.card-stack-section {
    padding-block: clamp(16px, 3vw, 24px);
}

/* Reduce top spacing when the stack is used as the completed-projects gallery */
.projects-chapter#completed .card-stack-section {
    padding-block: 8px;
    margin-top: 0.25rem;
}

.card-stack-shell {
    display: grid;
    gap: 1.4rem;
}

.card-stack-heading {
    display: flex;
    justify-content: space-between;
    align-items: end;
    gap: 1rem;
    flex-wrap: wrap;
}

.card-stack-copy {
    max-width: 760px;
}

.card-stack-copy h2 {
    margin-top: 0.45rem;
    font-size: clamp(1.8rem, 3vw, 2.5rem);
}

.card-stack-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.card-stack-toggle {
    border: 1px solid rgba(var(--color-border-rgb), 0.9);
    background: rgba(var(--color-panel-rgb), 0.78);
    color: var(--text-primary);
    padding: 0.65rem 0.95rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    backdrop-filter: blur(14px);
    box-shadow: inset 0 1px 0 rgba(var(--color-text-primary-rgb), 0.04);
    transition: var(--transition);
}

.card-stack-toggle:hover,
.card-stack-toggle:focus-visible {
    border-color: rgba(var(--color-accent-primary-rgb), 0.28);
    background: rgba(var(--color-accent-primary-rgb), 0.08);
    transform: translateY(-1px);
}

.card-stack-hint {
    color: var(--text-muted);
    font-size: 0.82rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.card-stack-stage {
    position: relative;
    width: min(100%, 960px);
    height: clamp(460px, 60vw, 620px);
    margin: 0 auto;
    perspective: 1600px;
    outline: none;
}

.card-stack-viewport {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
}

.card-stack-card {
    position: absolute;
    inset: 0;
    margin: auto;
    width: min(92%, 500px);
    height: min(78%, 410px);
    display: grid;
    gap: 1rem;
    padding: 1.15rem;
    border-radius: var(--radius-xl);
    border: 1px solid rgba(var(--color-border-rgb), 0.9);
    background: linear-gradient(145deg, rgba(var(--color-text-primary-rgb), 0.028), rgba(var(--color-text-primary-rgb), 0.01));
    backdrop-filter: blur(24px);
    box-shadow: 0 16px 40px rgba(4,6,10,0.2), inset 0 1px 0 rgba(var(--color-text-primary-rgb), 0.04);
    overflow: hidden;
    transform-origin: center center;
    transition: transform 700ms cubic-bezier(0.2, 0.88, 0.24, 1), opacity 700ms ease, box-shadow 700ms ease;
    cursor: pointer;
    user-select: none;
    will-change: transform, opacity;
}

.card-stack-card::before {
    content: "";
    position: absolute;
    inset: -1px;
    background: linear-gradient(135deg, rgba(var(--color-accent-primary-rgb), 0.08), transparent 35%, rgba(var(--color-accent-secondary-rgb), 0.06));
    pointer-events: none;
}

.card-stack-card::after {
    content: "";
    position: absolute;
    inset: auto 1rem 1rem auto;
    width: 110px;
    height: 110px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255,255,255,0.18), transparent 70%);
    filter: blur(12px);
    opacity: 0.85;
    pointer-events: none;
}

.card-stack-card.is-active {
    z-index: 5;
    box-shadow: 0 24px 56px rgba(4,6,10,0.24);
}

.card-stack-card.is-side {
    opacity: 0.78;
}

.card-stack-card.is-hidden {
    opacity: 0;
    pointer-events: none;
}

.card-stack-card.is-prev {
    transform: translateX(-54%) translateZ(-140px) rotateY(24deg) rotate(-12deg) scale(0.92);
}

.card-stack-card.is-next {
    transform: translateX(54%) translateZ(-140px) rotateY(-24deg) rotate(12deg) scale(0.92);
}

.card-stack-card.is-far-prev {
    transform: translateX(-80%) translateZ(-280px) rotateY(30deg) rotate(-18deg) scale(0.8);
}

.card-stack-card.is-far-next {
    transform: translateX(80%) translateZ(-280px) rotateY(-30deg) rotate(18deg) scale(0.8);
}

.card-stack-media {
    position: relative;
    min-height: 160px;
    border-radius: calc(var(--radius-lg) - 4px);
    border: 1px solid rgba(var(--color-border-rgb), 0.9);
    overflow: hidden;
    background: var(--card-stack-accent, linear-gradient(140deg, rgba(var(--color-accent-primary-rgb), 0.12), rgba(var(--color-accent-secondary-rgb), 0.08)));
    box-shadow: inset 0 1px 0 rgba(var(--color-text-primary-rgb), 0.04);
    padding: 1rem;
    display: flex;
    align-items: end;
    justify-content: space-between;
    isolation: isolate;
}

