/* 媧石皇家 demo 4 — 關於我們 (about.html). Auravell /about + /instructors lineage. Prefix a4- */

/* ---------- shared bits ---------- */
.a4-pill { position: absolute; left: 16px; top: 16px; display: inline-flex; align-items: center; gap: 8px; padding: 7px 14px; border-radius: 99px; background: #fff; color: var(--ink); font-size: var(--fs-label); letter-spacing: .08em; box-shadow: 0 6px 18px rgba(23,24,26,.08); }
.a4-pill i { width: 6px; height: 6px; border-radius: 50%; background: var(--burgundy); }
.a4-hero__grid { position: absolute; inset: 0; z-index: 1; display: grid; grid-template-columns: repeat(4, 1fr); pointer-events: none; }
.a4-hero__grid span { border-right: 1px solid rgba(255,255,255,.08); }
.a4-hero__grid span:first-child { border-left: 1px solid rgba(255,255,255,.08); }

/* ---------- 1. Hero ---------- */
.a4-hero { position: relative; min-height: max(640px, 100svh); display: flex; align-items: flex-end; overflow: hidden; background: var(--dark); color: var(--on-dark); }
.a4-hero__media { position: absolute; inset: 0; overflow: hidden; }
.a4-hero__media img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 40%; }
.a4-hero::after { content: ""; position: absolute; inset: 0; z-index: 0; background: linear-gradient(90deg, rgba(17,14,13,.78) 0%, rgba(17,14,13,.45) 48%, rgba(17,14,13,.15) 100%), linear-gradient(0deg, rgba(17,14,13,.7) 0%, rgba(17,14,13,0) 45%); }
.a4-hero__in { position: relative; z-index: 2; display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr); align-items: end; gap: 40px 64px; padding-top: calc(var(--hd-h) + 80px); padding-bottom: clamp(48px, 6vw, 88px); }
.a4-hero__copy { display: grid; gap: 24px; justify-items: start; }
.a4-hero__t { font-family: var(--f-zh-serif); font-size: clamp(2.3rem, 5vw, 4.75rem); line-height: 1.25; letter-spacing: .06em; color: #fff; }
.a4-hero__lead { max-width: 30em; font-size: var(--fs-lead); line-height: 1.9; color: rgba(244,237,227,.86); }
.a4-hero__stats { display: grid; gap: 0; border-top: 1px solid rgba(244,237,227,.22); }
.a4-hero__stats > div { padding-block: 16px; border-bottom: 1px solid rgba(244,237,227,.22); }
.a4-hero__stats dd { display: flex; align-items: baseline; gap: 16px; }
.a4-hero__stats .num { min-width: 2.6em; font-size: clamp(2rem, 3vw, 2.75rem); line-height: 1; color: #fff; }
.a4-hero__stats small { font-size: var(--fs-small); letter-spacing: .1em; color: rgba(244,237,227,.8); }

/* ---------- 2. Story ---------- */
.a4-story__panel { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(32px, 5vw, 80px); align-items: center; padding: clamp(16px, 2vw, 24px); background: var(--sand); border-radius: var(--r-lg); }
.a4-story__media { position: relative; height: 100%; }
.a4-story__img { height: 100%; min-height: 520px; }
.a4-story__img img { position: absolute; inset: 0; }
.a4-story__copy { display: grid; gap: 24px; justify-items: start; padding: clamp(8px, 3vw, 48px) clamp(8px, 3vw, 40px) clamp(8px, 3vw, 48px) 0; }
.a4-story__p { color: var(--muted); max-width: 32em; }
.a4-acc { width: 100%; margin-top: 16px; border-top: 1px solid var(--line); }
.a4-acc__row { border-bottom: 1px solid var(--line); }
.a4-acc__row summary { display: flex; justify-content: space-between; align-items: center; gap: 16px; padding: 18px 0; cursor: pointer; list-style: none; font: 400 1.125rem/1.5 var(--f-zh-serif); letter-spacing: .06em; }
.a4-acc__row summary::-webkit-details-marker { display: none; }
.a4-acc__row summary i, .a4-q summary i { position: relative; flex: none; width: 14px; height: 14px; }
.a4-acc__row summary i::before, .a4-acc__row summary i::after, .a4-q summary i::before, .a4-q summary i::after { content: ""; position: absolute; left: 0; right: 0; top: 50%; height: 1px; background: currentColor; transition: transform .45s var(--ease); }
.a4-acc__row summary i::after, .a4-q summary i::after { transform: rotate(90deg); }
.a4-acc__row[open] summary i::after, .a4-q[open] summary i::after { transform: rotate(0); }
.a4-acc__row summary:hover { color: var(--burgundy); }
.a4-acc__row p { padding-bottom: 20px; color: var(--muted); font-size: var(--fs-small); line-height: 1.95; max-width: 34em; }

