/* =========================================================
   Sella, Cichon + Stolberg GmbH — Design System
   Plain CSS, no frameworks, no external requests.
   ========================================================= */

:root {
  /* Brand */
  --green-500: #6cb52d;
  --green-600: #59991f;
  --green-700: #447516;
  --green-050: #f2f9ea;
  --green-100: #e3f3d3;

  /* Neutrals */
  --ink-900: #11150f;
  --ink-700: #333a2e;
  --ink-500: #5d6657;
  --ink-300: #9aa294;
  --line: #e2e6dd;
  --surface: #ffffff;
  --surface-alt: #f6f8f3;
  --page: #ffffff;

  /* Type */
  --font-sans: "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial,
    sans-serif;
  --step--1: clamp(0.86rem, 0.83rem + 0.15vw, 0.94rem);
  --step-0: clamp(1rem, 0.96rem + 0.2vw, 1.08rem);
  --step-1: clamp(1.2rem, 1.12rem + 0.4vw, 1.4rem);
  --step-2: clamp(1.5rem, 1.34rem + 0.8vw, 2rem);
  --step-3: clamp(1.9rem, 1.6rem + 1.5vw, 3rem);
  --step-4: clamp(2.3rem, 1.8rem + 2.4vw, 3.9rem);

  /* Space & shape */
  --gutter: clamp(1.1rem, 4vw, 2.5rem);
  --radius: 14px;
  --radius-sm: 9px;
  --shadow-sm: 0 1px 2px rgba(17, 21, 15, 0.05),
    0 4px 14px rgba(17, 21, 15, 0.05);
  --shadow-md: 0 10px 34px rgba(17, 21, 15, 0.1);
  --maxw: 1180px;
}

/* ---------- Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--page);
  color: var(--ink-700);
  font-family: var(--font-sans);
  font-size: var(--step-0);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--green-700);
  text-decoration-color: rgba(108, 181, 45, 0.4);
  text-underline-offset: 3px;
}

a:hover {
  color: var(--green-600);
  text-decoration-color: currentColor;
}

h1,
h2,
h3,
h4 {
  color: var(--ink-900);
  line-height: 1.18;
  letter-spacing: -0.015em;
  margin: 0 0 0.5em;
  font-weight: 700;
}

h1 {
  font-size: var(--step-4);
}
h2 {
  font-size: var(--step-3);
}
h3 {
  font-size: var(--step-2);
}
h4 {
  font-size: var(--step-1);
}

p {
  margin: 0 0 1.1em;
  max-width: 72ch;
}

:focus-visible {
  outline: 3px solid var(--green-500);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- Layout helpers ---------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(2.6rem, 6vw, 5rem);
}

.section--alt {
  background: var(--surface-alt);
  border-block: 1px solid var(--line);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--green-600);
  color: #fff;
  padding: 0.7rem 1.1rem;
  z-index: 100;
  border-radius: 0 0 var(--radius-sm) 0;
}

.skip-link:focus {
  left: 0;
  color: #fff;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}

.lightbox-open .site-header {
  backdrop-filter: none;
  z-index: 1;
}


.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 84px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  color: inherit;
}

.brand img {
  width: 132px;
  height: auto;
}

.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 46px;
  height: 42px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--ink-900);
  border-radius: 2px;
  transition: transform 0.22s ease, opacity 0.18s ease;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.site-nav {
  display: none;
}

.site-nav.is-open {
  display: block;
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  box-shadow: var(--shadow-md);
  padding: 0.6rem var(--gutter) 1.2rem;
}

.site-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.site-nav a {
  display: block;
  padding: 0.7rem 0.2rem;
  font-weight: 600;
  color: var(--ink-700);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.site-nav a[aria-current="page"] {
  color: var(--green-700);
}

@media (min-width: 1160px) {
  .nav-toggle {
    display: none;
  }

  .site-nav,
  .site-nav.is-open {
    display: block;
    position: static;
    padding: 0;
    border: 0;
    box-shadow: none;
    background: none;
  }

  .site-nav ul {
    flex-direction: row;
    align-items: center;
    gap: 0.15rem;
  }

  .site-nav a {
    border: 0;
    padding: 0.55rem 0.58rem;
    white-space: nowrap;
    border-radius: 999px;
    font-size: var(--step--1);
    letter-spacing: 0.01em;
    transition: background 0.18s ease, color 0.18s ease;
  }

  .site-nav a:hover {
    background: var(--green-050);
    color: var(--green-700);
  }

  .site-nav a[aria-current="page"] {
    background: var(--green-600);
    color: #fff;
  }

  .site-nav .nav-cta a {
    background: var(--ink-900);
    color: #fff;
    margin-left: 0.5rem;
  }

