/* ============================================================
   Technical page — overview, tool index, accordion of tools
   ============================================================ */

/* ---------- OVERVIEW ---------- */
.tech-overview {
    padding: clamp(3rem, 5vw, 5rem) 0;
    background: var(--paper);
}
.tech-overview__inner {
    width: var(--container);
    margin-inline: auto;
    display: grid;
    grid-template-columns: 1fr;
    gap: clamp(1.6rem, 3vw, 2.6rem);
}
@media (min-width: 920px) {
    .tech-overview__inner {
        grid-template-columns: 1.4fr 1fr;
        align-items: start;
    }
}
.tech-overview__figure {
    margin: 0;
    border: 1px solid var(--paper-line);
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--paper-2);
    box-shadow: var(--shadow-soft);
    position: sticky;
    top: calc(var(--header-h) + 1rem);
}
.tech-overview__figure img {
    width: 100%;
    height: auto;
    display: block;
}
.tech-overview__figure figcaption {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    color: var(--ink-muted);
    padding: 0.7rem 1rem;
    border-top: 1px solid var(--paper-line);
    background: var(--paper);
    letter-spacing: 0.02em;
}

/* ---------- TOOL INDEX (anchor rail) ---------- */
.tool-index {
    padding: clamp(2rem, 3vw, 2.6rem) 0;
    background: var(--paper-2);
    border-block: 1px solid var(--paper-line);
}
.tool-index__inner {
    width: var(--container);
    margin-inline: auto;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.2rem;
    align-items: baseline;
}
@media (min-width: 760px) {
    .tool-index__inner {
        grid-template-columns: auto 1fr;
        gap: 2rem;
    }
}
.tool-index__label {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.16em;
    color: var(--ink-muted);
    white-space: nowrap;
}
.tool-index__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}
.tool-index__list a {
    display: inline-flex;
    align-items: center;
    gap: 0.5em;
    padding: 0.45rem 0.85rem;
    border-radius: 999px;
    background: var(--paper);
    border: 1px solid var(--paper-line);
    font-size: 0.82rem;
    color: var(--ink-soft);
    transition: background 0.2s, border-color 0.2s, color 0.2s, transform 0.2s var(--ease);
}
.tool-index__list a::before {
    content: attr(data-num);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--accent);
    font-weight: 700;
    letter-spacing: 0.04em;
}
.tool-index__list a:hover {
    background: var(--ink);
    border-color: var(--ink);
    color: #ffffff;
    transform: translateY(-1px);
}
.tool-index__list a:hover::before {
    color: var(--accent-soft);
}

/* ---------- TOOLS LIST (accordion) ---------- */
.tools {
    padding: clamp(3rem, 5vw, 5rem) 0;
    background: var(--paper);
}
.tools__inner {
    width: var(--container);
    margin-inline: auto;
}
.tool {
    border-top: 1px solid var(--paper-rule);
    padding: 0;
    scroll-margin-top: calc(var(--header-h) + 1rem);
}
.tool:last-of-type { border-bottom: 1px solid var(--paper-rule); }

.tool__summary {
    list-style: none;
    cursor: pointer;
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: clamp(0.8rem, 1.5vw, 1.5rem);
    padding: clamp(1.2rem, 2vw, 1.7rem) 0;
    transition: color 0.2s;
}
.tool__summary::-webkit-details-marker { display: none; }
.tool__summary::marker { display: none; }
.tool__summary:hover { color: var(--accent); }
.tool__summary:hover .tool__title { color: var(--accent); }
.tool__summary:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 4px;
    border-radius: var(--radius-sm);
}

.tool__num {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 0.06em;
    min-width: 2.5em;
}
.tool__title {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: clamp(1.15rem, 0.9rem + 0.7vw, 1.5rem);
    line-height: 1.2;
    color: var(--ink);
    margin: 0;
    transition: color 0.2s;
}
.tool__sub {
    display: block;
    font-family: var(--font-body);
    font-weight: 400;
    font-size: var(--t-small);
    color: var(--ink-muted);
    margin-top: 0.3rem;
    line-height: 1.45;
    letter-spacing: 0;
}

