/* Dynasty Siege — website quảng bá. Phong cách: sơn mài đen, son đỏ, lá vàng, giấy dó. */
:root {
  --ink: #120a06;
  --lacquer: #1d0f09;
  --lacquer-2: #2a150c;
  --cinnabar: #b3202a;
  --cinnabar-hot: #e0342c;
  --gold: #e3b23c;
  --gold-hi: #ffe39a;
  --gold-lo: #9a6a18;
  --jade: #2e9e72;
  --paper: #f6e7c4;
  --paper-2: #ead2a0;
  --text: #f3e6c8;
  --muted: #c9b48c;

  --font-display: "Noto Serif", "Noto Serif SC", "Noto Serif JP", "Noto Serif KR", Georgia, serif;
  --font-deco: "Cinzel Decorative", "Noto Serif", Georgia, serif;
  --font-body: "Noto Sans", "Noto Sans SC", "Noto Sans JP", "Noto Sans KR", system-ui, sans-serif;

  --text-base: clamp(1rem, 0.94rem + 0.3vw, 1.125rem);
  --text-h2: clamp(2rem, 1.2rem + 3vw, 3.6rem);
  --text-hero: clamp(1.8rem, 1rem + 2.6vw, 3.2rem);
  --space-section: clamp(4.5rem, 3rem + 6vw, 9rem);
  --radius: 14px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --shadow-deep: 0 30px 60px -20px rgba(0, 0, 0, 0.8), 0 10px 24px rgba(0, 0, 0, 0.45);
  --gold-border: linear-gradient(135deg, var(--gold-hi), var(--gold) 30%, var(--gold-lo) 60%, var(--gold-hi));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--ink);
  color: var(--text);
  font: 400 var(--text-base)/1.65 var(--font-body);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
/* Hạt nhiễu nhẹ như sơn mài */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: 100; pointer-events: none; opacity: 0.06;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
img, video { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
:focus-visible { outline: 3px solid var(--gold); outline-offset: 3px; border-radius: 6px; }

/* ---------- Nút ---------- */
.btn {
  --lift: 0px;
  display: inline-flex; align-items: center; justify-content: center; gap: .5em;
  font: 800 1rem/1 var(--font-body); letter-spacing: .06em; text-transform: uppercase; text-decoration: none;
  border-radius: 999px; padding: .95em 1.8em; border: 0; cursor: pointer;
  transform: translateY(var(--lift));
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), filter .25s;
}
.btn:hover { --lift: -3px; }
.btn:active { --lift: 1px; filter: brightness(.95); }
.btn-gold {
  color: #3b1d05;
  background: linear-gradient(180deg, var(--gold-hi), var(--gold) 45%, #c98a1c);
  box-shadow: 0 0 0 2px #7a4c0c inset, 0 6px 0 #6e430b, 0 14px 30px rgba(227, 178, 60, .35);
}
.btn-gold:hover { box-shadow: 0 0 0 2px #7a4c0c inset, 0 9px 0 #6e430b, 0 20px 40px rgba(227, 178, 60, .5); }
.btn-ghost { color: var(--gold-hi); background: rgba(20, 10, 6, .45); box-shadow: 0 0 0 2px rgba(227, 178, 60, .7) inset; backdrop-filter: blur(6px); }
.btn-ghost:hover { background: rgba(179, 32, 42, .55); }
.btn-big { font-size: 1.12rem; padding: 1.1em 2.2em; }
.btn-small { font-size: .82rem; padding: .75em 1.3em; }

