/* Tiên Đồ Tam Giới · landing. Bảng màu theo design kit 14.12 (palette.json): UI mực tàu + vàng cổ, Thanh Vân sương / ngọc. */
:root {
  --ink: #0d0f17;
  --ink-2: #131414;
  --ink-3: #1c1d1b;
  --slate-edge: #3d5e66;
  --warm-edge: #ad804d;
  --gold: #cfa852;
  --gold-l: #ffe699;
  --text: #fcf2d9;
  --body: #dbd1b8;
  --jade: #73f2cc;
  --qi: #80ebff;
  --mist: #d6e6f2;
  --moss: #b8d6bd;
  --paper: #f3f1ea;
  --paper-2: #e9eee9;
  --navy: #1b2440;
  --indigo: #2e3b5c;
  --vermilion: #c23b2a;
  --ink-text: #1e2433;
  --ink-soft: #4a5468;
  --danger: #f2614a;
  --radius: 14px;
  --serif: "Cormorant Garamond", "Noto Serif", Georgia, serif;
  --sans: "Be Vietnam Pro", "Noto Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --han: "Zhi Mang Xing", "STKaiti", "KaiTi", "Songti SC", serif;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink-text);
  background: var(--paper);
  overflow-x: hidden;
}
html { overflow-x: clip; }
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
h1, h2, h3 { font-family: var(--serif); font-weight: 700; line-height: 1.15; margin: 0; letter-spacing: .01em; }
p { margin: 0 0 1em; }
code { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: .88em; padding: .1em .35em; border-radius: 5px; background: rgba(255,255,255,.08); }
.wrap { width: min(1180px, 100% - 32px); margin-inline: auto; }
.wrap-narrow { width: min(820px, 100% - 32px); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5em;
  font: 600 15px/1 var(--sans); letter-spacing: .02em; text-decoration: none;
  padding: 14px 22px; border-radius: 999px; border: 1px solid transparent;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease, color .18s ease;
  cursor: pointer; white-space: nowrap;
}
.btn:focus-visible { outline: 2px solid var(--qi); outline-offset: 3px; }
.btn-gold {
  color: #2a1d08;
  background: linear-gradient(180deg, #ffe9a8 0%, #e2bd66 45%, #b88a3a 100%);
  border-color: #8a6428;
  box-shadow: 0 1px 0 rgba(255,255,255,.6) inset, 0 6px 20px rgba(184,138,58,.35);
}
.btn-gold:hover { transform: translateY(-2px); box-shadow: 0 1px 0 rgba(255,255,255,.6) inset, 0 10px 28px rgba(207,168,82,.5); }
.btn-ghost { color: var(--navy); background: rgba(255,255,255,.55); border-color: rgba(27,36,64,.35); backdrop-filter: blur(6px); }
.btn-ghost:hover { background: rgba(255,255,255,.85); transform: translateY(-2px); }
.btn-lg { padding: 17px 28px; font-size: 16px; }
.btn-sm { padding: 10px 16px; font-size: 14px; }
.btn[aria-disabled="true"] { pointer-events: none; filter: grayscale(.7); opacity: .65; }

/* ---------- Nav ---------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 12px max(16px, calc((100% - 1180px) / 2));
  transition: background .25s ease, box-shadow .25s ease, padding .25s ease;
}
.nav.scrolled { background: rgba(13,15,23,.88); backdrop-filter: blur(10px); box-shadow: 0 1px 0 rgba(207,168,82,.25); }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font: 700 20px/1 var(--serif); color: var(--navy); transition: color .25s; }
.nav.scrolled .brand { color: var(--text); }
.brand img { border-radius: 8px; }
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a:not(.btn) { text-decoration: none; font-weight: 500; font-size: 15px; color: var(--navy); opacity: .85; transition: opacity .2s, color .25s; }
.nav.scrolled .nav-links a:not(.btn) { color: var(--body); }
.nav-links a:not(.btn):hover { opacity: 1; color: var(--gold); }
.nav-toggle { display: none; background: none; border: 0; padding: 8px; cursor: pointer; }
.nav-toggle span { display: block; width: 24px; height: 2px; margin: 5px 0; background: var(--navy); border-radius: 2px; transition: transform .25s, opacity .25s, background .25s; }
.nav.scrolled .nav-toggle span, .nav.open .nav-toggle span { background: var(--text); }

