/* ============================================================
   Excel - design system
   Paleta: zieleń Excela (zaufanie, dane) + złoto (wynik, insight)
   Typografia: Space Grotesk (display) / Karla (body 17px) / JetBrains Mono (formuły)
   ============================================================ */
:root{
  --bg:#F6F4EE;            /* krem */
  --bg-card:#FFFFFF;
  --bg-soft:#EFECE3;
  --text:#1E2A23;          /* głęboka zieleń-czerń ~12:1 */
  --muted:#5B6B60;         /* ~4.8:1 */
  --faint:#7A887E;
  --accent:#0E6B38;        /* zieleń Excela ~5.3:1 na kremie */
  --accent-strong:#0A5730;
  --accent-2:#B8740D;      /* złoto */
  --accent-subtle:rgba(14,107,56,.10);
  --gold-subtle:rgba(184,116,13,.12);
  --border:#E4E0D5;
  --border-strong:#D3CDBF;
  --header-bg:rgba(246,244,238,.92);
  --shadow:0 1px 2px rgba(30,42,35,.05),0 4px 16px rgba(30,42,35,.06);
  --shadow-hover:0 2px 4px rgba(30,42,35,.07),0 10px 28px rgba(14,107,56,.10);
  --radius:14px;
  --radius-sm:8px;
  --font-display:'Space Grotesk',sans-serif;
  --font-body:'Karla',sans-serif;
  --font-mono:'JetBrains Mono',monospace;
  --header-h:64px;
  --sidebar-w:300px;
  --transition:.2s ease-out;
}
@media (prefers-color-scheme: dark){
  :root{
    --bg:#0D1510;            /* głęboka zieleń-czerń */
    --bg-card:#14211A;
    --bg-soft:#101B15;
    --text:#E6EDE7;
    --muted:#9DB0A2;         /* ~7:1 */
    --faint:#7C8F82;
    --accent:#3ECF7A;        /* jaśniejsza zieleń ~10:1 */
    --accent-strong:#56E08C;
    --accent-2:#F0B04E;
    --accent-subtle:rgba(62,207,122,.12);
    --gold-subtle:rgba(240,176,78,.12);
    --border:#23332A;
    --border-strong:#31463A;
    --header-bg:rgba(13,21,16,.9);
    --shadow:0 1px 2px rgba(0,0,0,.3),0 4px 16px rgba(0,0,0,.25);
    --shadow-hover:0 2px 4px rgba(0,0,0,.35),0 12px 30px rgba(62,207,122,.08);
  }
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header-h) + 16px)}
body{
  font-family:var(--font-body);
  font-size:17px;line-height:1.7;
  color:var(--text);background:var(--bg);
  -webkit-font-smoothing:antialiased;
  /* subtelna głębia: dwie delikatne poświaty w rogach */
  background-image:
    radial-gradient(60vw 40vw at 110% -5%, var(--accent-subtle), transparent 60%),
    radial-gradient(50vw 38vw at -10% 105%, var(--gold-subtle), transparent 60%);
  background-attachment:fixed;
}
::selection{background:var(--accent);color:#fff}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;display:block}
button{font-family:inherit}

/* ===== TYPOGRAPHY ===== */
h1,h2,h3,h4{font-family:var(--font-display);color:var(--text);line-height:1.15;text-wrap:balance}
h1{font-size:clamp(1.75rem,4.2vw,2.7rem);font-weight:700;letter-spacing:-.02em}
h2{font-size:clamp(1.35rem,3vw,1.8rem);font-weight:600;letter-spacing:-.01em;margin:2em 0 .6em}
h3{font-size:1.15rem;font-weight:600;margin:1.6em 0 .5em}
h2:first-child{margin-top:0}
p{margin:0 0 1.1em;color:var(--text)}
ul,ol{margin:0 0 1.2em;padding-left:1.4em}
li{margin-bottom:.35em}
strong{color:var(--text)}
.skip-link{position:absolute;left:-9999px;top:0;background:var(--accent);color:#fff;padding:10px 16px;z-index:200;border-radius:0 0 8px 0}
.skip-link:focus{left:0}

/* formuły i klawisze - sygnatura mono */
.fn,code{font-family:var(--font-mono);font-size:.88em}
.fn{
  display:inline-block;background:var(--accent-subtle);color:var(--accent-strong);
