/* ================================================================
   FakeOsUpdateScreens.css
   Primary Color: #6366F1 (Indigo — tech, modern, trustworthy)
   Dark Mode: Full support
   ================================================================ */

/* ── CSS Variables ─────────────────────────────────────────────── */
:root {
    --fou-primary:       #6366F1;
    --fou-primary-dark:  #4F46E5;
    --fou-primary-light: #A5B4FC;
    --fou-primary-glow:  rgba(99, 102, 241, 0.25);

    --fou-bg:            #F1F5F9;
    --fou-surface:       #FFFFFF;
    --fou-surface-2:     #F8FAFC;
    --fou-border:        #E2E8F0;

    --fou-text:          #0F172A;
    --fou-text-2:        #475569;
    --fou-text-muted:    #94A3B8;

    --fou-success:       #10B981;
    --fou-warning:       #F59E0B;

    --fou-radius-sm:     8px;
    --fou-radius-md:     14px;
    --fou-radius-lg:     20px;
    --fou-radius-xl:     28px;

    --fou-shadow-sm:     0 1px 3px rgba(0,0,0,0.07);
    --fou-shadow-md:     0 4px 16px rgba(0,0,0,0.09);
    --fou-shadow-lg:     0 12px 40px rgba(0,0,0,0.11);

    --fou-transition:    all 0.2s cubic-bezier(0.4,0,0.2,1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --fou-bg:         #0B0F1A;
        --fou-surface:    #141824;
        --fou-surface-2:  #1E2235;
        --fou-border:     #2A3050;
        --fou-text:       #F0F4FF;
        --fou-text-2:     #94A3B8;
        --fou-text-muted: #64748B;
        --fou-shadow-sm:  0 1px 3px rgba(0,0,0,0.4);
        --fou-shadow-md:  0 4px 16px rgba(0,0,0,0.45);
        --fou-shadow-lg:  0 12px 40px rgba(0,0,0,0.55);
    }
}

[data-theme="dark"] {
    --fou-bg:         #0B0F1A;
    --fou-surface:    #141824;
    --fou-surface-2:  #1E2235;
    --fou-border:     #2A3050;
    --fou-text:       #F0F4FF;
    --fou-text-2:     #94A3B8;
    --fou-text-muted: #64748B;
}

/* ── Base ──────────────────────────────────────────────────────── */
.fou-page *, .fou-seo-section *, .fou-faq-section * { box-sizing: border-box; }

.fou-page {
    background: var(--fou-bg);
    min-height: 100vh;
    padding: 2.5rem 0 3rem;
    transition: var(--fou-transition);
}

.fou-page .container,
.fou-seo-section .container,
.fou-faq-section .container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ── Header ────────────────────────────────────────────────────── */
.fou-header {
    margin-bottom: 2.25rem;
}

.fou-header__title {
    font-size: clamp(1.9rem, 4vw, 2.8rem);
    font-weight: 800;
    color: var(--fou-text);
    letter-spacing: -0.03em;
    margin: 0 0 0.6rem;
    line-height: 1.15;
}

.fou-header__subtitle {
    font-size: 1.05rem;
    color: var(--fou-text-2);
    max-width: 580px;
    margin: 0 auto;
    line-height: 1.65;
}

/* ── OS Selector Grid ──────────────────────────────────────────── */
.fou-os-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 0.85rem;
    margin-bottom: 1.75rem;
}

.fou-os-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.55rem;
    padding: 1.1rem 0.75rem 0.9rem;
    background: var(--fou-surface);
    border: 2px solid var(--fou-border);
    border-radius: var(--fou-radius-md);
    cursor: pointer;
    transition: var(--fou-transition);
    position: relative;
    text-align: center;
    font-family: inherit;
}

.fou-os-card:hover {
    border-color: var(--fou-primary);
    box-shadow: var(--fou-shadow-md);
    transform: translateY(-2px);
}

.fou-os-card--active {
    border-color: var(--fou-primary);
    background: linear-gradient(135deg,
        rgba(99,102,241,0.08) 0%,
        rgba(99,102,241,0.03) 100%);
    box-shadow: 0 0 0 3px var(--fou-primary-glow), var(--fou-shadow-sm);
}

