/* GoGolang — Apple-inspired flat design system */

:root {
  --bg: #fbfbfd;
  --bg-alt: #f5f5f7;
  --surface: #ffffff;
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --line: rgba(0, 0, 0, 0.08);
  --line-strong: rgba(0, 0, 0, 0.12);
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --accent-soft: rgba(0, 113, 227, 0.12);
  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 24px;
  --radius-pill: 980px;
  --shadow-soft: 0 4px 24px rgba(0, 0, 0, 0.06);
  --header-h: 52px;
  --container: 1080px;
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "Segoe UI", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.47059;
  letter-spacing: -0.022em;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 200;
  padding: 0.75rem 1rem;
  background: var(--text);
  color: #fff;
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

.container {
  width: min(100% - 40px, var(--container));
  margin-inline: auto;
}

.hide-sm {
  display: none;
}

@media (min-width: 768px) {
  .hide-sm {
    display: inline;
  }
}

/* Header — glass, flat */
.header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(251, 251, 253, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.header--scrolled {
  background: rgba(251, 251, 253, 0.92);
  box-shadow: 0 1px 0 var(--line);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand__mark {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--text);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.brand__text {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.brand__muted {
  font-weight: 400;
  color: var(--text-secondary);
}

.nav {
  display: none;
  align-items: center;
  gap: 28px;
}

@media (min-width: 900px) {
  .nav {
    display: flex;
  }
}

.nav__link {
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.nav__link:hover {
  color: var(--text);
  text-decoration: none;
}

.header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.header__cta {
  display: none;
}

@media (min-width: 640px) {
  .header__cta {
    display: inline-flex;
  }
}

.menu-btn {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 40px;
  height: 40px;
  padding: 0;
  border: none;
  border-radius: 10px;
  background: transparent;
  cursor: pointer;
}

@media (min-width: 900px) {
  .menu-btn {
    display: none;
  }
}

.menu-btn__bar {
  display: block;
  width: 18px;
  height: 2px;
  margin-inline: auto;
  background: var(--text);
  border-radius: 1px;
  transition: transform 0.25s var(--ease), opacity 0.25s var(--ease);
}

.menu-btn[aria-expanded="true"] .menu-btn__bar:first-child {
  transform: translateY(4px) rotate(45deg);
}

.menu-btn[aria-expanded="true"] .menu-btn__bar:last-child {
  transform: translateY(-4px) rotate(-45deg);
}

.mobile-nav {
  position: fixed;
  top: var(--header-h);
  left: 0;
  right: 0;
  padding: 20px 20px 28px;
  background: rgba(251, 251, 253, 0.96);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--line);
}

.mobile-nav[hidden] {
  display: none;
}

.mobile-nav__links {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.mobile-nav__links a {
  padding: 12px 4px;
  font-size: 17px;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
}

.mobile-nav__links a:hover {
  color: var(--accent);
}

.mobile-nav__links .btn {
  margin-top: 12px;
  justify-content: center;
}

/* Buttons — flat Apple pills */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 11px 22px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.01em;
  border-radius: var(--radius-pill);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), transform 0.15s var(--ease);
}

.btn:active {
  transform: scale(0.98);
}

.btn--primary {
  background: var(--accent);
  color: #fff;
}

.btn--primary:hover {
  background: var(--accent-hover);
  text-decoration: none;
  color: #fff;
}

.btn--ghost {
  background: transparent;
  color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--line-strong);
}

.btn--ghost:hover {
  background: var(--surface);
  text-decoration: none;
}

.btn--sm {
  padding: 8px 16px;
  font-size: 13px;
}

.btn--block {
  width: 100%;
}

/* Hero */
.hero {
  position: relative;
  padding: calc(var(--header-h) + 56px) 0 80px;
  overflow: hidden;
}

@media (min-width: 900px) {
  .hero {
    padding-bottom: 100px;
  }
}

.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
  opacity: 0.55;
}

.hero__glow--a {
  width: 420px;
  height: 420px;
  top: -80px;
  right: -120px;
  background: radial-gradient(circle, rgba(0, 113, 227, 0.35), transparent 70%);
}

.hero__glow--b {
  width: 360px;
  height: 360px;
  bottom: -100px;
  left: -80px;
  background: radial-gradient(circle, rgba(90, 200, 250, 0.3), transparent 70%);
}

.hero__content {
  position: relative;
  text-align: center;
}

@media (min-width: 900px) {
  .hero__content {
    text-align: left;
    max-width: 720px;
  }
}

.eyebrow {
  margin: 0 0 16px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-tertiary);
}

.hero__title {
  margin: 0;
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
}

.text-gradient {
  background: linear-gradient(90deg, #0071e3 0%, #5ac8fa 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__lead {
  margin: 20px auto 0;
  max-width: 540px;
  font-size: 19px;
  line-height: 1.5;
  color: var(--text-secondary);
}