  padding:.05em .5em;border-radius:6px;font-weight:500;
  border:1px solid color-mix(in srgb, var(--accent) 22%, transparent);
}
@media (prefers-color-scheme: dark){ .fn{color:var(--accent)} }
kbd{
  font-family:var(--font-mono);font-size:.8em;background:var(--bg-soft);
  border:1px solid var(--border);border-bottom-width:2px;border-radius:5px;
  padding:.08em .45em;color:var(--text);white-space:nowrap;
}

/* ===== HEADER ===== */
.app-header{
  position:fixed;top:0;left:0;right:0;z-index:100;height:var(--header-h);
  background:var(--header-bg);backdrop-filter:blur(14px);
  border-bottom:1px solid var(--border);
}
.app-header::after{
  content:'';position:absolute;left:0;right:0;bottom:-1px;height:1px;
  background:linear-gradient(90deg,transparent,var(--accent),transparent);
  opacity:.3;pointer-events:none;
}
.header-inner{
  max-width:1240px;margin:0 auto;height:100%;padding:0 20px;
  display:flex;align-items:center;gap:24px;
}
.brand{display:flex;align-items:center;gap:10px;flex-shrink:0}
.brand-mark{
  width:38px;height:38px;border-radius:9px;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--accent),#16A34A);
  color:#fff;font-family:var(--font-display);font-weight:700;font-size:.95rem;
  box-shadow:0 2px 8px rgba(14,107,56,.35);
}
.brand-name{font-family:var(--font-display);font-weight:600;font-size:1.12rem;letter-spacing:-.01em}
.brand-accent{color:var(--accent)}
.search-wrap{position:relative;flex:1;max-width:440px;margin-left:auto}
.search-icon{position:absolute;left:12px;top:50%;transform:translateY(-50%);width:16px;height:16px;color:var(--faint);pointer-events:none}
#search-input{
  width:100%;padding:9px 14px 9px 36px;border-radius:10px;
  border:1px solid var(--border);background:var(--bg-card);color:var(--text);
  font-family:var(--font-body);font-size:.95rem;outline:none;transition:border-color var(--transition),box-shadow var(--transition);
}
#search-input::placeholder{color:var(--faint)}
#search-input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-subtle)}
.search-results{
  position:absolute;top:calc(100% + 8px);left:0;right:0;z-index:120;
  background:var(--bg-card);border:1px solid var(--border);border-radius:12px;
  box-shadow:var(--shadow-hover);max-height:380px;overflow-y:auto;padding:6px;
}
.search-results a{display:block;padding:9px 12px;border-radius:8px;font-size:.92rem;line-height:1.35}
.search-results a:hover,.search-results a:focus{background:var(--accent-subtle);outline:none}
.search-results .sr-title{font-weight:600;color:var(--text);font-family:var(--font-display)}
.search-results .sr-sec{font-size:.72rem;color:var(--faint);text-transform:uppercase;letter-spacing:.06em}
.search-results .sr-empty{padding:12px;color:var(--faint);font-size:.9rem}
.burger{display:none;flex-direction:column;gap:4px;background:none;border:none;cursor:pointer;padding:6px;margin-left:8px}
.burger span{display:block;width:22px;height:2px;background:var(--text);border-radius:2px;transition:var(--transition)}
.burger.open span:nth-child(1){transform:translateY(6px) rotate(45deg)}
.burger.open span:nth-child(2){opacity:0}
.burger.open span:nth-child(3){transform:translateY(-6px) rotate(-45deg)}

/* ===== SIDEBAR ===== */
.page-wrap{display:flex;min-height:100vh;padding-top:var(--header-h)}
.sidebar{
  width:var(--sidebar-w);position:fixed;top:var(--header-h);left:0;bottom:0;