/* ---------- Thanh điều hướng ---------- */
.nav {
  position: fixed; inset: 0 0 auto; z-index: 50;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: .6rem clamp(1rem, 3vw, 2.5rem);
  transition: background .3s, box-shadow .3s, padding .3s;
}
.nav.solid { background: rgba(18, 10, 6, .92); box-shadow: 0 1px 0 rgba(227, 178, 60, .35), 0 10px 30px rgba(0, 0, 0, .5); backdrop-filter: blur(10px); }
.nav-logo img { height: 54px; width: auto; filter: drop-shadow(0 4px 8px rgba(0, 0, 0, .6)); transition: transform .3s var(--ease); }
.nav-logo:hover img { transform: scale(1.06) rotate(-2deg); }
.nav-links { display: flex; gap: clamp(.8rem, 2vw, 2rem); }
.nav-links a {
  position: relative; text-decoration: none; font-weight: 600; font-size: .95rem; letter-spacing: .04em; color: var(--paper);
  padding: .4rem 0;
}
.nav-links a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 2px; background: var(--gold);
  transform: scaleX(0); transform-origin: left; transition: transform .3s var(--ease);
}
.nav-links a:hover::after, .nav-links a.active::after { transform: scaleX(1); }
.nav-right { display: flex; align-items: center; gap: .8rem; }
.lang { position: relative; }
.lang-btn {
  font: 700 .85rem var(--font-body); color: var(--gold-hi); background: rgba(0, 0, 0, .35);
  border: 1px solid rgba(227, 178, 60, .6); border-radius: 999px; padding: .55em 1em; cursor: pointer;
}
.lang-list {
  position: absolute; right: 0; top: calc(100% + 8px); margin: 0; padding: .4rem; list-style: none; min-width: 170px;
  background: var(--lacquer); border: 1px solid rgba(227, 178, 60, .5); border-radius: 12px; box-shadow: var(--shadow-deep);
  opacity: 0; transform: translateY(-6px); pointer-events: none; transition: opacity .2s, transform .2s var(--ease);
}
.lang.open .lang-list { opacity: 1; transform: none; pointer-events: auto; }
.lang-list button {
  width: 100%; text-align: left; font: 600 .95rem var(--font-body); color: var(--paper); background: none; border: 0;
  padding: .55rem .8rem; border-radius: 8px; cursor: pointer;
}
.lang-list button:hover, .lang-list button[aria-selected="true"] { background: rgba(227, 178, 60, .16); color: var(--gold-hi); }
.burger { display: none; background: none; border: 0; padding: 6px; cursor: pointer; }
.burger span { display: block; width: 26px; height: 3px; margin: 5px 0; background: var(--gold); border-radius: 2px; transition: transform .3s; }

/* ---------- Hero ---------- */
.hero { position: relative; min-height: 100svh; display: grid; place-items: center; overflow: hidden; isolation: isolate; }
.hero-video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: -2; transform: scale(1.04); }
.hero-shade {
  position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(ellipse 60% 50% at 50% 45%, rgba(18, 10, 6, .15), rgba(18, 10, 6, .75) 80%),
    linear-gradient(180deg, rgba(18, 10, 6, .55) 0%, transparent 25%, transparent 60%, var(--ink) 100%);
}
.hero-content { text-align: center; padding: 7rem 1.5rem 5rem; max-width: 1100px; }
.hero-logo {
  width: min(560px, 82vw); height: auto; margin: 0 auto -.5rem;
  filter: drop-shadow(0 18px 30px rgba(0, 0, 0, .7));
  animation: rise 1.2s var(--ease) both, float 6s ease-in-out 1.2s infinite;
}
.hero-title {
  font: 900 var(--text-hero)/1.15 var(--font-display); margin: .4rem auto .8rem; max-width: 30ch;
  color: var(--paper); text-shadow: 0 3px 0 #000, 0 8px 30px rgba(0, 0, 0, .8);
  animation: rise 1.2s .15s var(--ease) both;
}
.hero-sub { max-width: 640px; margin: 0 auto 2rem; color: var(--paper-2); font-size: 1.12rem; text-shadow: 0 2px 10px #000; animation: rise 1.2s .3s var(--ease) both; }
.hero-cta { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; animation: rise 1.2s .45s var(--ease) both; }
.stores { display: flex; gap: .8rem; justify-content: center; margin-top: 1.6rem; animation: rise 1.2s .6s var(--ease) both; }
.store {
  display: grid; text-align: left; padding: .55rem 1.1rem; border-radius: 12px; min-width: 150px;
  background: rgba(0, 0, 0, .55); border: 1px solid rgba(243, 230, 200, .35);
}
.store b { font-size: 1rem; }
.store small { color: var(--muted); font-size: .75rem; letter-spacing: .08em; text-transform: uppercase; }
.scroll-hint {
  position: absolute; bottom: 1.2rem; left: 50%; translate: -50% 0; font-size: 2.2rem; color: var(--gold); text-decoration: none;
  animation: bob 2s ease-in-out infinite;
}
@keyframes rise { from { opacity: 0; transform: translateY(28px); } to { opacity: 1; transform: none; } }
@keyframes float { 50% { transform: translateY(-10px); } }
@keyframes bob { 50% { transform: translateY(8px); } }