.fou-os-card:focus-visible {
    outline: 2px solid var(--fou-primary);
    outline-offset: 2px;
}

.fou-os-card__icon {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    background: var(--fou-surface-2);
    color: var(--fou-primary);
    transition: var(--fou-transition);
    flex-shrink: 0;
}

.fou-os-card--active .fou-os-card__icon {
    background: var(--fou-primary);
    color: #fff;
}

.fou-os-card__name {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--fou-text);
    line-height: 1.2;
}

.fou-os-card__badge {
    position: absolute;
    top: -8px;
    right: -6px;
    background: var(--fou-primary);
    color: #fff;
    font-size: 0.6rem;
    font-weight: 700;
    padding: 0.15rem 0.45rem;
    border-radius: 20px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.fou-os-card__badge--retro {
    background: #B45309;
}

/* ── Controls Bar ──────────────────────────────────────────────── */
.fou-controls-bar {
    background: var(--fou-surface);
    border: 1px solid var(--fou-border);
    border-radius: var(--fou-radius-lg);
    padding: 1.25rem 1.5rem;
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
    gap: 1.25rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--fou-shadow-sm);
}

.fou-ctrl-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
    flex: 1;
    min-width: 140px;
}

.fou-ctrl-label {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--fou-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.fou-ctrl-speed-wrap {
    display: flex;
    gap: 0.4rem;
    flex-wrap: wrap;
}

.fou-speed-btn {
    padding: 0.4rem 0.75rem;
    border: 1.5px solid var(--fou-border);
    border-radius: var(--fou-radius-sm);
    background: var(--fou-surface-2);
    color: var(--fou-text-2);
    font-size: 0.78rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: var(--fou-transition);
    white-space: nowrap;
}

.fou-speed-btn:hover {
    border-color: var(--fou-primary);
    color: var(--fou-primary);
}

.fou-speed-btn--active {
    background: var(--fou-primary);
    border-color: var(--fou-primary);
    color: #fff;
}

.fou-ctrl-inline {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.fou-ctrl-unit {
    font-size: 0.8rem;
    color: var(--fou-text-muted);
    font-weight: 600;
}

.fou-input {
    padding: 0.48rem 0.75rem;
    border: 1.5px solid var(--fou-border);
    border-radius: var(--fou-radius-sm);
    background: var(--fou-surface-2);
    color: var(--fou-text);
    font-size: 0.875rem;
    font-family: inherit;
    transition: var(--fou-transition);
    width: 100%;
}

.fou-input:focus {
    outline: none;
    border-color: var(--fou-primary);
    box-shadow: 0 0 0 3px var(--fou-primary-glow);
}

.fou-input--wide { min-width: 200px; }

input[type="number"].fou-input { width: 70px; }

.fou-ctrl-actions {
    display: flex;
    gap: 0.65rem;
    align-items: center;
    flex-shrink: 0;
}

/* ── Buttons ───────────────────────────────────────────────────── */
.fou-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    padding: 0.6rem 1.3rem;
    border-radius: var(--fou-radius-sm);
    border: none;
    font-size: 0.875rem;
    font-weight: 700;
    font-family: inherit;
    cursor: pointer;
    transition: var(--fou-transition);
    white-space: nowrap;
}

.fou-btn--primary {
    background: var(--fou-primary);
    color: #fff;
    box-shadow: 0 2px 10px rgba(99,102,241,0.35);
}

.fou-btn--primary:hover {
    background: var(--fou-primary-dark);
    box-shadow: 0 4px 16px rgba(99,102,241,0.45);
    transform: translateY(-1px);
}

.fou-btn--secondary {
    background: var(--fou-surface-2);
    color: var(--fou-text);
    border: 1.5px solid var(--fou-border);
}

.fou-btn--secondary:hover {
    border-color: var(--fou-primary);
    color: var(--fou-primary);
}

.fou-btn:focus-visible {
    outline: 2px solid var(--fou-primary);
    outline-offset: 2px;
}