/* ---------- 3. Steps ---------- */
.a4-steps__list { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: clamp(16px, 2vw, 28px); counter-reset: none; }
.a4-step { display: grid; align-content: start; gap: 10px; }
.a4-step:nth-child(even) { margin-top: clamp(0px, 4vw, 64px); }
.a4-step__img { aspect-ratio: 4 / 5; margin-bottom: 10px; }
.a4-step__img img { transition: transform 1.2s var(--ease); }
.a4-step:hover .a4-step__img img { transform: scale(1.05); }
.a4-step__n { font-size: 1rem; color: var(--burgundy); letter-spacing: .1em; }
.a4-step .h3 { font-family: var(--f-zh-serif); letter-spacing: .08em; }
.a4-step__d { color: var(--muted); font-size: var(--fs-small); line-height: 1.9; }
.a4-swipe { display: none; }

/* ---------- 4. Different ---------- */
.a4-diff__grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 clamp(32px, 5vw, 80px); max-width: 1180px; margin-inline: auto; }
.a4-feat { display: grid; grid-template-columns: 56px minmax(0, 1fr); gap: 24px; padding: 36px 0; border-bottom: 1px dashed var(--line); }
.a4-feat__ic { width: 48px; height: 48px; fill: none; stroke: var(--burgundy); stroke-width: 1.1; stroke-linecap: round; stroke-linejoin: round; }
.a4-feat .h3 { font-family: var(--f-zh-serif); letter-spacing: .08em; margin-bottom: 10px; }
.a4-feat p { color: var(--muted); font-size: var(--fs-small); line-height: 1.95; }

/* ---------- 5. Dark band ---------- */
.a4-band { position: relative; overflow: hidden; background: var(--dark); color: var(--on-dark); }
.a4-band__media { position: absolute; inset: 0; overflow: hidden; }
.a4-band__media img { width: 100%; height: 100%; object-fit: cover; }
.a4-band::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, rgba(17,14,13,.72), rgba(17,14,13,.6) 55%, rgba(17,14,13,.85)); }
.a4-band__in { position: relative; z-index: 2; display: grid; justify-items: center; gap: 28px; text-align: center; padding-top: clamp(110px, 13vw, 200px); padding-bottom: clamp(90px, 10vw, 160px); }
.a4-band__seal { width: 56px; height: 56px; color: #E9C9C3; }
.a4-band__t { max-width: 20em; font-family: var(--f-zh-serif); font-size: clamp(1.75rem, 3.6vw, 3.5rem); line-height: 1.45; color: #fff; }
.a4-band__by { letter-spacing: .24em; font-size: var(--fs-small); color: rgba(244,237,227,.8); }
.a4-band__strip { position: relative; z-index: 2; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); border-top: 1px solid rgba(244,237,227,.16); }
.a4-band__strip li { display: flex; align-items: center; justify-content: center; gap: 12px; padding: 26px 8px; font: 400 1.125rem/1 var(--f-zh-serif); letter-spacing: .3em; color: var(--on-dark); }
.a4-band__strip li + li { border-left: 1px solid rgba(244,237,227,.16); }
.a4-band__strip .num { font-size: .8125rem; color: #E9C9C3; letter-spacing: .08em; }

/* ---------- 6. Teacher ---------- */
.a4-teach__in { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(40px, 6vw, 96px); align-items: center; }
.a4-teach__copy { display: grid; gap: 24px; justify-items: start; }
.a4-teach__q p { font: 400 clamp(1.25rem, 1.8vw, 1.6rem)/1.6 var(--f-zh-serif); letter-spacing: .08em; color: var(--burgundy); }
.a4-tt { width: 100%; margin-top: 8px; }
.a4-tt__head, .a4-tt__row { display: grid; grid-template-columns: 96px minmax(0, 1fr); gap: 24px; }
.a4-tt__head { padding-bottom: 12px; border-bottom: 1px solid var(--line); font-size: var(--fs-label); letter-spacing: .2em; color: var(--burgundy); }
.a4-tt__row { padding-block: 20px; border-bottom: 1px solid var(--line); }
.a4-tt__row > span { font: 400 1.125rem/1.6 var(--f-zh-serif); letter-spacing: .2em; }
.a4-tt__row p { color: var(--muted); font-size: var(--fs-small); line-height: 1.95; }
.a4-teach__btn { margin-top: 8px; }
.a4-teach__fig { position: relative; }
.a4-teach__img { aspect-ratio: 4 / 5; border-radius: var(--r-lg); }
.a4-stat { position: absolute; left: clamp(-40px, -3vw, -16px); bottom: 48px; display: flex; align-items: center; gap: 16px; padding: 20px 28px; background: #fff; border-radius: var(--r); box-shadow: 0 18px 40px rgba(23,24,26,.12); }
.a4-stat > .num { font-size: clamp(2.4rem, 3.4vw, 3.25rem); line-height: 1; color: var(--burgundy); }
.a4-stat p { font-size: var(--fs-small); line-height: 1.6; letter-spacing: .1em; }