/* ---------- Hero ---------- */
.hero { position: relative; min-height: 100svh; display: flex; align-items: center; overflow: hidden; background: var(--mist); }
.hero-bg, .hero-bg img { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-bg img { object-fit: cover; object-position: 70% 40%; animation: drift 24s ease-in-out infinite alternate; }
@keyframes drift { from { transform: scale(1.04) translateX(0); } to { transform: scale(1.08) translateX(-1.2%); } }
.hero-veil {
  position: absolute; inset: 0;
  background:
    linear-gradient(90deg, rgba(243,246,250,.92) 0%, rgba(236,242,248,.72) 30%, rgba(236,242,248,.15) 55%, rgba(236,242,248,0) 70%),
    linear-gradient(0deg, rgba(243,241,234,1) 0%, rgba(243,241,234,0) 18%);
}
.hero-inner { position: relative; z-index: 2; width: min(1180px, 100% - 32px); margin-inline: auto; padding: 110px 0 90px; }
.hero-inner > * { max-width: 560px; }
.eyebrow { display: inline-block; font-size: 13px; font-weight: 600; letter-spacing: .16em; text-transform: uppercase; color: var(--indigo); padding: 6px 12px; border: 1px solid rgba(46,59,92,.3); border-radius: 999px; background: rgba(255,255,255,.5); margin-bottom: 22px; }
.hero-title { position: relative; font-size: clamp(54px, 9vw, 112px); line-height: .95; color: var(--navy); font-weight: 700; text-shadow: 0 2px 30px rgba(255,255,255,.8); }
.hero-han { display: block; font-family: var(--han); font-weight: 400; font-size: .42em; line-height: 1.2; color: var(--vermilion); letter-spacing: .12em; margin-bottom: .1em; }
.hero-tag { font-family: var(--serif); font-size: clamp(22px, 2.6vw, 30px); line-height: 1.3; color: var(--indigo); margin: 26px 0 14px; font-weight: 600; }
.hero-tag strong { color: var(--vermilion); }
.hero-sub { color: var(--ink-soft); font-size: 17px; max-width: 500px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin: 30px 0 22px; }
.hero-meta { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 8px 18px; font-size: 14px; font-weight: 500; color: var(--indigo); }
.hero-meta li { display: flex; align-items: center; gap: 8px; }
.hero-meta li::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--jade); box-shadow: 0 0 8px var(--jade); }
.scroll-hint { position: absolute; z-index: 2; left: 50%; bottom: 26px; translate: -50% 0; width: 26px; height: 42px; border: 2px solid rgba(27,36,64,.45); border-radius: 14px; }
.scroll-hint span { position: absolute; left: 50%; top: 8px; width: 4px; height: 8px; margin-left: -2px; border-radius: 2px; background: var(--navy); animation: hint 1.8s ease-in-out infinite; }
@keyframes hint { 0% { opacity: 0; transform: translateY(0); } 40% { opacity: 1; } 100% { opacity: 0; transform: translateY(14px); } }