/* ── Preview Panel ─────────────────────────────────────────────── */
.fou-preview-panel {
    background: var(--fou-surface);
    border: 1px solid var(--fou-border);
    border-radius: var(--fou-radius-lg);
    overflow: hidden;
    box-shadow: var(--fou-shadow-md);
    margin-bottom: 2.5rem;
}

.fou-preview-label {
    padding: 0.75rem 1.25rem;
    background: var(--fou-surface-2);
    border-bottom: 1px solid var(--fou-border);
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--fou-text-2);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.fou-preview-hint {
    margin-left: auto;
    font-size: 0.72rem;
    color: var(--fou-text-muted);
    font-weight: 400;
}

.fou-preview-screen {
    width: 100%;
    aspect-ratio: 16 / 9;
    cursor: pointer;
    overflow: hidden;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--fou-transition);
}

.fou-preview-screen:hover {
    opacity: 0.92;
}

/* ── Fullscreen Overlay ────────────────────────────────────────── */
.fou-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 99999;
    pointer-events: none;
    overflow: hidden;
}

.fou-overlay.fou-overlay--active {
    display: flex;
    pointer-events: auto;
}

.fou-overlay-exit-hint {
    position: absolute;
    bottom: 1.5rem;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: rgba(0,0,0,0.6);
    color: rgba(255,255,255,0.85);
    padding: 0.5rem 1.25rem;
    border-radius: 30px;
    font-size: 0.8rem;
    font-family: inherit;
    backdrop-filter: blur(8px);
    opacity: 0;
    transition: opacity 0.3s ease, transform 0.3s ease;
    pointer-events: none;
    z-index: 100001;
    white-space: nowrap;
}

.fou-overlay-exit-hint kbd {
    background: rgba(255,255,255,0.2);
    padding: 0.1em 0.4em;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.85em;
}

.fou-overlay.fou-overlay--hint .fou-overlay-exit-hint {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ════════════════════════════════════════════════════════════════
   OS SCREEN TEMPLATES
   Each screen fills 100% of its container (preview or overlay)
════════════════════════════════════════════════════════════════ */

/* ── Shared screen wrapper ── */
.fou-screen {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: absolute;
    inset: 0;
    font-family: inherit;
    overflow: hidden;
    user-select: none;
}

/* ════════════════════════════════════════
   WINDOWS 11
════════════════════════════════════════ */
.fou-screen--win11 {
    background: #0a0a0a;
    color: #fff;
    font-family: 'Segoe UI Variable', 'Segoe UI', system-ui, sans-serif;
}

.win11-logo {
    margin-bottom: 3em;
}

.win11-logo svg {
    width: clamp(40px, 6vw, 72px);
    height: clamp(40px, 6vw, 72px);
    fill: #fff;
}

.win11-spinner {
    width: clamp(28px, 4vw, 48px);
    height: clamp(28px, 4vw, 48px);
    border: 3px solid rgba(255,255,255,0.15);
    border-top-color: #fff;
    border-radius: 50%;
    animation: fou-spin 0.9s linear infinite;
    margin-bottom: 2.5em;
}

.win11-title {
    font-size: clamp(1rem, 2.5vw, 1.75rem);
    font-weight: 300;
    letter-spacing: -0.01em;
    margin-bottom: 0.5em;
    text-align: center;
}

.win11-pct {
    font-size: clamp(0.75rem, 1.5vw, 1rem);
    color: rgba(255,255,255,0.6);
    margin-bottom: 0.3em;
}

.win11-msg {
    font-size: clamp(0.65rem, 1.2vw, 0.875rem);
    color: rgba(255,255,255,0.45);
    margin-top: 2em;
    text-align: center;
    max-width: 60%;
}

/* ════════════════════════════════════════
   WINDOWS 10
════════════════════════════════════════ */
.fou-screen--win10 {
    background: #0078D7;
    color: #fff;
    font-family: 'Segoe UI', system-ui, sans-serif;
}

