/* The architecture presentation shares the site's Heebo / Inter Tight palette.
   Keep body copy at 18px or above; diagrams reflow instead of shrinking. */
.a15-section { --a15-line: #2a4149; --a15-soft: #b9cbd1; --a15-accent: #a2d9ec; background: radial-gradient(ellipse at 82% 14%, #11272f 0, transparent 48%), #070c0f; padding-block: clamp(64px, 7vw, 112px); scroll-margin-top: 80px; }
.a15-shell { position: relative; }
.a15-section h2, .a15-section h3, .a15-section h4, .a15-section p { margin: 0; }
.a15-section p, .a15-section li { font-size: 18px; line-height: 1.8; }
.a15-section h3 { font-size: clamp(25px, 2.4vw, 36px); line-height: 1.35; font-weight: 500; letter-spacing: -.025em; }
.a15-section h4 { font-size: 21px; line-height: 1.45; font-weight: 500; }
.a15-section :focus-visible { outline: 2px solid var(--a15-accent); outline-offset: 5px; }
.a15-section bdi { display: inline; }
.a15-heading { display: flex; align-items: end; justify-content: space-between; gap: 48px; padding-block-end: 48px; }
.a15-section .a15-eyebrow { font-family: "Inter Tight", sans-serif; color: var(--a15-accent); direction: ltr; text-align: right; font-size: 13px; font-weight: 600; line-height: 1.6; letter-spacing: .13em; margin-block-end: 18px; }
.a15-heading h2 { font-size: clamp(40px, 5.2vw, 76px); line-height: 1.14; font-weight: 500; letter-spacing: -.045em; }
.a15-heading h2 em { font-style: normal; color: var(--a15-accent); }
.a15-intro { max-width: 480px; padding-block-end: 5px; }
.a15-intro p { color: var(--a15-soft); font-size: 21px; line-height: 1.75; }
.a15-baseline { display: inline-flex; direction: ltr; gap: 10px; align-items: center; font-family: "Inter Tight", sans-serif; letter-spacing: .09em; font-size: 13px; margin-block-end: 18px; color: #c7e4e6; }
.a15-baseline i { width: 6px; height: 6px; background: #77c8bf; border-radius: 50%; box-shadow: 0 0 14px #77c8bf66; }
.a15-tabs { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--a15-line); margin-block-end: 42px; }
.a15-tabs button { appearance: none; font: inherit; display: flex; align-items: center; gap: 24px; min-width: 0; min-height: 114px; padding: 24px 30px; text-align: right; color: var(--a15-soft); border: 0; background: #091217; position: relative; cursor: pointer; transition: background .2s; }
.a15-tabs button + button { border-inline-start: 1px solid var(--a15-line); }
.a15-tabs button::after { position: absolute; content: ''; inset-inline: 0; bottom: -1px; height: 3px; background: transparent; }
.a15-tabs button[aria-selected="true"] { background: #132a34; color: #f3f8f8; }
.a15-tabs button[aria-selected="true"]::after { background: var(--a15-accent); }
.a15-tabs button:hover { background: #162f39; }
.a15-tabs button > span { font: 400 40px/1 "Inter Tight", sans-serif; direction: ltr; color: var(--a15-accent); }
.a15-tabs button strong { display: block; font-size: 23px; font-weight: 500; }
.a15-tabs button small { display: block; font-size: 16px; margin-block-start: 5px; color: var(--a15-soft); }
.a15-tabs button b { margin-inline-start: auto; font-size: 30px; font-weight: 400; color: var(--a15-accent); }
.a15-panel[hidden] { display: none; }
.a15-panel { animation: a15-enter .3s ease-out; }
@keyframes a15-enter { from { opacity: .4; transform: translateY(6px); } to { opacity: 1; transform: none; } }
.a15-panel-heading { display: flex; align-items: center; justify-content: space-between; gap: 28px; margin-block-end: 28px; }
.a15-panel-heading .a15-eyebrow { margin-block-end: 8px; }
.a15-panel-heading p:not(.a15-eyebrow) { margin-block-start: 12px; color: var(--a15-soft); }
.a15-diagram { border: 1px solid #43616d; background: linear-gradient(140deg, #0d1b23, #0a1319); padding: 28px; position: relative; }
