/* ========================================================================
   /bottleneck トップ専用（2026-09-10）
   ------------------------------------------------------------------------
   土台は style.css の --sc-* トークン（deslop-standard v3＝紙・墨・橙1色）。
   それまでは bottleneck-legacy.css で波0以前の青に固定していたが、
   CEO指示（9/10「見た目をよくしたい」）で青を外し、サイトの他のページと同じ
   見た目に揃えた。ページ内に散っていた7つの <style> をここに集約。
   ⚠️ /bottleneck/gpu/* などの下層は引き続き bottleneck-legacy.css（青）。
   ------------------------------------------------------------------------ */

:root {
    --bn-ok: var(--sc-ok-text);
    --bn-warn: #9a6b1f;
    --bn-bad: var(--sc-danger-text);
    --bn-track: #e9e2db;
    --bn-field: var(--sc-surface-white);
    --bn-rakuten: #bf0000;
}

[data-theme="dark"] {
    --bn-ok: var(--sc-ok-light);
    --bn-warn: #d9a441;
    --bn-bad: var(--sc-danger-light);
    --bn-track: #30343d;
    --bn-field: #1d2027;
    --bn-rakuten: #ff8b80;
}

/* ---------- 共通の幅 ---------- */
.bn-head,
.bottleneck-checker,
.bn-pillars,
.gpu-cta,
.bn-section,
.bn-experiment-card,
.bottleneck-faq,
.bn-discord,
.bn-support,
.scicirc-promo {
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    padding-left: 1rem;
    padding-right: 1rem;
    box-sizing: border-box;
}

/* ---------- 題名（カードの外・左揃え） ---------- */
.bn-head {
    margin-top: 1.75rem;
}

.checker-title {
    margin: 0 0 .5rem;
    font-size: clamp(1.5rem, 4vw, 2.1rem);
    font-weight: 800;
    line-height: 1.3;
    color: var(--sc-ink);
}

.checker-subtitle {
    margin: 0;
    max-width: 62ch;
    font-size: .95rem;
    line-height: 1.7;
    color: var(--sc-ink-soft);
}

/* ---------- 主役のカード（診断） ---------- */
.bottleneck-checker {
    margin-top: 1.25rem;
}

.checker-card {
    background: var(--sc-surface);
    border: 1px solid var(--sc-rule-strong);
    border-radius: 12px;
    padding: 1.5rem 1.75rem 1.75rem;
}

#checker {
    scroll-margin-top: 80px;
}

.parts-selection {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.part-group {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.part-label {
    display: block;
    margin-bottom: .2rem;
    font-size: 1rem;
    font-weight: 700;
    color: var(--sc-ink);
}

.part-icon,
.search-icon {
    display: none;
}

.step-no {
    color: var(--sc-accent);
    font-weight: 800;
    margin-right: .35rem;
}

.step-no::after {
    content: ".";
}

.part-hint {
    margin: 0 0 .7rem;
    font-size: .8rem;
    color: var(--sc-ink-soft);
}

/* フィルター */
.filter-row {
    display: flex;
    flex-wrap: wrap;
    gap: .4rem;
    margin-bottom: .6rem;
}

.filter-label {
    align-self: center;
    min-width: 0;   /* 3.4em 固定だと「種類」の行で「サーバー」だけが2行目に落ちていた（2026-09-25） */
    font-size: .74rem;
    font-weight: 600;
    color: var(--sc-ink-soft);
}

.filter-btn {
    padding: .42rem .6rem;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    background: transparent;
    color: var(--sc-ink);
    font-family: inherit;
    font-size: .8rem;
    font-weight: 500;
    cursor: pointer;
    transition: border-color .15s, background-color .15s, color .15s;
}

.filter-btn:hover {
    border-color: var(--sc-rule-strong);
}

.filter-btn.active {
    background: var(--sc-ink);
    color: var(--sc-paper);
    border-color: var(--sc-ink);
}

/* 検索 */
.search-box {
    margin-bottom: .6rem;
}

.search-input {
    width: 100%;
    padding: .65rem .9rem;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    font-family: inherit;
    font-size: 16px; /* 16px未満だとiOSでフォーカス時に自動ズームされる */
    background: var(--bn-field);
    color: var(--sc-ink);
    box-sizing: border-box;
}

