }
.step-dot.done { background: var(--aurora); color: #04160e; border-color: var(--aurora); }

.stepper-stage { background: var(--panel); border: 1px solid var(--border); border-radius: var(--r); padding: var(--s5); }
.step-panel { display: grid; grid-template-columns: 190px 1fr; gap: var(--s4); align-items: center; }
.step-panel[hidden] { display: none; }
.step-visual svg { width: 100%; height: auto; }
.step-copy .step-tag { font-size: 0.68rem; letter-spacing: 0.2em; text-transform: uppercase; color: var(--aurora); }
.step-copy h3 { font-size: 1.35rem; margin: 8px 0 8px; color: var(--text); }
.step-copy p { color: var(--muted); margin: 0; font-size: 1rem; }
.stepper-nav { display: flex; align-items: center; justify-content: space-between; gap: var(--s2); margin-top: var(--s3); }
.step-count { color: var(--muted); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; }
.stepper-nav .btn { padding: 11px 22px; font-size: 0.74rem; }
.stepper-nav .btn:disabled { opacity: 0.35; cursor: not-allowed; transform: none; }

@media (prefers-reduced-motion: no-preference) {
  .step-panel.step-anim { animation: stepIn 0.45s cubic-bezier(.22,1,.36,1); }
  .step-visual .spin-slow { transform-box: fill-box; transform-origin: center; animation: spinSlow 6s linear infinite; }
  .step-visual .drip { animation: drip 2.4s ease-in-out infinite; }
}
@keyframes stepIn { from { opacity: 0; transform: translateX(18px); } to { opacity: 1; transform: none; } }
@keyframes spinSlow { to { transform: rotate(360deg); } }
@keyframes drip { 0%,100% { transform: translateY(0); opacity: 0.4; } 50% { transform: translateY(6px); opacity: 1; } }

@media (max-width: 560px) {
  .step-panel { grid-template-columns: 1fr; text-align: center; }
  .step-visual { max-width: 150px; margin: 0 auto; }
}

/* Callout / note box */
.note {
  border: 1px solid var(--border-2); border-left: 3px solid var(--aurora);
  background: rgba(67,224,138,0.05); border-radius: var(--r-sm);
  padding: var(--s2) var(--s3); margin: var(--s3) 0;
}
.note.warn { border-left-color: var(--warn); background: rgba(255,207,107,0.06); }
.note .note-label { font-size: 0.68rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--aurora); margin-bottom: 6px; }
.note.warn .note-label { color: var(--warn); }
.note p { margin: 0; color: #d3dee2; }

/* Reference table */
.table-wrap { overflow-x: auto; margin: var(--s3) 0; border: 1px solid var(--border); border-radius: var(--r-sm); }
table { width: 100%; border-collapse: collapse; font-size: 0.94rem; min-width: 460px; }
th, td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--border); }
th { font-weight: 500; color: var(--aurora-2); font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; }
tr:last-child td { border-bottom: none; }
td:first-child { color: var(--text); }

/* ---------- Glossary ---------- */
.glossary { display: grid; gap: var(--s2); max-width: 820px; padding: var(--s5) 0 var(--s7); }
.gloss-item { background: var(--panel); border: 1px solid var(--border); border-radius: var(--r); padding: var(--s3) var(--s4); scroll-margin-top: 90px; }
.gloss-item dt { font-size: 1.15rem; color: var(--aurora); margin-bottom: 6px; }
.gloss-item dd { color: #d3dee2; margin: 0; }
.gloss-jump { display: flex; flex-wrap: wrap; gap: 8px; margin: var(--s3) 0 0; }
.gloss-jump a { font-size: 0.8rem; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border-2); color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; }
.gloss-jump a:hover { color: var(--aurora); border-color: var(--aurora); opacity: 1; }

