:root {
      --prussian:   #001f45;
      --cobalt:     #003cac;
      --orange:     #ff8100;
      --orange-deep:#ff4200;
      --purple:     #823183;
      --white:      #ffffff;
      --off-white:  #f5f7fc;
      --light-grey: #e4e9f2;
      --mid-grey:   #8a96b0;
      --text:       #0d1b35;
      --text-mid:   #3a4a6b;
      --font:       'Montserrat', sans-serif;
      --radius:     12px;
    }

    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body { font-family: var(--font); color: var(--text); background: var(--white); -webkit-font-smoothing: antialiased; }

    /* ── Sidebar nav ── */
    .sidebar {
      position: fixed; left: 0; top: 0; height: 100vh; width: 220px;
      background: var(--prussian); z-index: 100; overflow-y: auto;
      display: flex; flex-direction: column;
      border-right: 1px solid rgba(255,255,255,0.06);
    }
    .sidebar-logo {
      padding: 28px 24px 20px;
      border-bottom: 1px solid rgba(255,255,255,0.08);
      display: flex; align-items: center; gap: 10px;
    }
    .sidebar-logo-text { font-size: 1.1rem; font-weight: 700; color: var(--white); }
    .sidebar-logo-text span { color: var(--orange); }
    .sidebar-label {
      font-size: 0.62rem; font-weight: 700; letter-spacing: 0.14em;
      text-transform: uppercase; color: var(--mid-grey);
      padding: 20px 24px 8px;
    }
    .sidebar nav a {
      display: block; padding: 9px 24px;
      font-size: 0.8rem; font-weight: 600; color: rgba(255,255,255,0.55);
      text-decoration: none; letter-spacing: 0.02em;
      transition: color 0.15s, background 0.15s;
      border-left: 2px solid transparent;
    }
    .sidebar nav a:hover, .sidebar nav a.active {
      color: var(--white);
      background: rgba(255,255,255,0.05);
      border-left-color: var(--orange);
    }
    .sidebar-footer {
      margin-top: auto; padding: 20px 24px;
      border-top: 1px solid rgba(255,255,255,0.08);
      font-size: 0.72rem; color: rgba(255,255,255,0.3);
    }

    /* ── Main content ── */
    .main { margin-left: 220px; }

    /* ── Section shell ── */
    .section { padding: 80px 72px; border-bottom: 1px solid var(--light-grey); }
    .section:last-child { border-bottom: none; }
    .section-dark { background: linear-gradient(160deg, var(--prussian) 0%, #002260 100%); border-bottom-color: rgba(255,255,255,0.06); }
    .section-grey { background: var(--off-white); }
    .section-purple { background: linear-gradient(150deg, #001f45 0%, #4a1a6e 55%, var(--purple) 100%); border-bottom-color: rgba(255,255,255,0.06); }

    /* ── Section headers ── */
    .section-eyebrow {
      font-size: 0.68rem; font-weight: 700; letter-spacing: 0.18em;
      text-transform: uppercase; color: var(--orange); margin-bottom: 10px;
    }
    .section-title {
      font-size: clamp(1.8rem, 2.5vw, 2.6rem); font-weight: 300;
      line-height: 1.1; letter-spacing: 0em; color: var(--text);
      margin-bottom: 16px;
    }
    .section-title.light { color: var(--white); }
    .section-desc { font-size: 0.95rem; color: var(--text-mid); line-height: 1.7; max-width: 600px; }
    .section-desc.light { color: rgba(255,255,255,0.62); }
    .section-header { margin-bottom: 52px; }
    hr.divider { border: none; border-top: 1px solid var(--light-grey); margin: 48px 0; }
    hr.divider-dark { border: none; border-top: 1px solid rgba(255,255,255,0.10); margin: 48px 0; }

    /* ── COVER ── */
    .cover {
      min-height: 100vh; padding: 0;
      background: linear-gradient(135deg, var(--prussian) 0%, #002260 50%, var(--cobalt) 100%);
      display: flex; flex-direction: column; justify-content: flex-end;
      position: relative; overflow: hidden; border-bottom: none;
    }
    .cover-arcs {
      position: absolute; right: -120px; top: 50%; transform: translateY(-50%);
      width: 680px; height: 680px; opacity: 0.14; pointer-events: none;
    }
    .cover-content { padding: 0 72px 72px; position: relative; z-index: 2; }
    .cover-tag {
      font-size: 0.7rem; font-weight: 700; letter-spacing: 0.18em;
      text-transform: uppercase; color: var(--orange);
      border: 1px solid var(--orange); display: inline-block;
      padding: 5px 14px; border-radius: 2px; margin-bottom: 28px;
    }
    .cover h1 {
      font-size: clamp(2.5rem, 4vw, 4rem); font-weight: 300;
      color: var(--white); letter-spacing: -0.01em; line-height: 1.0;
      margin-bottom: 24px;
    }
    .cover h1 em { font-style: normal; color: var(--orange); }
    .cover-sub {
      font-size: 1rem; color: rgba(255,255,255,0.55); max-width: 500px;
      line-height: 1.65; margin-bottom: 48px;
    }
    .cover-meta {
      display: flex; gap: 40px; padding-top: 24px;
      border-top: 1px solid rgba(255,255,255,0.10);
    }
    .cover-meta-item { }
    .cover-meta-label { font-size: 0.65rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--mid-grey); margin-bottom: 4px; }
    .cover-meta-value { font-size: 0.85rem; font-weight: 600; color: rgba(255,255,255,0.7); }