.card-stack-media::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 18% 20%, rgba(255,255,255,0.2), transparent 28%),
        radial-gradient(circle at 86% 14%, rgba(255,255,255,0.12), transparent 24%),
        linear-gradient(135deg, rgba(255,255,255,0.1), transparent 60%);
    z-index: -1;
}

.card-stack-media::after {
    content: "";
    position: absolute;
    right: 1rem;
    bottom: 0.8rem;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255,255,255,0.16), transparent 70%);
    filter: blur(10px);
    z-index: -1;
}

.card-stack-media-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.42rem 0.7rem;
    border-radius: 999px;
    background: rgba(6, 10, 18, 0.36);
    border: 1px solid rgba(255,255,255,0.16);
    color: var(--text-primary);
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.16em;
    backdrop-filter: blur(14px);
}

.card-stack-media-glow {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.16);
    box-shadow: 0 0 34px rgba(255,255,255,0.14);
    background: rgba(255,255,255,0.08);
}

.card-stack-body {
    display: grid;
    gap: 0.8rem;
}

.card-stack-title {
    display: flex;
    justify-content: space-between;
    align-items: start;
    gap: 0.75rem;
}

.card-stack-title h3 {
    font-size: 1.3rem;
}

.card-stack-status {
    color: var(--accent-alt);
    font-size: 0.76rem;
    font-weight: 700;
    letter-spacing: 0.16em;
    text-transform: uppercase;
}

.card-stack-description {
    color: var(--text-secondary);
    font-size: 0.96rem;
    line-height: 1.7;
}

.card-stack-tech-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.card-stack-tech-pill {
    padding: 0.4rem 0.7rem;
    border-radius: 999px;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.08);
    color: var(--text-secondary);
    font-size: 0.78rem;
    letter-spacing: 0.02em;
}

.card-stack-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: auto;
}

.card-stack-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 128px;
    padding: 0.72rem 0.95rem;
    border-radius: 999px;
    border: 1px solid rgba(var(--color-accent-primary-rgb), 0.24);
    background: rgba(var(--color-accent-primary-rgb), 0.1);
    color: var(--text-primary);
    font-size: 0.9rem;
    font-weight: 650;
    transition: var(--transition);
}

.card-stack-btn:hover,
.card-stack-btn:focus-visible {
    background: rgba(var(--color-accent-primary-rgb), 0.16);
    transform: translateY(-1px);
}

.card-stack-btn--ghost {
    background: rgba(var(--color-text-primary-rgb), 0.03);
    border-color: rgba(var(--color-border-rgb), 0.9);
}

.card-stack-nav {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.7rem;
    flex-wrap: wrap;
}

.card-stack-nav button {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 1px solid rgba(var(--color-border-rgb), 0.9);
    background: rgba(var(--color-text-primary-rgb), 0.025);
    color: var(--text-primary);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.card-stack-nav button:hover,
.card-stack-nav button:focus-visible {
    background: rgba(var(--color-accent-primary-rgb), 0.08);
    border-color: rgba(var(--color-accent-primary-rgb), 0.24);
    transform: translateY(-1px);
}

.card-stack-meta {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

@media (max-width: 820px) {
    .card-stack-stage {
        height: clamp(500px, 78vw, 620px);
    }

    .card-stack-card {
        width: min(94%, 460px);
        height: min(84%, 420px);
        padding: 1rem;
    }

    .card-stack-card.is-prev {
        transform: translateX(-40%) translateZ(-140px) rotateY(20deg) rotate(-10deg) scale(0.94);
    }

    .card-stack-card.is-next {
        transform: translateX(40%) translateZ(-140px) rotateY(-20deg) rotate(10deg) scale(0.94);
    }

    .card-stack-card.is-far-prev {
        transform: translateX(-65%) translateZ(-280px) rotateY(28deg) rotate(-14deg) scale(0.82);
    }

    .card-stack-card.is-far-next {
        transform: translateX(65%) translateZ(-280px) rotateY(-28deg) rotate(14deg) scale(0.82);
    }
}

@media (max-width: 560px) {
    .card-stack-card {
        width: 100%;
        height: auto;
        min-height: 430px;
        padding: 0.95rem;
        gap: 0.9rem;
    }

    .card-stack-media {
        min-height: 140px;
    }

    .card-stack-actions {
        flex-direction: column;
    }

    .card-stack-btn {
        width: 100%;
    }
}