/* Bunchasake – landing pages + blog. Cùng hệ màu/chữ với trang chủ. */
:root {
  --bg: #0A0A0A; --raise: #131312; --ink: #F7F7F4; --muted: #9A9A95; --dim: #66665F;
  --line: #262624; --line-strong: #44443F; --mark: #FF4A2E;
  --card: #F7F7F4; --card-ink: #0A0A0A; --card-line: #BDBDB8;
  --sans: "Inter Tight", "Segoe UI", system-ui, -apple-system, sans-serif;
  --serif: "Fraunces", Georgia, "Times New Roman", serif;
  --gutter: clamp(16px, 2.8vw, 44px); --ease: cubic-bezier(.2, .7, .1, 1);
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 16px/1.55 var(--sans); padding-inline: var(--gutter); -webkit-font-smoothing: antialiased; }
::selection { background: var(--mark); color: #0A0A0A; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { font-weight: 500; text-wrap: balance; }
img { max-width: 100%; }
:focus-visible { outline: 2px solid var(--mark); outline-offset: 4px; }
.cap { font-size: 12px; font-weight: 500; text-transform: uppercase; letter-spacing: .02em; }
.it, h1 em, h2 em { font-family: var(--serif); font-style: italic; font-weight: 400; letter-spacing: -0.02em; }
.dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; background: var(--mark); flex: none; }
.skip { position: absolute; left: -9999px; top: 8px; z-index: 50; background: var(--ink); color: var(--bg); padding: 10px 14px; border-radius: 10px; }
.skip:focus { left: 12px; }
.wrap { max-width: 1280px; margin-inline: auto; }

/* Nav */
.nav { position: sticky; top: 0; z-index: 30; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-block: 16px; background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); margin-inline: calc(var(--gutter) * -1); padding-inline: var(--gutter); border-bottom: 1px solid var(--line); }
.logo { display: inline-flex; align-items: center; gap: 10px; font-size: 13px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; white-space: nowrap; }
.logo i { font-style: normal; color: var(--muted); font-weight: 400; letter-spacing: .02em; }
.nav ul { display: flex; gap: clamp(16px, 2.6vw, 40px); list-style: none; margin: 0; padding: 0; }
.nav ul a { color: var(--muted); transition: color .2s; }
.nav ul a:hover, .nav ul a[aria-current="page"] { color: var(--ink); }
.nav-r { display: flex; align-items: center; gap: 10px; }
.lang { display: inline-flex; padding: 3px; border-radius: 999px; box-shadow: inset 0 0 0 1px var(--line-strong); }
.lang a, .lang span { font-size: 11px; font-weight: 600; letter-spacing: .04em; padding: 7px 10px; border-radius: 999px; color: var(--muted); }
.lang a[aria-current="true"] { background: var(--ink); color: var(--bg); }
.lang span { opacity: .4; }
.pill { display: inline-flex; align-items: center; gap: 10px; padding: 11px 18px; border-radius: 999px; background: var(--ink); color: var(--bg); font-size: 13px; font-weight: 600; white-space: nowrap; transition: background .25s, color .25s, transform .25s var(--ease); }
.pill:hover { background: var(--mark); color: #0A0A0A; transform: translateY(-1px); }
.pill.ghost { background: transparent; color: var(--ink); box-shadow: inset 0 0 0 1px var(--line-strong); }
.pill.ghost:hover { box-shadow: inset 0 0 0 1px var(--ink); background: transparent; color: var(--ink); }
@media (max-width: 1180px) { .logo i { display: none; } }
@media (max-width: 860px) { .nav ul { display: none; } }
@media (max-width: 480px) { .nav .pill { padding: 10px 14px; font-size: 12px; } }

/* Hero */
.crumbs { display: flex; flex-wrap: wrap; gap: 8px; color: var(--dim); font-size: 13px; padding-top: clamp(28px, 4vw, 48px); list-style: none; margin: 0; padding-left: 0; }
.crumbs li + li::before { content: "/"; margin-right: 8px; color: var(--line-strong); }
.crumbs a { color: var(--muted); } .crumbs a:hover { color: var(--ink); }
.lp-hero { padding-block: clamp(28px, 4vw, 48px) clamp(40px, 6vw, 72px); }
.kicker { display: flex; align-items: center; gap: 10px; color: var(--muted); }
.lp-hero h1 { margin-top: clamp(18px, 2.4vw, 28px); font-size: clamp(38px, 6.4vw, 96px); line-height: .98; letter-spacing: -0.055em; max-width: 16em; }
.lp-hero h1 em { color: var(--muted); letter-spacing: -0.035em; }
.lead { margin-top: clamp(20px, 2.6vw, 32px); max-width: 58ch; font-size: clamp(17px, 1.5vw, 21px); font-weight: 300; color: var(--muted); }
.hero-cta { display: flex; gap: 10px; flex-wrap: wrap; margin-top: clamp(24px, 3vw, 36px); }