    /* ── LOGO SECTION ── */
    .logo-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-bottom: 48px; }
    .logo-swatch {
      border-radius: var(--radius); padding: 48px 32px;
      display: flex; flex-direction: column; align-items: center; justify-content: center;
      gap: 24px; min-height: 180px;
      border: 1px solid var(--light-grey);
    }
    .logo-swatch.dark { background: var(--prussian); border-color: transparent; }
    .logo-swatch.cobalt { background: var(--cobalt); border-color: transparent; }
    .logo-swatch.orange-bg { background: var(--orange); border-color: transparent; }
    .logo-swatch.purple-bg { background: var(--purple); border-color: transparent; }
    .logo-swatch.light { background: var(--off-white); }
    .logo-swatch-label {
      font-size: 0.7rem; font-weight: 700; letter-spacing: 0.10em;
      text-transform: uppercase;
    }
    .logo-swatch.dark .logo-swatch-label,
    .logo-swatch.cobalt .logo-swatch-label,
    .logo-swatch.orange-bg .logo-swatch-label,
    .logo-swatch.purple-bg .logo-swatch-label { color: rgba(255,255,255,0.5); }
    .logo-swatch.light .logo-swatch-label { color: var(--mid-grey); }

    /* SVG Logo inline */
    .logo-svg-full { display: flex; align-items: center; gap: 14px; }
    .logo-svg-full .wordmark {
      font-size: 2rem; font-weight: 300; letter-spacing: -0.01em; line-height: 1;
    }
    .logo-svg-full .wordmark.dark-text { color: var(--prussian); }
    .logo-svg-full .wordmark.white-text { color: var(--white); }
    .logo-svg-full .wordmark sup { font-size: 0.55em; font-weight: 500; }

    /* Icon clear space rule */
    .clearspace-demo {
      display: flex; align-items: center; justify-content: center;
      padding: 40px;
      border: 2px dashed var(--light-grey); border-radius: var(--radius);
      position: relative;
    }
    .clearspace-label {
      position: absolute; top: 8px; left: 12px;
      font-size: 0.68rem; color: var(--mid-grey); font-weight: 600;
    }

    /* Incorrect usage grid */
    .dont-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
    .dont-card {
      border-radius: var(--radius); overflow: hidden;
      border: 1px solid var(--light-grey);
    }
    .dont-preview {
      padding: 32px; background: var(--off-white);
      display: flex; align-items: center; justify-content: center; min-height: 120px;
    }
    .dont-badge {
      padding: 10px 16px;
      display: flex; gap: 8px; align-items: flex-start;
      border-top: 1px solid var(--light-grey);
    }
    .dont-badge .x { color: #e53935; font-weight: 900; font-size: 0.9rem; flex-shrink: 0; }
    .dont-badge p { font-size: 0.78rem; color: var(--text-mid); line-height: 1.45; }

    /* ── COLORS ── */
    .color-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; margin-bottom: 40px; }
    .color-card { border-radius: var(--radius); overflow: hidden; box-shadow: 0 2px 12px rgba(0,0,0,0.07); }
    .color-swatch { height: 120px; }
    .color-info { padding: 16px; background: var(--white); border: 1px solid var(--light-grey); border-top: none; }
    .color-name { font-size: 0.8rem; font-weight: 700; color: var(--text); margin-bottom: 6px; }
    .color-values { font-size: 0.72rem; color: var(--text-mid); line-height: 1.6; font-weight: 500; }
    .color-hex { font-size: 0.85rem; font-weight: 600; color: var(--text); letter-spacing: 0.04em; }

    .color-usage { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
    .color-usage-card {
      border-radius: var(--radius); padding: 24px;
      border: 1px solid var(--light-grey);
    }
    .color-usage-card h4 { font-size: 0.82rem; font-weight: 700; margin-bottom: 8px; color: var(--text); }
    .color-usage-card p  { font-size: 0.8rem; color: var(--text-mid); line-height: 1.55; }
    .color-dot-row { display: flex; gap: 8px; margin-bottom: 12px; }
    .color-dot { width: 20px; height: 20px; border-radius: 50%; border: 1px solid rgba(0,0,0,0.06); }

