/* ==========================================================================
   Envelope — building-physics consultancy template · archesign.studio
   1. Tokens  2. Base  3. Header  4. Components  5. Pages  6. Footer  7. Responsive
   ========================================================================== */

/* 1. Tokens ---------------------------------------------------------------- */
:root {
  --white: #ffffff;
  --mist: #f2f7f7;
  --teal: #0f766e;
  --mint: #5eead4;
  --navy: #0b2530;
  --grey: #5b6b70;
  --line: #dbe6e5;

  --font-sans: "Plus Jakarta Sans", "Segoe UI", Arial, sans-serif;
  --font-serif: "Source Serif 4", Georgia, serif;

  --radius: 16px;
  --gutter: clamp(16px, 3vw, 40px);
  --max: 1280px;
  --space: clamp(80px, 10vw, 140px);
  --ease: cubic-bezier(.2, .7, .2, 1);
}

/* 2. Base ------------------------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--white); color: var(--navy); font: 400 17px/1.7 var(--font-sans); -webkit-font-smoothing: antialiased; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
p { margin: 0 0 1em; }
h1, h2, h3, h4 { font-weight: 700; margin: 0; line-height: 1.1; letter-spacing: -0.03em; }
h4 { font-size: 13px; letter-spacing: .06em; text-transform: uppercase; color: var(--mint); margin-bottom: 10px; font-weight: 600; }
em, .serif { font-family: var(--font-serif); font-style: italic; font-weight: 400; letter-spacing: -0.01em; }
:focus-visible { outline: 2px solid var(--teal); outline-offset: 3px; border-radius: 6px; }
::selection { background: var(--mint); color: var(--navy); }
.skip { position: absolute; left: -999px; top: 8px; background: var(--teal); color: #fff; padding: 8px 12px; z-index: 100; }
.skip:focus { left: 8px; }
.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }
.section { padding: var(--space) 0; }
.section--mist { background: var(--mist); }
.eyebrow { font-size: 13px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--teal); margin: 0 0 16px; }
.eyebrow--mint { color: var(--mint); }
.grey { color: var(--grey); }
.h-l { font-size: clamp(34px, 4.4vw, 58px); }
.h-l em { color: var(--teal); }

/* 3. Header ---------------------------------------------------------------- */
.site-header { position: sticky; top: 0; z-index: 50; background: var(--white); border-bottom: 1px solid var(--line); }
.header-row { display: flex; align-items: center; justify-content: space-between; height: 76px; }
.logo { display: inline-flex; align-items: baseline; gap: 8px; font-weight: 700; font-size: 22px; letter-spacing: -0.03em; margin: 0; }
.logo small { font-size: 13px; font-weight: 500; color: var(--grey); letter-spacing: 0; }
.logo-mark { width: 14px; height: 14px; border-radius: 4px; background: linear-gradient(135deg, var(--mint), var(--teal)); display: inline-block; }
.site-nav { display: flex; align-items: center; gap: 28px; }
.site-nav a { font-weight: 500; font-size: 15px; color: var(--grey); transition: color .2s; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--navy); }
.site-nav a[aria-current="page"]:not(.nav-cta) { box-shadow: 0 2px 0 var(--teal); }
.site-nav .nav-cta { background: var(--navy); color: #fff; padding: 11px 18px; border-radius: 10px; }
.site-nav .nav-cta:hover, .site-nav .nav-cta[aria-current="page"] { background: var(--teal); color: #fff; }
.menu-btn { display: none; }

/* 4. Components ------------------------------------------------------------ */
.btn { display: inline-flex; align-items: center; gap: 10px; padding: 15px 24px; border-radius: 10px; background: var(--teal); color: #fff; font: 600 16px var(--font-sans); border: 0; cursor: pointer; transition: background .2s; }
.btn:hover { background: var(--navy); }
.btn--ghost { background: transparent; color: var(--navy); box-shadow: inset 0 0 0 1.5px var(--line); }
.btn--ghost:hover { background: var(--mist); }
.btn--mint { background: var(--mint); color: var(--navy); }
.btn--mint:hover { background: #fff; }
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); }
.pic { border-radius: var(--radius); overflow: hidden; background: var(--mist); }
.pic img { width: 100%; aspect-ratio: var(--ratio, 4 / 3); object-fit: cover; }
.chip { display: inline-block; padding: 4px 10px; border-radius: 999px; background: var(--mist); font-size: 13px; font-weight: 600; color: var(--teal); margin: 0 6px 6px 0; }
.js .reveal { opacity: 0; transform: translateY(16px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.js .reveal.is-in { opacity: 1; transform: none; }

/* score gauge */
.gauge { --v: 72; position: relative; width: 220px; aspect-ratio: 2 / 1; overflow: hidden; }
.gauge::before { content: ""; position: absolute; inset: 0 0 -100% 0; border-radius: 50%; background: conic-gradient(from -90deg, var(--teal) calc(var(--v) * 1.8deg), var(--line) 0 180deg, transparent 0); }
.gauge::after { content: ""; position: absolute; inset: 22px 22px -100% 22px; border-radius: 50%; background: #fff; }
.gauge b { position: absolute; left: 0; right: 0; bottom: 0; text-align: center; z-index: 1; font-size: 44px; letter-spacing: -0.04em; line-height: 1; }