/* ---------- Số liệu ---------- */
.stats {
  position: relative; z-index: 2; margin: -3.5rem auto 0; width: min(1150px, 92vw);
  display: grid; grid-template-columns: repeat(5, 1fr);
  background: linear-gradient(180deg, #3a1a0e, var(--lacquer));
  border-radius: var(--radius); box-shadow: var(--shadow-deep), 0 0 0 2px var(--gold-lo) inset, 0 0 0 4px #2a1209 inset;
}
.stat { padding: 1.5rem 1rem; text-align: center; position: relative; }
.stat + .stat::before { content: ""; position: absolute; left: 0; top: 22%; bottom: 22%; width: 1px; background: linear-gradient(transparent, var(--gold-lo), transparent); }
.stat b { display: block; font: 900 clamp(2rem, 1.4rem + 2vw, 3.2rem)/1 var(--font-deco); color: var(--gold); text-shadow: 0 2px 0 #4a2a06; }
.stat span { color: var(--muted); font-size: .9rem; letter-spacing: .04em; }

/* ---------- Khung section ---------- */
.section { padding: var(--space-section) clamp(1rem, 4vw, 3rem); position: relative; }
.section-dark {
  background:
    radial-gradient(ellipse at 20% 0%, rgba(179, 32, 42, .22), transparent 55%),
    radial-gradient(ellipse at 90% 100%, rgba(227, 178, 60, .12), transparent 50%),
    var(--lacquer);
}
.section-dark::before, .section-dark::after {
  content: ""; position: absolute; left: 0; right: 0; height: 14px;
  background: repeating-linear-gradient(90deg, var(--gold-lo) 0 2px, transparent 2px 22px), linear-gradient(var(--cinnabar), #6e1015);
  opacity: .55;
}
.section-dark::before { top: 0; }
.section-dark::after { bottom: 0; }
.section-head { text-align: center; max-width: 760px; margin: 0 auto clamp(2.5rem, 5vw, 4.5rem); }
.eyebrow {
  display: inline-block; font: 800 .8rem var(--font-body); letter-spacing: .3em; text-transform: uppercase; color: var(--cinnabar-hot);
  padding: .35em 1em; border: 1px solid rgba(224, 52, 44, .5); border-radius: 999px; margin-bottom: 1rem;
}
.section-head h2 { font: 900 var(--text-h2)/1.1 var(--font-display); margin: 0 0 .8rem; color: var(--paper); }
.section-head h2::after {
  content: ""; display: block; width: 120px; height: 14px; margin: .9rem auto 0;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 120 14'%3E%3Cpath d='M0 7h44M76 7h44' stroke='%23e3b23c' stroke-width='2'/%3E%3Cpath d='M60 0l7 7-7 7-7-7z' fill='%23b3202a' stroke='%23e3b23c' stroke-width='1.5'/%3E%3C/svg%3E") center/contain no-repeat;
}
.section-head p { color: var(--muted); margin: 0; }

/* ---------- Tính năng: hàng xen kẽ, ảnh nghiêng có khung vàng ---------- */
.features { display: grid; gap: clamp(4rem, 8vw, 7.5rem); max-width: 1240px; margin: 0 auto; }
.feature { display: grid; grid-template-columns: 1.25fr 1fr; gap: clamp(2rem, 5vw, 4.5rem); align-items: center; }
.feature:nth-child(even) { grid-template-columns: 1fr 1.25fr; }
.feature:nth-child(even) .feature-media { order: 2; }
.feature-media, .feature-text { min-width: 0; }
.feature-media { position: relative; perspective: 1400px; }
.shot {
  position: relative; border-radius: var(--radius); overflow: hidden; cursor: zoom-in;
  box-shadow: var(--shadow-deep);
  transform: rotateY(var(--ry, -6deg)) rotateX(2deg);
  transition: transform .7s var(--ease);
}
.feature:nth-child(even) .shot { --ry: 6deg; }
.shot::after { content: ""; position: absolute; inset: 0; border-radius: inherit; padding: 3px; background: var(--gold-border);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0); -webkit-mask-composite: xor; mask-composite: exclude; pointer-events: none; }
.shot:hover { transform: rotateY(0) rotateX(0) scale(1.02); }
.shot img, .shot video { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.feature-media .sticker {
  position: absolute; width: clamp(110px, 16vw, 200px); bottom: -2.2rem; right: -1.5rem; z-index: 2;
  filter: drop-shadow(0 16px 20px rgba(0, 0, 0, .7)); animation: float 6s ease-in-out infinite; pointer-events: none;
}
.feature:nth-child(even) .sticker { right: auto; left: -1.5rem; }
.feature-text .num { font: 900 4.5rem/1 var(--font-deco); color: transparent; -webkit-text-stroke: 1.5px rgba(227, 178, 60, .55); }
.feature-text h3 { font: 900 clamp(1.6rem, 1.1rem + 1.6vw, 2.4rem)/1.15 var(--font-display); margin: .2rem 0 .8rem; color: var(--gold-hi); }
.feature-text p { color: var(--text); margin: 0 0 1rem; }
.feature-text ul { margin: 0; padding: 0; list-style: none; display: grid; gap: .45rem; }
.feature-text li { padding-left: 1.6rem; position: relative; color: var(--paper-2); }
.feature-text li::before { content: "◆"; position: absolute; left: 0; color: var(--cinnabar-hot); font-size: .8rem; top: .25rem; }