.search-input::placeholder {
    color: var(--sc-ink-muted);
}

.search-input:focus {
    outline: none;
    border-color: var(--sc-accent);
}

/* パーツ一覧 */
.parts-list {
    max-height: 300px;
    overflow-y: auto;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    background: var(--bn-field);
}

.part-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: .5rem;
    padding: .65rem .9rem;
    border-bottom: 1px solid var(--sc-rule);
    cursor: pointer;
}

.part-item:last-child {
    border-bottom: none;
}

.part-item:hover,
.part-group-header:hover {
    background: var(--sc-surface-tint);
}

.part-item.selected {
    background: var(--sc-surface-tint);
}

/* 2026-10-01 左の線をやめた代わりに、選んだ部品は名前を太字にして見分ける */
.part-item.selected .part-name {
    font-weight: 700;
}

.part-name {
    font-weight: 500;
    font-size: .9rem;
    color: var(--sc-ink);
}

.part-score {
    flex-shrink: 0;
    font-size: .78rem;
    color: var(--sc-ink-soft);
    font-variant-numeric: tabular-nums;
}

.part-type-badge {
    display: inline-block;
    margin-left: .5rem;
    padding: .08rem .4rem;
    border: 1px solid currentColor;
    border-radius: 4px;
    font-size: .66rem;
    font-weight: 600;
    line-height: 1.5;
    vertical-align: middle;
}

.badge-desktop { color: var(--sc-ink-soft); }
.badge-laptop  { color: var(--bn-ok); }
.badge-server  { color: var(--bn-warn); }

.part-year {
    margin-left: .5rem;
    font-size: .7rem;
    color: var(--sc-ink-soft);
}

.series-header {
    position: sticky;
    top: 0;
    z-index: 10;
    padding: .45rem .9rem;
    background: var(--sc-surface-tint);
    border-bottom: 1px solid var(--sc-rule);
    font-size: .76rem;
    font-weight: 700;
    letter-spacing: .03em;
    color: var(--sc-ink-soft);
}

.variant-count {
    margin-left: .5rem;
    padding: .1rem .45rem;
    border: 1px solid var(--sc-rule);
    border-radius: 4px;
    font-size: .68rem;
    color: var(--sc-ink-soft);
}

.part-group-expanded {
    margin: .5rem;
    border: 1px solid var(--sc-accent);
    border-radius: var(--sc-radius);
    overflow: hidden;
}

.part-group-expanded .group-header {
    display: flex;
    justify-content: space-between;
    padding: .65rem .9rem;
    background: var(--sc-surface-tint);
    color: var(--sc-accent);
    border-bottom: 1px solid var(--sc-rule);
    font-weight: 700;
    font-size: .88rem;
    cursor: pointer;
}

.part-group-expanded .close-btn {
    font-size: .8rem;
    opacity: .85;
}

.part-group-expanded .variant-item {
    padding-left: 1.4rem;
}

.suffix-badge {
    display: inline-block;
    min-width: 2.4rem;
    margin-right: .5rem;
    padding: .15rem .45rem;
    background: var(--sc-surface-tint);
    color: var(--sc-accent);
    border-radius: 4px;
    font-size: .72rem;
    font-weight: 700;
    text-align: center;
}

.no-results {
    padding: 2rem;
    text-align: center;
    color: var(--sc-ink-soft);
}

/* 選んだもの */
.selected-display {
    /* 2026-10-01 左だけ橙の縦線（角丸の箱＋左の色線）はAIが作った画面によくある形なのでやめ、罫1本だけにする（CEO「ここなんかaiっぽい」） */
    display: none;
    margin-top: .6rem;
    padding: .7rem .9rem;
    background: var(--sc-surface);
    border: 1px solid var(--sc-rule-strong);
    border-radius: var(--sc-radius);
}

.selected-display.show {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: .5rem;
}

.selected-name {
    font-weight: 600;
    font-size: .9rem;
    color: var(--sc-ink);
}