.win10-logo svg {
    width: clamp(36px, 5.5vw, 64px);
    height: clamp(36px, 5.5vw, 64px);
    fill: #fff;
    margin-bottom: 1.5em;
    display: block;
}

.win10-ring {
    width: clamp(32px, 4.5vw, 56px);
    height: clamp(32px, 4.5vw, 56px);
    border: 4px solid rgba(255,255,255,0.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: fou-spin 1s linear infinite;
    margin-bottom: 2em;
}

.win10-title {
    font-size: clamp(1.1rem, 2.8vw, 2rem);
    font-weight: 300;
    margin-bottom: 0.3em;
    text-align: center;
}

.win10-pct {
    font-size: clamp(1.5rem, 4vw, 3rem);
    font-weight: 200;
    margin-bottom: 0.2em;
}

.win10-sub {
    font-size: clamp(0.7rem, 1.3vw, 0.95rem);
    color: rgba(255,255,255,0.75);
    text-align: center;
}


/* ════════════════════════════════════════
   WINDOWS XP BOOT SCREEN — Pixel Accurate
════════════════════════════════════════ */
.fou-screen--winxp {
    background: #050505;
    color: #fff;
    font-family: 'Tahoma', 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: absolute;
    inset: 0;
    gap: 0;
}

/* ── Logo block: flag + text side by side ── */
.winxp-logo-block {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: clamp(12px, 2.5vw, 28px);
    margin-bottom: clamp(40px, 8vw, 100px);
}

/* ── Colorful Windows flag ── */
.winxp-flag {
    flex-shrink: 0;
    /* Subtle drop shadow like the real logo */
    filter: drop-shadow(2px 3px 6px rgba(0,0,0,0.7));
}

.winxp-flag-svg {
    width:  clamp(52px, 8vw, 96px);
    height: clamp(52px, 8vw, 96px);
    /* Slight perspective skew — matches real XP flag */
    transform: skewY(-3deg);
}

/* ── Text block ── */
.winxp-text-block {
    display: flex;
    flex-direction: column;
    gap: 0;
    line-height: 1;
}

/* "Microsoft®" — small, light weight */
.winxp-microsoft {
    font-size: clamp(0.55rem, 1vw, 0.85rem);
    font-weight: 400;
    color: rgba(255,255,255,0.85);
    letter-spacing: 0.04em;
    margin-bottom: clamp(2px, 0.4vw, 5px);
}

/* "Windows®xp" row */
.winxp-windows-xp {
    display: flex;
    align-items: baseline;
    gap: clamp(2px, 0.3vw, 4px);
    line-height: 1;
}

.winxp-windows {
    font-size: clamp(1.4rem, 3.2vw, 3rem);
    font-weight: 300;
    color: #ffffff;
    letter-spacing: -0.01em;
    font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
}

.winxp-xp {
    font-size: clamp(1rem, 2.4vw, 2.2rem);
    font-weight: 700;
    color: #FF6600;
    font-style: italic;
    font-family: 'Tahoma', Arial, sans-serif;
    letter-spacing: -0.02em;
    margin-left: clamp(1px, 0.2vw, 3px);
}

.winxp-reg {
    font-size: clamp(0.35rem, 0.6vw, 0.55rem);
    vertical-align: super;
    color: rgba(255,255,255,0.7);
    font-weight: 400;
}

.winxp-reg--tm {
    color: rgba(255,255,255,0.6);
    font-size: clamp(0.3rem, 0.5vw, 0.5rem);
}

/* ── Marquee progress bar ── */
.winxp-marquee-wrap {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    margin-bottom: clamp(40px, 8vw, 100px);
}

.winxp-marquee-track {
    width: clamp(140px, 22vw, 260px);
    height: clamp(8px, 1.2vw, 14px);
    background: transparent;
    border: 1.5px solid rgba(255,255,255,0.35);
    border-radius: 999px;
    position: relative;
    overflow: hidden;
}