/* 5. Pages ----------------------------------------------------------------- */
/* hero */
.hero { padding: clamp(40px, 6vw, 88px) 0 var(--space); }
.hero-grid { display: grid; grid-template-columns: 6fr 6fr; gap: clamp(32px, 5vw, 72px); align-items: center; }
.hero h1 { font-size: clamp(42px, 5.6vw, 82px); letter-spacing: -0.045em; line-height: 1.02; }
.hero h1 em { color: var(--teal); }
.hero .lead { font-size: 19px; color: var(--grey); margin: 22px 0 30px; max-width: 46ch; }
.hero .actions { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-visual { position: relative; }
.hero-visual .pic img { aspect-ratio: 4 / 3; }
.scorecard { position: absolute; left: -32px; bottom: -36px; padding: 20px 22px; display: grid; grid-template-columns: auto 1fr; gap: 16px; align-items: center; box-shadow: 0 30px 50px -30px rgba(11, 37, 48, .4); }
.scorecard .gauge { width: 120px; }
.scorecard .gauge::after { inset: 14px 14px -100% 14px; }
.scorecard .gauge b { font-size: 26px; }
.scorecard p { margin: 0; font-size: 14px; color: var(--grey); }
.scorecard strong { display: block; font-size: 16px; color: var(--navy); }

/* kpis */
.kpis { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.kpi { padding: 26px; }
.kpi b { display: block; font-size: clamp(34px, 3.6vw, 48px); letter-spacing: -0.04em; color: var(--teal); }
.kpi span { color: var(--grey); font-size: 15px; }

/* services cards */
.svc-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.svc { padding: 30px; transition: border-color .2s, transform .3s var(--ease); display: flex; flex-direction: column; gap: 10px; }
.svc:hover { border-color: var(--teal); transform: translateY(-3px); }
.svc .ico { width: 44px; height: 44px; border-radius: 12px; background: var(--mist); display: grid; place-items: center; color: var(--teal); font-weight: 700; }
.svc h3 { font-size: 21px; }
.svc p { color: var(--grey); margin: 0; font-size: 15px; }

/* compare IR */
.ir { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.ir figure { margin: 0; }
.ir figcaption { display: flex; justify-content: space-between; margin-top: 10px; font-size: 14px; color: var(--grey); }
.ir figcaption b { color: var(--navy); }

/* certifications */
.certs { display: flex; flex-wrap: wrap; gap: 12px; }
.cert { display: inline-flex; align-items: center; gap: 10px; padding: 12px 18px; border: 1px solid var(--line); border-radius: 12px; font-weight: 600; }
.cert i { width: 10px; height: 10px; border-radius: 50%; background: var(--mint); }

/* insights */
.insights { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.post { padding: 26px; display: flex; flex-direction: column; gap: 10px; transition: border-color .2s; }
.post:hover { border-color: var(--teal); }
.post .meta { font-size: 13px; color: var(--grey); }
.post h3 { font-size: 20px; }
.post .more { margin-top: auto; color: var(--teal); font-weight: 600; font-size: 15px; }

/* page head */
.page-head { background: var(--mist); padding: clamp(48px, 7vw, 100px) 0 clamp(40px, 5vw, 72px); }
.page-head h1 { font-size: clamp(42px, 6vw, 88px); letter-spacing: -0.045em; line-height: 1.02; }
.page-head h1 em { color: var(--teal); }
.page-head p { max-width: 58ch; color: var(--grey); font-size: 19px; margin-top: 18px; }
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin: 40px 0; }
.filters button { font: 600 15px var(--font-sans); padding: 10px 16px; border-radius: 999px; border: 1px solid var(--line); background: #fff; color: var(--grey); cursor: pointer; }
.filters button:hover { color: var(--navy); }
.filters button[aria-pressed="true"] { background: var(--navy); border-color: var(--navy); color: #fff; }
.cases { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px 20px; }
.case-card { display: flex; flex-direction: column; gap: 10px; }
.case-card h3 { font-size: 21px; }
.case-card p { margin: 0; color: var(--grey); font-size: 15px; }
.case-card .result { font-weight: 700; color: var(--teal); font-size: 15px; }
.case-card[hidden] { display: none; }

/* case study */
.metrics-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.metric { padding: 22px; }
.metric span { font-size: 13px; color: var(--grey); font-weight: 600; }
.metric b { display: block; font-size: 30px; letter-spacing: -0.03em; margin-top: 4px; }
.metric small { color: var(--teal); font-weight: 600; }
.compare-table { width: 100%; border-collapse: collapse; }
.compare-table th, .compare-table td { padding: 14px 12px; border-bottom: 1px solid var(--line); text-align: left; font-size: 15px; }
.compare-table th { font-size: 13px; color: var(--grey); text-transform: uppercase; letter-spacing: .06em; }
.compare-table td:last-child { color: var(--teal); font-weight: 700; }
.table-wrap { overflow-x: auto; }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 5vw, 72px); align-items: center; }
.quote { font-family: var(--font-serif); font-style: italic; font-size: clamp(24px, 2.8vw, 36px); line-height: 1.3; }