.clear-btn {
    flex-shrink: 0;
    background: none;
    border: none;
    color: var(--sc-ink-soft);
    font-family: inherit;
    font-size: .82rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: underline;
    text-underline-offset: 2px;
}

.clear-btn:hover {
    color: var(--bn-bad);
}

/* 診断ボタン＝サイト共通の duo-btn を使う。ここは補助だけ */
.diagnose-btn {
    gap: .6rem;
}

.diagnose-btn:disabled {
    background: var(--sc-surface-tint);
    color: var(--sc-ink-muted);
    box-shadow: 0 var(--btn-depth) 0 var(--sc-rule);
    cursor: not-allowed;
    transform: none;
}

.diagnose-btn svg {
    width: 20px;
    height: 20px;
}

.reset-all-btn {
    margin-top: .6rem;
    min-height: 44px;
    font-size: .9rem;
    color: var(--sc-ink-soft);
}

/* ---------- 結果 ---------- */
.result-section {
    display: none;
    margin-top: 1.75rem;
}

.result-section.show {
    display: block;
    animation: bnFadeIn .25s ease;
}

@keyframes bnFadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}

.result-card {
    padding: 1.75rem 0 0;
    border-top: 1px solid var(--sc-rule);
    text-align: center;
}

.bottleneck-meter {
    position: relative;
    width: 180px;
    height: 180px;
    margin: 0 auto 1rem;
}

.meter-circle {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: conic-gradient(var(--meter-color, var(--sc-accent)) calc(var(--percent, 0) * 1%), var(--bn-track) 0);
}

.meter-circle::before {
    content: '';
    position: absolute;
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: var(--sc-surface);
}

.meter-value {
    position: relative;
    z-index: 1;
    font-size: 2.3rem;
    font-weight: 800;
    color: var(--sc-ink);
    font-variant-numeric: tabular-nums;
}

.meter-label {
    position: relative;
    z-index: 1;
    margin-top: .2rem;
    font-size: .8rem;
    color: var(--sc-ink-soft);
}

.meter-guide {
    margin: 0 0 .6rem;
    font-size: .8rem;
    color: var(--sc-ink-soft);
}

.result-status {
    display: inline-block;
    margin-bottom: .75rem;
    font-size: 1.15rem;
    font-weight: 800;
}

.status-excellent { color: var(--bn-ok); }
.status-good      { color: var(--bn-warn); }
.status-warning   { color: var(--bn-bad); }

.result-detail {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: .9rem;
    margin: 1rem 0 1.5rem;
}

.detail-item {
    padding: .9rem;
    background: var(--sc-surface-tint);
    border-radius: var(--sc-radius);
}

.detail-label {
    margin-bottom: .35rem;
    font-size: .8rem;
    color: var(--sc-ink-soft);
}

.detail-value {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--sc-ink);
}

.detail-score {
    font-size: .8rem;
    color: var(--sc-ink-soft);
    font-variant-numeric: tabular-nums;
}

.affiliate-link-btn {
    display: inline-block;
    margin-left: 10px;
    padding: 3px 10px;
    border: 1px solid var(--bn-rakuten);
    border-radius: 4px;
    color: var(--bn-rakuten);
    font-size: .78rem;
    font-weight: 700;
    text-decoration: none;
    vertical-align: middle;
    transition: background-color .15s, color .15s;
}

.detail-value .affiliate-link-btn {
    display: block;
    width: fit-content;
    margin: 8px auto 0;
}

.affiliate-link-btn:hover {
    background: var(--bn-rakuten);
    color: #fff;
}

/* 性能比較バー */
.comparison-bar {
    margin-top: .5rem;
}

.bar-container {
    display: flex;
    align-items: center;
    gap: .75rem;
    margin-top: 1.6rem;
}

.bar-label {
    width: 44px;
    font-size: .82rem;
    font-weight: 700;
    color: var(--sc-ink);
    text-align: left;
}

.bar-track {
    position: relative;
    flex: 1;
    height: 14px;
    background: var(--bn-track);
    border-radius: 3px;
}

