/* ============================================================
   NerkiProsto - design system "Czysta woda / nefron"
   Paleta: gleboka zielen-butelka + medyczna zielen + blekit wody + krem
   Typografia: Lora (display) + Nunito Sans (body) + IBM Plex Mono (badania)
   ============================================================ */
:root {
  /* paleta - tryb jasny */
  --ink: #0c1a1f;
  --panel: #13262c;
  --panel-2: #1a3138;
  --accent: #127a63;
  --accent-strong: #0f5c4a;
  --accent-2: #166f8a;
  --accent-glow: rgba(18, 122, 99, 0.35);
  --paper: #f4f1e8;
  --paper-2: #e9e4d6;
  --paper-3: #ddd6c4;
  --text: #1a2420;
  --text-dim: #4c5a54;
  --mono: #166f8a;
  --border: rgba(12, 26, 31, 0.14);
  --header-bg: #0c1a1f;
  --card-bg: #fbf9f3;
  --shadow: 0 1px 2px rgba(12,26,31,.06), 0 8px 24px rgba(12,26,31,.07);
  --shadow-hover: 0 2px 4px rgba(12,26,31,.08), 0 14px 34px rgba(18,122,99,.14);
  --radius: 14px;
  --header-h: 60px;
  --sidebar-w: 300px;
  --transition: all .2s ease-out;
  --body-grad-1: rgba(18, 122, 99, 0.05);
  --body-grad-2: rgba(22, 111, 138, 0.05);
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8ece5;
    --panel: #d8ded7;
    --panel-2: #c9d2ca;
    --accent: #3fae8f;
    --accent-strong: #4db896;
    --accent-2: #1d8fa8;
    --accent-glow: rgba(63, 174, 143, 0.3);
    --paper: #0b1214;
    --paper-2: #10191c;
    --paper-3: #172226;
    --text: #e8ece5;
    --text-dim: #9fb8b0;
    --mono: #4fc3de;
    --border: rgba(232, 236, 229, 0.14);
    --header-bg: #0b1214;
    --card-bg: #0e1719;
    --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.35);
    --shadow-hover: 0 2px 4px rgba(0,0,0,.45), 0 14px 34px rgba(63,174,143,.12);
    --body-grad-1: rgba(63, 174, 143, 0.06);
    --body-grad-2: rgba(29, 143, 168, 0.06);
  }
}

/* ---------- reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; overflow-x: clip; }
body {
  font-family: 'Nunito Sans', system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.7;
  color: var(--text);
  background: var(--paper);
  background-image:
    radial-gradient(ellipse 700px 500px at -10% -5%, var(--body-grad-1), transparent 60%),
    radial-gradient(ellipse 700px 500px at 110% 105%, var(--body-grad-2), transparent 60%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { font-family: 'Lora', Georgia, serif; text-wrap: balance; line-height: 1.25; }
a { color: var(--accent-strong); text-decoration: none; }
a:hover { text-decoration: underline; }
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 300;
  background: var(--accent); color: #fff; padding: 10px 16px; border-radius: 0 0 8px 0;
  font-weight: 700;
}
.skip-link:focus { left: 0; color: #fff; }
:focus-visible { outline: 3px solid var(--accent-2); outline-offset: 2px; border-radius: 4px; }