  border-right:1px solid var(--border);overflow-y:auto;padding:14px 0 40px;z-index:50;
  background:var(--bg);
}
.sidebar::-webkit-scrollbar{width:4px}
.sidebar::-webkit-scrollbar-thumb{background:var(--border-strong);border-radius:4px}
.sidebar-sec{
  padding:16px 18px 5px;font-size:.7rem;font-weight:700;text-transform:uppercase;
  letter-spacing:.11em;color:var(--faint);font-family:var(--font-display);
}
.sidebar-link{
  display:flex;align-items:center;gap:9px;
  padding:7px 18px;font-size:.9rem;font-weight:400;color:var(--muted);
  border-left:2px solid transparent;transition:all .15s;line-height:1.4;
}
.sidebar-link:hover{color:var(--text);background:var(--accent-subtle);border-left-color:var(--accent)}
.sidebar-link.active{color:var(--accent-strong);border-left-color:var(--accent);background:var(--accent-subtle);font-weight:600}
@media (prefers-color-scheme: dark){ .sidebar-link.active{color:var(--accent)} }
.sidebar-link .s-ico{font-size:.78rem;width:22px;text-align:center;flex-shrink:0;opacity:.72;filter:grayscale(.15)}
.sidebar-overlay{display:none}

/* ===== MAIN / ARTICLE ===== */
.main{margin-left:var(--sidebar-w);padding:36px 44px 80px;min-height:100vh;max-width:1000px;width:100%}
.content-article{animation:fadeUp .28s ease-out both}
.breadcrumbs{
  font-size:.8rem;color:var(--faint);margin-bottom:14px;display:flex;align-items:center;gap:8px;flex-wrap:wrap;
}
.breadcrumbs a{color:var(--muted);transition:color .15s}
.breadcrumbs a:hover{color:var(--accent-strong)}
@media (prefers-color-scheme: dark){ .breadcrumbs a:hover{color:var(--accent)} }
.breadcrumbs .sep{color:var(--border-strong)}
@keyframes fadeUp{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.article-meta{
  display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:14px;
}
.article-section{
  font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.1em;
  color:var(--accent-strong);background:var(--accent-subtle);
  padding:4px 12px;border-radius:999px;font-family:var(--font-display);
}
@media (prefers-color-scheme: dark){ .article-section{color:var(--accent)} }
.article-ico{font-size:1.15rem}
.content-article h1{margin-bottom:.35em}
.article-excerpt{
  font-size:1.1rem;color:var(--muted);line-height:1.6;margin-bottom:1.6em;
  padding-bottom:1.2em;border-bottom:1px solid var(--border);
}
.toc{
  background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);
  padding:18px 22px;margin:0 0 2em;box-shadow:var(--shadow);
}
@media(min-width:901px){
  .toc{position:sticky;top:calc(var(--header-h) + 18px);max-height:calc(100vh - var(--header-h) - 40px);overflow-y:auto;z-index:5}
}
.toc-title{font-family:var(--font-display);font-weight:600;font-size:.85rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin-bottom:10px}
.toc a{
  display:block;padding:4px 0;color:var(--muted);font-size:.92rem;
  border-bottom:1px dashed var(--border);transition:color .15s,padding-left .15s;
}
.toc a:hover{color:var(--accent-strong);padding-left:4px}
@media (prefers-color-scheme: dark){ .toc a:hover{color:var(--accent)} }
.toc a.toc-h3{padding-left:16px;font-size:.85rem}

/* komponenty treści */
.info-box{
  background:var(--accent-subtle);border-left:4px solid var(--accent);
  border-radius:0 var(--radius-sm) var(--radius-sm) 0;
  padding:16px 20px;margin:1.4em 0;font-size:.97rem;
}