/* The moving blue dot/capsule */
.winxp-marquee-dot {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: clamp(16px, 3vw, 32px);
    height: calc(100% - 4px);
    background: linear-gradient(
        to bottom,
        #60B0FF 0%,
        #1A78E8 40%,
        #0A5ACC 100%
    );
    border-radius: 999px;
    box-shadow:
        0 0 clamp(4px, 0.8vw, 8px) rgba(30,120,255,0.8),
        0 0 clamp(8px, 1.5vw, 16px) rgba(30,120,255,0.4);
    /* Smooth continuous movement handled by JS via style.left */
    transition: left 0.08s linear;
}

/* ── Footer row ── */
.winxp-footer-row {
    position: absolute;
    bottom: clamp(16px, 3vw, 36px);
    left: clamp(20px, 4vw, 60px);
    right: clamp(20px, 4vw, 60px);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.winxp-copyright {
    font-size: clamp(0.55rem, 0.9vw, 0.75rem);
    color: rgba(255,255,255,0.45);
    font-family: 'Tahoma', Arial, sans-serif;
}

.winxp-ms-brand {
    font-size: clamp(0.65rem, 1.1vw, 0.9rem);
    color: rgba(255,255,255,0.55);
    font-style: italic;
    font-family: 'Tahoma', Arial, sans-serif;
    font-weight: 600;
}



/* ════════════════════════════════════════
   macOS — Pixel Accurate
════════════════════════════════════════ */
.fou-screen--macos {
    background: #000000;
    color: #fff;
    font-family: -apple-system, 'SF Pro Display',
                 'Helvetica Neue', Helvetica, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0;
    position: absolute;
    inset: 0;
}

/* Apple Logo */
.macos-apple-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: clamp(20px, 4vw, 48px);
    /* Subtle white glow — exactly like real macOS */
    filter: drop-shadow(0 0 clamp(6px, 1.2vw, 14px) rgba(255,255,255,0.55));
}

.macos-apple-svg {
    width:  clamp(52px, 8vw, 110px);
    height: clamp(52px, 8vw, 110px);
}

/* Progress bar wrapper */
.macos-update-wrap {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    width: clamp(200px, 30vw, 340px);
    gap: clamp(6px, 0.8vw, 10px);
}

/* Track — very subtle */
.macos-bar-track {
    width: 100%;
    height: clamp(3px, 0.45vw, 5px);
    background: rgba(255, 255, 255, 0.15);
    border-radius: 999px;
    overflow: hidden;
    position: relative;
}

/* Fill — bright white with soft glow */
.macos-bar-fill {
    height: 100%;
    background: rgba(255, 255, 255, 0.90);
    border-radius: 999px;
    transition: width 0.5s ease;
    width: 0%;
    box-shadow: 0 0 6px rgba(255,255,255,0.4);
}

/* "About X minutes remaining…" */
.macos-time-remaining {
    font-size: clamp(0.6rem, 1vw, 0.78rem);
    color: rgba(255, 255, 255, 0.50);
    font-weight: 300;
    letter-spacing: 0.01em;
    white-space: nowrap;
    text-align: left;
    width: 100%;
}




/* ════════════════════════════════════════
   UBUNTU
════════════════════════════════════════ */
.fou-screen--ubuntu {
    background: #300A24;
    color: #fff;
    font-family: 'Ubuntu', 'Cantarell', 'DejaVu Sans', sans-serif;
}

.ubuntu-logo {
    font-size: clamp(0.9rem, 2.2vw, 1.4rem);
    font-weight: 300;
    letter-spacing: 0.1em;
    margin-bottom: 0.3em;
    color: #E95420;
}

.ubuntu-logo-icon {
    font-size: clamp(2rem, 5vw, 4rem);
    margin-bottom: 0.5em;
    line-height: 1;
}

.ubuntu-bar-wrap {
    width: clamp(180px, 50%, 400px);
    margin-bottom: 1em;
}

.ubuntu-bar-outer {
    width: 100%;
    height: clamp(6px, 1vw, 10px);
    background: rgba(255,255,255,0.1);
    border-radius: 5px;
    overflow: hidden;
}

.ubuntu-bar-inner {
    height: 100%;
    background: #E95420;
    border-radius: 5px;
    transition: width 0.4s ease;
    width: 0%;
}

