/* ══════════════════════════════════════════════
   nFOLD — Stylesheet (Apple-inspired)
   ══════════════════════════════════════════════ */

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

/* ── Tokens ── */
:root {
  --bg:            #ffffff;
  --bg-alt:        #f5f5f7;
  --text:          #1d1d1f;
  --text-2:        #6e6e73;
  --text-3:        #86868b;
  --border:        #d2d2d7;
  --border-light:  #e8e8ed;
  --nav-h:         52px;
  --radius-sm:     8px;
  --radius:        16px;
  --max-w:         980px;
  --max-w-wide:    1200px;
  --ease:          cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Base ── */
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 17px;
  line-height: 1.47;
  color: var(--text);
  background: var(--bg);
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ── Layout ── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 13px 28px;
  border-radius: 980px;
  font-family: inherit;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: -0.01em;
  cursor: pointer;
  border: none;
  transition: background 0.2s var(--ease), opacity 0.2s var(--ease);
  white-space: nowrap;
  text-decoration: none;
}
.btn--primary {
  background: var(--text);
  color: #fff;
}
.btn--primary:hover { background: #424245; }
.btn--ghost {
  background: transparent;
  color: var(--text);
  border: 1.5px solid var(--border);
}
.btn--ghost:hover { background: var(--bg-alt); }
.btn--full {
  width: 100%;
  justify-content: center;
  border-radius: var(--radius-sm);
  padding: 15px;
}

/* ══════════════════════════════════════════════
   NAV
   ══════════════════════════════════════════════ */
.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease);
}
.nav.scrolled { border-bottom-color: var(--border-light); }

.nav__inner {
  max-width: var(--max-w-wide);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.nav__logo-img {
  height: 32px;
  width: auto;
  display: block;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav__link {
  font-size: 13px;
  color: var(--text-2);
  padding: 6px 12px;
  border-radius: 6px;
  transition: color 0.2s;
}
.nav__link:hover { color: var(--text); }

.nav__cta {
  font-size: 13px;
  font-weight: 500;
  color: #0071e3;
  padding: 6px 12px;
  transition: opacity 0.2s;
}
.nav__cta:hover { opacity: 0.7; }

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav__toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s var(--ease), opacity 0.25s;
}
.nav__toggle[aria-expanded="true"] span:first-child {
  transform: translateY(6.5px) rotate(45deg);
}
.nav__toggle[aria-expanded="true"] span:last-child {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* ══════════════════════════════════════════════
   HERO
   ══════════════════════════════════════════════ */
.hero {
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-h) + 80px) 24px 100px;
  background: var(--bg);
}

.hero__content {
  max-width: 760px;
  animation: heroIn 0.8s var(--ease) both;
}

@keyframes heroIn {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: none; }
}

.hero__eyebrow {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 20px;
}

.hero__title {
  font-size: clamp(40px, 6.5vw, 72px);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 24px;
}

.hero__desc {
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.55;
  color: var(--text-2);
  margin-bottom: 40px;
}

.hero__ctas {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ══════════════════════════════════════════════
   SECTIONS
   ══════════════════════════════════════════════ */
.section { padding: 100px 0; }
.section--alt { background: var(--bg-alt); }

.section__header {
  text-align: center;
  max-width: 620px;
  margin: 0 auto 64px;
}

.section__eyebrow {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 14px;
}

.section__title {
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.06;
  color: var(--text);
  margin-bottom: 16px;
}

.section__subtitle {
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-2);
}

/* ══════════════════════════════════════════════
   SERVICE CARDS
   ══════════════════════════════════════════════ */
.services__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.card {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 40px 36px;
  border: 1px solid var(--border-light);
  transition: box-shadow 0.3s var(--ease), transform 0.3s var(--ease);
}
.card:hover {
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.07);
  transform: translateY(-3px);
}

.card__number {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 20px;
}

.card__title {
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text);
  margin-bottom: 14px;
}

.card__desc {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-2);
  margin-bottom: 28px;
}

.card__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.card__list li {
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-2);
  padding-left: 16px;
  position: relative;
}
.card__list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--border);
}

/* Card reveal stagger */
.services__grid .card:nth-child(2) { transition-delay: 0.08s; }
.services__grid .card:nth-child(3) { transition-delay: 0.16s; }

/* ══════════════════════════════════════════════
   METHODOLOGY STEPS
   ══════════════════════════════════════════════ */
.steps__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}

.step {
  padding: 28px 40px 0 0;
  border-top: 1px solid var(--border-light);
}
.step + .step { border-left: none; }

.step__number {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 16px;
}

.step__title {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 12px;
}

.step__desc {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-2);
}

/* Step reveal stagger */
.steps__grid .step:nth-child(2) { transition-delay: 0.06s; }
.steps__grid .step:nth-child(3) { transition-delay: 0.12s; }
.steps__grid .step:nth-child(4) { transition-delay: 0.18s; }