.info-box .ib-title{font-family:var(--font-display);font-weight:700;color:var(--accent-strong);font-size:.9rem;text-transform:uppercase;letter-spacing:.06em;margin-bottom:6px;display:block}
@media (prefers-color-scheme: dark){ .info-box .ib-title{color:var(--accent)} }
.warn-box{
  background:var(--gold-subtle);border-left:4px solid var(--accent-2);
  border-radius:0 var(--radius-sm) var(--radius-sm) 0;
  padding:16px 20px;margin:1.4em 0;font-size:.97rem;
}
.warn-box .ib-title{font-family:var(--font-display);font-weight:700;color:var(--accent-2);font-size:.9rem;text-transform:uppercase;letter-spacing:.06em;margin-bottom:6px;display:block}
.table-responsive{overflow-x:auto;margin:1.4em 0;border-radius:var(--radius-sm);border:1px solid var(--border)}
table{width:100%;border-collapse:collapse;font-size:.93rem;background:var(--bg-card)}
th{
  background:var(--bg-soft);font-family:var(--font-display);font-weight:600;text-align:left;
  padding:11px 14px;border-bottom:2px solid var(--border-strong);white-space:nowrap;color:var(--text);
}
td{padding:10px 14px;border-bottom:1px solid var(--border);vertical-align:top}
tr:last-child td{border-bottom:none}
tbody tr{transition:background .15s}
tbody tr:hover{background:var(--accent-subtle)}
table.error-table th{background:var(--accent);color:#fff;border-bottom:none}
table.error-table th:first-child{border-radius:var(--radius-sm) 0 0 0}
table.error-table th:last-child{border-radius:0 var(--radius-sm) 0 0}
.faq-item{
  border:1px solid var(--border);border-radius:var(--radius);margin:0 0 14px;
  background:var(--bg-card);overflow:hidden;box-shadow:var(--shadow);
}
.faq-q{
  padding:15px 20px;font-family:var(--font-display);font-weight:600;font-size:1.02rem;
  cursor:pointer;display:flex;justify-content:space-between;align-items:center;gap:14px;
  transition:background .15s;
}
.faq-q:hover{background:var(--accent-subtle)}
.faq-q::after{content:'+';font-family:var(--font-mono);color:var(--accent);font-size:1.2rem;transition:transform .2s}
.faq-item.open .faq-q::after{transform:rotate(45deg)}
.faq-a{display:none;padding:0 20px 16px;color:var(--muted);font-size:.95rem}
.faq-item.open .faq-a{display:block;animation:fadeUp .2s ease-out}
dl.glossary dt{
  font-family:var(--font-display);font-weight:600;color:var(--accent-strong);
  margin-top:1.1em;font-size:1.02rem;
}
@media (prefers-color-scheme: dark){ dl.glossary dt{color:var(--accent)} }
dl.glossary dd{margin:.15em 0 0 0;color:var(--muted);font-size:.95rem;line-height:1.6}
.steps{counter-reset:step;list-style:none;padding-left:0}
.steps li{
  counter-increment:step;position:relative;padding:0 0 1.1em 44px;margin:0;
}
.steps li::before{
  content:counter(step);position:absolute;left:0;top:0;
  width:30px;height:30px;border-radius:9px;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--accent),#16A34A);color:#fff;
  font-family:var(--font-mono);font-weight:700;font-size:.85rem;
  box-shadow:0 2px 6px rgba(14,107,56,.3);
}
.content-article ul li::marker{color:var(--accent)}
.content-article ol li::marker{color:var(--accent);font-weight:600}
.checklist{list-style:none;padding-left:0}
.checklist li{padding-left:30px;position:relative;margin-bottom:.55em}
.checklist li::before{
  content:'✓';position:absolute;left:0;top:0;color:var(--accent-strong);
  font-family:var(--font-mono);font-weight:700;
}
@media (prefers-color-scheme: dark){ .checklist li::before{color:var(--accent)} }