.a15-diagram-head { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin-block-end: 26px; padding-block-end: 22px; border-bottom: 1px solid var(--a15-line); }
.a15-diagram-head strong { font-family: "Inter Tight", sans-serif; font-size: clamp(26px, 2.3vw, 34px); font-weight: 500; color: #e4f5ff; }
.a15-diagram-head > span { font-size: 17px; color: var(--a15-soft); }
.a15-diagram-scroll { overflow-x: auto; overscroll-behavior-inline: contain; scrollbar-color: #7096a5 #0a161d; scrollbar-width: auto; padding-block-end: 12px; }
.a15-nodes { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 36px; min-width: 1100px; }
.a15-section .a15-pan-hint { display: none; color: var(--a15-soft); font-size: 17px; margin-block-end: 20px; }
.a15-node { position: relative; padding: 24px 21px; border: 1px solid #355260; border-top: 2px solid #7caabe; background: #0c1b23; min-width: 0; transition: border-color .2s, background .2s; }
.a15-edge { position: absolute; overflow: visible; pointer-events: none; z-index: 1; }
.a15-edge path { fill: none; stroke: #addce9; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.a15-edge-horizontal { width: 36px; height: 16px; left: -37px; top: calc(50% - 8px); }
.a15-edge-vertical { width: 16px; height: 36px; bottom: -37px; left: calc(50% - 8px); }
.a15-node:hover { border-color: #91cada; background: #11252e; }
.a15-node:nth-child(4n+1) { border-top-color: #73c2b5; }
.a15-node:nth-child(4n) { border-top-color: #c7ac75; }
.a15-node-code { display: block; color: var(--a15-accent); font: 500 13px/1.6 "Inter Tight", sans-serif; letter-spacing: .055em; margin-block-end: 12px; }
.a15-node h4 { color: #f0f7f8; margin-block-end: 12px; }
.a15-node p { color: var(--a15-soft); }
.a15-foundations { display: grid; grid-template-columns: repeat(3, 1fr); margin-block-start: 24px; border: 1px solid var(--a15-line); background: #0a141a; }
.a15-foundations span { text-align: center; color: #c4dade; padding: 15px 14px; font-size: 17px; line-height: 1.6; }
.a15-foundations span + span { border-inline-start: 1px solid var(--a15-line); }
.a15-subheading { display: flex; align-items: baseline; justify-content: space-between; gap: 22px; margin-block: 44px 22px; }
.a15-subheading p { color: var(--a15-soft); font-size: 16px; }
.a15-phases { margin: 0; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); border: 1px solid var(--a15-line); }
.a15-phases li { position: relative; padding: 23px 15px; background: #0c171d; min-width: 0; }
.a15-phases li + li { border-inline-start: 1px solid var(--a15-line); }
.a15-phases li:nth-child(4) { background: #202321; }
.a15-phases span { display: block; color: #91b8c7; font: 500 13px/1 "Inter Tight", sans-serif; margin-block-end: 18px; }
.a15-phases strong { display: block; font-size: 18px; font-weight: 500; line-height: 1.5; }
.a15-phases small { display: block; color: var(--a15-soft); font-size: 16px; line-height: 1.7; margin-block-start: 8px; }
.a15-metrics { display: grid; grid-template-columns: repeat(4, 1fr); margin-block-end: 24px; border-block: 1px solid var(--a15-line); }
.a15-metrics > div { padding: 28px 26px; }
.a15-metrics > div + div { border-inline-start: 1px solid var(--a15-line); }
.a15-metrics span { display: block; font-size: 17px; color: var(--a15-soft); margin-block-end: 13px; }
.a15-metrics strong { display: block; color: var(--a15-accent); font-size: clamp(30px, 3vw, 46px); line-height: 1.2; font-weight: 400; white-space: nowrap; }
.a15-metrics strong bdi { font-family: "Inter Tight", sans-serif; }
.a15-metrics strong small { color: #b2c6cd; font-size: 18px; font-weight: 400; }
.a15-detail { border: 1px solid var(--a15-line); background: #0c171d; margin-block: 12px; }