/* Sections */
.sec { padding-top: clamp(64px, 9vw, 128px); }
.sec-head { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 16px 48px; align-items: end; padding-bottom: clamp(22px, 3vw, 34px); border-bottom: 1px solid var(--line-strong); }
.sec-head h2 { font-size: clamp(30px, 4vw, 56px); line-height: 1.02; letter-spacing: -0.05em; }
.sec-head p { color: var(--muted); max-width: 46ch; font-size: 15px; font-weight: 300; justify-self: end; }
@media (max-width: 760px) { .sec-head { grid-template-columns: 1fr; } .sec-head p { justify-self: start; } }

.pains { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); }
.pain { padding: clamp(22px, 3vw, 36px) clamp(16px, 2.4vw, 32px) 8px 0; display: grid; gap: 16px; align-content: start; min-width: 0; }
.pain + .pain { padding-left: clamp(16px, 2.4vw, 32px); border-left: 1px solid var(--line); }
.pain q { font: 400 clamp(21px, 2vw, 28px)/1.2 var(--serif); font-style: italic; quotes: "“" "”"; }
.pain p { color: var(--muted); font-size: 15px; font-weight: 300; }
@media (max-width: 820px) { .pains { grid-template-columns: 1fr; } .pain + .pain { padding-left: 0; border-left: 0; border-top: 1px solid var(--line); } }

.svc { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; padding-top: clamp(24px, 3.4vw, 40px); }
.svc div { background: var(--raise); border: 1px solid var(--line); border-radius: 16px; padding: 22px; display: grid; gap: 10px; align-content: start; min-width: 0; }
.svc .n { color: var(--mark); }
.svc h3 { font-size: clamp(19px, 1.6vw, 23px); letter-spacing: -0.03em; line-height: 1.15; }
.svc p { font-size: 14.5px; color: var(--muted); font-weight: 300; }
@media (max-width: 900px) { .svc { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 560px) { .svc { grid-template-columns: 1fr; } }

.split { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.3fr); gap: 20px clamp(28px, 5vw, 80px); padding-top: clamp(28px, 4vw, 44px); border-top: 1px solid var(--line-strong); }
.split h2 { font-size: clamp(26px, 2.9vw, 42px); line-height: 1.05; letter-spacing: -0.045em; }
.sec.block { padding-top: clamp(56px, 7vw, 96px); }
@media (max-width: 860px) { .split { grid-template-columns: 1fr; } }

.prose { font-size: 17px; line-height: 1.65; color: #CFCFCA; font-weight: 300; max-width: 68ch; }
.prose > * + * { margin-top: 1.05em; }
.prose h2 { font-size: clamp(26px, 2.8vw, 38px); line-height: 1.1; letter-spacing: -0.04em; color: var(--ink); font-weight: 500; margin-top: 1.9em; scroll-margin-top: 90px; }
.prose h3 { font-size: clamp(20px, 1.8vw, 24px); letter-spacing: -0.03em; color: var(--ink); font-weight: 500; margin-top: 1.6em; }
.prose strong { color: var(--ink); font-weight: 500; }
.prose a { color: var(--ink); text-decoration: underline; text-decoration-color: var(--mark); text-decoration-thickness: 2px; text-underline-offset: 4px; }
.prose a:hover { color: var(--mark); }
.prose ul, .prose ol { padding-left: 1.2em; display: grid; gap: .5em; }
.prose li::marker { color: var(--mark); }
.prose blockquote { margin: 1.4em 0; padding: 4px 0 4px 20px; border-left: 2px solid var(--mark); font: 400 1.15em/1.4 var(--serif); font-style: italic; color: var(--ink); }
.table { overflow-x: auto; max-width: 100%; margin-block: 1.4em; border: 1px solid var(--line); border-radius: 14px; }
.prose table { border-collapse: collapse; width: 100%; font-size: 15px; min-width: 520px; }
.prose th, .prose td { text-align: left; vertical-align: top; padding: 12px 14px; border-bottom: 1px solid var(--line); }
.prose th { color: var(--ink); font-weight: 500; background: var(--raise); }
.prose tr:last-child td { border-bottom: 0; }