@media (min-width: 900px) {
  .hero__lead {
    margin-left: 0;
  }
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-top: 32px;
}

@media (min-width: 900px) {
  .hero__actions {
    justify-content: flex-start;
  }
}

.hero__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 56px 0 0;
  padding: 24px 0 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.hero__stats li {
  text-align: center;
}

@media (min-width: 900px) {
  .hero__stats li {
    text-align: left;
  }
}

.hero__stat-label {
  display: block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-tertiary);
}

.hero__stat-value {
  display: block;
  margin-top: 4px;
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

/* Sections */
.section {
  padding: 72px 0;
}

@media (min-width: 900px) {
  .section {
    padding: 96px 0;
  }
}

.section--alt {
  background: var(--bg-alt);
}

.section__head {
  max-width: 560px;
  margin-bottom: 48px;
}

.section__title {
  margin: 0;
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.section__subtitle {
  margin: 12px 0 0;
  font-size: 19px;
  color: var(--text-secondary);
  line-height: 1.45;
}

/* Bento grid — flat tiles */
.bento {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .bento {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .bento {
    grid-template-columns: repeat(3, 1fr);
  }
}

.tile {
  padding: 28px;
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.tile:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.tile--wide {
  grid-column: 1 / -1;
}

@media (min-width: 900px) {
  .tile--wide {
    grid-column: span 2;
  }
}

.tile__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  margin-bottom: 16px;
  border-radius: var(--radius-sm);
  background: var(--bg-alt);
  color: var(--text);
}

.tile__title {
  margin: 0;
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.tile__text {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.5;
  color: var(--text-secondary);
}

/* About */
.about {
  display: grid;
  gap: 32px;
  align-items: start;
}

@media (min-width: 900px) {
  .about {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 48px;
  }
}

.prose {
  margin: 16px 0 0;
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.55;
}

.prose--muted {
  color: var(--text-tertiary);
}

.panel {
  padding: 32px;
  background: var(--text);
  color: #f5f5f7;
  border-radius: var(--radius-lg);
}

.panel__quote {
  margin: 0;
  font-size: 22px;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

.panel__list {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.panel__list li {
  position: relative;
  padding-left: 22px;
  margin-top: 12px;
  font-size: 15px;
  color: rgba(245, 245, 247, 0.85);
}

.panel__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

/* Steps */
.steps {
  display: grid;
  gap: 20px;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 768px) {
  .steps {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .steps {
    grid-template-columns: repeat(4, 1fr);
  }
}

.step {
  padding: 24px;
  background: var(--surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
}

.step__index {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--accent);
}

.step__title {
  margin: 12px 0 0;
  font-size: 17px;
  font-weight: 600;
}

.step__text {
  margin: 8px 0 0;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Contact */
.contact-card {
  display: grid;
  gap: 40px;
  padding: 32px;
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-soft);
}

@media (min-width: 900px) {
  .contact-card {
    grid-template-columns: 1fr 1fr;
    padding: 48px;
    gap: 56px;
  }
}

.contact-email {
  margin: 20px 0 0;
}

.contact-email__link {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--accent);
  text-decoration: none;
}

.contact-email__link:hover {
  text-decoration: underline;
}

.contact-meta {
  margin: 28px 0 0;
}

.contact-meta div {
  margin-top: 16px;
}

.contact-meta dt {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
}

.contact-meta dd {
  margin: 4px 0 0;
  font-size: 17px;
}

.form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.field__label {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.field__optional {
  font-weight: 400;
  color: var(--text-tertiary);
}

.field__input {
  width: 100%;
  padding: 12px 14px;
  font: inherit;
  font-size: 16px;
  color: var(--text);
  background: var(--bg-alt);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s, background 0.2s;
}

.field__input:focus {
  background: var(--surface);
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.field__input--area {
  resize: vertical;
  min-height: 120px;
}

.form__status {
  margin: 0;
  font-size: 14px;
}

.form__status[data-type="error"] {
  color: #d70015;
}

.form__status[data-type="ok"] {
  color: #248a3d;
}

.form__hint {
  margin: 0;
  font-size: 12px;
  color: var(--text-tertiary);
  line-height: 1.4;
}

/* Footer */
.footer {
  padding: 48px 0 32px;
  background: var(--bg-alt);
  border-top: 1px solid var(--line);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

@media (min-width: 640px) {
  .footer__inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }
}

.footer__brand {
  margin: 0;
  font-size: 14px;
  font-weight: 600;
}

.footer__tagline {
  margin: 6px 0 0;
  font-size: 14px;
  color: var(--text-secondary);
}

.footer__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.footer__nav a {
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
}