/* ---------- Tướng ---------- */
.generals { display: grid; grid-template-columns: repeat(6, 1fr); gap: 1rem; max-width: 1320px; margin: 0 auto; }
.general {
  position: relative; border-radius: 18px 18px 60px 18px; padding: 1rem 1rem 1.4rem; text-align: center; overflow: hidden;
  background: linear-gradient(180deg, var(--c1, #5a1a12), #1a0c07 75%);
  box-shadow: 0 0 0 1px rgba(227, 178, 60, .45) inset, var(--shadow-deep);
  transition: transform .4s var(--ease), box-shadow .4s;
}
.general:hover { transform: translateY(-10px); box-shadow: 0 0 0 2px var(--gold) inset, 0 30px 60px -15px var(--c1, #5a1a12); }
.general img { width: 100%; aspect-ratio: 1; object-fit: contain; transition: transform .5s var(--ease); filter: drop-shadow(0 12px 14px rgba(0, 0, 0, .6)); }
.general:hover img { transform: scale(1.08) translateY(-4px); }
.general h3 { font: 900 1.25rem var(--font-display); margin: .4rem 0 0; color: var(--gold-hi); }
.general .title { color: var(--muted); font-size: .85rem; }
.general .skill {
  display: inline-block; margin-top: .6rem; font: 700 .78rem var(--font-body); letter-spacing: .05em; color: #fff;
  background: rgba(179, 32, 42, .85); border-radius: 999px; padding: .3em .8em;
}
.general p { font-size: .85rem; color: var(--paper-2); margin: .6rem 0 0; }

/* ---------- Trailer ---------- */
.trailer-frame {
  max-width: 1200px; margin: 0 auto; padding: 10px; border-radius: 20px;
  background: var(--gold-border); box-shadow: var(--shadow-deep), 0 0 120px rgba(179, 32, 42, .35);
}
.trailer-frame video { width: 100%; border-radius: 12px; background: #000; aspect-ratio: 16 / 9; }

/* ---------- Hướng dẫn ---------- */
.guide { list-style: none; padding: 0; margin: 0 auto; max-width: 1240px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.4rem; counter-reset: step; }
.step {
  position: relative; background: linear-gradient(180deg, var(--paper), var(--paper-2)); color: #3a2414; border-radius: var(--radius);
  padding: 0 0 1.3rem; overflow: hidden; box-shadow: var(--shadow-deep); transition: transform .35s var(--ease);
}
.step:hover { transform: translateY(-6px) rotate(-.4deg); }
.step img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; border-bottom: 3px solid var(--gold-lo); cursor: zoom-in; }
.step::before {
  counter-increment: step; content: counter(step);
  position: absolute; top: .7rem; left: .7rem; width: 2.6rem; height: 2.6rem; display: grid; place-items: center;
  font: 900 1.3rem var(--font-deco); color: var(--gold-hi); background: var(--cinnabar); border-radius: 50%;
  box-shadow: 0 0 0 3px var(--gold), 0 6px 12px rgba(0, 0, 0, .5);
}
.step h3 { font: 900 1.15rem/1.25 var(--font-display); margin: 1rem 1.1rem .4rem; color: #8a1a1f; }
.step p { margin: 0 1.1rem; font-size: .92rem; }
.tips {
  max-width: 1000px; margin: 3.5rem auto 0; padding: 2rem clamp(1.2rem, 3vw, 2.5rem); border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(46, 158, 114, .18), rgba(0, 0, 0, .3)); border: 1px solid rgba(46, 158, 114, .55);
}
.tips h3 { margin: 0 0 1rem; font: 900 1.4rem var(--font-display); color: #9fe0bf; }
.tips ul { margin: 0; padding-left: 1.2rem; display: grid; gap: .5rem; columns: 2; column-gap: 2.5rem; }
.tips li { break-inside: avoid; }