/* about */
.team { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.member img { width: 100%; aspect-ratio: 1; border-radius: var(--radius); object-fit: cover; background: var(--mist); }
.member h3 { font-size: 19px; margin-top: 14px; }
.member p { margin: 2px 0 0; color: var(--grey); font-size: 14px; }

/* process */
.process { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; counter-reset: p; }
.process li { counter-increment: p; padding: 26px; }
.process li::before { content: "0" counter(p); font-weight: 700; color: var(--teal); font-size: 14px; display: block; margin-bottom: 14px; }
.process h3 { font-size: 20px; margin-bottom: 8px; }
.process p { color: var(--grey); font-size: 15px; margin: 0; }
.faq { max-width: 860px; display: grid; gap: 10px; }
.faq details { padding: 20px 24px; }
.faq summary { cursor: pointer; list-style: none; display: block; position: relative; padding-right: 36px; font-weight: 600; font-size: 17px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 0; top: -2px; width: 26px; height: 26px; border-radius: 8px; background: var(--mist); display: grid; place-items: center; color: var(--teal); transition: transform .3s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin: 12px 0 0; color: var(--grey); }

/* contact */
.contact { display: grid; grid-template-columns: 7fr 5fr; gap: var(--gutter); align-items: start; }
.form-card { padding: clamp(24px, 3.4vw, 40px); }
.form { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field--full { grid-column: 1 / -1; }
.field label { font-size: 14px; font-weight: 600; }
.field input, .field select, .field textarea { font: 400 16px var(--font-sans); color: var(--navy); background: var(--mist); border: 1px solid transparent; border-radius: 10px; padding: 13px 14px; appearance: none; }
.field textarea { min-height: 130px; resize: vertical; }
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--teal); background: #fff; }
.form-note { grid-column: 1 / -1; background: #e3f6f3; color: var(--teal); border-radius: 10px; padding: 14px 16px; margin: 0; font-weight: 600; }
.aside { padding: 28px; background: var(--navy); color: #fff; border: 0; }
.aside h3 { font-size: 22px; margin-bottom: 10px; }
.aside ul { margin: 0 0 18px; padding-left: 18px; color: #b9c9cd; }

/* 6. Footer ---------------------------------------------------------------- */
.site-footer { background: var(--navy); color: #fff; margin-top: var(--space); padding: clamp(64px, 8vw, 110px) 0 28px; }
.f-top { display: flex; justify-content: space-between; align-items: end; gap: 24px; flex-wrap: wrap; padding-bottom: 48px; border-bottom: 1px solid rgba(255, 255, 255, .1); }
.f-top h2 { font-size: clamp(30px, 4vw, 54px); max-width: 18ch; }
.f-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.4fr; gap: var(--gutter); padding: 44px 0 30px; font-size: 15px; }
.f-grid .logo { color: #fff; margin-bottom: 10px; }
.f-dim { color: #9fb6bb; }
.f-grid a:hover { color: var(--mint); }
.f-base { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; font-size: 13px; color: #7f989e; border-top: 1px solid rgba(255, 255, 255, .1); padding-top: 22px; }

/* 7. Responsive ------------------------------------------------------------ */
@media (max-width: 1080px) {
  .svc-grid, .insights, .cases { grid-template-columns: repeat(2, 1fr); }
  .kpis, .metrics-row, .team, .process { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 860px) {
  body { font-size: 16px; }
  .menu-btn { display: inline-block; background: var(--mist); border: 0; border-radius: 10px; padding: 11px 18px; font: 600 15px var(--font-sans); color: var(--navy); cursor: pointer; position: relative; z-index: 60; }
  .site-nav { position: fixed; inset: 0; z-index: 55; background: #fff; flex-direction: column; align-items: stretch; justify-content: center; padding: 0 var(--gutter); gap: 6px; opacity: 0; visibility: hidden; transition: opacity .3s, visibility .3s; }
  .site-nav a { font-size: 30px; font-weight: 700; color: var(--navy); letter-spacing: -0.03em; padding: 10px 0; }
  .site-nav .nav-cta { margin-top: 16px; text-align: center; font-size: 20px; }
  .menu-open .site-nav { opacity: 1; visibility: visible; }
  .menu-open { overflow: hidden; }
  .hero-grid, .ir, .two, .contact, .form { grid-template-columns: 1fr; }
  .scorecard { left: 12px; right: 12px; bottom: -48px; }
  .hero-visual { margin-bottom: 56px; }
  .f-grid { grid-template-columns: 1fr 1fr; }
  .f-grid > :first-child { grid-column: 1 / -1; }
}
@media (max-width: 560px) {
  .svc-grid, .insights, .cases, .kpis, .metrics-row, .process { grid-template-columns: 1fr; }
  .team { grid-template-columns: 1fr 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}