/* ============================================================
   CarbonTradeX — style.css
   Premium climate-tech advisory site
   Fonts: Cabinet Grotesk (display) + Satoshi (body) from Fontshare
   Accent: #10b981 (emerald green)
   ============================================================ */

/* --- Fonts --- */
@import url('https://api.fontshare.com/v2/css?f[]=cabinet-grotesk@100,200,300,400,500,600,700,800,900&f[]=satoshi@300,400,500,600,700&display=swap');

/* --- Design Tokens --- */
:root {
  /* Typography */
  --font-display: 'Cabinet Grotesk', 'Helvetica Neue', Arial, sans-serif;
  --font-body: 'Satoshi', 'Helvetica Neue', Arial, sans-serif;

  /* Type Scale (fluid) */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);
  --text-hero: clamp(3rem,     0.5rem  + 7vw,    8rem);

  /* Spacing (4px base) */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Colors — Light theme (white/clean) */
  --color-bg:       #ffffff;
  --color-surface:  #f8f9fa;
  --color-surface-2:#f1f3f5;
  --color-border:   #e1e4e8;
  --color-text:     #111111;
  --color-text-muted:#5c6370;
  --color-text-faint:#9ca3af;
  --color-accent:   #10b981;
  --color-accent-hover: #059669;
  --color-accent-light: rgba(16, 185, 129, 0.08);
  --color-accent-medium: rgba(16, 185, 129, 0.15);

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;
  --radius-full: 9999px;

  /* Shadows (light mode) */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.08);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.1);

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-fast: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-mid: 300ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 500ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-narrow: 720px;
  --content-default: 1040px;
  --content-wide: 1280px;
}

/* ============================================================
   GLOBAL LAYOUT
   ============================================================ */

.container {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

@media (min-width: 768px) {
  .container { padding-inline: var(--space-8); }
}

@media (min-width: 1024px) {
  .container { padding-inline: var(--space-12); }
}

/* ============================================================
   HEADER
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-mid), box-shadow var(--transition-mid);
}

.site-header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo-link {
  display: flex;
  align-items: center;
  text-decoration: none;
  gap: var(--space-2);
}

/* Logo wordmark */
.logo-wordmark {
  display: inline-flex;
  align-items: baseline;
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 1rem + 0.5vw, 1.35rem);
  letter-spacing: 0.04em;
  color: var(--color-text);
  line-height: 1;
  white-space: nowrap;
  user-select: none;
}

.logo-carbon {
  font-weight: 400;
}

.logo-trade {
  font-weight: 700;
}

.logo-x {
  font-weight: 800;
  position: relative;
  display: inline-block;
}

.logo-arrow {
  position: absolute;
  top: -8px;
  right: -4px;
  width: 10px;
  height: 12px;
  display: block;
  color: var(--color-text);
}

.footer-logo-wordmark {
  color: #fff;
  font-size: 1.2rem;
}

.footer-logo-wordmark .logo-arrow {
  color: #fff;
}

.nav-desktop {
  display: none;
  align-items: center;
  gap: var(--space-8);
}

@media (min-width: 768px) {
  .nav-desktop { display: flex; }
}

.nav-desktop a {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  letter-spacing: -0.01em;
  transition: color var(--transition-fast);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: var(--text-sm);
  text-decoration: none;
  border-radius: var(--radius-full);
  padding: 0.65em 1.5em;
  transition: all var(--transition-fast);
  cursor: pointer;
  white-space: nowrap;
  line-height: 1.4;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border: 2px solid var(--color-accent);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(16, 185, 129, 0.25);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: none;
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.7);
}

.btn-outline-dark {
  background: transparent;
  color: var(--color-text);
  border: 2px solid var(--color-border);
}

.btn-outline-dark:hover {
  border-color: var(--color-text);
  background: var(--color-surface);
}

.header-btn {
  padding: 0.5em 1.4em;
  font-size: var(--text-xs);
}

/* Mobile hamburger */
.hamburger {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 28px;
  padding: 4px 0;
  cursor: pointer;
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-mid);
}

.hamburger.active span:first-child {
  transform: translateY(7px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:last-child {
  transform: translateY(-7px) rotate(-45deg);
}

@media (min-width: 768px) {
  .hamburger { display: none; }
}

.initiative-tag {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
  opacity: 0.8;
  transition: opacity var(--transition-fast);
}

.initiative-tag:hover {
  opacity: 1;
}

.initiative-tag-text {
  font-family: var(--font-body);
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
}

.initiative-tag img {
  height: 18px;
  width: auto;
}

.logo-container {
  display: flex;
  flex-direction: column;
}

/* Mobile menu */
.mobile-menu {
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  height: calc(100vh - 72px);
  height: calc(100dvh - 72px);
  background: #ffffff;
  display: flex;
  flex-direction: column;
  padding: var(--space-8) var(--space-6);
  gap: var(--space-6);
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-8px);
  transition: opacity var(--transition-mid), transform var(--transition-mid);
  overflow-y: auto;
}

