:root {
    --bg: #f4f5f7;
    --paper: #ffffff;
    --ink: #14213d;
    --ink-soft: #3a4661;
    --line: #e3e7ee;
    --blue-1: #0c2440;
    --blue-2: #1f3b6f;
    --blue-3: #2d5096;
    --gold: #b08d4f;
    --gold-soft: #c9a96b;
  }
  * { box-sizing: border-box; margin: 0; padding: 0; }
  html, body {
    background: var(--bg);
    color: var(--ink);
    font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Inter", Helvetica, Arial, sans-serif;
    font-size: 16.5px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
  }

  /* Top header --------------------------------------------------- */
  .topnav-wrap {
    position: relative;
    background:
      linear-gradient(135deg, rgba(8, 22, 48, 0.85) 0%, rgba(20, 50, 100, 0.78) 60%, rgba(8, 22, 48, 0.92) 100%),
      var(--blue-1);
    overflow: hidden;
  }
  .topnav-wrap::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
      linear-gradient(45deg, transparent 30%, rgba(80, 130, 200, 0.18) 30%, rgba(80, 130, 200, 0.18) 31%, transparent 31%) 0 0/240px 240px,
      linear-gradient(-45deg, transparent 60%, rgba(40, 80, 150, 0.18) 60%, rgba(40, 80, 150, 0.18) 61%, transparent 61%) 0 0/280px 280px,
      radial-gradient(ellipse at 80% 20%, rgba(0, 0, 0, 0.45) 0%, transparent 60%);
    pointer-events: none;
  }
  .topnav {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 32px 6vw 28px;
    color: #fff;
  }
  .brand { display: flex; align-items: center; gap: 14px; }
  .brand-mark {
    width: 56px; height: 56px;
    border: 2px solid #fff;
    display: flex; align-items: center; justify-content: center;
    font-weight: 700; font-size: 22px; letter-spacing: -0.03em;
  }
  .brand-text { line-height: 1.15; font-size: 20px; font-weight: 500; letter-spacing: 0.005em; }
  .brand-text .small { display: block; font-size: 14px; font-weight: 400; color: #cfd9e8; letter-spacing: 0.04em; }
  .nav-items { display: flex; gap: 38px; font-size: 16px; }
  .nav-items a {
    color: #fff; text-decoration: none; padding: 6px 0;
    border-bottom: 2px solid transparent; transition: border-color 0.2s ease;
  }
  .nav-items a:hover, .nav-items a.active { border-bottom-color: var(--gold-soft); }

  /* Burger toggle (responsive) ---------------------------------- */
  .nav-toggle {
    display: none; background: transparent; border: 0; width: 44px; height: 36px;
    padding: 8px 6px; cursor: pointer; flex-direction: column; justify-content: space-between;
  }
  .nav-toggle span {
    display: block; height: 2px; background: #fff; width: 100%;
    transition: transform 0.2s ease, opacity 0.2s ease; transform-origin: center;
  }
  .nav-toggle.open span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

  @media (max-width: 1000px) {
    .nav-toggle { display: flex; }
    .nav-items {
      display: none; position: absolute; top: 100%; left: 0; right: 0;
      flex-direction: column; gap: 0; background: var(--blue-1);
      padding: 8px 6vw 16px; z-index: 50; box-shadow: 0 8px 20px rgba(0,0,0,0.3);
    }
    .nav-items.open { display: flex; }
    .nav-items a { padding: 14px 0; border-bottom: 1px solid rgba(255,255,255,0.08); }
    .nav-items a:last-child { border-bottom: 0; }
  }

  /* Page header -------------------------------------------------- */
  .page-header {
    position: relative;
    padding: 7vh 6vw 8vh;
    color: #fff;
  }
  .page-header .eyebrow-light {
    text-transform: uppercase; letter-spacing: 0.22em;
    font-size: 12px; color: var(--gold-soft);
    margin-bottom: 18px; display: block;
  }
  .page-header h1 {
    font-size: clamp(32px, 3.8vw, 50px);
    font-weight: 500; line-height: 1.15;
    letter-spacing: -0.005em; max-width: 18em;
  }
  .page-header .lead {
    margin-top: 22px; max-width: 44em; color: #d8e0ec;
    font-size: 17px; line-height: 1.65;
  }

  /* Sections ---------------------------------------------------- */
  section {
    padding: 84px 6vw 96px;
    background: var(--bg);
  }
  section.dark { background: var(--blue-1); color: #f3f6fa; }
  section h2 {
    font-size: clamp(26px, 2.6vw, 36px);
    font-weight: 500; margin-bottom: 12px; letter-spacing: -0.005em;
  }
  .eyebrow {
    text-transform: uppercase; letter-spacing: 0.22em;
    font-size: 12px; color: var(--gold);
    margin-bottom: 14px; display: block;
  }
  section.dark .eyebrow { color: var(--gold-soft); }
  .section-lead { color: var(--ink-soft); max-width: 56em; margin-bottom: 8px; font-size: 16px; }
  section.dark .section-lead { color: #cfd9e8; }

