/* ════════════════════════════════════════════════════════════
   SIGNAL REVIEW — Briefing family, re-architected
   Keeps: dark + mint, Space Grotesk + JetBrains Mono labels,
   hairline rules, operational tone, blinking cursor, pulse dots.
   Drops: dashboard shell, persistent rail, live feeds, metrics,
   tickers, sliders, toasts — replaced by an editorial
   "signal review" composition: proposition → illustrated field
   notes → honest case-study scaffold → service matrix.
   Self-contained overlay on base.css reset/tokens only.
   ════════════════════════════════════════════════════════════ */

.signal {
  --bg: #050608;
  --bg-2: #0a0d11;
  --bg-3: #0e1217;
  --line: rgba(79,227,154,.10);
  --line-2: rgba(79,227,154,.24);
  --line-cool: rgba(255,255,255,.07);
  --text: #d8e4dc;
  --text-2: #8ea096;
  --text-3: #4d5a52;
  --accent: #4fe39a;
  --accent-bright: #62ffae;
  --amber: #ffb84a;

  background:
    radial-gradient(ellipse 1100px 520px at 70% -8%, rgba(79,227,154,.07), transparent 70%),
    var(--bg);
  color: var(--text);
  font-family: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  min-height: 100vh;
}

.signal ::selection { background: rgba(79,227,154,.28); color: #eafff3; }

/* Shared kickers — mono section numbering */
.sr-kicker {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 18px;
}

.sr-sec {
  padding: 88px 32px;
  border-bottom: 1px solid var(--line);
  position: relative;
}
.sr-sec > .sr-kicker:first-child,
.sr-prop .sr-kicker { max-width: 1180px; margin-left: auto; margin-right: auto; }

.sr-sechead {
  max-width: 1180px;
  margin: 0 auto 48px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 32px;
  align-items: end;
}
.sr-sechead .sr-kicker { grid-column: 1 / -1; margin-bottom: 0; }
.sr-sechead h2 {
  font-size: clamp(26px, 3.4vw, 42px);
  font-weight: 500;
  letter-spacing: -0.028em;
  line-height: 1.08;
  color: var(--text);
}
.sr-sechead__meta {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-3);
  padding-bottom: 6px;
  white-space: nowrap;
}

/* ─── MASTHEAD ───────────────────────────────────────────── */
.sr-mast {
  position: sticky; top: 0; z-index: 60;
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  align-items: center;
  gap: 20px;
  padding: 12px 24px;
  background: rgba(5,6,8,.9);
  backdrop-filter: blur(12px) saturate(130%);
  -webkit-backdrop-filter: blur(12px) saturate(130%);
  border-bottom: 1px solid var(--line-2);
  font-size: 14px;
}
.sr-mast__brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--text);
}
.sr-mast__brand i {
  width: 15px; height: 15px;
  border: 1px solid var(--accent);
  background:
    linear-gradient(45deg, transparent 45%, var(--accent) 45%, var(--accent) 55%, transparent 55%),
    linear-gradient(-45deg, transparent 45%, var(--accent) 45%, var(--accent) 55%, transparent 55%);
}
.sr-mast__brand b { font-weight: 600; letter-spacing: -0.01em; }
.sr-mast__brand span {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-3);
  padding-left: 10px;
  border-left: 1px solid var(--line-cool);
}
.sr-mast__nav { display: flex; gap: 4px; justify-content: center; }
.sr-mast__nav a {
  padding: 7px 14px;
  color: var(--text-2);
  border-radius: 6px;
  font-size: 13.5px;
  transition: color .2s, background .2s;
}
.sr-mast__nav a:hover { color: var(--accent-bright); background: rgba(79,227,154,.07); }
.sr-mast__status {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--text-2);
  padding: 5px 12px;
  background: rgba(79,227,154,.08);
  border: 1px solid var(--line);
  border-radius: 999px;
}
.sr-mast__status i {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 6px var(--accent);
  animation: sr-pulse 1.8s ease-in-out infinite;
}
@keyframes sr-pulse { 0%,100% { opacity: 1; } 50% { opacity: .35; } }

