:root { --bg: #f5f4ed; --surface: #faf9f3; --fg: #24231f; --muted: #66645b; --border: #cbc8bb; --accent: #1B365D; --tag: #E4ECF5; --serif: Charter, Georgia, Palatino, "Times New Roman", serif; --sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; --mono: ui-monospace, "SFMono-Regular", Consolas, monospace; --shadow: 0 4px 24px rgba(0,0,0,0.05); } * { box-sizing: border-box; } html { background: var(--bg); scroll-behavior: smooth; } body { margin: 0; color: var(--fg); background: var(--bg); font-family: var(--serif); font-weight: 500; letter-spacing: 0; line-height: 1.5; -webkit-font-smoothing: antialiased; } a { color: inherit; text-underline-offset: 0.2em; } a:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; } /* Language switching: default state (no data-lang, or data-lang="vi") shows Vietnamese only. Setting data-lang="en" on shows English only. Content never mixes. */ html[data-lang="en"] .i18n-vi { display: none; } html:not([data-lang="en"]) .i18n-en { display: none; } .lang-switch { display: inline-flex; align-items: center; gap: 8px; } .lang-btn { background: none; border: none; padding: 0; margin: 0; font: inherit; letter-spacing: inherit; color: var(--muted); cursor: pointer; } .lang-btn:hover { color: var(--fg); } .lang-btn[data-lang-btn="vi"] { color: var(--fg); } html[data-lang="en"] .lang-btn[data-lang-btn="vi"] { color: var(--muted); } html[data-lang="en"] .lang-btn[data-lang-btn="en"] { color: var(--fg); } .lang-sep { color: var(--muted); } .sheet { width: min(1180px, calc(100% - 64px)); margin: 32px auto; background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow); } .page-pad { padding-inline: clamp(32px, 6vw, 92px); } .eyebrow { min-height: 54px; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 24px; border-bottom: 1px solid var(--border); font-family: var(--sans); font-size: 12px; font-weight: 600; letter-spacing: 0.12em; line-height: 1.2; text-transform: uppercase; color: var(--muted); } .eyebrow-center { color: var(--fg); } .eyebrow-right { text-align: right; font-variant-numeric: tabular-nums; } .hero { padding-top: clamp(70px, 10vw, 126px); padding-bottom: clamp(68px, 8vw, 104px); border-bottom: 1px solid var(--border); } .section-num { margin: 0 0 26px; color: var(--accent); font-size: 14px; line-height: 1; font-variant-numeric: tabular-nums; } h1, h2, h3, p { margin-top: 0; } h1 { max-width: 970px; margin-bottom: 36px; font-size: clamp(58px, 8.3vw, 104px); font-weight: 500; letter-spacing: -0.045em; line-height: 0.96; text-wrap: balance; } .accent { color: var(--accent); } .tagline { max-width: 740px; margin-bottom: 36px; font-size: clamp(19px, 2.1vw, 23px); line-height: 1.45; color: var(--muted); } .tagline strong { color: var(--fg); font-weight: 500; } .tags { display: flex; flex-wrap: wrap; gap: 10px; } .tag { display: inline-flex; align-items: center; min-height: 34px; padding: 7px 13px; background: var(--bg); border: 1px solid var(--border); border-radius: 999px; font-family: var(--sans); font-size: 11px; font-weight: 600; letter-spacing: 0.08em; line-height: 1; text-transform: uppercase; color: var(--muted); } .manifesto-wrap { display: grid; grid-template-columns: 0.8fr 1.2fr; gap: clamp(42px, 7vw, 92px); padding-top: 74px; padding-bottom: 74px; border-bottom: 1px solid var(--border); } .manifesto-kicker h2 { max-width: 400px; margin-bottom: 22px; font-size: clamp(30px, 4vw, 46px); font-weight: 500; letter-spacing: -0.025em; line-height: 1.1; } .manifesto-kicker p { max-width: 360px; color: var(--muted); font-size: 14px; line-height: 1.55; } .quote { margin: 0; padding-left: clamp(24px, 3vw, 40px); border-left: 3px solid var(--accent); } .quote p { margin-bottom: 