/* ---------- Sections ---------- */
.sec { position: relative; padding: clamp(72px, 10vw, 128px) 0; overflow-x: clip; }
.sec-paper {
  background:
    radial-gradient(1200px 500px at 85% 0%, rgba(184,214,189,.35), transparent 60%),
    radial-gradient(900px 400px at 0% 100%, rgba(214,230,242,.6), transparent 60%),
    var(--paper);
}
.sec-ink {
  color: var(--body);
  background:
    radial-gradient(900px 420px at 15% 0%, rgba(61,94,102,.35), transparent 65%),
    radial-gradient(700px 380px at 100% 100%, rgba(128,235,255,.08), transparent 60%),
    linear-gradient(180deg, var(--ink) 0%, var(--ink-2) 100%);
}
.sec-ink-2 { background: radial-gradient(800px 380px at 80% 10%, rgba(115,242,204,.08), transparent 60%), linear-gradient(180deg, var(--ink-2) 0%, var(--ink) 100%); }
.sec-ink h2, .sec-ink h3 { color: var(--text); }
.sec-head { text-align: center; max-width: 760px; margin: 0 auto clamp(40px, 6vw, 64px); position: relative; }
.sec-head .han { position: absolute; left: 50%; top: -0.55em; translate: -50% 0; font-family: var(--han); font-size: clamp(90px, 14vw, 150px); line-height: 1; white-space: nowrap; color: rgba(27,36,64,.06); pointer-events: none; user-select: none; }
.sec-ink .sec-head .han { color: rgba(207,168,82,.07); }
.kicker { position: relative; font-size: 13px; font-weight: 600; letter-spacing: .2em; text-transform: uppercase; color: var(--vermilion); margin-bottom: 10px; }
.sec-ink .kicker { color: var(--jade); }
.sec-head h2 { position: relative; font-size: clamp(36px, 5vw, 56px); color: var(--navy); }
.divider { margin: 14px auto 0; width: 200px; opacity: .9; }
.sec-paper .divider { filter: brightness(.8) saturate(1.2); }
.lead { position: relative; margin-top: 18px; font-size: 18px; color: var(--ink-soft); }
.sec-ink .lead { color: var(--body); }
.lead a { color: var(--vermilion); font-weight: 600; }
.sec-ink .lead a { color: var(--gold-l); }
.caption-note { text-align: center; font-size: 13px; opacity: .65; margin-top: 18px; }

.split { display: grid; grid-template-columns: 1.15fr 1fr; gap: clamp(28px, 5vw, 64px); align-items: center; }
.split-rev { grid-template-columns: 1fr 1.05fr; }
.frame { margin: 0; position: relative; border-radius: var(--radius); overflow: hidden; box-shadow: 0 24px 60px rgba(27,36,64,.22); outline: 1px solid rgba(173,128,77,.55); outline-offset: 6px; }
.frame-dark { box-shadow: 0 24px 60px rgba(0,0,0,.5); outline-color: rgba(207,168,82,.45); }
.frame img { width: 100%; }
.prose { font-size: 17px; color: var(--ink-soft); }
.prose strong { color: var(--navy); }
.quote { font-family: var(--serif); font-size: 22px; line-height: 1.4; font-style: italic; color: var(--indigo); border-left: 3px solid var(--vermilion); padding-left: 18px; margin-top: 1.4em; }

/* Bốn Quyển */
.books { list-style: none; padding: 0; margin: clamp(48px, 7vw, 80px) 0 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; counter-reset: b; }
.book { position: relative; padding: 26px 22px 22px; border-radius: var(--radius); background: rgba(255,255,255,.65); border: 1px solid rgba(61,94,102,.2); box-shadow: 0 10px 30px rgba(27,36,64,.07); display: flex; flex-direction: column; }
.book::before { content: ""; position: absolute; inset: 0 auto 0 0; width: 3px; border-radius: 3px; background: linear-gradient(180deg, var(--gold), transparent); }
.book-no { font: 600 13px/1 var(--sans); letter-spacing: .18em; text-transform: uppercase; color: var(--warm-edge); }
.book h3 { font-size: 26px; color: var(--navy); margin: 8px 0 4px; }
.book-realm { font-size: 13px; font-weight: 600; color: var(--slate-edge); margin-bottom: 10px; }
.book p:not(.book-realm) { font-size: 15px; color: var(--ink-soft); flex: 1; }
.chip { align-self: flex-start; font-size: 12px; font-weight: 600; padding: 5px 10px; border-radius: 999px; background: rgba(27,36,64,.07); color: var(--ink-soft); }
.chip-jade { background: rgba(64,242,179,.16); color: #136c55; }