/* Buttons */
.sr-cta {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 18px;
  background: var(--accent);
  color: var(--bg);
  border-radius: 7px;
  font-size: 13.5px;
  font-weight: 500;
  transition: background .25s, transform .25s;
}
.sr-cta:hover { background: var(--accent-bright); transform: translateY(-1px); }
.sr-cta .arr, .sr-btn .arr, .sr-read .arr { transition: transform .25s; }
.sr-cta:hover .arr { transform: translateX(2px); }

.sr-btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 14px 24px;
  font-size: 15px;
  font-weight: 500;
  border-radius: 8px;
  background: var(--accent);
  color: var(--bg);
  transition: background .25s, transform .25s;
}
.sr-btn:hover { background: var(--accent-bright); transform: translateY(-1px); }
.sr-btn:hover .arr { transform: translateX(3px); }
.sr-btn--ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid rgba(255,255,255,.14);
}
.sr-btn--ghost:hover {
  background: rgba(255,255,255,.04);
  border-color: rgba(255,255,255,.3);
  color: var(--text);
}

/* ─── 01 · PROPOSITION ───────────────────────────────────── */
.sr-prop { padding-top: 96px; padding-bottom: 96px; }
.sr-prop__grid {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(280px, .9fr);
  gap: 56px;
  align-items: start;
}
.sr-prop h1 {
  font-size: clamp(42px, 6vw, 84px);
  font-weight: 500;
  letter-spacing: -0.038em;
  line-height: 0.99;
  color: var(--text);
  margin-bottom: 28px;
}
.sr-prop h1 .acc { color: var(--accent); }
.sr-cursor {
  display: inline-block;
  width: .5em; height: .92em;
  background: var(--accent);
  vertical-align: text-bottom;
  margin-left: 6px;
  animation: sr-blink 1.1s steps(1) infinite;
}
@keyframes sr-blink { 50% { opacity: 0; } }

.sr-prop__lede {
  font-size: 18px;
  line-height: 1.65;
  color: var(--text);
  max-width: 58ch;
  margin-bottom: 34px;
}
.sr-prop__ctas { display: flex; gap: 12px; flex-wrap: wrap; }

/* Table-of-contents index card */
.sr-prop__index {
  border: 1px solid var(--line-2);
  background: var(--bg-2);
  padding: 24px;
}
.sr-prop__index-title {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 16px;
}
.sr-prop__index ol { display: flex; flex-direction: column; }
.sr-prop__index li {
  display: grid;
  grid-template-columns: 34px 1fr;
  grid-template-rows: auto auto;
  column-gap: 12px;
  padding: 13px 0;
  border-top: 1px solid var(--line-cool);
}
.sr-prop__index li:first-child { border-top: none; padding-top: 0; }
.sr-prop__index .n {
  grid-row: 1 / 3;
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  color: var(--accent);
  padding-top: 2px;
}
.sr-prop__index .t { font-size: 15px; font-weight: 500; color: var(--text); }
.sr-prop__index .d { font-size: 12.5px; color: var(--text-3); margin-top: 2px; }
.sr-prop__index-rule {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px dashed var(--line-2);
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px;
  line-height: 1.6;
  color: var(--text-3);
}

/* ─── 02 · FIELD NOTES ───────────────────────────────────── */
.sr-notes { background: var(--bg-2); }
.sr-notes > * { max-width: 1180px; margin-left: auto; margin-right: auto; }

/* Feature — image-led, asymmetric split */
.sr-feature {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 0;
  border: 1px solid var(--line-2);
  background: var(--bg);
}
.sr-feature__art {
  border-right: 1px solid var(--line-2);
  background: #07090c;
  display: flex; flex-direction: column;
}
.sr-feature__art img { width: 100%; height: auto; }
.sr-feature__art figcaption {
  display: flex; gap: 12px; align-items: baseline;
  padding: 12px 18px;
  border-top: 1px solid var(--line);
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.05em;
  color: var(--text-3);
}
.sr-feature__art figcaption span { color: var(--accent); }

