/* ── Research index page ─────────────────────────────── */

.research-intro {
    position: relative;
    z-index: 1;
    padding-top: clamp(48px, 5.5vw, 64px);
    padding-bottom: 32px;
}

.research-intro h1 {
    margin: 0 0 12px;
    font-size: clamp(3.6rem, 8vw, 6rem);
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.055em;
    color: var(--page-ink);
}

.research-intro-sub {
    margin: 0;
    font-size: 0.98rem;
    line-height: 1.7;
    color: var(--page-ink-soft);
}

/* ── Featured hero card ─────────────────────────────── */

.research-featured {
    position: relative;
    z-index: 1;
    padding-bottom: 108px;
}

.research-hero-card {
    display: grid;
    grid-template-columns: minmax(260px, 2fr) 3fr;
    border-radius: 24px;
    overflow: hidden;
    border: 1px solid var(--line);
    background: linear-gradient(
        180deg,
        color-mix(in srgb, var(--surface-strong) 88%, transparent 12%) 0%,
        var(--surface) 100%
    );
    box-shadow: var(--shadow-strong);
    transition: transform 300ms ease, box-shadow 300ms ease;
}

.research-hero-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 44px 96px rgba(0, 243, 255, 0.07), var(--shadow-strong);
}

/* ── Stat panel (left) ──────────────────────────────── */

.research-hero-stat-panel {
    position: relative;
    padding: 44px 40px;
    border-right: 1px solid var(--line);
    background: var(--surface-soft);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.research-hero-stat-panel::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle, rgba(0, 243, 255, 0.055) 1px, transparent 1px);
    background-size: 22px 22px;
    pointer-events: none;
}

.research-hero-kf-label {
    position: relative;
    z-index: 1;
    margin: 0 0 18px;
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.13em;
    text-transform: uppercase;
    color: var(--cyan-text);
}

.research-hero-stat-number {
    position: relative;
    z-index: 1;
    display: block;
    font-family: "IBM Plex Mono", monospace;
    font-size: clamp(3.6rem, 6.5vw, 5.6rem);
    font-weight: 500;
    line-height: 1;
    letter-spacing: -0.045em;
    color: var(--cyan-text);
    margin-bottom: 10px;
}

.research-hero-stat-desc {
    position: relative;
    z-index: 1;
    margin: 0 0 22px;
    font-size: 0.86rem;
    line-height: 1.52;
    color: var(--ink-soft);
    max-width: 210px;
}

.research-hero-stat-bar {
    position: relative;
    z-index: 1;
    width: 100%;
    height: 2px;
    background: var(--line-strong);
    border-radius: 999px;
    margin-bottom: 30px;
    overflow: hidden;
}

.research-hero-stat-bar-fill {
    height: 100%;
    width: 0%;
    background: var(--cyan-text);
    border-radius: 999px;
    transition: width 1.5s cubic-bezier(0.25, 1, 0.5, 1);
}

.research-hero-stat-bar-fill.is-animated {
    width: 76%;
}

.research-hero-secondary-stats {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: auto;
}

.research-hero-secondary-stat {
    display: flex;
    align-items: baseline;
    gap: 8px;
}

.research-hero-secondary-stat strong {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--page-ink);
}

.research-hero-secondary-stat span {
    font-size: 0.78rem;
    color: var(--ink-soft);
}

/* ── Content panel (right) ──────────────────────────── */

.research-hero-content {
    padding: 44px 48px;
    display: flex;
    flex-direction: column;
}

.research-hero-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

.research-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.research-tag {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 999px;
    border: 1px solid var(--line-strong);
    font-size: 0.71rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--ink-soft);
}

.research-hero-readtime {
    margin-left: auto;
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.76rem;
    font-weight: 500;
    color: var(--ink-soft);
}

.research-hero-title {
    margin: 0 0 12px;
    font-size: clamp(1.35rem, 2.6vw, 1.8rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.03em;
    color: var(--page-ink);
    text-wrap: balance;
}

.research-hero-title a {
    color: inherit;
    text-decoration: none;
    transition: color 200ms ease;
}

.research-hero-title a:hover {
    color: var(--cyan-text);
}

.research-hero-byline {
    margin: 0 0 20px;
    font-size: 0.84rem;
    font-weight: 600;
    color: var(--ink-soft);
}

.research-hero-excerpt {
    margin: 0 0 32px;
    font-size: 1rem;
    line-height: 1.76;
    color: var(--page-ink-soft);
    flex-grow: 1;
}

.research-hero-actions {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 14px;
}

/* ── Responsive ─────────────────────────────────────── */

@media (max-width: 860px) {
    .research-hero-card {
        grid-template-columns: 1fr;
    }

    .research-hero-stat-panel {
        border-right: none;
        border-bottom: 1px solid var(--line);
        padding: 36px;
    }

    .research-hero-secondary-stats {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 24px;
        margin-top: 24px;
    }

    .research-hero-content {
        padding: 36px;
    }
}

@media (max-width: 540px) {
    .research-intro {
        padding-top: 48px;
        padding-bottom: 24px;
    }

    .research-hero-card {
        border-radius: 18px;
    }

    .research-hero-stat-panel {
        padding: 28px 24px;
    }

    .research-hero-content {
        padding: 28px 24px;
    }

    .research-hero-readtime {
        margin-left: 0;
        width: 100%;
    }

    .research-featured {
        padding-bottom: 72px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .research-hero-card {
        transition: none;
    }

    .research-hero-stat-bar-fill {
        transition: none;
        width: 76%;
    }
}