/* Cảnh giới */
.realms { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.realms li { position: relative; padding: 12px 14px; border-radius: 10px; border: 1px solid rgba(61,94,102,.5); background: rgba(28,29,27,.6); display: flex; align-items: baseline; justify-content: space-between; gap: 8px; }
.realms b { font-family: var(--serif); font-size: 19px; color: var(--body); font-weight: 600; }
.realms i { font-family: var(--han); font-style: normal; font-size: 20px; color: rgba(219,209,184,.45); }
.realms li.open { border-color: rgba(207,168,82,.7); background: linear-gradient(180deg, rgba(69,56,36,.75), rgba(28,29,27,.7)); box-shadow: 0 0 18px rgba(207,168,82,.15); }
.realms li.open b { color: var(--gold-l); }
.realms li.open i { color: var(--gold); }
.note { font-size: 14px; color: var(--jade); margin: 12px 0 26px; }
.facts { margin: 0; display: grid; gap: 18px; }
.facts dt { font-family: var(--serif); font-size: 22px; font-weight: 700; color: var(--text); }
.facts dd { margin: 4px 0 0; color: var(--body); opacity: .9; }

/* Ngũ hành */
.elements { list-style: none; padding: 0; margin: 0 0 48px; display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; }
.el { --c: #fff; text-align: center; padding: 22px 12px 18px; border-radius: var(--radius); background: radial-gradient(120% 90% at 50% 0%, color-mix(in srgb, var(--c) 22%, transparent), rgba(13,15,23,.6) 70%); border: 1px solid color-mix(in srgb, var(--c) 45%, transparent); transition: transform .25s, box-shadow .25s; }
.el:hover { transform: translateY(-4px); box-shadow: 0 12px 34px color-mix(in srgb, var(--c) 25%, transparent); }
.el img { width: 64px; height: 64px; margin: 0 auto 10px; filter: drop-shadow(0 0 12px color-mix(in srgb, var(--c) 60%, transparent)); }
.el b { display: block; font-family: var(--serif); font-size: 24px; color: var(--c); }
.el span { display: block; font-size: 13px; line-height: 1.45; color: var(--body); opacity: .85; margin-top: 4px; }
.el-kim { --c: #f2e68c; } .el-moc { --c: #73e673; } .el-thuy { --c: #73b3ff; } .el-hoa { --c: #ff7a52; } .el-tho { --c: #d9a066; }
.combat { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; margin-bottom: 40px; }
.combat > div { padding: 24px 26px; border-radius: var(--radius); border: 1px solid rgba(61,94,102,.55); background: rgba(13,15,23,.5); }
.combat h3 { font-size: 26px; margin-bottom: 8px; }
.combat strong { color: var(--gold-l); font-weight: 600; }
.strip { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.strip figure { margin: 0; position: relative; border-radius: 10px; overflow: hidden; border: 1px solid rgba(207,168,82,.35); }
.strip img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.strip figcaption, .g-item span { position: absolute; left: 0; right: 0; bottom: 0; padding: 22px 12px 8px; font-size: 13px; font-weight: 600; color: var(--text); background: linear-gradient(0deg, rgba(13,15,23,.85), transparent); text-align: left; }

/* Tính năng */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-bottom: 22px; }
.feat { border-radius: var(--radius); overflow: hidden; background: #fff; border: 1px solid rgba(61,94,102,.18); box-shadow: 0 14px 40px rgba(27,36,64,.1); display: flex; flex-direction: column; transition: transform .25s, box-shadow .25s; }
.feat:hover { transform: translateY(-4px); box-shadow: 0 20px 50px rgba(27,36,64,.16); }
.feat img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.feat-body { padding: 20px 22px 22px; }
.feat h3, .card h3 { font-size: 26px; color: var(--navy); margin-bottom: 6px; }
.feat p, .card p { font-size: 15px; color: var(--ink-soft); margin: 0; }
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card { padding: 24px 22px; border-radius: var(--radius); background: rgba(255,255,255,.6); border: 1px solid rgba(61,94,102,.18); position: relative; overflow: hidden; }
.card::after { content: ""; position: absolute; right: -30px; top: -30px; width: 90px; height: 90px; border-radius: 50%; background: radial-gradient(circle, rgba(115,242,204,.25), transparent 70%); }