.sr-feature__body {
  padding: 40px 36px;
  display: flex; flex-direction: column; align-items: flex-start;
  gap: 18px;
}
.sr-feature__body h3 {
  font-size: clamp(24px, 2.6vw, 34px);
  font-weight: 500;
  letter-spacing: -0.025em;
  line-height: 1.12;
  color: var(--text);
}
.sr-feature__dek {
  font-size: 15.5px;
  line-height: 1.65;
  color: var(--text-2);
}
.sr-feature__meta {
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--text-3);
}

.sr-tag {
  display: inline-block;
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid var(--line-2);
  padding: 4px 10px;
  margin-right: 8px;
}
.sr-tag--amber { color: var(--amber); border-color: rgba(255,184,74,.35); }
.sr-tag--feat { color: var(--text); border-color: var(--line-cool); background: var(--bg-3); }

.sr-read {
  margin-top: auto;
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--accent);
  padding-bottom: 3px;
  border-bottom: 1px solid var(--line-2);
  transition: color .25s, border-color .25s;
}
.sr-read:hover { color: var(--accent-bright); border-color: var(--accent); }
.sr-read:hover .arr { transform: translateX(4px); }

/* Supporting duo — deliberately uneven */
.sr-notes__duo {
  margin-top: 24px;
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: 24px;
}
.sr-note {
  border: 1px solid var(--line-cool);
  background: var(--bg);
  display: flex; flex-direction: column;
  transition: border-color .3s;
}
.sr-note:hover { border-color: var(--line-2); }
.sr-note__art { background: #07090c; border-bottom: 1px solid var(--line); }
.sr-note__art img { width: 100%; height: auto; }
.sr-note__body {
  padding: 28px 26px 30px;
  display: flex; flex-direction: column; align-items: flex-start;
  gap: 14px;
  flex: 1;
}
.sr-note__body h3 {
  font-size: 21px;
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text);
}
.sr-note__body p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-2);
}
/* narrow note runs body-over-art */
.sr-note--narrow .sr-note__body { border-bottom: none; }
.sr-note--narrow .sr-note__art { border-bottom: none; border-top: 1px solid var(--line); }

/* ─── 03 · CASE STUDIES — scaffold ───────────────────────── */
.sr-cases__statement {
  margin: -20px auto 44px;
  padding: 22px 26px;
  border-left: 2px solid var(--accent);
  background: var(--bg-2);
  max-width: 860px;
}
.sr-cases__statement p {
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--text-2);
}
.sr-cases__statement p b { color: var(--text); font-weight: 500; }

.sr-scaffold {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px dashed var(--line-2);
}
.sr-stage {
  padding: 30px 26px 34px;
  border-right: 1px dashed var(--line-2);
  display: flex; flex-direction: column; gap: 16px;
  min-height: 260px;
  background:
    repeating-linear-gradient(-45deg, transparent 0 10px, rgba(79,227,154,.018) 10px 11px);
}
.sr-stage:last-child { border-right: none; }
.sr-stage__num {
  font-family: "JetBrains Mono", monospace;
  font-size: 13px;
  color: var(--accent);
  width: 34px; height: 34px;
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--line-2);
}
.sr-stage__body h3 {
  font-size: 19px;
  font-weight: 500;
  letter-spacing: -0.015em;
  color: var(--text);
  margin-bottom: 10px;
}
.sr-stage__body p {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--text-2);
}
.sr-stage__status {
  margin-top: auto;
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-3);
  padding-top: 14px;
  border-top: 1px dashed var(--line-cool);
}
.sr-stage__status::before {
  content: "◇";
  color: var(--accent);
  margin-right: 7px;
}

.sr-cases__rule {
  max-width: 1180px;
  margin: 26px auto 0;
  display: flex; align-items: center; gap: 12px;
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.05em;
  color: var(--text-3);
}
.sr-cases__rule::before {
  content: "";
  width: 26px; height: 1px;
  background: var(--accent);
  flex: none;
}

