.st-diff {
    padding: 30px 5vw;
    position: relative;
    overflow: hidden;
}

.st-diff-header {
    text-align: center;
    margin-bottom: 24px;
}

.st-diff-heading {
    font-size: clamp(2rem, 4.5vw, 4rem);
    line-height: 1.1;
    margin: 4px 0;
    text-transform: uppercase;
    font-family: var(--font-heading);
    font-weight: 800;
    color: var(--text-main);
}

.st-diff-heading-outline {
    color: transparent;
    -webkit-text-stroke: 1.5px var(--text-main);
}

.st-diff-sub {
    font-family: var(--font-text);
    font-size: 0.9rem;
    color: var(--text-desc);
    line-height: 1.5;
    max-width: 520px;
    margin: 4px auto 0;
    text-align: center;
}

.st-diff-container {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
}

/* ── Timeline line ── */
.st-diff-timeline {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    background: var(--border-medium);
    z-index: 1;
}

.st-diff-timeline-fill {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    background: var(--color-primary);
    height: 0%;
    border-radius: 1px;
    z-index: 2;
}

/* ── Tracker dot ── */
.st-diff-tracker {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 16px;
    height: 16px;
    z-index: 5;
}

.st-diff-tracker svg {
    width: 16px;
    height: 16px;
}

/* ── Item row ── */
.st-diff-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    position: relative;
    z-index: 4;
}

.st-diff-item:last-child {
    margin-bottom: 0;
}

.st-diff-item:nth-child(odd) {
    flex-direction: row-reverse;
}

.st-diff-item:nth-child(even) {
    flex-direction: row;
}

.st-diff-empty {
    width: 42%;
}

/* ── Card ── */
.st-diff-content {
    box-sizing: border-box;
    width: 42%;
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 10px;
    padding: 16px 18px;
    position: relative;
    transition: border-color 0.3s;
    overflow: hidden;
}

.st-diff-item:hover .st-diff-content {
    border-color: var(--border-medium);
}

/* ── Central dots ── */
.st-diff-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--color-primary);
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    z-index: 3;
}

/* ── Connector line ── */
.st-diff-connector {
    position: absolute;
    top: 50%;
    height: 1px;
    width: 6%;
    background: var(--border-medium);
    z-index: 2;
}

.st-diff-item:nth-child(odd) .st-diff-connector {
    left: 50%;
}

.st-diff-item:nth-child(even) .st-diff-connector {
    right: 50%;
}

/* ── Stat label ── */
.st-diff-stat {
    font-family: var(--font-heading);
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 6px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.st-diff-stat svg {
    width: 16px;
    height: 16px;
}

/* ── Title ── */
.st-diff-title {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-main);
    margin: 0 0 4px 0;
}

/* ── Description ── */
.st-diff-desc {
    font-family: var(--font-text);
    font-size: 0.8rem;
    color: var(--text-desc);
    line-height: 1.45;
    margin: 0;
}

/* ── Mobile ── */
@media (max-width: 900px) {
    .st-diff {
        padding: 24px 20px;
    }
    .st-diff-header {
        margin-bottom: 20px;
    }
    .st-diff-timeline {
        left: 18px;
        transform: none;
    }
    .st-diff-timeline-fill {
        left: 18px;
        transform: translateX(-1px);
    }
    .st-diff-tracker {
        left: 18px;
    }
    .st-diff-item {
        flex-direction: column !important;
        align-items: stretch;
        padding-left: 0;
        margin-bottom: 20px;
        gap: 0;
    }
    .st-diff-empty {
        display: none;
    }
    .st-diff-content {
        width: calc(100% - 40px);
        padding: 14px 16px;
        margin-left: 40px;
    }
    .st-diff-dot {
        left: 18px;
        top: 24px;
        width: 8px;
        height: 8px;
        position: absolute;
    }
    .st-diff-connector {
        left: 22px !important;
        right: auto !important;
        top: 24px !important;
        width: 18px !important;
    }
    .st-diff-title {
        font-size: 0.9rem;
    }
    .st-diff-desc {
        font-size: 0.78rem;
    }
}