.tool__toggle {
    width: 2.4rem;
    height: 2.4rem;
    border-radius: 999px;
    border: 1px solid var(--paper-rule);
    display: grid;
    place-items: center;
    background: var(--paper);
    transition: background 0.25s, border-color 0.25s, transform 0.3s var(--ease);
    flex-shrink: 0;
}
.tool__toggle::before,
.tool__toggle::after {
    content: "";
    position: absolute;
    width: 0.85rem;
    height: 1.5px;
    background: var(--ink);
    border-radius: 1px;
    transition: transform 0.3s var(--ease), background 0.25s;
}
.tool__toggle::after { transform: rotate(90deg); }
.tool__toggle { position: relative; }
.tool[open] .tool__toggle {
    background: var(--accent);
    border-color: var(--accent);
}
.tool[open] .tool__toggle::before,
.tool[open] .tool__toggle::after {
    background: #ffffff;
}
.tool[open] .tool__toggle::after { transform: rotate(180deg); }
.tool__summary:hover .tool__toggle { border-color: var(--accent); }

.tool__body {
    padding: 0 0 clamp(2rem, 3vw, 2.6rem);
    display: grid;
    gap: 1.2rem;
    max-width: 78ch;
    animation: tool-reveal 0.4s var(--ease);
}

@keyframes tool-reveal {
    from { opacity: 0; transform: translateY(6px); }
    to   { opacity: 1; transform: none; }
}
@media (prefers-reduced-motion: reduce) {
    .tool__body { animation: none; }
}

.tool__body p {
    margin: 0;
    font-size: var(--t-body);
    line-height: 1.7;
    color: var(--ink);
}
.tool__body strong { color: var(--ink); font-weight: 700; }
.tool__body ul,
.tool__body ol {
    margin: 0;
    padding-left: 1.4em;
    display: grid;
    gap: 0.45rem;
}
.tool__body ul li::marker { color: var(--accent); }
.tool__body ol li::marker {
    color: var(--accent);
    font-weight: 700;
}
.tool__body ul ul,
.tool__body ol ul {
    margin-top: 0.45rem;
    padding-left: 1.2em;
}
.tool__body h4 {
    font-family: var(--font-display);
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--ink);
    margin: 0.6rem 0 -0.4rem;
    letter-spacing: -0.005em;
}
.tool__body a {
    color: var(--accent);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
}

/* Inline scheme image (clean figure) */
.tool__figure {
    margin: 0.5rem 0;
    border: 1px solid var(--paper-line);
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--paper-2);
}
.tool__figure img {
    width: 100%;
    height: auto;
    display: block;
}
.tool__figure figcaption {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--ink-muted);
    padding: 0.6rem 0.9rem;
    border-top: 1px solid var(--paper-line);
    background: var(--paper);
    letter-spacing: 0.02em;
}

/* Two-up figures side by side */
.tool__figure-pair {
    display: grid;
    gap: 1rem;
    grid-template-columns: 1fr;
}
@media (min-width: 720px) {
    .tool__figure-pair { grid-template-columns: 1fr 1fr; }
}

/* YouTube embed wrapper — responsive 16:9 */
.tool__video {
    margin: 0.6rem 0 0;
    border-radius: var(--radius);
    overflow: hidden;
    background: #000;
    box-shadow: var(--shadow-soft);
    aspect-ratio: 16 / 9;
}
.tool__video iframe {
    width: 100%;
    height: 100%;
    border: 0;
    display: block;
}

/* Pull-quote / callout */
.tool__callout {
    margin: 0.4rem 0;
    padding: 1.1rem 1.3rem;
    border-left: 3px solid var(--accent);
    background: var(--paper-2);
    font-style: italic;
    color: var(--ink-soft);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    font-weight: 300;
    line-height: 1.6;
}

/* Hover affordance line on tool row */
.tool__summary {
    position: relative;
}
.tool__summary::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.35s var(--ease);
}
.tool[open] .tool__summary::before,
.tool__summary:hover::before {
    width: 3rem;
}