.bar-grid {
    position: absolute;
    inset: 0;
    display: flex;
    pointer-events: none;
    z-index: 1;
}

.grid-line {
    position: absolute;
    top: 0;
    width: 1px;
    height: 100%;
    background: var(--sc-rule);
}

.grid-label {
    position: absolute;
    top: -16px;
    transform: translateX(-50%);
    font-size: .62rem;
    font-weight: 600;
    color: var(--sc-ink-soft);
    white-space: nowrap;
}

.bar-fill {
    position: relative;
    z-index: 2;
    height: 100%;
    border-radius: 3px;
    transition: width .6s ease;
}

.bar-cpu { background: var(--sc-accent-solid); }
.bar-gpu { background: var(--sc-ink-soft); }

/* アドバイス（罫で囲む。左の橙の線は 2026-10-01 に外した＝選択中の箱と同じ理由） */
.advice-section {
    margin-top: 1.5rem;
    padding: 1.1rem 1.25rem;
    border: 1px solid var(--sc-rule-strong);
    border-radius: var(--sc-radius);
    text-align: left;
}

.advice-title {
    margin-bottom: .5rem;
    font-size: 1rem;
    font-weight: 700;
    color: var(--sc-ink);
}

.advice-text {
    font-size: .93rem;
    line-height: 1.8;
    color: var(--sc-ink);
    white-space: pre-line;
}

.recommendation-chips {
    display: flex;
    flex-wrap: wrap;
    gap: .45rem;
    margin-top: .9rem;
}

.rec-chip,
a.rec-chip {
    display: inline-block;
    padding: .4rem .8rem;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    background: var(--sc-surface);
    color: var(--sc-ink);
    font-size: .82rem;
    text-decoration: none;
    cursor: pointer;
    transition: border-color .15s, color .15s;
}

.rec-chip:hover,
a.rec-chip:hover {
    border-color: var(--sc-accent);
    color: var(--sc-accent);
}

.result-gpu-link {
    margin-top: .9rem;
    font-size: .9rem;
}

.result-gpu-link a {
    color: var(--sc-accent);
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 3px;
}

.ai-advice-btn {
    width: 100%;
    min-height: 44px;
    margin-top: 1rem;
    padding: .7rem 1rem;
    border: 1px solid var(--sc-rule-strong);
    border-radius: var(--sc-radius);
    background: var(--sc-surface);
    color: var(--sc-ink);
    font-family: inherit;
    font-size: .92rem;
    font-weight: 700;
    cursor: pointer;
    transition: background-color .15s;
}

.ai-advice-btn:hover {
    background: var(--sc-surface-tint);
}

/* 診断直後の SciCirc への一言（CEO決定 F：ここと末尾の実証実験の2つだけ） */
.result-scicirc-nudge {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: .75rem 1rem;
    margin-top: 1.25rem;
    padding: 1rem 1.15rem;
    background: var(--sc-surface-tint);
    border-radius: var(--sc-radius);
}

.result-scicirc-nudge__txt {
    flex: 1 1 260px;
    font-size: .9rem;
    line-height: 1.7;
    color: var(--sc-ink);
}

.result-scicirc-nudge__txt b {
    color: var(--sc-accent);
}

.result-scicirc-nudge__btn {
    flex: 0 0 auto;
    display: inline-block;
    padding: .65rem 1.2rem;
    border: 1px solid var(--sc-rule-strong);
    border-radius: var(--sc-radius);
    background: var(--sc-surface);
    color: var(--sc-ink);
    font-size: .9rem;
    font-weight: 700;
    text-decoration: none;
    white-space: nowrap;
}

.result-scicirc-nudge__btn:hover {
    background: var(--sc-paper);
    color: var(--sc-accent);
}

/* ---------- 本体の下の1行リンク ---------- */
.bn-pillars {
    display: flex;
    flex-wrap: wrap;
    gap: .4rem 1.4rem;
    margin-top: .9rem;
    font-size: .88rem;
}

.bn-pillars a {
    color: var(--sc-accent);
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* ---------- 脇の節（カードにしない。上に罫線1本） ---------- */
.gpu-cta,
.bn-section,
.bottleneck-faq,
.bn-discord {
    margin-top: 2.25rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--sc-rule);
}