/* ─── 04 · SERVICE MATRIX ────────────────────────────────── */
.sr-matrix { background: var(--bg-2); }
.sr-matrix__grid {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line-2);
  background: var(--bg);
}
.sr-cell {
  padding: 34px 32px;
  border-bottom: 1px solid var(--line);
  border-right: 1px solid var(--line);
  display: flex; flex-direction: column; gap: 14px;
  transition: background .3s;
}
.sr-cell:nth-child(2n) { border-right: none; }
.sr-cell:nth-child(3), .sr-cell:nth-child(4) { border-bottom: none; }
.sr-cell:hover { background: rgba(79,227,154,.035); }
.sr-cell__idx {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--accent);
}
.sr-cell h3 {
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--text);
}
.sr-cell p {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--text-2);
}
.sr-cell__when {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px !important;
  line-height: 1.7 !important;
  letter-spacing: 0.03em;
  color: var(--text-3) !important;
  padding-top: 12px;
  border-top: 1px solid var(--line-cool);
}
.sr-matrix__foot {
  grid-column: 1 / -1;
  padding: 22px 32px;
  background: var(--bg-3);
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-2);
  border-top: 1px solid var(--line);
}
.sr-matrix__foot::before {
  content: "▸ ";
  color: var(--accent);
}

/* ─── 05 · CONTACT ───────────────────────────────────────── */
.sr-contact {
  max-width: 1180px;
  margin: 0 auto;
  padding-top: 104px;
  padding-bottom: 104px;
  background:
    radial-gradient(ellipse 700px 320px at 30% 50%, rgba(79,227,154,.07), transparent 70%);
}
.sr-contact h2 {
  font-size: clamp(38px, 5vw, 64px);
  font-weight: 500;
  letter-spacing: -0.035em;
  line-height: 1;
  color: var(--text);
  margin-bottom: 22px;
}
.sr-contact > p {
  font-size: 17px;
  line-height: 1.65;
  color: var(--text-2);
  max-width: 56ch;
  margin-bottom: 30px;
}
.sr-contact__actions { display: flex; gap: 12px; flex-wrap: wrap; }
.sr-contact__note {
  margin-top: 22px;
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--text-3);
}

/* ─── FOOTER ─────────────────────────────────────────────── */
.sr-footer {
  padding: 18px 32px;
  border-top: 1px solid var(--line);
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--text-3);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px;
}
.sr-footer b { color: var(--text-2); font-weight: 400; }
.sr-footer .acc { color: var(--accent); }

/* ─── RESPONSIVE ─────────────────────────────────────────── */
@media (max-width: 1000px) {
  .sr-prop__grid { grid-template-columns: 1fr; gap: 44px; }
  .sr-prop__index { max-width: 560px; }
  .sr-feature { grid-template-columns: 1fr; }
  .sr-feature__art { border-right: none; border-bottom: 1px solid var(--line-2); }
  .sr-notes__duo { grid-template-columns: 1fr; }
  .sr-scaffold { grid-template-columns: 1fr 1fr; }
  .sr-stage { border-bottom: 1px dashed var(--line-2); min-height: 0; }
  .sr-stage:nth-child(2n) { border-right: none; }
  .sr-stage:nth-child(3), .sr-stage:nth-child(4) { border-bottom: none; }
  .sr-sechead { grid-template-columns: 1fr; }
  .sr-sechead__meta { white-space: normal; padding-bottom: 0; }
}

