:root {
        --bg-0: #0b1a2c;
        --bg-1: #14345a;
        --bg-2: #204b7c;
        --ink: #f5f1e6;
        --ink-soft: #d8d0bd;
        --ink-dim: #b3aa93;
        --gold: #e8c874;
        --gold-deep: #c9a24b;
        --card: rgba(255, 255, 255, 0.045);
        --card-border: rgba(232, 200, 116, 0.22);
        --shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
        --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
        --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
      }

      * { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
      html, body { height: 100%; margin: 0; }

      body {
        font-family: var(--serif);
        color: var(--ink);
        background:
          radial-gradient(1200px 600px at 50% -10%, var(--bg-2), transparent 60%),
          linear-gradient(160deg, var(--bg-1), var(--bg-0) 70%);
        background-attachment: fixed;
        overflow: hidden;
        -webkit-font-smoothing: antialiased;
        text-rendering: optimizeLegibility;
      }

      .app {
        display: grid;
        grid-template-rows: auto 1fr auto;
        height: 100dvh;
        padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
      }

      /* ---------- Header ---------- */
      header {
        text-align: center;
        padding: 18px 20px 10px;
      }
      .eyebrow {
        font-family: var(--sans);
        font-size: 11px;
        letter-spacing: 0.32em;
        text-transform: uppercase;
        color: var(--gold);
        margin: 0 0 4px;
        opacity: 0.9;
      }
      header .eyebrow {
        margin: 10px 0 0;
      }
      .brand {
        font-size: clamp(19px, 5.4vw, 24px);
        font-weight: 600;
        margin: 0;
        letter-spacing: 0.01em;
      }
      .rule {
        width: 54px;
        height: 2px;
        margin: 10px auto 0;
        background: linear-gradient(90deg, transparent, var(--gold-deep), transparent);
        border-radius: 2px;
      }

      /* ---------- Carousel ---------- */
      .carousel {
        display: flex;
        overflow-x: auto;
        overflow-y: hidden;
        scroll-snap-type: x mandatory;
        scroll-behavior: smooth;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
      }
      .carousel::-webkit-scrollbar { display: none; }

      .slide {
        flex: 0 0 100%;
        width: 100%;
        scroll-snap-align: center;
        scroll-snap-stop: always;
        display: flex;
        justify-content: center;
        align-items: flex-start;
        padding: 6px 18px 4px;
        overflow: hidden;
      }

      .card {
        width: 100%;
        max-width: 620px;
        height: 100%;
        background: var(--card);
        border: 1px solid var(--card-border);
        border-radius: 22px;
        box-shadow: var(--shadow);
        backdrop-filter: blur(8px);
        -webkit-backdrop-filter: blur(8px);
        padding: 26px 22px 30px;
        overflow-y: auto;
        overscroll-behavior: contain;
        touch-action: pan-y;
        scrollbar-width: thin;
        scrollbar-color: var(--gold-deep) transparent;
      }
      .card::-webkit-scrollbar { width: 4px; }
      .card::-webkit-scrollbar-thumb { background: var(--gold-deep); border-radius: 4px; }

      .num {
        font-family: var(--sans);
        font-size: 12px;
        letter-spacing: 0.18em;
        text-transform: uppercase;
        color: var(--gold);
        display: inline-block;
        margin-bottom: 12px;
        padding: 4px 12px;
        border: 1px solid var(--card-border);
        border-radius: 999px;
      }
      h2 {
        font-size: clamp(22px, 6.4vw, 30px);
        line-height: 1.2;
        font-weight: 600;
        margin: 0 0 16px;
        color: var(--ink);
      }
      h3 {
        font-family: var(--sans);
        font-size: 13px;
        letter-spacing: 0.12em;
        text-transform: uppercase;
        color: var(--gold);
        margin: 22px 0 10px;
        font-weight: 600;
      }
      p {
        font-size: clamp(16px, 4.4vw, 18px);
        line-height: 1.62;
        color: var(--ink-soft);
        margin: 0 0 14px;
      }
      ul { margin: 0; padding: 0; list-style: none; }
      li {
        position: relative;
        padding: 0 0 0 22px;
        margin: 0 0 14px;
        font-size: clamp(15.5px, 4.2vw, 17.5px);
        line-height: 1.55;
        color: var(--ink-soft);
      }
      li::before {
        content: "";
        position: absolute;
        left: 2px;
        top: 0.72em;
        width: 7px;
        height: 7px;
        border-radius: 50%;
        background: var(--gold);
        box-shadow: 0 0 8px rgba(232, 200, 116, 0.6);
      }

      blockquote {
        margin: 4px 0 0;
        padding: 16px 18px;
        border-left: 3px solid var(--gold-deep);
        background: rgba(232, 200, 116, 0.06);
        border-radius: 0 14px 14px 0;
      }
      blockquote p {
        font-style: italic;
        font-size: clamp(15px, 4.1vw, 17px);
        color: var(--ink-soft);
      }
      blockquote p:last-child { margin-bottom: 0; }
      cite {
        display: block;
        margin-top: 12px;
        font-family: var(--sans);
        font-style: normal;
        font-size: 12px;
        letter-spacing: 0.1em;
        text-transform: uppercase;
        color: var(--ink-dim);
      }