28px; font-size: clamp(19px, 2vw, 22px); line-height: 1.62; } .quote footer { color: var(--muted); font-family: var(--sans); font-size: 11px; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; } .proof { padding-top: 66px; padding-bottom: 66px; border-bottom: 1px solid var(--border); } .proof-labels, .proof-line { display: grid; grid-template-columns: 1fr auto 1fr; gap: clamp(18px, 4vw, 54px); align-items: baseline; } .proof-labels { margin-bottom: 17px; color: var(--muted); font-family: var(--sans); font-size: 11px; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; } .proof-labels span:last-child { text-align: right; } .proof-line { padding: 28px 0 25px; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); font-size: clamp(34px, 5.7vw, 70px); letter-spacing: -0.035em; line-height: 1; } .proof-line .arrow { color: var(--muted); font-size: 0.64em; } .proof-line .output { color: var(--accent); text-align: right; } .download-row { display: flex; justify-content: space-between; align-items: center; gap: 24px; margin-top: 27px; } .download-note { margin: 0; color: var(--muted); font-size: 14px; } .download-link { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 13px 19px; background: var(--accent); color: var(--surface); border: 1px solid var(--accent); box-shadow: var(--shadow); font-family: var(--sans); font-size: 12px; font-weight: 600; letter-spacing: 0.06em; text-decoration: none; text-transform: uppercase; } .metrics { display: grid; grid-template-columns: repeat(4, 1fr); border-bottom: 1px solid var(--border); } .metric { min-height: 130px; padding: 33px clamp(20px, 3vw, 34px); border-right: 1px solid var(--border); } .metric:last-child { border-right: 0; } .metric-value { display: block; margin-bottom: 12px; color: var(--accent); font-size: 25px; line-height: 1; font-variant-numeric: tabular-nums; } .metric-label { display: block; color: var(--muted); font-size: 12px; line-height: 1.35; } .chapters { padding-top: 82px; padding-bottom: 84px; } .chapter { display: grid; grid-template-columns: 82px 0.8fr 1.35fr; gap: clamp(24px, 4vw, 58px); padding: 48px 0 52px; border-top: 1px solid var(--border); } .chapter:first-of-type { margin-top: 39px; } .section-title { margin-bottom: 16px; font-size: clamp(27px, 3vw, 32px); font-weight: 500; letter-spacing: -0.025em; line-height: 1.12; } .section-lede { margin-bottom: 0; color: var(--muted); font-size: 15px; line-height: 1.55; } .chapter-body { font-size: 15px; line-height: 1.55; } .chapter-body p:last-child { margin-bottom: 0; } ul.dash { margin: 0; padding: 0; list-style: none; } ul.dash li { position: relative; padding-left: 22px; } ul.dash li + li { margin-top: 11px; } ul.dash li::before { content: "—"; position: absolute; left: 0; color: var(--accent); } .steps { counter-reset: steps; } .step { position: relative; padding-left: 36px; } .step + .step { margin-top: 17px; } .step::before { counter-increment: steps; content: "0" counter(steps); position: absolute; left: 0; top: 0.1em; color: var(--muted); font-family: var(--sans); font-size: 10px; font-weight: 600; font-variant-numeric: tabular-nums; } .code { margin-top: 22px; padding: 18px 20px; background: var(--bg); border: 1px solid var(--border); font-family: var(--mono); font-size: 13px; font-variant-numeric: tabular-nums; line-height: 1.5; overflow-wrap: anywhere; } .footer { padding-top: 72px; padding-bottom: 56px; border-top: 1px solid var(--border); } .footer-kicker { margin: 0 0 66px; font-size: clamp(76px, 14vw, 168px); font-weight: 500; letter-spacing: -0.065em; line-height: 0.78; } .footer-grid { display: grid; grid-template-columns: 1.3fr repeat(3, 1fr); gap: clamp(28px, 5vw, 