@media (max-width: 700px) {
  .sr-sec { padding: 64px 20px; }
  .sr-mast {
    grid-template-columns: auto 1fr auto;
    gap: 12px;
    padding: 10px 16px;
  }
  .sr-mast__nav, .sr-mast__status { display: none; }
  .sr-mast__brand span { display: none; }
  .sr-prop { padding-top: 64px; padding-bottom: 64px; }
  .sr-prop h1 { font-size: clamp(36px, 11vw, 48px); }
  .sr-prop__lede { font-size: 16px; }
  .sr-feature__body { padding: 28px 22px 30px; }
  .sr-scaffold { grid-template-columns: 1fr; }
  .sr-stage { border-right: none; }
  .sr-stage:nth-child(4) { border-bottom: none; }
  .sr-matrix__grid { grid-template-columns: 1fr; }
  .sr-cell { border-right: none; }
  .sr-cell:nth-child(3) { border-bottom: 1px solid var(--line); }
  .sr-cell:nth-child(4) { border-bottom: none; }
  .sr-contact { padding-top: 72px; padding-bottom: 72px; }
}

@media (prefers-reduced-motion: reduce) {
  .sr-cursor, .sr-mast__status i { animation: none; }
}

/* ════════════════════════════════════════════════════════════
   CURRENT-MATERIAL EXTENSIONS (hero register, proof rows,
   3-wide service matrix + scope chips, expectations, 3×2
   notes grid, notes footer, footer mid-line)
   ════════════════════════════════════════════════════════════ */

/* Hero — alternate framings register */
.sr-register {
  margin-top: 34px;
  padding-top: 20px;
  border-top: 1px dashed var(--line-2);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  align-items: center;
  max-width: 640px;
}
.sr-register__label {
  flex-basis: 100%;
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 4px;
}
.sr-register span {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-2);
  border: 1px solid var(--line-cool);
  padding: 5px 11px;
  background: var(--bg-2);
}
.sr-register span.is-not {
  color: var(--amber);
  border-color: rgba(255,184,74,.35);
  background: rgba(255,184,74,.05);
}

/* ─── 02 · PROOF ROWS ────────────────────────────────────── */
.sr-proof__rows {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--line-2);
}
.sr-proof__row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 40px;
  align-items: center;
  padding: 38px 8px;
  border-bottom: 1px solid var(--line);
  transition: background .3s;
}
.sr-proof__row:hover { background: rgba(79,227,154,.03); }
.sr-proof__big {
  font-family: "JetBrains Mono", monospace;
  font-size: clamp(44px, 5vw, 64px);
  font-weight: 500;
  letter-spacing: -0.04em;
  color: var(--accent);
  line-height: 1;
  text-align: center;
}
.sr-proof__big .u {
  font-size: .38em;
  color: var(--text-3);
  letter-spacing: 0.1em;
  margin-left: 4px;
}
.sr-proof__body h3 {
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 10px;
}
.sr-proof__body p {
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-2);
  max-width: 66ch;
}

/* ─── 03 · SERVICES: 3-wide matrix variant + scope chips ─── */
.sr-matrix__grid--3 { grid-template-columns: repeat(3, 1fr); }
.sr-matrix__grid--3 .sr-cell:nth-child(2n) { border-right: 1px solid var(--line); }
.sr-matrix__grid--3 .sr-cell:nth-child(3n) { border-right: none; }
.sr-matrix__grid--3 .sr-cell:nth-child(3), .sr-matrix__grid--3 .sr-cell:nth-child(4) { border-bottom: 1px solid var(--line); }
.sr-matrix__grid--3 .sr-cell:nth-child(5), .sr-matrix__grid--3 .sr-cell:nth-child(6) { border-bottom: none; }

.sr-scope {
  max-width: 1180px;
  margin: 22px auto 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}
.sr-scope__label {
  font-family: "JetBrains Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-right: 6px;
}
.sr-scope__item {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-2);
  border: 1px solid var(--line-cool);
  background: var(--bg);
  padding: 7px 14px;
  transition: border-color .25s, color .25s;
}
.sr-scope__link:hover { border-color: var(--accent); color: var(--accent-bright); }