/* ---------- Calculator ---------- */
.calc-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s4); max-width: 940px; margin: var(--s5) auto 0; align-items: start; }
.calc-inputs { display: flex; flex-direction: column; gap: var(--s2); background: var(--panel); border: 1px solid var(--border); border-radius: var(--r); padding: var(--s4); }
.field { display: block; }
.field label { display: block; font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin-bottom: 6px; }
.input-unit { display: flex; align-items: center; background: rgba(5,10,15,0.6); border: 1px solid var(--border-2); border-radius: var(--r-sm); overflow: hidden; }
.input-unit input { flex: 1; background: none; border: none; color: var(--text); font: inherit; padding: 12px 14px; }
.input-unit input:focus { outline: none; }
.input-unit .unit { padding: 0 14px; color: var(--muted); font-size: 0.85rem; letter-spacing: 0.1em; }
.input-unit:focus-within { border-color: var(--aurora); box-shadow: 0 0 0 3px rgba(67,224,138,0.16); }
.calc-inputs select { width: 100%; border: 1px solid var(--border-2); border-radius: var(--r-sm); background: rgba(5,10,15,0.6); color: var(--text); font: inherit; padding: 12px 14px; }
.calc-inputs select:focus { outline: none; border-color: var(--aurora); }

.calc-results { background: var(--panel); border: 1px solid var(--border); border-radius: var(--r); padding: var(--s4); text-align: center; }
.result-main { padding-bottom: var(--s2); border-bottom: 1px solid var(--border); }
.result-label { display: block; font-size: 0.72rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted); }
.result-value { display: block; font-size: 3rem; color: var(--aurora); line-height: 1.1; margin: 4px 0; }
.result-unit { display: block; font-size: 0.8rem; color: var(--muted); }
.result-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 10px; margin-top: var(--s2); }
.result-cell { padding: 12px 8px; }
.rc-label { display: block; font-size: 0.66rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); margin-bottom: 4px; }
.rc-value { display: block; font-size: 1.05rem; }
.result-note { margin-top: var(--s2); font-size: 0.85rem; color: var(--muted); min-height: 1.2em; }
.result-note.warn { color: var(--warn); }
.result-note.error { color: var(--bad); }

/* Syringe graphic */
.syringe-box { grid-column: 1 / -1; margin-top: var(--s2); background: var(--panel); border: 1px solid var(--border); border-radius: var(--r); padding: var(--s4); }
.syringe-box .syr-caption { font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); margin-bottom: var(--s2); text-align: center; }
.syringe svg { width: 100%; height: auto; }

/* ---------- Footer / disclaimer ---------- */
.ruo-line { color: var(--muted); font-size: 0.82rem; font-style: italic; text-align: center; margin-top: var(--s5); }
.disclaimer { max-width: 820px; margin: 0 auto; text-align: center; padding: 0 var(--s3); }
.disclaimer h3 { font-size: 0.8rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted); margin-bottom: 10px; }
.disclaimer p { color: var(--muted); font-size: 0.88rem; }
.footer { max-width: var(--maxw); margin: 0 auto; padding: var(--s5) var(--s3) var(--s6); border-top: 1px solid var(--border); text-align: center; display: flex; flex-direction: column; align-items: center; gap: var(--s2); }
.footer-word { font-size: 1rem; letter-spacing: 0.32em; text-transform: uppercase; }
.footer-word b { color: var(--aurora); font-weight: 400; }
.footer p { color: var(--muted); font-size: 0.9rem; }
.footer-fine { color: var(--muted); font-size: 0.78rem; letter-spacing: 0.06em; }

/* =====================================================================
   MOTION LAYER — programmatic transitions & animations.
   All guarded by prefers-reduced-motion so it never fights accessibility.
   ===================================================================== */

/* Cross-document page transitions (Chromium): a soft crossfade on navigation. */
@view-transition { navigation: auto; }

/* Slow-drifting aurora wash behind everything (replaces the static one). */
@media (prefers-reduced-motion: no-preference) {
  body::before { animation: auroraDrift 24s ease-in-out infinite alternate; }
}
@keyframes auroraDrift {
  0%   { transform: translate3d(0, 0, 0) scale(1); }
  100% { transform: translate3d(-3%, 2%, 0) scale(1.08); }
}

/* Second, brighter aurora ribbon that breathes across the top. */
body::after {
  content: ""; position: fixed; inset: -20% 0 auto 0; height: 60vh; z-index: -1; pointer-events: none;
  background: radial-gradient(60% 100% at 20% 0%, rgba(67,224,138,0.10), transparent 60%),
              radial-gradient(50% 100% at 80% 0%, rgba(95,230,198,0.09), transparent 60%);
  opacity: 0.9;
}
@media (prefers-reduced-motion: no-preference) {
  body::after { animation: ribbon 18s ease-in-out infinite alternate; }
}
@keyframes ribbon {
  0%   { transform: translateX(-4%); opacity: 0.55; }
  100% { transform: translateX(4%);  opacity: 1; }
}