/* ---------- header ---------- */
.app-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200;
  height: var(--header-h);
  background: var(--header-bg);
  border-bottom: 1px solid rgba(255,255,255,.07);
}
.app-header::after {
  content: ''; position: absolute; left: 0; right: 0; bottom: -1px; height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-glow), transparent);
  opacity: .5;
}
.header-inner {
  max-width: 1500px; margin: 0 auto; padding: 0 22px; height: 100%;
  display: flex; align-items: center; gap: 22px;
}
.mark { display: flex; align-items: center; gap: 9px; color: #fff; flex-shrink: 0; }
.mark:hover { text-decoration: none; }
.mark-svg { color: #fff; }
.mark-text { font-family: 'Lora', serif; font-size: 1.28rem; font-weight: 700; letter-spacing: .01em; }
.mark-text em { font-style: normal; color: var(--accent); }
.header-search { flex: 1; max-width: 460px; margin-left: auto; position: relative; }
#search-input {
  width: 100%; padding: 10px 16px; font-size: .95rem; font-family: inherit;
  border: 1px solid rgba(255,255,255,.16); border-radius: 10px;
  background: rgba(255,255,255,.07); color: #fff; outline: none;
  transition: border-color .2s, background .2s;
}
#search-input::placeholder { color: rgba(255,255,255,.55); }
#search-input:focus { border-color: var(--accent); background: rgba(255,255,255,.12); }
.search-results {
  position: absolute; top: calc(100% + 8px); left: 0; right: 0; z-index: 210;
  background: var(--card-bg); color: var(--text);
  border: 1px solid var(--border); border-radius: 12px; box-shadow: var(--shadow-hover);
  overflow: hidden; max-height: 380px; overflow-y: auto;
}
.sr-item { display: block; padding: 10px 16px; border-bottom: 1px solid var(--border); }
.sr-item:hover { background: var(--paper-2); text-decoration: none; }
.sr-title { font-weight: 700; font-size: .92rem; }
.sr-meta { font-size: .78rem; color: var(--text-dim); font-family: 'IBM Plex Mono', monospace; }
.sr-empty { padding: 12px 16px; color: var(--text-dim); font-size: .9rem; }
.burger { display: none; background: none; border: 0; cursor: pointer; padding: 8px; margin-left: auto; }
.burger span { display: block; width: 24px; height: 2.5px; background: #fff; margin: 5px 0; border-radius: 2px; transition: var(--transition); }
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* ---------- layout ---------- */
.layout { display: flex; max-width: 1500px; margin: 0 auto; padding-top: var(--header-h); min-height: calc(100vh - var(--header-h)); }
.sidebar {
  width: var(--sidebar-w); flex-shrink: 0;
  position: sticky; top: var(--header-h); height: calc(100vh - var(--header-h));
  overflow-y: auto; padding: 22px 14px 30px;
  border-right: 1px solid var(--border);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
}
.side-group { margin-bottom: 18px; }
.side-group-title {
  font-family: 'IBM Plex Mono', monospace; font-size: .7rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: .12em;
  color: var(--accent-strong); padding: 0 10px; margin-bottom: 5px;
}
.side-links { display: flex; flex-direction: column; }
.sidebar-link {
  display: flex; align-items: center; gap: 8px;
  font-size: .9rem; line-height: 1.35; color: var(--text);
  padding: 6px 10px; border-radius: 8px; border-left: 2px solid transparent;
  transition: var(--transition);
}
.sidebar-link:hover { background: var(--paper-2); text-decoration: none; color: var(--accent-strong); }
.sidebar-link.active { background: var(--paper-2); border-left-color: var(--accent); color: var(--accent-strong); font-weight: 700; }
.sl-ic { font-size: .85rem; flex-shrink: 0; }
.sidebar-foot { margin-top: 26px; padding: 14px 10px; border-top: 1px solid var(--border); }
.sidebar-foot p { font-size: .8rem; color: var(--text-dim); line-height: 1.55; }
.main { flex: 1; min-width: 0; padding: 34px 44px 60px; }
.overlay { position: fixed; inset: 0; background: rgba(0,0,0,.5); z-index: 150; }

/* ---------- home hero ---------- */
.home-hero { position: relative; padding: 38px 0 30px; margin-bottom: 34px; }
.hero-eyebrow {
  display: inline-block; font-family: 'IBM Plex Mono', monospace; font-size: .78rem;
  letter-spacing: .08em; color: var(--accent-strong); margin-bottom: 12px;
}
.home-hero h1 { font-size: clamp(2.1rem, 4.4vw, 3.3rem); font-weight: 700; letter-spacing: -.01em; }
.home-hero h1 .hl { color: var(--accent-strong); }
.hero-lead { max-width: 620px; margin-top: 14px; font-size: 1.08rem; color: var(--text-dim); }
.hero-cta { display: flex; gap: 12px; margin-top: 22px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: 10px; font-weight: 700; font-size: .98rem;
  transition: var(--transition); cursor: pointer;
}
.btn:hover { text-decoration: none; transform: translateY(-2px); }
.btn-primary { background: var(--accent); color: #fff; box-shadow: 0 4px 14px var(--accent-glow); }
.btn-primary:hover { background: var(--accent-strong); }
.btn-ghost { border: 1.5px solid var(--border); color: var(--text); background: transparent; }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent-strong); }
.hero-stats { display: flex; gap: 34px; margin-top: 28px; flex-wrap: wrap; }
.hs-num { font-family: 'Lora', serif; font-size: 1.9rem; font-weight: 700; color: var(--accent-strong); line-height: 1.1; }
.hs-label { font-size: .8rem; color: var(--text-dim); }