/* ===== HOMEPAGE ===== */
.home-hero{
  border-radius:calc(var(--radius) + 6px);overflow:hidden;position:relative;
  background:linear-gradient(135deg,#0B3D24 0%,#0E6B38 55%,#128A4A 100%);
  color:#fff;padding:44px 44px 40px;margin-bottom:40px;
  box-shadow:0 12px 40px rgba(14,107,56,.28);
}
.home-hero .hero-label{
  font-family:var(--font-display);font-size:.75rem;font-weight:700;letter-spacing:.14em;
  text-transform:uppercase;color:#9FE3BC;margin-bottom:14px;display:inline-flex;align-items:center;gap:8px;
}
.home-hero h1{color:#fff;font-size:clamp(1.9rem,4.5vw,2.9rem);max-width:640px}
.home-hero p.hero-sub{color:#D5EBDD;font-size:1.08rem;max-width:560px;margin:14px 0 26px;line-height:1.6}
.hero-ctas{display:flex;gap:12px;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;gap:8px;padding:11px 22px;border-radius:11px;
  font-family:var(--font-display);font-weight:600;font-size:.95rem;
  transition:transform var(--transition),box-shadow var(--transition),background var(--transition);
}
.btn-primary{background:#fff;color:#0B3D24}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 20px rgba(0,0,0,.25)}
.btn-ghost{border:1.5px solid rgba(255,255,255,.45);color:#fff}
.btn-ghost:hover{background:rgba(255,255,255,.12);transform:translateY(-2px)}
.hero-grid-bg{
  position:absolute;inset:0;pointer-events:none;opacity:.16;
  background-image:
    linear-gradient(rgba(255,255,255,.5) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.5) 1px,transparent 1px);
  background-size:44px 44px;
  mask-image:radial-gradient(70% 90% at 80% 20%,#000 30%,transparent 100%);
  -webkit-mask-image:radial-gradient(70% 90% at 80% 20%,#000 30%,transparent 100%);
}
/* mini-mockup arkusza w hero */
.hero-sheet{
  position:absolute;right:36px;top:50%;transform:translateY(-50%);
  width:min(340px,34%);background:#fff;border-radius:12px;overflow:hidden;
  box-shadow:0 24px 60px rgba(0,0,0,.35);display:none;
}
@media(min-width:1000px){ .hero-sheet{display:block} }
.hero-sheet .hs-bar{
  display:flex;align-items:center;gap:6px;padding:8px 12px;background:#0B3D24;
}
.hero-sheet .hs-bar i{width:9px;height:9px;border-radius:50%;display:block}
.hero-sheet .hs-bar i:nth-child(1){background:#F87171}
.hero-sheet .hs-bar i:nth-child(2){background:#FBBF24}
.hero-sheet .hs-bar i:nth-child(3){background:#34D399}
.hero-sheet .hs-bar span{margin-left:8px;font-family:var(--font-mono);font-size:.62rem;color:#9FE3BC}
.hero-sheet table{font-size:.68rem;background:#fff}
.hero-sheet th{background:#F0F5F1;color:#33413A;padding:5px 9px;font-size:.6rem}
.hero-sheet td{padding:5px 9px;color:#22301F;border-bottom:1px solid #EDEAE2}
.hero-sheet .hs-formula{background:#E7F6EC;color:#0E6B38;font-family:var(--font-mono);font-weight:500}
.hero-sheet .hs-total{background:#0E6B38;color:#fff;font-weight:700}
.hero-stats{
  display:flex;gap:34px;margin-top:34px;flex-wrap:wrap;
}
.hero-stats .hs-num{font-family:var(--font-display);font-size:1.5rem;font-weight:700;color:#fff}
.hero-stats .hs-lbl{font-size:.78rem;color:#9FE3BC;text-transform:uppercase;letter-spacing:.08em}

.home-section{margin-bottom:38px}
.home-section h2{
  font-size:1.3rem;margin:0 0 16px;display:flex;align-items:center;gap:10px;
}
.home-section h2 .sec-ico{width:34px;height:34px;border-radius:9px;display:grid;place-items:center;background:var(--accent-subtle);font-size:1rem}