/* ---------- 7. People ---------- */
.a4-people__grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(16px, 2vw, 28px); max-width: 1180px; margin-inline: auto; }
.a4-person { display: grid; gap: 4px; padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.a4-person__img { aspect-ratio: 4 / 5; margin-bottom: 16px; background: #fff; }
.a4-person:first-child .a4-person__img img { object-fit: contain; padding: 8%; }
.a4-person__img img { transition: transform 1.2s var(--ease); }
.a4-person__more { position: absolute; left: 12px; right: 12px; bottom: 12px; padding: 16px 18px; background: rgba(254,249,239,.95); border-radius: var(--r); font-size: var(--fs-small); line-height: 1.8; color: var(--ink); opacity: 0; transform: translateY(16px); transition: opacity .5s var(--ease), transform .6s var(--ease); }
.a4-person:hover .a4-person__more, .a4-person:focus-within .a4-person__more { opacity: 1; transform: none; }
.a4-person:hover .a4-person__img img { transform: scale(1.04); }
.a4-person__n { font: 400 1.375rem/1.4 var(--f-zh-serif); letter-spacing: .12em; }
.a4-person__r { color: var(--muted); font-size: var(--fs-small); letter-spacing: .1em; }
.a4-people__note { margin-top: 28px; text-align: center; font-size: var(--fs-label); letter-spacing: .1em; color: var(--muted); }

/* ---------- 8. FAQ ---------- */
.a4-faq__in { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.4fr); gap: 40px clamp(40px, 6vw, 96px); align-items: start; }
.a4-faq__head { display: grid; gap: 20px; position: sticky; top: calc(var(--hd-h) + 40px); }
.a4-faq__list { display: grid; gap: 12px; }
.a4-q { border: 1px solid var(--line); border-radius: var(--r); background: #fff; transition: border-color .3s; }
.a4-q[open] { border-color: var(--burgundy); }
.a4-q summary { display: flex; align-items: center; gap: 18px; padding: 20px 24px; cursor: pointer; list-style: none; font: 400 1.0625rem/1.6 var(--f-zh-serif); letter-spacing: .06em; }
.a4-q summary::-webkit-details-marker { display: none; }
.a4-q summary .num { flex: none; color: var(--burgundy); font-size: .9375rem; }
.a4-q summary span:not(.num) { flex: 1; }
.a4-q__a { padding: 0 24px 22px calc(24px + 2.2em); color: var(--muted); font-size: var(--fs-small); line-height: 1.95; }
.a4-q__a p + p { margin-top: .8em; }

/* ---------- Responsive ---------- */
@media (max-width: 1100px) {
  .a4-hero__in { grid-template-columns: minmax(0, 1fr); }
  .a4-hero__stats { grid-template-columns: repeat(3, minmax(0, 1fr)); border-bottom: 1px solid rgba(244,237,227,.22); }
  .a4-hero__stats > div { border-bottom: 0; padding-right: 12px; }
  .a4-hero__stats dd { flex-direction: column; gap: 8px; }
}
@media (max-width: 991px) {
  .a4-story__panel, .a4-teach__in, .a4-faq__in { grid-template-columns: minmax(0, 1fr); }
  .a4-story__img { min-height: 0; aspect-ratio: 4 / 3; height: auto; }
  .a4-story__copy { padding: 8px 8px 16px; }
  .a4-steps__list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .a4-step:nth-child(even) { margin-top: 0; }
  .a4-diff__grid { grid-template-columns: minmax(0, 1fr); }
  .a4-people__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .a4-faq__head { position: static; }
  .a4-teach__fig { max-width: 560px; }
  .a4-stat { left: 16px; }
  .a4-person__more { opacity: 1; transform: none; position: static; margin: 0; background: transparent; padding: 0; display: none; }
}
@media (max-width: 640px) {
  .a4-hero { min-height: max(600px, 100svh); }
  .a4-hero__in { padding-top: calc(var(--hd-h) + 56px); gap: 32px; }
  .a4-hero__stats small { font-size: .8125rem; letter-spacing: .04em; }
  .a4-hero__grid { grid-template-columns: repeat(2, 1fr); }
  .a4-hero__grid span:nth-child(3) { display: none; }
  /* swipeable steps */
  .a4-steps__list { display: flex; gap: 14px; overflow-x: auto; scroll-snap-type: x mandatory; margin-inline: calc(var(--gutter) * -1); padding-inline: var(--gutter); scrollbar-width: none; }
  .a4-steps__list::-webkit-scrollbar { display: none; }
  .a4-step { flex: 0 0 78%; scroll-snap-align: start; }
  .a4-swipe { display: block; margin-top: 18px; font-size: var(--fs-label); letter-spacing: .14em; color: var(--muted); }
  .a4-feat { grid-template-columns: 44px minmax(0, 1fr); gap: 16px; padding: 28px 0; }
  .a4-feat__ic { width: 40px; height: 40px; }
  .a4-band__strip { grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .a4-band__strip li { flex-direction: column; gap: 6px; padding: 18px 2px; font-size: .9375rem; letter-spacing: .1em; }
  .a4-tt__head, .a4-tt__row { grid-template-columns: 56px minmax(0, 1fr); gap: 14px; }
  .a4-tt__row > span { letter-spacing: .1em; font-size: 1rem; }
  .a4-stat { left: 12px; bottom: 16px; padding: 14px 18px; }
  .a4-people__grid { grid-template-columns: minmax(0, 1fr); }
  .a4-q summary { padding: 16px 18px; gap: 12px; }
  .a4-q__a { padding: 0 18px 18px; }
}