  .site-nav .nav-cta a:hover {
    background: var(--green-600);
    color: #fff;
  }
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background: var(--ink-900);
  color: #fff;
  overflow: hidden;
}

.hero__media {
  position: absolute;
  inset: 0;
}

.hero__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.42;
  filter: saturate(115%);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    100deg,
    rgba(17, 21, 15, 0.92) 0%,
    rgba(17, 21, 15, 0.72) 46%,
    rgba(68, 117, 22, 0.45) 100%
  );
}

.hero__inner {
  position: relative;
  z-index: 2;
  padding-block: clamp(3.2rem, 9vw, 7rem);
  max-width: 62ch;
}

.hero h1,
.hero h2 {
  color: #fff;
  margin-bottom: 0.4em;
}

.hero p {
  color: rgba(255, 255, 255, 0.85);
  font-size: var(--step-1);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--green-500);
  margin-bottom: 1rem;
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--green-500);
}

.hero--compact .hero__inner {
  padding-block: clamp(2.4rem, 6vw, 4.4rem);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.8rem 1.5rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: var(--step--1);
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.16s ease, background 0.18s ease, color 0.18s ease,
    border-color 0.18s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn--primary {
  background: var(--green-600);
  color: #fff;
}

.btn--primary:hover {
  background: var(--green-700);
  color: #fff;
}

.btn--ghost {
  border-color: rgba(255, 255, 255, 0.45);
  color: #fff;
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

.btn--outline {
  border-color: var(--line);
  color: var(--ink-900);
  background: var(--surface);
}

.btn--outline:hover {
  border-color: var(--green-500);
  color: var(--green-700);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.6rem;
}

/* ---------- Prose ---------- */
.prose h2 {
  margin-top: 0;
}

.prose h3 {
  margin-top: 2.2rem;
  font-size: var(--step-1);
}

.prose ul {
  margin: 0 0 1.4rem;
  padding-left: 1.1rem;
  max-width: 72ch;
}

.prose li {
  margin-bottom: 0.35rem;
}

.lead {
  font-size: var(--step-1);
  color: var(--ink-700);
}

/* ---------- Content grid (text + aside) ---------- */
.layout {
  display: grid;
  gap: clamp(2rem, 5vw, 3.4rem);
}

.layout > * {
  min-width: 0;
}

@media (min-width: 960px) {
  .layout {
    grid-template-columns: minmax(0, 1fr) 300px;
    align-items: start;
  }
}

.aside {
  display: grid;
  gap: 1rem;
  position: sticky;
  top: 110px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  box-shadow: var(--shadow-sm);
}

.card h3 {
  font-size: var(--step-1);
  margin-bottom: 0.6rem;
}

.card p {
  margin-bottom: 0.6rem;
  font-size: var(--step--1);
}

.card--accent {
  background: var(--green-050);
  border-color: var(--green-100);
}

.contact-lines {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: var(--step--1);
}

.contact-lines li {
  padding: 0.28rem 0;
}

.contact-lines strong {
  color: var(--ink-900);
}

/* ---------- Feature / keyword chips ---------- */
.chip-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.7rem;
  grid-template-columns: repeat(auto-fill, minmax(min(200px, 100%), 1fr));
}

.chip-grid li {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--green-500);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  font-weight: 600;
  color: var(--ink-900);
  font-size: var(--step--1);
  transition: transform 0.18s ease, box-shadow 0.18s ease,
    border-color 0.18s ease;
}

.chip-grid li:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
  border-left-color: var(--green-700);
}

/* ---------- Check lists ---------- */
.check-list {
  list-style: none;
  margin: 0 0 1.6rem;
  padding: 0;
  display: grid;
  gap: 0.4rem;
  grid-template-columns: repeat(auto-fill, minmax(min(260px, 100%), 1fr));
}

.check-list li {
  position: relative;
  padding-left: 1.7rem;
  font-size: var(--step--1);
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 9px;
  height: 9px;
  border-radius: 2px;
  background: var(--green-500);
}

/* ---------- Numbered process ---------- */
.steps {
  list-style: none;
  counter-reset: step;
  margin: 0 0 1.8rem;
  padding: 0;
  display: grid;
  gap: 0.6rem;
  grid-template-columns: repeat(auto-fill, minmax(min(240px, 100%), 1fr));
}

.steps li {
  counter-increment: step;
  position: relative;
  padding: 0.8rem 1rem 0.8rem 3rem;
  background: var(--surface-alt);
  border-radius: var(--radius-sm);
  font-size: var(--step--1);
  font-weight: 600;
  color: var(--ink-900);
}

.steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0.9rem;
  top: 0.8rem;
  font-size: 0.75rem;
  font-weight: 800;
  color: var(--green-600);
  letter-spacing: 0.04em;
}

/* ---------- Reference groups ---------- */
.ref-grid {
  display: grid;
  gap: 1.2rem;
  grid-template-columns: repeat(auto-fill, minmax(min(270px, 100%), 1fr));
}

.ref-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  box-shadow: var(--shadow-sm);
}

.ref-card h3 {
  font-size: 1.02rem;
  color: var(--green-700);
  margin-bottom: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.ref-card ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.ref-card li {
  padding: 0.34rem 0;
  border-top: 1px solid var(--line);
  font-size: var(--step--1);
}

.ref-card li:first-child {
  border-top: 0;
}

/* ---------- Partner profiles ---------- */
.partner-list {
  display: grid;
  gap: clamp(3rem, 7vw, 5.5rem);
}

.partner-entry {
  display: grid;
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
  min-width: 0;
  padding-bottom: clamp(3rem, 7vw, 5.5rem);
  border-bottom: 1px solid var(--line);
}

.partner-entry > * {
  min-width: 0;
}

.partner-entry a,
.ref-card a {
  overflow-wrap: anywhere;
}

.partner-entry:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.partner-entry .figure {
  margin: 0;
}

@media (min-width: 900px) {
  .partner-entry {
    grid-template-columns: minmax(300px, 0.8fr) minmax(0, 1.2fr);
  }
}

/* ---------- Gallery + lightbox ---------- */
.gallery {
  display: grid;
  gap: 0.9rem;
  grid-template-columns: repeat(auto-fill, minmax(min(230px, 100%), 1fr));
  margin: 0;
  padding: 0;
  list-style: none;
}

.gallery button {
  display: block;
  width: 100%;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  cursor: zoom-in;
}

.gallery img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.gallery button:hover img {
  transform: scale(1.05);
}

.figure {
  margin: 0 0 2rem;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
}

.figure-btn {
  display: block;
  width: 100%;
  padding: 0;
  margin: 0;
  border: 0;
  background: none;
  cursor: zoom-in;
  font: inherit;
  color: inherit;
}

.figure-btn img {
  width: 100%;
}



.figure figcaption {
  font-size: var(--step--1);
  color: var(--ink-500);
  padding: 0.7rem 1rem;
  background: var(--surface-alt);
}

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: clamp(1rem, 5vw, 3rem);
  background: rgba(12, 15, 10, 0.9);
}

.lightbox.is-open {
  display: flex;
}

.lightbox img {
  max-width: 100%;
  max-height: 84vh;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
}

.lightbox__caption {
  position: absolute;
  bottom: 1.2rem;
  left: 0;
  right: 0;
  text-align: center;
  color: rgba(255, 255, 255, 0.85);
  font-size: var(--step--1);
  padding-inline: 1rem;
}

.lightbox__close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.4);
  background: transparent;
  color: #fff;
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
}

.lightbox__close:hover {
  background: rgba(255, 255, 255, 0.15);
}

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--ink-900);
  color: #fff;
  border-radius: var(--radius);
  padding: clamp(1.8rem, 4vw, 3rem);
  display: grid;
  gap: 1.4rem;
  align-items: center;
}

@media (min-width: 860px) {
  .cta-band {
    grid-template-columns: 1fr auto;
  }
}

.cta-band h2 {
  color: #fff;
  font-size: var(--step-2);
  margin-bottom: 0.3em;
}

.cta-band p {
  color: rgba(255, 255, 255, 0.78);
  margin: 0;
}

.cta-band .btn-row {
  margin-top: 0;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--surface-alt);
  border-top: 1px solid var(--line);
  padding-block: clamp(2.4rem, 5vw, 3.6rem) 1.4rem;
  margin-top: 0;
}

.footer-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(min(230px, 100%), 1fr));
}

.site-footer h3 {
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-500);
  margin-bottom: 1rem;
}

.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: var(--step--1);
}

.site-footer li {
  padding: 0.22rem 0;
}

.site-footer a {
  text-decoration: none;
  color: var(--ink-700);
}

.site-footer a:hover {
  color: var(--green-700);
}

.footer-logo img {
  width: 138px;
  margin-bottom: 0.9rem;
}

.partner-logo {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.9rem;
  display: inline-block;
  margin-bottom: 0.7rem;
}

.partner-logo img {
  width: 150px;
}

.footer-bottom {
  margin-top: 2.4rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.4rem;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--ink-500);
}

/* ---------- Reveal on scroll ---------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn:hover,
  .chip-grid li:hover,
  .gallery button:hover img {
    transform: none;
  }
}