.ubuntu-pct {
    font-size: clamp(0.65rem, 1.1vw, 0.82rem);
    color: rgba(255,255,255,0.5);
    text-align: center;
    margin-top: 0.4em;
}

.ubuntu-msg {
    font-size: clamp(0.65rem, 1.1vw, 0.82rem);
    color: rgba(255,255,255,0.4);
    text-align: center;
    margin-top: 1.5em;
    max-width: 55%;
}

/* ════════════════════════════════════════
   ANDROID
════════════════════════════════════════ */
.fou-screen--android {
    background: #000;
    color: #fff;
    font-family: 'Google Sans', 'Roboto', sans-serif;
}

.android-logo {
    font-size: clamp(2rem, 5vw, 4rem);
    margin-bottom: 1em;
    line-height: 1;
}

.android-title {
    font-size: clamp(0.85rem, 2vw, 1.3rem);
    font-weight: 400;
    color: rgba(255,255,255,0.87);
    margin-bottom: 2em;
    text-align: center;
}

.android-bar-wrap {
    width: clamp(180px, 50%, 380px);
    margin-bottom: 1em;
}

.android-bar-outer {
    width: 100%;
    height: clamp(3px, 0.5vw, 5px);
    background: rgba(255,255,255,0.12);
    border-radius: 3px;
    overflow: hidden;
}

.android-bar-inner {
    height: 100%;
    background: #4CAF50;
    border-radius: 3px;
    transition: width 0.4s ease;
    width: 0%;
}

.android-pct {
    font-size: clamp(0.65rem, 1.1vw, 0.82rem);
    color: rgba(255,255,255,0.4);
    text-align: center;
    margin-top: 0.4em;
}

.android-msg {
    font-size: clamp(0.65rem, 1.1vw, 0.82rem);
    color: rgba(255,255,255,0.35);
    text-align: center;
    margin-top: 1.5em;
    max-width: 55%;
}



/* ════════════════════════════════════════
   CHROME OS UPDATE SCREEN
════════════════════════════════════════ */
.fou-screen--chromeos {
    background: #ffffff;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: absolute;
    inset: 0;
    gap: 0;
    font-family: 'Google Sans', 'Roboto', Arial, sans-serif;
}

/* ── Chrome Logo ── */
.chromeos-logo {
    margin-bottom: clamp(20px, 3.5vw, 36px);
    /* Slow spin animation — matches real ChromeOS update screen */
    animation: chromeos-spin 3s linear infinite;
}

.chromeos-logo-svg {
    width:  clamp(56px, 8vw, 88px);
    height: clamp(56px, 8vw, 88px);
}

@keyframes chromeos-spin {
    from { transform: rotate(0deg);   }
    to   { transform: rotate(360deg); }
}

/* ── Title ── */
.chromeos-title {
    font-size:   clamp(1.1rem, 2.2vw, 1.6rem);
    font-weight: 400;
    color:       #202124;
    margin:      0 0 clamp(20px, 3vw, 32px) 0;
    letter-spacing: 0;
    text-align: center;
}

/* ── Progress bar ── */
.chromeos-bar-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: clamp(6px, 1vw, 10px);
    width: 100%;
}

.chromeos-bar-track {
    width:            clamp(200px, 32vw, 360px);
    height:           clamp(4px, 0.6vw, 6px);
    background:       #e8eaed;
    border-radius:    999px;
    overflow:         hidden;
}

.chromeos-bar-inner {
    height:           100%;
    background:       #4285F4;
    border-radius:    999px;
    transition:       width 0.4s ease;
}

/* ── Percentage ── */
.chromeos-pct {
    font-size:   clamp(0.75rem, 1.2vw, 0.9rem);
    font-weight: 400;
    color:       #5f6368;
}

/* ── Footer ── */
.chromeos-footer {
    margin-top:  clamp(16px, 2.5vw, 28px);
    font-size:   clamp(0.72rem, 1.1vw, 0.85rem);
    font-weight: 400;
    color:       #5f6368;
    text-align:  center;
}