/* Gallery */
.gallery { display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; }
.g-item { position: relative; padding: 0; border: 1px solid rgba(207,168,82,.3); border-radius: 10px; overflow: hidden; cursor: zoom-in; background: var(--ink-3); grid-column: span 2; aspect-ratio: 4 / 3; }
.g-item.g-wide { grid-column: span 2; }
.g-item img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.g-item:hover img { transform: scale(1.05); }
.g-item:focus-visible { outline: 2px solid var(--qi); outline-offset: 2px; }
.lightbox { position: fixed; inset: 0; z-index: 100; display: grid; place-items: center; padding: 16px; background: rgba(6,8,11,.92); backdrop-filter: blur(6px); }
.lightbox[hidden] { display: none; }
.lightbox figure { margin: 0; max-width: min(1400px, 100%); }
.lightbox img { max-height: 82vh; width: auto; margin: 0 auto; border-radius: 8px; }
.lightbox figcaption { text-align: center; color: var(--body); margin-top: 12px; font-size: 15px; }
.lb-close { position: absolute; top: 12px; right: 16px; width: 44px; height: 44px; border-radius: 50%; border: 1px solid rgba(207,168,82,.5); background: rgba(13,15,23,.7); color: var(--text); font-size: 28px; line-height: 1; cursor: pointer; }

/* Tải về */
.sec-download {
  color: var(--body);
  background:
    linear-gradient(180deg, rgba(13,15,23,.88), rgba(13,15,23,.96)),
    url("img/hero.webp") center 30% / cover no-repeat;
}
.sec-download h2, .sec-download h3 { color: var(--text); }
.sec-download .kicker { color: var(--gold); }
.sec-download .sec-head .han { color: rgba(207,168,82,.08); }
.dl-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.dl {
  position: relative; text-align: center; padding: 30px 24px 26px; border-radius: 18px;
  background: linear-gradient(180deg, rgba(54,54,48,.75), rgba(19,20,20,.85));
  border: 1px solid rgba(61,94,102,.8);
  box-shadow: 0 18px 50px rgba(0,0,0,.4);
  display: flex; flex-direction: column; align-items: center;
  transition: border-color .25s, transform .25s, box-shadow .25s;
}
.dl:hover, .dl.recommended { border-color: var(--warm-edge); box-shadow: 0 0 0 1px rgba(207,168,82,.35), 0 18px 50px rgba(0,0,0,.45), 0 0 40px rgba(207,168,82,.15); }
.dl.recommended::before { content: "Phù hợp với máy bạn"; position: absolute; top: -12px; left: 50%; translate: -50% 0; font-size: 12px; font-weight: 600; padding: 4px 12px; border-radius: 999px; color: #2a1d08; background: var(--gold); white-space: nowrap; }
.dl-icon { width: 64px; height: 64px; display: grid; place-items: center; border-radius: 50%; border: 1px solid rgba(207,168,82,.6); background: radial-gradient(circle, rgba(207,168,82,.2), transparent 70%); margin-bottom: 14px; }
.dl-icon svg { width: 30px; height: 30px; fill: var(--gold-l); }
.dl h3 { font-size: 30px; }
.dl-meta { font-size: 14px; color: var(--body); opacity: .85; margin: 6px 0 20px; min-height: 2.9em; }
.dl-size { display: inline-block; font-weight: 600; color: var(--jade); }
.dl-btn { width: 100%; max-width: 260px; }
.dl-btn.soon { background: rgba(61,94,102,.4); color: var(--body); border-color: rgba(61,94,102,.8); box-shadow: none; }
.dl-how { font-size: 13px; color: var(--body); opacity: .75; margin: 16px 0 0; }
.dl-how em { font-style: normal; color: var(--gold-l); }
.dl-ios { text-align: center; font-size: 14px; opacity: .6; margin-top: 18px; }