.gpu-cta h2,
.ai-consult-title,
.bottleneck-faq h2 {
    margin: 0 0 .4rem;
    font-size: 1.2rem;
    font-weight: 700;
    line-height: 1.4;
    color: var(--sc-ink);
}

.gpu-cta__desc,
.ai-consult-sub {
    margin: 0 0 1rem;
    font-size: .9rem;
    line-height: 1.75;
    color: var(--sc-ink-soft);
}

.gpu-cta__desc strong {
    color: var(--sc-ink);
}

.gpu-cta__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: .45rem;
    margin-bottom: .9rem;
}

.gpu-cta__grid a {
    padding: .5rem .5rem;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    color: var(--sc-ink);
    font-size: .84rem;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    transition: border-color .15s, color .15s;
}

.gpu-cta__grid a:hover {
    border-color: var(--sc-accent);
    color: var(--sc-accent);
}

.gpu-cta__more {
    display: inline-block;
    color: var(--sc-accent);
    font-weight: 600;
    font-size: .9rem;
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* 試した組み合わせ／相談履歴 */
.bn-login-nudge {
    padding: .8rem 1rem;
    border: 1px dashed var(--sc-rule);
    border-radius: var(--sc-radius);
    font-size: .88rem;
    line-height: 1.7;
    color: var(--sc-ink-soft);
}

.bn-login-nudge a {
    color: var(--sc-accent);
    font-weight: 700;
    text-decoration: underline;
    text-underline-offset: 3px;
}

.bn-combo-list {
    display: flex;
    flex-direction: column;
    gap: .5rem;
}

.bn-combo-item {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: .4rem .9rem;
    padding: .65rem .9rem;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    font-size: .88rem;
}

.bn-combo-item__parts {
    font-weight: 600;
    color: var(--sc-ink);
}

.bn-combo-item__meta {
    font-size: .78rem;
    color: var(--sc-ink-soft);
    white-space: nowrap;
}

.bn-combo-empty,
.bn-consult-empty {
    padding: 1rem;
    text-align: center;
    font-size: .88rem;
    color: var(--sc-ink-soft);
}

.bn-consult-history {
    margin: 0 0 14px;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    overflow: hidden;
}

.bn-consult-history summary {
    padding: .65rem .9rem;
    font-size: .88rem;
    font-weight: 600;
    color: var(--sc-ink);
    cursor: pointer;
    list-style: none;
}

.bn-consult-history summary::-webkit-details-marker { display: none; }
.bn-consult-history summary::before { content: '▸ '; color: var(--sc-ink-soft); }
.bn-consult-history[open] summary::before { content: '▾ '; }

.bn-consult-history__body {
    display: flex;
    flex-direction: column;
    gap: .6rem;
    padding: 0 .9rem .9rem;
}

.bn-consult-item {
    padding: .55rem .7rem;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    font-size: .84rem;
    line-height: 1.6;
}

.bn-consult-item__q { margin-bottom: .3rem; font-weight: 700; color: var(--sc-ink); }
.bn-consult-item__a { color: var(--sc-ink-soft); white-space: pre-wrap; }
.bn-consult-item__date { margin-top: .3rem; font-size: .7rem; color: var(--sc-ink-soft); }

/* ---------- 実証実験（末尾の2つ目のCTA。主役カードと同じ枠） ---------- */
.bn-experiment-card {
    margin-top: 2.25rem;
}

.bn-experiment-card__inner {
    padding: 1.5rem 1.75rem;
    background: var(--sc-surface-tint);
    border: 1px solid var(--sc-rule-strong);
    border-radius: 12px;
}

.bn-experiment-card__badge {
    display: block;
    margin-bottom: .5rem;
    font-size: .78rem;
    font-weight: 700;
    letter-spacing: .04em;
    color: var(--sc-accent);
}

.bn-experiment-card__title {
    margin: 0 0 .6rem;
    font-size: 1.2rem;
    font-weight: 800;
    line-height: 1.45;
    color: var(--sc-ink);
}