      /* ---------- Cover slide ---------- */
      .cover .card {
        display: flex;
        flex-direction: column;
        justify-content: center;
        text-align: center;
        border-color: rgba(232, 200, 116, 0.35);
      }
      .cover .mark {
        font-size: 46px;
        line-height: 1;
        margin-bottom: 18px;
        filter: drop-shadow(0 4px 12px rgba(0,0,0,0.4));
      }
      .cover h2 { font-size: clamp(30px, 9vw, 44px); margin-bottom: 14px; }
      .cover .lede {
        font-size: clamp(16px, 4.4vw, 19px);
        color: var(--ink-dim);
        max-width: 34ch;
        margin: 0 auto;
        font-style: italic;
      }
      .cover .hint {
        margin-top: 30px;
        font-family: var(--sans);
        font-size: 12px;
        letter-spacing: 0.14em;
        text-transform: uppercase;
        color: var(--gold);
        animation: pulse 2.4s ease-in-out infinite;
      }
      @keyframes pulse { 0%,100% { opacity: .4; } 50% { opacity: 1; } }

      /* ---------- Controls ---------- */
      footer {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 16px;
        padding: 12px 20px 16px;
      }
      .nav-btn {
        flex: 0 0 auto;
        width: 46px;
        height: 46px;
        border-radius: 50%;
        border: 1px solid var(--card-border);
        background: var(--card);
        color: var(--gold);
        font-size: 20px;
        display: grid;
        place-items: center;
        cursor: pointer;
        transition: transform .15s ease, background .2s ease, opacity .2s ease;
      }
      .nav-btn:active { transform: scale(0.9); }
      .nav-btn:disabled { opacity: 0.28; cursor: default; }

      .dots {
        display: flex;
        align-items: center;
        gap: 8px;
        flex-wrap: wrap;
        justify-content: center;
        max-width: 62vw;
      }
      .dot {
        width: 8px;
        height: 8px;
        border-radius: 50%;
        border: none;
        padding: 0;
        background: rgba(255,255,255,0.22);
        cursor: pointer;
        transition: all .25s ease;
      }
      .dot.active {
        width: 26px;
        border-radius: 6px;
        background: linear-gradient(90deg, var(--gold), var(--gold-deep));
      }

      @media (min-height: 760px) {
        .slide { padding-top: 14px; }
        .card { padding: 34px 28px 38px; }
      }

      /* ---------- Update / upgrade toast ---------- */
      .update-toast {
        position: fixed;
        left: 50%;
        bottom: calc(92px + env(safe-area-inset-bottom));
        transform: translateX(-50%) translateY(16px);
        z-index: 60;
        display: flex;
        align-items: center;
        gap: 12px;
        padding: 11px 12px 11px 18px;
        max-width: calc(100vw - 32px);
        font-family: var(--sans);
        background: rgba(11, 26, 44, 0.94);
        border: 1px solid var(--card-border);
        border-radius: 14px;
        box-shadow: var(--shadow);
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        opacity: 0;
        pointer-events: none;
        transition: opacity .3s ease, transform .3s ease;
      }
      .update-toast.show {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
        pointer-events: auto;
      }
      .update-toast p { margin: 0; font-size: 14px; line-height: 1.3; color: var(--ink-soft); }
      .update-toast .up {
        flex: 0 0 auto;
        border: none;
        cursor: pointer;
        font-family: var(--sans);
        font-size: 13px;
        font-weight: 600;
        letter-spacing: 0.03em;
        color: #0b1a2c;
        background: linear-gradient(90deg, var(--gold), var(--gold-deep));
        padding: 9px 16px;
        border-radius: 999px;
        transition: transform .15s ease;
      }
      .update-toast .up:active { transform: scale(0.94); }
      .update-toast .dismiss {
        flex: 0 0 auto;
        border: none;
        background: transparent;
        color: var(--ink-dim);
        font-size: 20px;
        line-height: 1;
        cursor: pointer;
        padding: 4px 6px;
      }
      .install-toast {
        bottom: calc(150px + env(safe-area-inset-bottom));
      }