.footer__nav a:hover {
  color: var(--text);
}

.footer__legal {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  color: var(--text-tertiary);
}

.section__head--center {
  margin-inline: auto;
  text-align: center;
}

.section__head--center .section__subtitle {
  margin-inline: auto;
}

/* Trust strip */
.trust {
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}

.trust__inner {
  text-align: center;
}

@media (min-width: 768px) {
  .trust__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    text-align: left;
  }
}

.trust__label {
  margin: 0 0 16px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-tertiary);
  letter-spacing: -0.01em;
}

@media (min-width: 768px) {
  .trust__label {
    margin: 0;
    flex-shrink: 0;
  }
}

.trust__pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 768px) {
  .trust__pills {
    justify-content: flex-end;
  }
}

.trust__pills li {
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-alt);
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
}

/* Industries */
.industry-grid {
  display: grid;
  gap: 16px;
}

@media (min-width: 640px) {
  .industry-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .industry-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.industry {
  padding: 24px;
  background: var(--surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  transition: border-color 0.2s var(--ease);
}

.industry:hover {
  border-color: var(--line-strong);
}

.industry__title {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.industry__text {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-secondary);
}

/* Why us */
.why-grid {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 640px) {
  .why-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .why-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.why-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 22px;
  background: var(--surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
}

.why-card__title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.why-card__text {
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-secondary);
  font-weight: 400;
}

/* Testimonials */
.quotes {
  display: grid;
  gap: 20px;
}

@media (min-width: 900px) {
  .quotes {
    grid-template-columns: repeat(3, 1fr);
  }
}

.quote {
  margin: 0;
  padding: 28px;
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
}

.quote__text {
  margin: 0;
  font-size: 16px;
  line-height: 1.55;
  color: var(--text);
  letter-spacing: -0.01em;
}

.quote__text::before {
  content: "“";
  color: var(--accent);
}

.quote__cite {
  margin-top: 20px;
  font-size: 13px;
  color: var(--text-tertiary);
  font-style: normal;
}

.quote__name {
  font-weight: 600;
  color: var(--text-secondary);
}

/* Tech stack */
.stack__groups {
  display: grid;
  gap: 20px;
}

@media (min-width: 768px) {
  .stack__groups {
    grid-template-columns: repeat(2, 1fr);
  }
}

.stack__group {
  padding: 22px 24px;
  background: var(--surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
}

.stack__label {
  margin: 0;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-tertiary);
}

.stack__items {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.5;
  color: var(--text-secondary);
}

/* FAQ */
.faq-wrap {
  max-width: 720px;
}

.faq {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.faq__item {
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: var(--surface);
  overflow: hidden;
}

.faq__item[open] {
  border-color: var(--line-strong);
}

.faq__question {
  padding: 18px 20px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.02em;
  cursor: pointer;
  list-style: none;
}

.faq__question::-webkit-details-marker {
  display: none;
}

.faq__question::after {
  content: "+";
  float: right;
  font-size: 20px;
  font-weight: 400;
  color: var(--accent);
  line-height: 1;
}

.faq__item[open] .faq__question::after {
  content: "−";
}

.faq__answer {
  margin: 0;
  padding: 0 20px 18px;
  font-size: 15px;
  line-height: 1.55;
  color: var(--text-secondary);
}

/* CTA band */
.cta-band {
  padding: 56px 0;
  background: linear-gradient(180deg, var(--bg-alt) 0%, var(--bg) 100%);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.cta-band__inner {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 24px;
  padding: 40px;
  background: var(--text);
  color: #f5f5f7;
  border-radius: var(--radius-lg);
}

@media (min-width: 768px) {
  .cta-band__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
  }
}

.cta-band__title {
  margin: 0;
  font-size: clamp(1.35rem, 2.5vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.cta-band__text {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.5;
  color: rgba(245, 245, 247, 0.75);
  max-width: 420px;
}

.cta-band .btn--primary {
  flex-shrink: 0;
  background: #fff;
  color: var(--text);
}

.cta-band .btn--primary:hover {
  background: #f5f5f7;
  color: var(--text);
}

.btn--lg {
  padding: 14px 28px;
  font-size: 15px;
}

/* Motion */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.8s var(--ease) forwards;
}

.reveal:nth-child(2) { animation-delay: 0.06s; }
.reveal:nth-child(3) { animation-delay: 0.12s; }
.reveal:nth-child(4) { animation-delay: 0.18s; }
.reveal:nth-child(5) { animation-delay: 0.24s; }
.reveal:nth-child(6) { animation-delay: 0.3s; }

@keyframes fadeUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.reveal-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal,
  .reveal-on-scroll {
    opacity: 1;
    transform: none;
    animation: none;
    transition: none;
  }
}