.steps-wrap { display: grid; grid-template-columns: 1.4fr 1fr; gap: 24px; margin-top: 56px; align-items: stretch; }
.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; counter-reset: s; }
.steps li { counter-increment: s; position: relative; padding: 20px 20px 18px 66px; border-radius: var(--radius); background: rgba(13,15,23,.55); border: 1px solid rgba(61,94,102,.55); }
.steps li::before { content: counter(s); position: absolute; left: 18px; top: 18px; width: 34px; height: 34px; border-radius: 50%; display: grid; place-items: center; font: 700 18px/1 var(--serif); color: #2a1d08; background: linear-gradient(180deg, #ffe9a8, #c99a45); }
.steps b { display: block; font-family: var(--serif); font-size: 21px; color: var(--text); }
.steps span { font-size: 14px; opacity: .85; }
.invite { position: relative; overflow: hidden; padding: 28px 26px; border-radius: 18px; border: 1px solid var(--warm-edge); background: linear-gradient(160deg, rgba(69,56,36,.85), rgba(19,20,20,.92)); box-shadow: 0 0 40px rgba(207,168,82,.12); }
.invite .han { position: absolute; right: 14px; top: -6px; font-family: var(--han); font-size: 120px; line-height: 1; color: rgba(207,168,82,.12); }
.invite h3 { position: relative; font-size: 28px; color: var(--gold-l); margin-bottom: 10px; }
.invite p { position: relative; font-size: 15px; }
.invite strong { color: var(--text); }
.invite-note { font-size: 13px !important; opacity: .7; margin: 0; }

.req { margin-top: 56px; }
.req h3 { font-size: 28px; margin-bottom: 14px; text-align: center; }
.req-table { border: 1px solid rgba(61,94,102,.6); border-radius: var(--radius); overflow: hidden; }
.req-table > div { display: grid; grid-template-columns: 170px 1fr 1fr; }
.req-table > div + div { border-top: 1px solid rgba(61,94,102,.4); }
.req-table span { padding: 12px 16px; font-size: 14.5px; }
.req-table [role="rowheader"] { font-weight: 600; color: var(--gold-l); background: rgba(13,15,23,.5); }
.req-head span { font-weight: 600; color: var(--text); background: rgba(61,94,102,.25); }
.req-table .span2 { grid-column: span 2; }
.sums { margin-top: 16px; font-size: 14px; }
.sums summary { cursor: pointer; opacity: .75; }
.sums pre { max-width: 100%; overflow-x: auto; padding: 12px 14px; border-radius: 10px; background: rgba(0,0,0,.4); font-size: 12px; line-height: 1.6; }
.sums code { background: none; padding: 0; }

/* FAQ */
.faq details { border-bottom: 1px solid rgba(27,36,64,.14); }
.faq summary { list-style: none; cursor: pointer; padding: 20px 44px 20px 0; position: relative; font-family: var(--serif); font-size: 22px; font-weight: 700; color: var(--navy); }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 6px; top: 50%; translate: 0 -50%; font: 400 28px/1 var(--sans); color: var(--warm-edge); transition: transform .25s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { color: var(--ink-soft); padding-bottom: 18px; margin: 0; }
.faq a { color: var(--vermilion); font-weight: 600; }

/* Footer */
.foot { background: var(--ink); color: var(--body); padding: 48px 0 40px; border-top: 1px solid rgba(207,168,82,.3); }
.foot-inner { display: grid; gap: 14px; text-align: center; justify-items: center; }
.foot-brand { display: flex; align-items: center; gap: 12px; text-align: left; }
.foot-brand img { border-radius: 9px; }
.foot-brand b { display: block; font: 700 22px/1.1 var(--serif); color: var(--text); }
.foot-brand span { font-size: 13px; opacity: .7; }
.foot-note { max-width: 640px; font-size: 13px; opacity: .6; margin: 0; }
.foot-copy { font-size: 13px; opacity: .5; margin: 0; }