/* ── Spinner animation ─────────────────────────────────────────── */
@keyframes fou-spin {
    to { transform: rotate(360deg); }
}

/* ── SEO Sections ──────────────────────────────────────────────── */
.fou-seo-section,
.fou-faq-section {
    background: var(--fou-bg);
    padding: 3.5rem 0;
    border-top: 1px solid var(--fou-border);
}

.fou-seo-title {
    font-size: clamp(1.4rem, 3vw, 1.9rem);
    font-weight: 800;
    color: var(--fou-text);
    text-align: center;
    margin: 0 0 0.75rem;
    letter-spacing: -0.02em;
}

.fou-seo-intro {
    text-align: center;
    color: var(--fou-text-2);
    max-width: 600px;
    margin: 0 auto 2.5rem;
    line-height: 1.7;
    font-size: 0.95rem;
}

.fou-feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.1rem;
}

.fou-feature-card {
    background: var(--fou-surface);
    border: 1px solid var(--fou-border);
    border-radius: var(--fou-radius-md);
    padding: 1.4rem;
    transition: var(--fou-transition);
}

.fou-feature-card:hover {
    border-color: var(--fou-primary);
    box-shadow: var(--fou-shadow-md);
    transform: translateY(-2px);
}

.fou-feature-card__icon {
    font-size: 1.75rem;
    margin-bottom: 0.65rem;
    display: block;
}

.fou-feature-card h3 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--fou-text);
    margin: 0 0 0.4rem;
}

.fou-feature-card p {
    font-size: 0.85rem;
    color: var(--fou-text-2);
    line-height: 1.65;
    margin: 0;
}

/* ── FAQ ───────────────────────────────────────────────────────── */
.fou-faq-list {
    max-width: 760px;
    margin: 2rem auto 0;
    display: flex;
    flex-direction: column;
    gap: 0.7rem;
}

.fou-faq-item {
    background: var(--fou-surface);
    border: 1px solid var(--fou-border);
    border-radius: var(--fou-radius-md);
    overflow: hidden;
    transition: var(--fou-transition);
}

.fou-faq-item[open] {
    border-color: var(--fou-primary);
    box-shadow: var(--fou-shadow-sm);
}

.fou-faq-q {
    padding: 1rem 1.25rem;
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--fou-text);
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    user-select: none;
}

.fou-faq-q::-webkit-details-marker { display: none; }

.fou-faq-q::after {
    content: '+';
    font-size: 1.4rem;
    font-weight: 300;
    color: var(--fou-primary);
    flex-shrink: 0;
    transition: transform 0.25s ease;
    line-height: 1;
}

.fou-faq-item[open] .fou-faq-q::after { transform: rotate(45deg); }
.fou-faq-q:hover { color: var(--fou-primary); }

.fou-faq-a {
    padding: 0 1.25rem 1rem;
    border-top: 1px solid var(--fou-border);
}

.fou-faq-a p {
    font-size: 0.875rem;
    color: var(--fou-text-2);
    line-height: 1.7;
    margin: 0.75rem 0 0;
}

.fou-faq-a kbd {
    display: inline-block;
    padding: 0.1em 0.4em;
    font-size: 0.8em;
    font-family: monospace;
    background: var(--fou-surface-2);
    border: 1px solid var(--fou-border);
    border-radius: 4px;
    color: var(--fou-text);
}

/* ── Responsive ────────────────────────────────────────────────── */
@media (max-width: 768px) {
    .fou-controls-bar {
        flex-direction: column;
        align-items: stretch;
    }
    .fou-ctrl-actions {
        flex-direction: column;
    }
    .fou-btn { width: 100%; justify-content: center; }
    .fou-os-grid { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 480px) {
    .fou-os-grid { grid-template-columns: repeat(2, 1fr); }
}


/* ── Reduced Motion ────────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
    .win11-spinner,
    .win10-ring {
        animation: none !important;
        border-top-color: #fff;
        opacity: 0.6;
    }
}

/* ── Print ─────────────────────────────────────────────────────── */
@media print {
    .fou-overlay,
    .fou-controls-bar,
    .fou-os-grid { display: none !important; }
}