:root {
    --accent-green: #26ff96;
    /* primary (you provided) */
    --accent-gray: #e6e6e6;
    /* light off-gray */
    --accent-blue: #0099ff;
    /* 90's electric blue */

    /* light theme bases */
    --bg-light: #f7f9fb;
    --text-light: #071022;

    /* dark theme bases */
    --bg-dark: #04121a;
    --text-dark: #e6fff4;

    /* parchment variants */
    --paper-bg-light: #f6e8c3;
    --paper-text-light: #071022;
    --paper-bg-dark: #2b2416;
    --paper-text-dark: #f6e8c3;

    --paper-edge: #d1b37a;
    /* parchment border */

    /* dashed inner border color for the button (will be overridden by prefers-color-scheme below) */
    --btn-inner-dash: rgba(0, 0, 0, 0.06);
}

/* Use system preference when available; JS also keeps a live listener as a fallback */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: var(--bg-dark);
        --text: var(--text-dark);
        --paper-bg: var(--paper-bg-dark);
        --paper-text: var(--paper-text-dark);
        --btn-inner-dash: rgba(255, 255, 255, 0.06);
    }
}

@media (prefers-color-scheme: light) {
    :root {
        --bg: var(--bg-light);
        --text: var(--text-light);
        --paper-bg: var(--paper-bg-light);
        --paper-text: var(--paper-text-light);
        --btn-inner-dash: rgba(0, 0, 0, 0.06);
    }
}

html,
body {
    height: 100%;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Courier New', Courier, monospace;
    background: var(--bg);
    color: var(--text);
    transition: background .25s, color .25s;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Retro header with all three accents in a neon gradient */
header {
    padding: 1rem;
    text-align: center;
    font-weight: 800;
    letter-spacing: 1px;
    background-image: linear-gradient(90deg, var(--accent-blue), var(--accent-gray), var(--accent-green));
    color: #001;
    text-shadow: 0 1px 0 rgba(255, 255, 255, 0.45);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.25);
}

h1 {
    text-align: center;
    margin: 2rem 0 1rem;
    font-size: 2.6rem;
}

/* Centering wrapper */
.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 0 1rem 40vh;
}

/* The button wrapper keeps things tidy */
.download-wrap {
    display: flex;
    align-items: center;
    justify-content: center;
}

/* --- Square Download Button (explicitly square) --- */
.download-btn {
    width: 160px;
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: #001;
    font-weight: 900;
    font-size: 1rem;
    text-align: center;
    user-select: none;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(0, 0, 0, 0.04));
    border: 6px solid rgba(0, 0, 0, 0.14);
    position: relative;
    /* for the dashed inner border pseudo element */
    /* 90s-style offset twin shadows to feel "layered" */
    box-shadow: 8px 8px 0 var(--accent-gray), -8px -8px 0 var(--accent-blue);
    transform: translateZ(0);
    touch-action: manipulation;
    transition: transform 160ms ease, box-shadow 200ms ease, border-color 200ms ease;
}

/* tiny inner dashed border for that 90s era 'decor' */
.download-btn::after {
    content: "";
    position: absolute;
    inset: 8px;
    border: 3px dashed var(--btn-inner-dash);
    pointer-events: none;
    border-radius: 4px;
}

.download-btn:active {
    box-shadow: 4px 4px 0 var(--accent-gray), -4px -4px 0 var(--accent-blue);
    transform: translateY(2px);
}

/* Hover & focus highlight — makes the button glow and lifts it slightly */
.download-btn:hover,
.download-btn:focus-visible {
    box-shadow: 12px 12px 0 var(--accent-gray), -12px -12px 0 var(--accent-blue), 0 0 28px 6px rgba(38, 255, 150, 0.12);
    transform: translateY(-6px) scale(1.02);
    border-color: var(--accent-green);
    outline: none;
}

.download-btn:focus-visible {
    box-shadow: 12px 12px 0 var(--accent-gray), -12px -12px 0 var(--accent-blue), 0 0 32px 6px rgba(38, 255, 150, 0.18);
}

/* A sentinel sits just after the button (JS observes this) */
.sentinel {
    height: 1px;
    width: 100%;
}

/* --- Parchment scroll (CSS-only visual, animated reveal) --- */
.parchment {
    max-width: 760px;
    margin: 2rem auto;
    padding: 28px 34px;
    border-radius: 8px;
    border: 6px solid var(--paper-edge);
    background-color: var(--paper-bg);
    /* faint paper texture made with repeating-linear-gradients */
    background-image:
        linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(0, 0, 0, 0.03)),
        repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.018) 0px, rgba(0, 0, 0, 0.018) 2px, rgba(255, 255, 255, 0.01) 2px, rgba(255, 255, 255, 0.01) 8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.36);
    color: var(--paper-text);
    opacity: 0;
    transform: translateY(30px) scale(0.985);
    transition: opacity 600ms cubic-bezier(.2, .9, .2, 1), transform 600ms cubic-bezier(.2, .9, .2, 1);
    position: relative;
}

/* visible state toggled by JS */
.parchment.visible {
    opacity: 1;
    transform: none;
}

/* rolled edges using pseudo-elements for subtle scroll feel */
.parchment::before,
.parchment::after {
    content: "";
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 75%;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.08), rgba(255, 255, 255, 0.22));
    top: -30px;
    box-shadow: 0 10px 12px rgba(0, 0, 0, 0.2);
    pointer-events: none;
}

.parchment::after {
    bottom: -30px;
    top: auto;
    transform: translateX(-50%) rotate(180deg);
}

footer {
    text-align: center;
    margin: 4rem 0 2rem;
    opacity: 0.85;
    font-size: .9rem;
}

/* Responsive tweak */
@media (max-width:480px){ .download-btn{ width:140px; height:140px } h1{ font-size:1.8rem } .parchment{ margin:1rem; padding:18px } }