.a15-detail > summary { list-style: none; display: flex; gap: 24px; justify-content: space-between; align-items: center; padding: 26px 30px; cursor: pointer; }
.a15-detail > summary::-webkit-details-marker { display: none; }
.a15-detail > summary strong { display: block; color: #edf6f8; font-size: 23px; font-weight: 500; line-height: 1.4; }
.a15-detail > summary small { display: block; color: var(--a15-soft); font-size: 17px; margin-block-start: 7px; }
.a15-detail > summary i { width: 32px; height: 32px; border: 1px solid #45606b; flex-shrink: 0; position: relative; border-radius: 50%; }
.a15-detail > summary i::before, .a15-detail > summary i::after { content: ''; position: absolute; background: #b4dfeb; width: 12px; height: 1px; top: 15px; left: 9px; }
.a15-detail > summary i::after { transform: rotate(90deg); transition: transform .2s; }
.a15-detail[open] > summary i::after { transform: none; }
.a15-detail[open] { border-color: #5e8597; }
.a15-detail[open] > summary { background: #132631; }
.a15-detail-body { padding: 28px 30px 32px; border-top: 1px solid var(--a15-line); color: var(--a15-soft); }
.a15-detail-body h4 { color: #d6eef7; margin-block-end: 12px; }
.a15-detail-body p + p { margin-block-start: 16px; }
.a15-detail-body ul { margin: 0; padding-inline-start: 22px; }
.a15-detail-body li + li { margin-block-start: 8px; }
/* Section 02: a brief light reveal, with the text kept above the effect. */
#a15-details .a15-detail { transition: border-color .25s ease, box-shadow .25s ease; }
#a15-details .a15-detail > summary { transition: background .25s ease; }
#a15-details .a15-detail > summary:hover { background: #142a35; }
#a15-details .a15-detail > summary i { transition: border-color .25s ease, background .25s ease, box-shadow .25s ease; }
#a15-details .a15-detail[open] { border-color: #76a9bd; box-shadow: 0 0 28px #84cce812, inset 0 0 0 1px #a2d9ec0a; }
#a15-details .a15-detail[open] > summary { background: linear-gradient(105deg, #11232d, #193947); }
#a15-details .a15-detail[open] > summary i { background: #214857; border-color: #a2d9ec; box-shadow: 0 0 15px #a2d9ec30; }
#a15-details .a15-detail-body { position: relative; isolation: isolate; overflow: hidden; background: linear-gradient(125deg, #0c171d, #10232c); }
#a15-details .a15-detail-body::before { content: ''; position: absolute; z-index: -1; inset: 0; pointer-events: none; opacity: 0; background: linear-gradient(110deg, transparent 15%, #9eddf62b 46%, transparent 75%); }
#a15-details .a15-detail[open] > .a15-detail-body { animation: a15-detail-reveal .28s ease-out; }
#a15-details .a15-detail[open] > .a15-detail-body::before { animation: a15-detail-light .7s ease-out; }
@keyframes a15-detail-reveal { from { opacity: .35; transform: translateY(-5px); } to { opacity: 1; transform: none; } }
@keyframes a15-detail-light { from { opacity: 0; transform: translateX(45%); } 25% { opacity: 1; } to { opacity: 0; transform: translateX(-45%); } }
.a15-info-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.a15-tags { display: flex; gap: 9px; flex-wrap: wrap; margin-block-end: 20px; }
.a15-tags span { padding: 8px 12px; background: #152832; border: 1px solid #3a5664; color: #cee8f1; font-size: 16px; line-height: 1.5; }
.a15-value-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.a15-value-grid > div { border-top: 2px solid #507b8c; padding-block-start: 24px; }
.a15-value-grid h4 { color: #daedf4; margin-block-end: 12px; }
.a15-value-grid p { color: var(--a15-soft); }
.a15-edition { font: 500 13px/1.6 "Inter Tight", sans-serif; color: #adcbd6; letter-spacing: .07em; direction: ltr; white-space: nowrap; }
.a15-note { border-inline-start: 2px solid #97b4be; padding: 12px 20px; margin-block-start: 24px !important; background: #14242d; color: #c7d7de; }