  /* Hero-Cover-Grid (Vos-Stimmen) ------------------------------- */
  .hero-covers {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 36px;
    margin-top: 44px;
  }
  .cover {
    display: block;
    position: relative;
    text-decoration: none;
    color: inherit;
    transition: transform 0.25s ease;
  }
  .cover:hover { transform: translateY(-4px); }
  .cover-img {
    position: relative;
    background: #d8dde6;
    box-shadow: 0 14px 30px rgba(8, 22, 48, 0.18), 0 2px 6px rgba(8, 22, 48, 0.12);
    overflow: hidden;
  }
  .cover-img img {
    display: block;
    width: 100%;
    height: auto;
  }
  .cover-tag {
    position: absolute;
    top: 12px;
    left: 12px;
    background: var(--blue-1);
    color: #fff;
    font-size: 10.5px;
    text-transform: uppercase;
    letter-spacing: 0.16em;
    padding: 5px 11px;
    z-index: 2;
  }
  .cover-tag.author { background: var(--gold); }
  .cover-tag.interview { background: var(--blue-3); }
  .cover-meta {
    margin-top: 14px;
    font-size: 14px;
    line-height: 1.45;
    color: var(--ink-soft);
  }
  .cover-meta strong { color: var(--ink); font-weight: 600; display: block; font-size: 14.5px; margin-bottom: 2px; }

  /* PDF Inline Viewer (Vos-Stimmen) ----------------------------- */
  .pdf-viewer-row {
    grid-column: 1 / -1;
    height: 0;
    overflow: hidden;
    transition: height 0.4s ease, margin 0.4s ease;
    margin: 0;
    background: var(--paper);
  }
  .pdf-viewer-row.open {
    height: 760px;
    margin-top: 8px;
    border: 1px solid var(--line);
  }
  .pdf-viewer-row iframe { width: 100%; height: 100%; border: 0; }
  .pdf-viewer-row .close-row {
    position: absolute; top: 10px; right: 14px;
    background: var(--ink); color: #fff;
    padding: 6px 12px; font-size: 12px;
    text-transform: uppercase; letter-spacing: 0.12em;
    cursor: pointer; border: none; z-index: 5;
  }
  .pdf-viewer-row { position: relative; }

  /* Branchen-Band ----------------------------------------------- */
  .industries {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 32px;
  }
  .industry-tag {
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.18);
    color: #f3f6fa;
    padding: 12px 20px;
    font-size: 14.5px;
    letter-spacing: 0.02em;
  }

  /* Cluster-Listen ---------------------------------------------- */
  .clusters {
    display: grid;
    grid-template-columns: 1fr;
    gap: 14px;
    margin-top: 36px;
  }
  details.cluster {
    background: var(--paper);
    border-left: 3px solid var(--gold-soft);
    box-shadow: 0 4px 12px rgba(8, 22, 48, 0.06);
  }
  details.cluster > summary {
    cursor: pointer;
    padding: 22px 28px;
    font-size: 18px;
    font-weight: 600;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--ink);
  }
  details.cluster > summary::-webkit-details-marker { display: none; }
  details.cluster > summary::after {
    content: "+";
    font-size: 24px;
    color: var(--gold);
    font-weight: 400;
    transition: transform 0.3s;
  }
  details.cluster[open] > summary::after { content: "−"; }
  details.cluster .cluster-meta {
    font-size: 14px;
    font-weight: 400;
    color: var(--ink-soft);
    margin-left: auto;
    margin-right: 18px;
  }
  .cover-grid {
    padding: 8px 28px 32px;
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 28px;
  }
  .cover-grid .cover-meta { font-size: 13px; }
  .cover-grid .cover-meta strong { font-size: 13.5px; }
  .cover-grid .cover-tag { font-size: 9.5px; padding: 4px 9px; letter-spacing: 0.14em; }

  /* Footer ------------------------------------------------------ */
  .bottombar {
    background: #07172e;
    color: #6a7a96;
    padding: 26px 6vw;
    font-size: 13px;
    display: flex;
    justify-content: space-between;
  }

  /* Mobile ------------------------------------------------------ */
  @media (max-width: 1100px) {
    .hero-covers { grid-template-columns: repeat(2, 1fr); }
    .cover-grid { grid-template-columns: repeat(3, 1fr); }
  }
  @media (max-width: 720px) {
    .hero-covers { grid-template-columns: 1fr 1fr; gap: 22px; }
    .cover-grid { grid-template-columns: 1fr 1fr; padding: 8px 18px 24px; gap: 18px; }
    .pdf-viewer-row.open { height: 520px; }
  }