/* ─── 04 · EXPECTATIONS ──────────────────────────────────── */
.sr-expect { background: var(--bg-2); }
.sr-expect__head {
  max-width: 1180px;
  margin: 0 auto 44px;
}
.sr-expect__head h2 {
  font-size: clamp(24px, 3vw, 38px);
  font-weight: 500;
  letter-spacing: -0.028em;
  line-height: 1.16;
  color: var(--text);
  max-width: 30ch;
}
.sr-expect__grid {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--line-2);
  background: var(--bg);
}
.sr-exp {
  padding: 30px 28px 32px;
  border-bottom: 1px solid var(--line);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: background .3s;
}
.sr-exp:hover { background: rgba(79,227,154,.035); }
.sr-exp:nth-child(3n) { border-right: none; }
.sr-exp:nth-child(4), .sr-exp:nth-child(5), .sr-exp:nth-child(6) { border-bottom: none; }
.sr-exp__idx {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--amber);
}
.sr-exp h3 {
  font-size: 18.5px;
  font-weight: 500;
  letter-spacing: -0.015em;
  color: var(--text);
}
.sr-exp p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-2);
}

/* ─── 05 · NOTES: 3×2 grid + footer ──────────────────────── */
.sr-notes__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.sr-note__tags { display: flex; flex-wrap: wrap; gap: 6px; }
.sr-note__tags .sr-tag { margin-right: 0; }
.sr-notes__foot {
  margin-top: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.sr-read--lg { font-size: 16px; padding-bottom: 4px; }
.sr-notes__sysnote {
  font-family: "JetBrains Mono", monospace;
  font-size: 10.5px;
  letter-spacing: 0.04em;
  line-height: 1.7;
  color: var(--text-3);
  max-width: 520px;
}
.sr-notes__sysnote a { color: var(--text-2); border-bottom: 1px solid var(--line-2); }
.sr-notes__sysnote a:hover { color: var(--accent-bright); border-color: var(--accent); }

/* Footer mid-line */
.sr-footer { grid-column: 1 / -1; align-items: center; }
.sr-footer__mid { max-width: 560px; line-height: 1.6; }

/* Responsive — extensions */
@media (max-width: 1000px) {
  .sr-proof__row { grid-template-columns: 140px 1fr; gap: 24px; }
  .sr-matrix__grid--3 { grid-template-columns: 1fr 1fr; }
  .sr-matrix__grid--3 .sr-cell:nth-child(3n) { border-right: 1px solid var(--line); }
  .sr-matrix__grid--3 .sr-cell:nth-child(2n) { border-right: none; }
  .sr-matrix__grid--3 .sr-cell:nth-child(5), .sr-matrix__grid--3 .sr-cell:nth-child(6) { border-bottom: 1px solid var(--line); }
  .sr-matrix__grid--3 .sr-cell:nth-last-child(-n+1) { border-bottom: none; }
  .sr-expect__grid { grid-template-columns: 1fr 1fr; }
  .sr-exp:nth-child(3n) { border-right: 1px solid var(--line); }
  .sr-exp:nth-child(2n) { border-right: none; }
  .sr-exp:nth-child(4), .sr-exp:nth-child(5), .sr-exp:nth-child(6) { border-bottom: 1px solid var(--line); }
  .sr-exp:nth-child(5), .sr-exp:nth-child(6) { border-bottom: none; }
  .sr-notes__grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 700px) {
  .sr-cursor { display: none; }
  .sr-proof__row { grid-template-columns: 1fr; gap: 14px; padding: 30px 4px; }
  .sr-proof__big { text-align: left; }
  .sr-matrix__grid--3 { grid-template-columns: 1fr; }
  .sr-matrix__grid--3 .sr-cell { border-right: none; border-bottom: 1px solid var(--line); }
  .sr-matrix__grid--3 .sr-cell:nth-child(6) { border-bottom: none; }
  .sr-expect__grid { grid-template-columns: 1fr; }
  .sr-exp { border-right: none; border-bottom: 1px solid var(--line); }
  .sr-exp:nth-child(6) { border-bottom: none; }
  .sr-notes__grid { grid-template-columns: 1fr; }
  .sr-footer { flex-direction: column; align-items: flex-start; }
}