.a15-timeline { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); padding: 0; gap: 0; margin: 28px 0 0; border-top: 1px solid var(--a15-line); border-inline-start: 1px solid var(--a15-line); }
.a15-timeline li { padding: 24px; border-bottom: 1px solid var(--a15-line); border-inline-end: 1px solid var(--a15-line); }
.a15-timeline bdi { display: block; font: 400 27px/1.3 "Inter Tight", sans-serif; color: var(--a15-accent); margin-block-end: 10px; }
.a15-timeline span { color: #d3e0e5; font-size: 18px; }
.a15-footer { margin-block-start: 44px; padding-block-start: 22px; border-top: 1px solid var(--a15-line); display: flex; justify-content: space-between; gap: 24px; color: #9fb7c1; font-size: 15px; line-height: 1.6; }
.a15-footer span:first-child { font-family: "Inter Tight", sans-serif; direction: ltr; letter-spacing: .08em; }
@media (max-width: 1200px) {
  .a15-section .a15-pan-hint { display: block; }
  .a15-phases { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .a15-phases li { border-bottom: 1px solid var(--a15-line); }
  .a15-phases li:nth-child(5) { border-inline-start: 0; }
  .a15-heading { align-items: start; }
  .a15-intro { max-width: 340px; }
}
@media (max-width: 800px) {
  .a15-heading { display: grid; gap: 25px; padding-block-end: 32px; }
  .a15-intro { max-width: none; }
  .a15-intro p { font-size: 19px; }
  .a15-tabs button { gap: 16px; padding: 21px 18px; }
  .a15-tabs button strong { font-size: 20px; }
  .a15-tabs button > span { font-size: 32px; }
  .a15-tabs button small { display: none; }
  .a15-tabs button b { display: none; }
  .a15-info-grid, .a15-value-grid { grid-template-columns: 1fr; gap: 28px; }
  .a15-foundations { grid-template-columns: 1fr; }
  .a15-foundations span + span { border-inline-start: 0; border-top: 1px solid var(--a15-line); }
  .a15-subheading { display: grid; gap: 8px; }
  .a15-metrics { grid-template-columns: 1fr 1fr; }
  .a15-metrics > div { border-bottom: 1px solid var(--a15-line); }
  .a15-metrics > div:nth-child(3) { border-inline-start: 0; }
  .a15-timeline { grid-template-columns: 1fr 1fr; }
  .a15-panel-heading { flex-wrap: wrap; align-items: start; }
  .a15-footer { flex-direction: column; gap: 12px; }
}
@media (max-width: 540px) {
  .a15-shell { width: calc(100% - 32px); }
  .a15-heading h2 { font-size: 40px; }
  .a15-section .a15-eyebrow { font-size: 12px; letter-spacing: .075em; }
  .a15-tabs { margin-block-end: 32px; }
  .a15-tabs button { align-items: start; flex-direction: column; min-height: 130px; gap: 14px; }
  .a15-tabs button strong { font-size: 19px; }
  .a15-diagram { padding: 18px 14px; }
  .a15-diagram-head { display: grid; gap: 10px; }
  .a15-diagram-head > span { font-size: 16px; }
  .a15-node { padding: 22px; }
  .a15-phases { grid-template-columns: 1fr 1fr; }
  .a15-phases li:nth-child(odd) { border-inline-start: 0; }
  .a15-phases li { padding: 22px 17px; }
  .a15-phases li:last-child { grid-column: 1 / -1; }
  .a15-metrics > div { padding: 22px 14px; }
  .a15-metrics span { font-size: 16px; }
  .a15-metrics strong { font-size: 30px; }
  .a15-detail > summary { padding: 22px 18px; gap: 16px; }
  .a15-detail > summary strong { font-size: 21px; }
  .a15-detail-body { padding: 24px 20px; }
  .a15-timeline { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  .a15-panel { animation: none; }
  .a15-section *, .a15-section *::after { transition: none; }
  #a15-details .a15-detail, #a15-details .a15-detail > summary, #a15-details .a15-detail > summary i { transition: none; }
  #a15-details .a15-detail[open] > .a15-detail-body,
  #a15-details .a15-detail[open] > .a15-detail-body::before { animation: none; }
}