.steps4 { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0; }
.steps4 div { padding: clamp(22px, 3vw, 34px) clamp(14px, 2vw, 26px) 8px 0; display: grid; gap: 12px; align-content: start; min-width: 0; }
.steps4 div + div { padding-left: clamp(14px, 2vw, 26px); border-left: 1px solid var(--line); }
.steps4 .n { color: var(--mark); }
.steps4 h3 { font-size: clamp(22px, 2.2vw, 32px); letter-spacing: -0.045em; line-height: 1; }
.steps4 p { font-size: 14.5px; color: var(--muted); font-weight: 300; }
@media (max-width: 900px) { .steps4 { grid-template-columns: repeat(2, minmax(0, 1fr)); } .steps4 div:nth-child(3) { padding-left: 0; border-left: 0; } .steps4 div:nth-child(n+3) { border-top: 1px solid var(--line); } }
@media (max-width: 520px) { .steps4 { grid-template-columns: 1fr; } .steps4 div + div { padding-left: 0; border-left: 0; border-top: 1px solid var(--line); } }

.work { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: clamp(12px, 1.4vw, 20px); padding-top: clamp(24px, 3.4vw, 40px); }
.work.n2 { grid-template-columns: repeat(2, minmax(0, 1fr)); } .work.n3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.wcard { display: grid; gap: 12px; align-content: start; min-width: 0; }
.wcard .img { display: block; aspect-ratio: 4 / 3; overflow: hidden; background: #161615; border-radius: 14px; }
.wcard img { width: 100%; height: 100%; object-fit: cover; display: block; filter: grayscale(1) brightness(.82); transition: filter .6s ease, transform .9s var(--ease); }
.wcard:hover img { filter: none; transform: scale(1.04); }
.wcard h3 { font-size: 18px; letter-spacing: -0.03em; }
.wcard p { font-size: 14px; color: var(--muted); }
@media (max-width: 860px) { .work, .work.n3 { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 460px) { .work, .work.n2, .work.n3 { grid-template-columns: 1fr; } }

.faq details { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; list-style: none; display: grid; grid-template-columns: minmax(0, 1fr) 20px; gap: 16px; align-items: center; padding-block: clamp(18px, 2.2vw, 26px); font-size: clamp(18px, 1.6vw, 22px); letter-spacing: -0.03em; font-weight: 500; color: var(--ink); }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; justify-self: end; font-weight: 300; font-size: 24px; line-height: 1; color: var(--mark); transition: transform .3s var(--ease); }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { padding-bottom: 24px; font-size: 16px; font-weight: 300; color: var(--muted); max-width: 66ch; margin: 0; }
.faq details p a { color: var(--ink); text-decoration: underline; text-decoration-color: var(--mark); text-underline-offset: 4px; }
.prose .faq { margin-top: 2.2em; }
.prose .faq h2 { margin-top: 0; margin-bottom: .4em; }

.links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 clamp(24px, 4vw, 56px); padding-top: 6px; }
.links a { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 16px; align-items: baseline; padding-block: 18px; border-bottom: 1px solid var(--line); font-size: clamp(17px, 1.5vw, 20px); letter-spacing: -0.02em; }
.links a span { color: var(--mark); transition: transform .3s var(--ease); }
.links a:hover span { transform: translateX(4px); }
.links a small { display: block; font-size: 13px; color: var(--muted); letter-spacing: 0; margin-top: 4px; font-weight: 300; }
@media (max-width: 760px) { .links { grid-template-columns: 1fr; } }