64px); padding-top: 34px; border-top: 1px solid var(--border); font-size: 12px; line-height: 1.55; } .footer-grid h3 { margin-bottom: 13px; color: var(--muted); font-family: var(--sans); font-size: 10px; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; } .footer-grid p { margin-bottom: 0; } .footer-grid a { display: block; margin-bottom: 7px; overflow-wrap: anywhere; } .numeric { font-variant-numeric: tabular-nums; } @media (max-width: 980px) { .sheet { width: min(100% - 32px, 900px); margin: 16px auto; } .manifesto-wrap { grid-template-columns: 1fr 1.35fr; } .chapter { grid-template-columns: 54px 0.85fr 1.25fr; } .footer-grid { grid-template-columns: 1.2fr 1fr 1fr; } .footer-grid > :last-child { grid-column: 2 / -1; } } @media (max-width: 768px) { .page-pad { padding-inline: 30px; } .eyebrow { grid-template-columns: 1fr 1fr; } .eyebrow-center { display: none; } .manifesto-wrap { grid-template-columns: 1fr; } .manifesto-kicker p { max-width: 600px; } .metrics { grid-template-columns: repeat(2, 1fr); } .metric:nth-child(2) { border-right: 0; } .metric:nth-child(-n+2) { border-bottom: 1px solid var(--border); } .chapter { grid-template-columns: 48px 1fr; } .chapter-body { grid-column: 2; } .footer-grid { grid-template-columns: repeat(2, 1fr); } .footer-grid > :last-child { grid-column: auto; } } @media (max-width: 560px) { .sheet { width: 100%; margin: 0; border-left: 0; border-right: 0; box-shadow: none; } .page-pad { padding-inline: 22px; } .eyebrow { gap: 12px; min-height: 50px; font-size: 10px; } .hero { padding-top: 62px; padding-bottom: 62px; } h1 { font-size: clamp(49px, 15.5vw, 70px); } .manifesto-wrap { padding-top: 58px; padding-bottom: 58px; } .proof-labels { grid-template-columns: 1fr 1fr; } .proof-labels span:nth-child(2) { display: none; } .proof-line { grid-template-columns: 1fr; gap: 16px; font-size: clamp(42px, 13vw, 62px); } .proof-line .arrow { transform: rotate(90deg); width: fit-content; } .proof-line .output { text-align: left; } .download-row { align-items: stretch; flex-direction: column; } .download-link { width: 100%; } .metrics { grid-template-columns: 1fr; } .metric, .metric:nth-child(2) { border-right: 0; border-bottom: 1px solid var(--border); } .metric:last-child { border-bottom: 0; } .chapter { grid-template-columns: 1fr; gap: 20px; } .chapter-body { grid-column: 1; } .footer-kicker { margin-bottom: 48px; } .footer-grid { grid-template-columns: 1fr; } } @media print { @page { size: A3 portrait; margin: 10mm; } html, body { background: var(--bg); print-color-adjust: exact; -webkit-print-color-adjust: exact; } .sheet { width: 100%; margin: 0; border: 1px solid var(--border); box-shadow: none; } .page-pad { padding-inline: 12mm; } .eyebrow { min-height: 10mm; } .hero { padding-top: 12mm; padding-bottom: 11mm; } .hero h1 { max-width: 230mm; margin-bottom: 7mm; font-size: 68px; } .tagline { margin-bottom: 6mm; font-size: 18px; } .manifesto-wrap, .proof { padding-top: 10mm; padding-bottom: 10mm; } .manifesto-wrap { gap: 12mm; } .manifesto-kicker h2 { font-size: 31px; } .quote p { font-size: 17px; line-height: 1.48; } .proof-line { padding-block: 5mm; font-size: 48px; } .metrics .metric { min-height: 24mm; padding: 6mm; } .chapters { padding-top: 10mm; padding-bottom: 9mm; } .chapter { gap: 7mm; padding: 5.5mm 0; } .section-title { font-size: 23px; } .section-lede, .chapter-body { font-size: 11.5px; line-height: 1.42; } .footer { padding-top: 9mm; padding-bottom: 9mm; } .footer-kicker { margin-bottom: 8mm; font-size: 92px; } .footer-grid { padding-top: 6mm; gap: 8mm; font-size: 10px; } .download-link { box-shadow: none; } .chapter, .proof, .metric, .footer-grid { break-inside: avoid; } }