/* ══════════════════════════════════════════════
   ABOUT
   ══════════════════════════════════════════════ */
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: start;
}

.about__text p {
  font-size: 17px;
  line-height: 1.7;
  color: var(--text-2);
  margin-bottom: 20px;
}
.about__text p:last-of-type { margin-bottom: 32px; }

.about__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.about__tags span {
  font-size: 13px;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 980px;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-2);
}

.about__quote {
  font-size: 20px;
  font-weight: 500;
  font-style: italic;
  line-height: 1.5;
  letter-spacing: -0.02em;
  color: var(--text);
  border-left: 2px solid var(--border);
  padding-left: 24px;
  margin-bottom: 48px;
}

.about__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.about__stats div {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.about__stats strong {
  font-size: 30px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text);
}
.about__stats span {
  font-size: 13px;
  color: var(--text-3);
}

/* ══════════════════════════════════════════════
   CONTACT
   ══════════════════════════════════════════════ */
.contact__grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 80px;
  align-items: start;
}

.contact__info {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.contact__label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 6px;
}

.contact__value {
  font-size: 16px;
  line-height: 1.5;
  color: var(--text-2);
}
a.contact__value { color: #0071e3; }
a.contact__value:hover { text-decoration: underline; }

/* ── Form ── */
.form {
  display: flex;
  flex-direction: column;
  gap: 20px;
  position: relative;
}

.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form__group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form__label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
}

.form__input,
.form__select,
.form__textarea {
  font-family: inherit;
  font-size: 15px;
  color: var(--text);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  outline: none;
  width: 100%;
  transition: border-color 0.2s, box-shadow 0.2s;
  appearance: none;
}
.form__input::placeholder,
.form__textarea::placeholder { color: var(--text-3); }
.form__input:focus,
.form__select:focus,
.form__textarea:focus {
  border-color: var(--text);
  background: var(--bg);
  box-shadow: 0 0 0 3px rgba(29, 29, 31, 0.08);
}
.form__textarea { resize: vertical; min-height: 120px; }
.form__select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='7' viewBox='0 0 12 7'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%2386868b' stroke-width='1.5' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
  cursor: pointer;
}

/* ══════════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════════ */
.footer {
  padding: 28px 0;
  background: var(--bg-alt);
  border-top: 1px solid var(--border-light);
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer__copy {
  font-size: 13px;
  color: var(--text-3);
}

.footer__nav {
  display: flex;
  gap: 24px;
}
.footer__nav a {
  font-size: 13px;
  color: var(--text-3);
  transition: color 0.2s;
}
.footer__nav a:hover { color: var(--text-2); }

/* ══════════════════════════════════════════════
   SCROLL REVEAL
   ══════════════════════════════════════════════ */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
.reveal.visible {
  opacity: 1;
  transform: none;
}

/* ══════════════════════════════════════════════
   RESPONSIVE — Tablet (≤900px)
   ══════════════════════════════════════════════ */
@media (max-width: 900px) {
  .nav__links { display: none; }
  .nav__toggle { display: flex; }

  .nav__links.open {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 32px 28px;
    gap: 4px;
    z-index: 99;
  }
  .nav__links.open .nav__link,
  .nav__links.open .nav__cta {
    font-size: 24px;
    font-weight: 500;
    letter-spacing: -0.02em;
    padding: 12px 0;
    color: var(--text);
    width: 100%;
    border-bottom: 1px solid var(--border-light);
  }
  .nav__links.open .nav__cta {
    color: #0071e3;
    border-bottom: none;
  }

  .services__grid { grid-template-columns: 1fr; gap: 12px; }
  .steps__grid { grid-template-columns: 1fr 1fr; gap: 32px 24px; }
  .step { padding: 24px 0 0; }
  .about__grid { grid-template-columns: 1fr; gap: 48px; }
  .contact__grid { grid-template-columns: 1fr; gap: 48px; }
}

/* ══════════════════════════════════════════════
   RESPONSIVE — Mobile (≤600px)
   ══════════════════════════════════════════════ */
@media (max-width: 600px) {
  .section { padding: 72px 0; }
  .section__header { margin-bottom: 48px; }

  .hero__desc br { display: none; }
  .hero__title br { display: none; }
  .hero__ctas { flex-direction: column; align-items: center; }

  .steps__grid { grid-template-columns: 1fr; gap: 28px; }
  .steps__grid .step:nth-child(n) { transition-delay: 0s; }

  .about__stats { gap: 16px; }
  .about__stats strong { font-size: 24px; }

  .form__row { grid-template-columns: 1fr; }
  .contact__info { gap: 24px; }

  .footer__inner { flex-direction: column; align-items: flex-start; gap: 12px; }
  .footer__nav { gap: 16px; flex-wrap: wrap; }
}