/* Blog */
.article { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 300px); gap: clamp(28px, 5vw, 80px); align-items: start; padding-top: clamp(28px, 4vw, 48px); }
.article > * { min-width: 0; }
.article-head h1 { margin-top: 18px; font-size: clamp(34px, 4.8vw, 68px); line-height: 1.02; letter-spacing: -0.05em; max-width: 18em; }
.article-head .lead { max-width: 62ch; }
.meta { margin-top: 22px; color: var(--dim); font-size: 13px; display: flex; gap: 14px; flex-wrap: wrap; }
.takeaways { margin-top: clamp(28px, 4vw, 44px); background: var(--raise); border: 1px solid var(--line); border-radius: 18px; padding: clamp(20px, 2.4vw, 30px); max-width: 68ch; }
.takeaways b { color: var(--muted); display: block; margin-bottom: 12px; }
.takeaways ul { margin: 0; padding-left: 1.1em; display: grid; gap: 10px; font-size: 16px; }
.takeaways li::marker { color: var(--mark); }
.aside { position: sticky; top: 92px; display: grid; gap: 14px; }
.cta-box { background: var(--card); color: var(--card-ink); border-radius: 18px; padding: 22px; display: grid; gap: 14px; }
.cta-box p { font-size: clamp(19px, 1.6vw, 22px); font-weight: 600; letter-spacing: -0.03em; line-height: 1.2; }
.cta-box small { font-size: 13px; color: #55554F; }
.btn { display: flex; justify-content: space-between; align-items: center; gap: 12px; background: var(--card-ink); color: var(--card); font-size: 14px; font-weight: 600; padding: 14px 18px; border-radius: 12px; transition: background .2s, color .2s; }
.btn:hover { background: var(--mark); color: #0A0A0A; }
.btn.line { background: transparent; color: var(--card-ink); box-shadow: inset 0 0 0 1px var(--card-line); }
.btn.line:hover { background: transparent; box-shadow: inset 0 0 0 1px var(--card-ink); color: var(--card-ink); }
.toc { border: 1px solid var(--line); border-radius: 18px; padding: 20px 22px; display: grid; gap: 10px; font-size: 14px; }
.toc b { color: var(--muted); }
.toc a { color: var(--muted); } .toc a:hover { color: var(--ink); }
@media (max-width: 980px) { .article { grid-template-columns: 1fr; } .aside { position: static; } .toc { display: none; } }

.posts { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; padding-top: clamp(24px, 3.4vw, 40px); }
.post { background: var(--raise); border: 1px solid var(--line); border-radius: 18px; padding: clamp(20px, 2.4vw, 30px); display: grid; gap: 12px; align-content: start; min-width: 0; transition: border-color .3s, transform .4s var(--ease); }
.post:hover { border-color: var(--line-strong); transform: translateY(-4px); }
.post .cap { color: var(--mark); }
.post h2 { font-size: clamp(21px, 2vw, 28px); letter-spacing: -0.04em; line-height: 1.12; }
.post p { font-size: 15px; color: var(--muted); font-weight: 300; }
@media (max-width: 760px) { .posts { grid-template-columns: 1fr; } }

/* Footer */
.foot { margin-top: clamp(96px, 12vw, 160px); border-top: 1px solid var(--line-strong); padding-block: clamp(48px, 7vw, 96px) 28px; }
.foot-top { display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr); gap: 32px clamp(32px, 6vw, 96px); align-items: end; }
.foot-top h2 { font-size: clamp(36px, 5.4vw, 84px); line-height: .97; letter-spacing: -0.055em; }
.foot-top h2 em { color: var(--muted); }
.foot-top .sub { margin-top: 18px; color: var(--muted); font-weight: 300; max-width: 46ch; }
.mail-card { background: var(--card); color: var(--card-ink); border-radius: 20px; padding: clamp(22px, 3vw, 36px); display: grid; gap: 16px; }
.mail-card .cap { color: #55554F; }
.mail-big { font-size: clamp(22px, 2.4vw, 34px); font-weight: 600; letter-spacing: -0.04em; line-height: 1.1; overflow-wrap: anywhere; text-decoration: underline; text-decoration-color: var(--mark); text-decoration-thickness: 3px; text-underline-offset: 8px; }
.mail-act { display: grid; grid-template-columns: 1fr auto; gap: 10px; }
.mail-copy { all: unset; box-sizing: border-box; cursor: pointer; display: grid; place-items: center; padding: 0 18px; border-radius: 12px; border: 1px solid var(--card-line); font-size: 14px; font-weight: 600; }
.mail-copy:hover { border-color: var(--card-ink); }
.foot-cols { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 28px clamp(20px, 3vw, 48px); margin-top: clamp(48px, 7vw, 88px); padding-top: 28px; border-top: 1px solid var(--line); }
.foot-cols div { display: grid; gap: 8px; align-content: start; font-size: 14px; }
.foot-cols b { color: var(--ink); font-weight: 500; margin-bottom: 6px; }
.foot-cols a { color: var(--muted); } .foot-cols a:hover { color: var(--ink); }
.legal { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; color: var(--dim); margin-top: 36px; padding-top: 22px; border-top: 1px solid var(--line); }
@media (max-width: 860px) { .foot-top { grid-template-columns: 1fr; } .foot-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 440px) { .foot-cols { grid-template-columns: 1fr; } }

.notfound { min-height: 60vh; display: grid; align-content: center; gap: 22px; justify-items: start; }
.notfound h1 { font-size: clamp(44px, 8vw, 120px); letter-spacing: -0.06em; line-height: .95; }

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { animation: none !important; transition: none !important; } }