/* ---------- hero art: kropla / nefron (signature) ---------- */
.hero-art { margin-top: 34px; display: flex; flex-direction: column; gap: 18px; }
.droplet-wrap { max-width: 520px; }
.droplet-svg { width: 100%; height: auto; display: block; }
.droplet-svg .drop-outer { fill: none; stroke: var(--accent); stroke-width: 3; }
.droplet-svg .drop-inner { fill: none; stroke: var(--accent-2); stroke-width: 2.4; stroke-dasharray: 340; stroke-dashoffset: 340; }
.droplet-svg .drop-wave { fill: none; stroke: var(--accent); stroke-width: 2; stroke-dasharray: 130; stroke-dashoffset: 130; }
.droplet-svg .drop-drip { fill: var(--accent-2); opacity: 0; }
.droplet-svg.anim .drop-inner { animation: drawDash 2.2s ease-out forwards; }
.droplet-svg.anim .drop-wave { animation: drawDash 1.6s ease-out .9s forwards; }
.droplet-svg.anim .drop-drip { animation: dripFall 2.4s ease-in 1.4s infinite; }
@keyframes drawDash { to { stroke-dashoffset: 0; } }
@keyframes dripFall {
  0% { opacity: 0; transform: translateY(0); }
  20% { opacity: 1; }
  100% { opacity: 0; transform: translateY(26px); }
}
.spec-chips { display: flex; gap: 10px; flex-wrap: wrap; }
.spec-chip {
  font-family: 'IBM Plex Mono', monospace; font-size: .8rem;
  padding: 7px 13px; border-radius: 999px;
  border: 1px solid var(--border); background: var(--card-bg);
  color: var(--text);
}
.spec-chip b { color: var(--accent-strong); font-weight: 600; }

/* ---------- home sections / cards ---------- */
.home-section { margin-top: 44px; }
.home-section-head { display: flex; align-items: baseline; gap: 14px; margin-bottom: 16px; border-bottom: 1px solid var(--border); padding-bottom: 10px; }
.home-section-head h2 { font-size: 1.55rem; font-weight: 700; }
.sec-count { font-family: 'IBM Plex Mono', monospace; font-size: .75rem; color: var(--text-dim); }
.home-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 16px; }
.home-card {
  position: relative; display: flex; flex-direction: column; gap: 6px;
  padding: 18px 18px 16px; border-radius: var(--radius);
  background: var(--card-bg); border: 1px solid var(--border);
  box-shadow: var(--shadow); transition: var(--transition);
}
.home-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); text-decoration: none; border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.hc-icon { font-size: 1.35rem; line-height: 1; }
.hc-title { font-weight: 800; font-size: .9rem; line-height: 1.4; color: var(--text); }
.home-card:hover .hc-title { color: var(--accent-strong); }
.hc-excerpt { font-size: .85rem; color: var(--text-dim); line-height: 1.5; }
.hc-arrow { position: absolute; top: 14px; right: 16px; color: var(--accent); opacity: 0; transform: translateX(-8px); transition: var(--transition); font-size: 1.05rem; }
.home-card:hover .hc-arrow { opacity: 1; transform: translateX(0); }

/* ---------- article ---------- */
.crumbs { font-size: .82rem; color: var(--text-dim); margin-bottom: 14px; }
.crumbs a { color: var(--accent-strong); }
.crumb-sep { margin: 0 7px; opacity: .6; }
.article-head { margin-bottom: 18px; }
.article-tag {
  display: inline-block; font-family: 'IBM Plex Mono', monospace; font-size: .72rem;
  text-transform: uppercase; letter-spacing: .1em;
  color: var(--accent-strong); border: 1px solid color-mix(in srgb, var(--accent) 50%, var(--border));
  padding: 4px 11px; border-radius: 999px; margin-bottom: 12px;
}
.article-head h1 { font-size: clamp(1.7rem, 3.2vw, 2.5rem); font-weight: 700; }
.article-meta { display: flex; gap: 16px; margin-top: 12px; font-size: .82rem; color: var(--text-dim); flex-wrap: wrap; }
.article-meta .am-icon { margin-right: 3px; }

.toc {
  margin: 20px 0 26px; border: 1px solid var(--border); border-radius: 12px;
  background: var(--card-bg); padding: 6px 18px;
}
.toc summary { cursor: pointer; font-weight: 800; font-size: .95rem; padding: 10px 0; color: var(--accent-strong); }
.toc ol { padding: 0 0 12px 22px; display: flex; flex-direction: column; gap: 5px; }
.toc li { font-size: .92rem; }
.toc a { color: var(--text); }
.toc a:hover { color: var(--accent-strong); }

.content-article { max-width: 780px; }
.content-article h2 {
  font-size: 1.45rem; font-weight: 700; margin: 34px 0 12px; padding-top: 6px;
  scroll-margin-top: calc(var(--header-h) + 20px);
}
.content-article h3 { font-size: 1.15rem; font-weight: 700; margin: 24px 0 8px; }
.content-article p { margin-bottom: 14px; }
.content-article ul, .content-article ol { margin: 0 0 16px 22px; display: flex; flex-direction: column; gap: 7px; }
.content-article li { line-height: 1.65; }
.content-article strong { font-weight: 800; }
.content-article a { text-decoration: underline; text-underline-offset: 2px; }
.content-article a:hover { text-decoration-thickness: 2px; }