.bn-experiment-card__desc {
    margin: 0 0 1.1rem;
    font-size: .92rem;
    line-height: 1.8;
    color: var(--sc-ink);
}

.bn-experiment-card__desc b {
    color: var(--sc-accent);
}

.bn-experiment-card__actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: .7rem 1.1rem;
}

.bn-experiment-card__btn {
    min-height: 44px;
    padding: .7rem 1.5rem;
    border: none;
    border-radius: var(--sc-radius);
    background: var(--sc-accent-solid);
    color: var(--sc-accent-ink);
    font-family: inherit;
    font-size: .95rem;
    font-weight: 700;
    box-shadow: 0 var(--btn-depth) 0 var(--sc-accent);
    cursor: pointer;
}

.bn-experiment-card__btn:hover:not(:disabled) { background: var(--sc-accent-hover-light); }
.bn-experiment-card__btn:active { transform: translateY(2px); box-shadow: 0 2px 0 var(--sc-accent); }
.bn-experiment-card__btn:disabled { opacity: .6; cursor: default; }

.bn-experiment-card__more {
    color: var(--sc-accent);
    font-size: .9rem;
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 3px;
}

.bn-experiment-card__status {
    font-size: .9rem;
    font-weight: 700;
    color: var(--bn-ok);
}

/* ---------- AI PC相談 ---------- */
.ai-chat {
    display: flex;
    flex-direction: column;
    gap: 10px;
    max-height: 420px;
    margin-bottom: 14px;
    padding: 4px;
    overflow-y: auto;
}

.ai-msg {
    max-width: 85%;
    padding: 10px 14px;
    border-radius: 10px;
    font-size: .92rem;
    line-height: 1.7;
    white-space: pre-wrap;
    word-break: break-word;
}

.ai-msg--bot {
    align-self: flex-start;
    background: var(--sc-surface-tint);
    color: var(--sc-ink);
    border-bottom-left-radius: 4px;
}

.ai-msg--user {
    align-self: flex-end;
    background: var(--sc-ink);
    color: var(--sc-paper);
    border-bottom-right-radius: 4px;
}

.ai-msg--typing {
    color: var(--sc-ink-soft);
    font-style: italic;
}

.ai-input-row {
    display: flex;
    align-items: flex-end;
    gap: 8px;
}

.ai-input {
    flex: 1;
    max-height: 120px;
    padding: 10px 13px;
    border: 1px solid var(--sc-rule);
    border-radius: var(--sc-radius);
    background: var(--bn-field);
    color: var(--sc-ink);
    font-family: inherit;
    font-size: 16px; /* 16px未満はiOS自動ズーム */
    resize: none;
}

.ai-input:focus {
    outline: none;
    border-color: var(--sc-accent);
}

.ai-send-btn {
    min-height: 44px;
    padding: 10px 18px;
    border: none;
    border-radius: var(--sc-radius);
    background: var(--sc-accent-solid);
    color: var(--sc-accent-ink);
    font-family: inherit;
    font-weight: 700;
    white-space: nowrap;
    cursor: pointer;
    transition: background-color .15s;
}

.ai-send-btn:hover:not(:disabled) { background: var(--sc-accent-hover-light); }
.ai-send-btn:disabled { opacity: .5; cursor: default; }

/* ---------- FAQ（箱にしない。1問ごとに下罫線） ---------- */
.bottleneck-faq h2 {
    margin-bottom: .5rem;
}

.bottleneck-faq details {
    padding: .85rem 0;
    border-bottom: 1px solid var(--sc-rule);
}

.bottleneck-faq summary {
    font-size: .95rem;
    font-weight: 600;
    color: var(--sc-ink);
    cursor: pointer;
}

.bottleneck-faq details p {
    margin: .7rem 0 0;
    font-size: .92rem;
    line-height: 1.8;
    color: var(--sc-ink);
}

.bottleneck-faq .faq-links {
    margin-top: 1rem;
    font-size: .86rem;
    line-height: 1.9;
    color: var(--sc-ink-soft);
}

.bottleneck-faq .faq-links a {
    color: var(--sc-accent);
    font-weight: 600;
}