/* ---------- Lộ trình: dòng thời gian ---------- */
.roadmap { position: relative; max-width: 1000px; margin: 0 auto; }
.roadmap::before { content: ""; position: absolute; left: 50%; top: 0; bottom: 0; width: 4px; translate: -50% 0; background: linear-gradient(var(--gold), var(--cinnabar), transparent); border-radius: 2px; }
.phase { position: relative; width: calc(50% - 2.5rem); margin-bottom: 2rem; }
.phase:nth-child(odd) { margin-right: auto; }
.phase:nth-child(even) { margin-left: auto; }
.phase::before {
  content: ""; position: absolute; top: 1.6rem; width: 22px; height: 22px; border-radius: 50%;
  background: var(--state, var(--muted)); box-shadow: 0 0 0 4px var(--lacquer), 0 0 0 6px var(--gold-lo), 0 0 24px var(--state, transparent);
}
.phase:nth-child(odd)::before { right: calc(-2.5rem - 11px); }
.phase:nth-child(even)::before { left: calc(-2.5rem - 11px); }
.phase-card {
  background: linear-gradient(180deg, #2c160c, #1a0d07); border-radius: var(--radius); padding: 1.4rem 1.6rem;
  box-shadow: 0 0 0 1px rgba(227, 178, 60, .35) inset, var(--shadow-deep);
}
.phase-top { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: .4rem; }
.phase-when { font: 900 1rem var(--font-deco); color: var(--gold); }
.badge { font: 800 .7rem var(--font-body); letter-spacing: .12em; text-transform: uppercase; padding: .35em .8em; border-radius: 999px; color: #120a06; background: var(--state); }
.phase h3 { margin: 0 0 .6rem; font: 900 1.35rem var(--font-display); color: var(--paper); }
.phase ul { margin: 0; padding-left: 1.1rem; color: var(--paper-2); font-size: .95rem; display: grid; gap: .3rem; }
.phase.live { --state: var(--jade); }
.phase.building { --state: var(--gold); }
.phase.planned { --state: #8a7a66; }

/* ---------- Thư viện ảnh: bento ---------- */
.gallery { max-width: 1320px; margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr); grid-auto-rows: 180px; gap: .9rem; }
.gallery button { position: relative; padding: 0; border: 0; border-radius: 12px; overflow: hidden; cursor: zoom-in; background: #000; box-shadow: var(--shadow-deep); }
.gallery button:nth-child(1) { grid-column: span 2; grid-row: span 2; }
.gallery button:nth-child(6) { grid-column: span 2; grid-row: span 2; }
.gallery img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s var(--ease), filter .4s; filter: saturate(.92); }
.gallery button:hover img { transform: scale(1.07); filter: saturate(1.1); }
.gallery span {
  position: absolute; left: 0; right: 0; bottom: 0; padding: 1.4rem .8rem .6rem; text-align: left; font: 700 .85rem var(--font-body); color: var(--paper);
  background: linear-gradient(transparent, rgba(0, 0, 0, .85)); transform: translateY(100%); transition: transform .35s var(--ease);
}
.gallery button:hover span, .gallery button:focus-visible span { transform: none; }

/* ---------- Hỏi đáp ---------- */
.faq { max-width: 860px; margin: 0 auto; display: grid; gap: .8rem; }
.faq details { background: rgba(246, 231, 196, .06); border: 1px solid rgba(227, 178, 60, .3); border-radius: 12px; padding: 0 1.3rem; transition: background .3s; }
.faq details[open] { background: rgba(246, 231, 196, .1); }
.faq summary { cursor: pointer; list-style: none; padding: 1.1rem 0; font: 700 1.05rem var(--font-body); color: var(--gold-hi); display: flex; justify-content: space-between; gap: 1rem; }
.faq summary::after { content: "+"; font-size: 1.4rem; line-height: 1; color: var(--cinnabar-hot); transition: transform .3s var(--ease); }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq p { margin: 0 0 1.2rem; color: var(--paper-2); }