.home-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(268px,1fr));gap:14px}
.home-card{
  display:flex;flex-direction:column;gap:6px;position:relative;
  background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);
  padding:16px 18px;box-shadow:var(--shadow);
  transition:transform var(--transition),box-shadow var(--transition),border-color var(--transition);
}
.home-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-hover);border-color:color-mix(in srgb,var(--accent) 35%,var(--border))}
/* mini-motyw arkusza: subtelna siatka w rogu karty */
.home-card::after{
  content:'';position:absolute;top:10px;right:10px;width:30px;height:30px;
  border-radius:6px;border:1px solid var(--border);opacity:.55;pointer-events:none;
  background-image:
    linear-gradient(var(--border) 1px,transparent 1px),
    linear-gradient(90deg,var(--border) 1px,transparent 1px);
  background-size:10px 10px;
  transition:opacity var(--transition),border-color var(--transition);
}
.home-card:hover::after{opacity:1;border-color:var(--accent)}
.home-card .hc-top{display:flex;align-items:center;gap:8px}
.home-card .hc-ico{font-size:1.05rem}
.home-card .hc-tag{
  font-size:.62rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em;
  color:var(--accent-2);background:var(--gold-subtle);padding:2px 8px;border-radius:999px;
  font-family:var(--font-display);
}
.home-card h3{font-size:.95rem;font-weight:600;margin:2px 0 0;font-family:var(--font-display)}
.home-card p{font-size:.85rem;color:var(--muted);line-height:1.55;margin:0;flex:1}
.home-card .hc-link{
  font-size:.8rem;font-weight:600;color:var(--accent-strong);font-family:var(--font-display);
  display:inline-flex;align-items:center;gap:4px;margin-top:4px;transition:gap var(--transition);
}
@media (prefers-color-scheme: dark){ .home-card .hc-link{color:var(--accent)} }
.home-card:hover .hc-link{gap:8px}
.home-seo-note{
  margin-top:44px;padding-top:26px;border-top:1px solid var(--border);
  display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:22px;
}
.home-seo-note h3{font-size:.8rem;text-transform:uppercase;letter-spacing:.1em;color:var(--faint);font-family:var(--font-display);margin-bottom:8px}
.home-seo-note p{font-size:.88rem;color:var(--muted);margin:0}

/* ===== RESPONSIVE ===== */
@media(max-width:900px){
  .sidebar{left:calc(-1 * var(--sidebar-w));transition:left .28s ease;box-shadow:4px 0 24px rgba(0,0,0,.15);background:var(--bg-card)}
  .sidebar.open{left:0}
  .sidebar-overlay{display:block;position:fixed;inset:0;background:rgba(10,16,12,.5);z-index:49;opacity:0;pointer-events:none;transition:opacity .25s}
  .sidebar-overlay.show{opacity:1;pointer-events:auto}
  .main{margin-left:0;padding:26px 20px 60px}
  .burger{display:flex}
  .search-wrap{max-width:none}
  .home-hero{padding:34px 26px 30px}
  .hero-sheet{display:none}
}
@media(max-width:600px){
  body{font-size:16px}
  .header-inner{gap:10px}
  .brand-name{font-size:1rem}
  #search-input{font-size:.88rem;padding:8px 12px 8px 32px}
  .search-icon{left:10px}
  .home-grid{grid-template-columns:1fr}
  .hero-stats{gap:22px}
  .content-article h1{font-size:1.6rem}
  .main{padding:22px 16px 56px}
}
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation-duration:.01ms !important;transition-duration:.01ms !important;scroll-behavior:auto !important}
}