    /* ── TYPOGRAPHY ── */
    .type-scale { margin-bottom: 48px; }
    .type-row {
      display: flex; align-items: baseline; gap: 32px;
      padding: 20px 0; border-bottom: 1px solid var(--light-grey);
    }
    .type-row:last-child { border-bottom: none; }
    .type-meta { width: 160px; flex-shrink: 0; }
    .type-meta-name { font-size: 0.72rem; font-weight: 700; color: var(--text); letter-spacing: 0.05em; text-transform: uppercase; }
    .type-meta-spec { font-size: 0.68rem; color: var(--mid-grey); margin-top: 4px; line-height: 1.5; }
    .type-sample { flex: 1; }

    .type-pair {
      display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 40px;
    }
    .type-pair-card {
      border-radius: var(--radius); padding: 32px;
      border: 1px solid var(--light-grey); background: var(--off-white);
    }
    .type-pair-card.dark { background: var(--prussian); border-color: transparent; }
    .type-pair-card .label {
      font-size: 0.65rem; font-weight: 700; letter-spacing: 0.14em;
      text-transform: uppercase; color: var(--orange); margin-bottom: 16px;
    }

    /* ── VISUAL ELEMENTS ── */
    .motif-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-bottom: 40px; }
    .motif-card {
      border-radius: var(--radius); padding: 32px; min-height: 160px;
      display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 16px;
      border: 1px solid var(--light-grey); background: var(--off-white);
      text-align: center;
    }
    .motif-card.dark { background: var(--prussian); border-color: transparent; }
    .motif-card.cobalt { background: var(--cobalt); border-color: transparent; }
    .motif-card.purple { background: var(--purple); border-color: transparent; }
    .motif-label { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--mid-grey); }
    .motif-card.dark .motif-label,
    .motif-card.cobalt .motif-label,
    .motif-card.purple .motif-label { color: rgba(255,255,255,0.45); }

    .pattern-examples { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
    .pattern-box {
      border-radius: var(--radius); overflow: hidden;
      border: 1px solid var(--light-grey);
    }
    .pattern-bg {
      height: 160px; position: relative; overflow: hidden;
      display: flex; align-items: center; justify-content: center;
    }
    .pattern-caption { padding: 14px 16px; border-top: 1px solid var(--light-grey); }
    .pattern-caption h4 { font-size: 0.8rem; font-weight: 700; color: var(--text); }
    .pattern-caption p  { font-size: 0.72rem; color: var(--mid-grey); margin-top: 3px; }

    /* ── BRAND VOICE ── */
    .voice-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-bottom: 48px; }
    .voice-card {
      border-radius: var(--radius); padding: 28px;
      border: 1px solid var(--light-grey);
    }
    .voice-card-icon { font-size: 1.6rem; margin-bottom: 14px; }
    .voice-card h3 { font-size: 0.95rem; font-weight: 500; color: var(--text); margin-bottom: 8px; }
    .voice-card p { font-size: 0.83rem; color: var(--text-mid); line-height: 1.6; }
    .voice-card .voice-do { margin-top: 12px; font-size: 0.78rem; color: var(--cobalt); font-weight: 600; }
    .voice-card .voice-dont { font-size: 0.78rem; color: #c0392b; font-weight: 600; }

    .tagline-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
    .tagline-card {
      border-radius: var(--radius); padding: 24px 20px;
      background: var(--prussian);
      border-left: 3px solid var(--orange);
    }
    .tagline-card .tagline-text {
      font-size: 1rem; font-weight: 400; color: var(--white); letter-spacing: 0em; line-height: 1.3;
    }
    .tagline-card .tagline-use { font-size: 0.72rem; color: rgba(255,255,255,0.45); margin-top: 8px; }

    /* ── APPLICATIONS ── */
    .app-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
    .app-card {
      border-radius: var(--radius); overflow: hidden;
      border: 1px solid var(--light-grey);
    }
    .app-preview { padding: 32px; min-height: 200px; position: relative; overflow: hidden; }
    .app-info { padding: 16px 20px; border-top: 1px solid var(--light-grey); }
    .app-info h4 { font-size: 0.82rem; font-weight: 700; color: var(--text); }
    .app-info p { font-size: 0.75rem; color: var(--mid-grey); margin-top: 3px; }

    /* Responsive */
    @media (max-width: 1100px) {
      .sidebar { width: 180px; }
      .main { margin-left: 180px; }
      .section { padding: 60px 40px; }
      .cover-content { padding: 0 40px 60px; }
    }
    @media (max-width: 780px) {
      .sidebar { display: none; }
      .main { margin-left: 0; }
      .section { padding: 48px 24px; }
      .cover-content { padding: 0 24px 48px; }
      .color-grid { grid-template-columns: repeat(2, 1fr); }
      .logo-grid { grid-template-columns: 1fr 1fr; }
      .type-pair { grid-template-columns: 1fr; }
      .motif-grid { grid-template-columns: 1fr 1fr; }
      .voice-grid { grid-template-columns: 1fr; }
      .tagline-grid { grid-template-columns: 1fr; }
      .app-grid { grid-template-columns: 1fr; }
      .dont-grid { grid-template-columns: 1fr; }
    }