/* ---------- Discord ---------- */
.bn-discord {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: .9rem 1.25rem;
}

.bn-discord__txt {
    flex: 1 1 260px;
    margin: 0;
    font-size: .9rem;
    line-height: 1.75;
    color: var(--sc-ink);
}

.bn-discord__txt b {
    color: var(--sc-ink);
}

.bn-discord__btn {
    flex: 0 0 auto;
    display: inline-block;
    padding: .65rem 1.25rem;
    border: 1px solid var(--sc-rule-strong);
    border-radius: var(--sc-radius);
    background: var(--sc-surface);
    color: var(--sc-ink);
    font-size: .9rem;
    font-weight: 700;
    text-decoration: none;
    white-space: nowrap;
}

.bn-discord__btn:hover {
    background: var(--sc-surface-tint);
    color: var(--sc-ink);
}

/* ---------- 応援（1行だけ） ---------- */
.bn-support {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: .6rem .9rem;
    margin-top: 1.75rem;
}

.bn-support__txt {
    font-size: .84rem;
    line-height: 1.6;
    color: var(--sc-ink-soft);
    text-align: center;
}

.bn-support__btn {
    flex: 0 0 auto;
    padding: .45rem .95rem;
    border: 1px solid var(--sc-rule);
    border-radius: 999px;
    color: var(--sc-ink-soft);
    font-size: .84rem;
    font-weight: 600;
    text-decoration: none;
    white-space: nowrap;
    transition: color .15s, border-color .15s;
}

.bn-support__btn:hover {
    color: var(--sc-accent);
    border-color: var(--sc-accent);
}

/* ---------- SciCirc（末尾の読み物） ---------- */
.scicirc-promo {
    margin-top: 2.25rem;
}

.scicirc-promo__inner {
    padding: 1.5rem 1.75rem;
    background: var(--sc-surface);
    border: 1px solid var(--sc-rule);
    border-radius: 12px;
}

.scicirc-promo__badge {
    display: block;
    margin-bottom: .5rem;
    font-size: .78rem;
    font-weight: 700;
    letter-spacing: .04em;
    color: var(--sc-ink-soft);
}

.scicirc-promo__title {
    margin: 0 0 .7rem;
    font-size: 1.3rem;
    font-weight: 800;
    line-height: 1.45;
    color: var(--sc-ink);
}

.scicirc-promo__title b {
    color: var(--sc-accent);
}

.scicirc-promo__desc {
    margin: 0 0 .9rem;
    font-size: .92rem;
    line-height: 1.8;
    color: var(--sc-ink);
}

.scicirc-promo__desc:last-child {
    margin-bottom: 0;
}

.scicirc-promo__desc a {
    color: var(--sc-accent);
    font-weight: 700;
    text-decoration: underline;
    text-underline-offset: 3px;
}

.scicirc-promo__chips {
    display: flex;
    flex-wrap: wrap;
    gap: .5rem;
    margin-bottom: 1rem;
}

.scicirc-promo__chips span {
    padding: .3rem .8rem;
    border: 1px solid var(--sc-rule);
    border-radius: 999px;
    font-size: .8rem;
    font-weight: 600;
    color: var(--sc-ink-soft);
}

/* ---------- スマホ ---------- */
@media (max-width: 600px) {
    .checker-card,
    .bn-experiment-card__inner,
    .scicirc-promo__inner {
        padding: 1.25rem 1.1rem;
    }

    .parts-selection,
    .result-detail {
        grid-template-columns: 1fr;
    }

    .gpu-cta__grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .filter-btn {
        min-height: 44px;
        padding: .5rem .9rem;
    }

    .part-item {
        padding: .8rem .9rem;
    }

    .search-input {
        padding: .75rem .9rem;
    }

    /* 見た目を変えずにタップ領域だけ44px相当に */
    .clear-btn {
        padding: .7rem .6rem;
        margin: -.7rem -.6rem;
    }

    .bottleneck-meter {
        width: 150px;
        height: 150px;
    }

    .meter-circle::before {
        width: 124px;
        height: 124px;
    }

    .meter-value {
        font-size: 2rem;
    }
}