/* Scroll progress bar (top of viewport). Width set by JS via --scroll. */
.scroll-progress {
  position: fixed; top: 0; left: 0; height: 2px; z-index: 80;
  width: var(--scroll, 0%);
  background: linear-gradient(90deg, var(--aurora), var(--aurora-2));
  box-shadow: 0 0 12px rgba(67,224,138,0.6);
  transition: width 0.1s linear;
}

/* Scroll-reveal: elements start hidden (only when JS + motion are on). */
@media (prefers-reduced-motion: no-preference) {
  html.anim .section-card,
  html.anim .steps > li,
  html.anim .gloss-item,
  html.anim .prose > h2,
  html.anim .prose > h3,
  html.anim .note,
  html.anim .table-wrap,
  html.anim .calc-inputs,
  html.anim .calc-results,
  html.anim .syringe-box,
  html.anim .intro > *,
  html.anim .article-head > * {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.7s cubic-bezier(.22,1,.36,1), transform 0.7s cubic-bezier(.22,1,.36,1);
    will-change: opacity, transform;
  }
  html.anim .reveal-in { opacity: 1 !important; transform: none !important; }
}

/* Intro headline: a gentle staggered lift on load. */
@media (prefers-reduced-motion: no-preference) {
  html.anim .intro > *  { transition-delay: calc(var(--i, 0) * 90ms); }
  html.anim .article-head > * { transition-delay: calc(var(--i, 0) * 70ms); }
}

/* Buttons: gl/subtle press + shimmer on the primary. */
.btn-primary { position: relative; overflow: hidden; }
.btn-primary::after {
  content: ""; position: absolute; inset: 0; transform: translateX(-120%);
  background: linear-gradient(110deg, transparent 30%, rgba(255,255,255,0.35) 50%, transparent 70%);
}
@media (prefers-reduced-motion: no-preference) {
  .btn-primary:hover::after { animation: shimmer 0.9s ease; }
}
@keyframes shimmer { to { transform: translateX(120%); } }
.btn:active { transform: translateY(0) scale(0.98); }

/* Section cards: moving sheen + lifting accent line on hover. */
.section-card { position: relative; overflow: hidden; }
.section-card::before {
  content: ""; position: absolute; left: 0; top: 0; height: 2px; width: 0;
  background: linear-gradient(90deg, var(--aurora), var(--aurora-2));
  transition: width 0.4s cubic-bezier(.22,1,.36,1);
}
.section-card:hover::before { width: 100%; }
.section-card .go { display: inline-block; transition: transform 0.25s ease; }
.section-card:hover .go { transform: translateX(6px); }

/* Nav link underline grows from center. */
.nav-links a { position: relative; }
.nav-links a::after {
  content: ""; position: absolute; left: 50%; right: 50%; bottom: 4px; height: 1.5px;
  background: var(--aurora); transition: left 0.22s ease, right 0.22s ease;
}
.nav-links a:hover::after, .nav-links a.active::after { left: 14px; right: 14px; }

/* Calculator: animate the syringe fill + the big number. */
.result-value { transition: color 0.3s ease; }
.result-value.pulse { animation: pop 0.4s cubic-bezier(.22,1,.36,1); }
@keyframes pop { 0% { transform: scale(1); } 40% { transform: scale(1.12); } 100% { transform: scale(1); } }
#syringeGraphic .syr-fill { transition: width 0.55s cubic-bezier(.22,1,.36,1); }
#syringeGraphic .syr-line, #syringeGraphic .syr-line-label { transition: transform 0.55s cubic-bezier(.22,1,.36,1); }

/* TOC active link slides its marker. */
.toc a { transition: color 0.15s ease, border-color 0.15s ease, padding-left 0.2s ease; }
.toc a.active { padding-left: 18px; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; }
}

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .article-layout { grid-template-columns: 1fr; gap: var(--s3); }
  .toc { position: static; display: none; }
  .section-list { grid-template-columns: 1fr; }
  .calc-wrap { grid-template-columns: 1fr; }
  .result-row { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .nav { flex-wrap: wrap; justify-content: center; gap: 8px; padding: 12px; }
  .nav-links { width: 100%; }
  .nav-links a { padding: 7px 11px; font-size: 0.66rem; letter-spacing: 0.08em; }
}