/* Reveal */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .hero-bg img, .scroll-hint span { animation: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .books { grid-template-columns: repeat(2, 1fr); }
  .features, .cards { grid-template-columns: repeat(2, 1fr); }
  .features .feat:last-child { grid-column: span 2; }
  .features .feat:last-child img { aspect-ratio: 16 / 7; }
  .elements { grid-template-columns: repeat(5, 1fr); gap: 10px; }
  .el span { display: none; }
  .steps-wrap { grid-template-columns: 1fr; }
}
@media (max-width: 900px) {
  .nav-toggle { display: block; position: relative; z-index: 2; }
  .nav-links {
    position: fixed; inset: 0 0 auto 0; flex-direction: column; align-items: stretch; gap: 0;
    padding: 72px 16px 20px; background: rgba(13,15,23,.97); border-bottom: 1px solid rgba(207,168,82,.3);
    transform: translateY(-105%); transition: transform .3s ease;
  }
  .nav.open .nav-links { transform: none; }
  .nav.open .brand { color: var(--text); position: relative; z-index: 2; }
  .nav-links a:not(.btn) { color: var(--body) !important; padding: 14px 4px; border-bottom: 1px solid rgba(61,94,102,.35); font-size: 17px; }
  .nav-links .btn { margin-top: 16px; }
  .nav.open .nav-toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav.open .nav-toggle span:nth-child(2) { opacity: 0; }
  .nav.open .nav-toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .split, .split-rev { grid-template-columns: 1fr; }
  .dl-grid { grid-template-columns: 1fr; max-width: 520px; margin-inline: auto; }
  .dl-meta { min-height: 0; }
  .combat { grid-template-columns: 1fr; gap: 16px; }
  .gallery { grid-template-columns: repeat(2, 1fr); }
  .g-item, .g-item.g-wide { grid-column: span 1; }
}
@media (max-width: 760px) {
  .hero { align-items: flex-end; }
  .hero-bg img { object-position: 50% 20%; }
  .hero-veil { background: linear-gradient(0deg, rgba(243,241,234,1) 0%, rgba(243,241,234,.92) 32%, rgba(236,242,248,.35) 58%, rgba(236,242,248,0) 75%); }
  .hero-inner { padding: 96px 0 76px; }
  .scroll-hint { display: none; }
  .hero-title { font-size: clamp(48px, 14vw, 72px); }
  .hero-sub { font-size: 15.5px; }
  .hero-cta .btn { flex: 1 1 100%; }
  .books, .features, .cards, .strip, .steps { grid-template-columns: 1fr; }
  .features .feat:last-child { grid-column: auto; }
  .features .feat:last-child img { aspect-ratio: 4 / 3; }
  .realms { grid-template-columns: repeat(2, 1fr); }
  .elements { grid-template-columns: repeat(3, 1fr); }
  .el span { display: block; }
  .req-table > div { grid-template-columns: 1fr; }
  .req-head { display: none !important; }
  .req-table [role="cell"]::before { display: block; font-size: 12px; opacity: .6; }
  .req-table [role="cell"]:nth-child(2)::before { content: "PC"; }
  .req-table [role="cell"]:nth-child(3)::before { content: "Android"; }
  .req-table .span2 { grid-column: auto; }
  .req-table .span2::before { content: "" !important; display: none !important; }
  .quote { font-size: 19px; }
  .faq summary { font-size: 19px; }
}
@media (max-width: 400px) {
  .elements { grid-template-columns: repeat(2, 1fr); }
  .gallery { grid-template-columns: 1fr; }
  .brand span { font-size: 18px; }
}

/* Tiêu đề / dẫn nhập trên nền tối */
.sec-ink .sec-head h2, .sec-download .sec-head h2 { color: var(--text); }
.sec-download .lead { color: var(--body); }
.sec-download .lead a { color: var(--gold-l); }

/* Hero di động: chữ đè lên nhân vật nên phủ sương đều hơn */
@media (max-width: 760px) {
  .hero-veil {
    background:
      linear-gradient(90deg, rgba(243,246,250,.86) 0%, rgba(243,246,250,.62) 55%, rgba(243,246,250,.2) 100%),
      linear-gradient(0deg, rgba(243,241,234,1) 0%, rgba(243,241,234,.6) 30%, rgba(243,241,234,0) 60%);
  }
  .hero-title { text-shadow: 0 0 24px rgba(255,255,255,.95), 0 0 6px rgba(255,255,255,.8); }
  .hero-tag, .hero-sub { text-shadow: 0 0 14px rgba(255,255,255,.95); }
  .eyebrow { letter-spacing: .08em; font-size: 12px; }
}
@media (max-width: 400px) {
  .elements .el:last-child { grid-column: span 2; }
}