/* ---------- Kêu gọi cuối ---------- */
.final-cta {
  position: relative; padding: clamp(6rem, 12vw, 11rem) 1.5rem; text-align: center; overflow: hidden;
  background: linear-gradient(180deg, rgba(18, 10, 6, .3), rgba(18, 10, 6, .85)), url("../img/key_general.webp") center 30%/cover no-repeat;
}
.final-inner { max-width: 760px; margin: 0 auto; }
.final-cta h2 { font: 900 clamp(2.2rem, 1.4rem + 3.5vw, 4.2rem)/1.1 var(--font-display); margin: 0 0 1rem; text-shadow: 0 4px 20px #000; }
.final-cta p { color: var(--paper-2); margin: 0 0 2rem; font-size: 1.15rem; text-shadow: 0 2px 10px #000; }

.footer { text-align: center; padding: 2.5rem 1rem 3rem; color: var(--muted); font-size: .85rem; border-top: 1px solid rgba(227, 178, 60, .25); }
.footer-logo { height: 70px; width: auto; margin: 0 auto .8rem; opacity: .9; }

/* ---------- Xem ảnh lớn ---------- */
.lightbox { position: fixed; inset: 0; z-index: 200; background: rgba(8, 4, 2, .94); display: grid; place-items: center; padding: 3rem 4rem; }
.lightbox[hidden] { display: none; }
.lightbox img { max-height: 82vh; border-radius: 10px; box-shadow: 0 0 0 2px var(--gold-lo), var(--shadow-deep); }
.lb-caption { position: absolute; bottom: 1.2rem; left: 0; right: 0; text-align: center; color: var(--paper); margin: 0; }
.lb-close, .lb-nav { position: absolute; background: rgba(0, 0, 0, .5); color: var(--gold-hi); border: 1px solid rgba(227, 178, 60, .5); border-radius: 50%; width: 52px; height: 52px; font-size: 1.6rem; cursor: pointer; }
.lb-close { top: 1rem; right: 1rem; }
.lb-prev { left: 1rem; top: 50%; translate: 0 -50%; }
.lb-next { right: 1rem; top: 50%; translate: 0 -50%; }
.lb-close:hover, .lb-nav:hover { background: var(--cinnabar); }

/* ---------- Hiện dần khi cuộn ---------- */
.reveal { opacity: 0; transform: translateY(40px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ---------- Màn nhỏ ---------- */
@media (max-width: 1100px) {
  .generals { grid-template-columns: repeat(3, 1fr); }
  .guide { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 860px) {
  .nav-links {
    position: fixed; inset: 70px 0 auto; flex-direction: column; gap: 0; padding: .5rem 1.5rem 1.5rem;
    background: rgba(18, 10, 6, .97); border-bottom: 1px solid var(--gold-lo);
    transform: translateY(-120%); transition: transform .35s var(--ease);
  }
  .nav-links.open { transform: none; }
  .nav-links a { padding: .9rem 0; border-bottom: 1px solid rgba(227, 178, 60, .15); }
  .burger { display: block; }
  .nav .play-link { display: none; }
  .stats { grid-template-columns: repeat(3, 1fr); }
  .stat:nth-child(4)::before { display: none; }
  .feature, .feature:nth-child(even) { grid-template-columns: 1fr; }
  .feature:nth-child(even) .feature-media { order: 0; }
  .shot { transform: none; }
  .roadmap::before { left: 12px; }
  .phase, .phase:nth-child(odd), .phase:nth-child(even) { width: auto; margin-left: 2.6rem; }
  .phase:nth-child(odd)::before, .phase:nth-child(even)::before { left: calc(-2.6rem + 1px); right: auto; }
  .gallery { grid-template-columns: repeat(2, 1fr); grid-auto-rows: 140px; }
  .tips ul { columns: 1; }
}
@media (max-width: 560px) {
  .generals, .guide { grid-template-columns: 1fr 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat::before { display: none; }
  .lightbox { padding: 3rem .5rem; }
  .general p { display: none; }
}
@media (max-width: 420px) {
  .guide { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}