/* info-box */
.info-box {
  margin: 18px 0; padding: 16px 18px; border-radius: 12px;
  border-left: 4px solid var(--accent);
  background: color-mix(in srgb, var(--accent) 8%, var(--card-bg));
  font-size: .95rem;
}
.info-box.warn { border-left-color: #b45309; background: color-mix(in srgb, #b45309 8%, var(--card-bg)); }
.info-box .ib-title { font-weight: 800; display: block; margin-bottom: 4px; }

/* tables */
.table-responsive { overflow-x: auto; margin: 18px 0; border-radius: 12px; border: 1px solid var(--border); }
table { width: 100%; border-collapse: collapse; font-size: .93rem; background: var(--card-bg); }
th, td { padding: 11px 14px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
th { font-family: 'Lora', serif; font-size: .95rem; background: var(--paper-2); }
tr:last-child td { border-bottom: 0; }
.error-table td:first-child { font-family: 'IBM Plex Mono', monospace; font-weight: 600; color: var(--accent-strong); white-space: nowrap; }

/* FAQ */
.faq-item { margin: 14px 0; border: 1px solid var(--border); border-radius: 12px; padding: 4px 20px; background: var(--card-bg); }
.faq-item h3 { font-size: 1.05rem; margin: 14px 0 6px; }
.faq-item p { margin-bottom: 14px; }

/* glossary */
.glossary dl { display: grid; grid-template-columns: 200px 1fr; gap: 0; }
.glossary dt { font-weight: 800; padding: 10px 0; border-bottom: 1px solid var(--border); font-family: 'Lora', serif; }
.glossary dd { padding: 10px 0 10px 22px; border-bottom: 1px solid var(--border); margin: 0; }

/* prevnext */
.prevnext { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 44px; }
.pn-card {
  display: block; padding: 16px 18px; border: 1px solid var(--border); border-radius: 12px;
  background: var(--card-bg); transition: var(--transition);
}
.pn-card:hover { box-shadow: var(--shadow-hover); text-decoration: none; transform: translateY(-2px); }
.pn-card.next { text-align: right; }
.pn-dir { font-family: 'IBM Plex Mono', monospace; font-size: .74rem; color: var(--accent-strong); margin-bottom: 4px; }
.pn-title { font-weight: 800; font-size: .95rem; color: var(--text); }

/* ---------- footer ---------- */
.app-footer { border-top: 1px solid var(--border); background: var(--header-bg); color: rgba(255,255,255,.72); }
.footer-inner { max-width: 1500px; margin: 0 auto; padding: 34px 44px 40px; display: flex; flex-direction: column; gap: 10px; }
.footer-inner strong { color: #fff; font-family: 'Lora', serif; font-size: 1.05rem; }
.footer-inner strong em { font-style: normal; color: var(--accent); }
.footer-inner p { max-width: 860px; font-size: .86rem; line-height: 1.6; }
.footer-meta { font-family: 'IBM Plex Mono', monospace; font-size: .76rem; opacity: .65; }

/* ---------- motion ---------- */
.page-enter { animation: fadeUp .28s ease-out both; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(8px); } }
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .5s ease-out, transform .5s ease-out; }
.reveal.on { opacity: 1; transform: none; }

/* ---------- glow orb ---------- */
body.orb-on::before {
  content: ''; position: fixed; pointer-events: none; z-index: 0;
  width: 520px; height: 520px; border-radius: 50%;
  background: radial-gradient(circle, var(--accent-glow), transparent 65%);
  transform: translate(calc(var(--ox, -300px) - 260px), calc(var(--oy, -300px) - 260px));
  opacity: .5; transition: opacity .4s;
}
.main, .sidebar { position: relative; z-index: 1; }

/* ---------- responsive ---------- */
@media (max-width: 1100px) {
  .main { padding: 28px 28px 50px; }
  .glossary dl { grid-template-columns: 150px 1fr; }
}
@media (max-width: 900px) {
  .sidebar {
    position: fixed; left: 0; top: var(--header-h); bottom: 0; z-index: 160;
    width: min(320px, 86vw);
    background: var(--paper);
    transform: translateX(-105%);
    transition: transform .26s ease-out;
    box-shadow: 4px 0 24px rgba(0,0,0,.18);
  }
  .sidebar.open { transform: translateX(0); }
  .burger { display: block; }
  .header-search { max-width: none; }
}
@media (max-width: 600px) {
  body { font-size: 16.5px; }
  .header-inner { padding: 0 14px; gap: 12px; }
  .mark-text { font-size: 1.12rem; }
  .main { padding: 22px 16px 44px; }
  .home-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 22px; }
  .prevnext { grid-template-columns: 1fr; }
  .glossary dl { grid-template-columns: 1fr; }
  .glossary dd { padding-left: 0; }
  .footer-inner { padding: 28px 18px 34px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
  .droplet-svg .drop-inner, .droplet-svg .drop-wave { stroke-dashoffset: 0; }
  .droplet-svg .drop-drip { opacity: 0; }
}