.mobile-menu.active {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}

.mobile-menu a {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
}

/* ============================================================
   HERO SECTION
   ============================================================ */

.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(0, 0, 0, 0.45) 0%,
    rgba(0, 0, 0, 0.55) 50%,
    rgba(0, 0, 0, 0.7) 100%
  );
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 780px;
  padding: var(--space-32) 0 var(--space-16);
}

.hero h1 {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: var(--space-6);
}

.hero-subtitle {
  font-family: var(--font-body);
  font-size: var(--text-lg);
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.6;
  max-width: 580px;
  margin-bottom: var(--space-10);
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

/* ============================================================
   TRUST BAR
   ============================================================ */

.trust-bar {
  background: var(--color-surface-2);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-6) 0;
  overflow: hidden;
}

.trust-bar-label {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  text-align: center;
  margin-bottom: var(--space-4);
}

.trust-logos {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-6);
}

@media (min-width: 768px) {
  .trust-logos { gap: var(--space-12); }
}

.trust-logo {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text-muted);
  letter-spacing: 0.06em;
  white-space: nowrap;
  opacity: 0.65;
}

.trust-divider {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--color-text-faint);
  flex-shrink: 0;
}

@media (max-width: 640px) {
  .trust-divider { display: none; }
  .trust-logos { gap: var(--space-4) var(--space-6); }
}

/* ============================================================
   ABOUT / VALUE PROP
   ============================================================ */

.about {
  padding: clamp(var(--space-16), 8vw, var(--space-32)) 0;
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  align-items: center;
}

@media (min-width: 768px) {
  .about-grid {
    grid-template-columns: 1.1fr 1fr;
    gap: var(--space-16);
  }
}

.about-image-wrapper {
  position: relative;
  border-radius: var(--radius-2xl);
  overflow: hidden;
  aspect-ratio: 4/3;
}

.about-image-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.about-image-accent {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--color-accent);
}

.about-eyebrow {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: var(--space-4);
}

.about h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.025em;
  margin-bottom: var(--space-6);
}

.about-text {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-8);
}

.differentiators {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-5);
}

.differentiator {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
}

.differentiator-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-lg);
  background: var(--color-accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.differentiator-icon svg {
  width: 20px;
  height: 20px;
  color: var(--color-accent);
}

.differentiator-label {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.4;
}

@media (max-width: 480px) {
  .differentiators { grid-template-columns: 1fr; }
}

/* ============================================================
   HOW IT WORKS
   ============================================================ */

.how-it-works {
  padding: clamp(var(--space-16), 8vw, var(--space-32)) 0;
  background: var(--color-surface);
}

.section-header {
  text-align: center;
  margin-bottom: clamp(var(--space-10), 5vw, var(--space-16));
}

.section-eyebrow {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: var(--space-3);
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.025em;
}

.steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  max-width: var(--content-default);
  margin-inline: auto;
}

@media (min-width: 768px) {
  .steps { grid-template-columns: repeat(3, 1fr); gap: var(--space-10); }
}

.step {
  position: relative;
  background: var(--color-bg);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  border: 1px solid var(--color-border);
  transition: box-shadow var(--transition-mid), transform var(--transition-mid);
}

.step:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.step-number {
  font-family: var(--font-display);
  font-size: clamp(3rem, 6vw, 5rem);
  font-weight: 800;
  color: var(--color-accent);
  opacity: 0.15;
  line-height: 1;
  margin-bottom: var(--space-4);
}

.step h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  letter-spacing: -0.015em;
}

.step p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
}

/* ============================================================
   SOLUTIONS GRID
   ============================================================ */

.solutions {
  position: relative;
  padding: clamp(var(--space-16), 8vw, var(--space-32)) 0;
  overflow: hidden;
}

.solutions-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.solutions-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.solutions-bg-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(0, 0, 0, 0.82) 0%,
    rgba(0, 0, 0, 0.88) 100%
  );
}

.solutions .container {
  position: relative;
  z-index: 2;
}

.solutions .section-header {
  margin-bottom: clamp(var(--space-10), 5vw, var(--space-16));
}

.solutions .section-eyebrow {
  color: var(--color-accent);
}

.solutions .section-title {
  color: #fff;
}

.solutions-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

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

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

.solution-card {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background var(--transition-mid), border-color var(--transition-mid), transform var(--transition-mid);
}

.solution-card:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-3px);
}

.solution-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  background: rgba(16, 185, 129, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-5);
}

.solution-icon svg {
  width: 24px;
  height: 24px;
  color: var(--color-accent);
}

.solution-card h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-2);
  letter-spacing: -0.015em;
}

.solution-card .solution-type {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.04em;
  margin-bottom: var(--space-4);
}

.solution-card p {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.6;
}

/* ============================================================
   TESTIMONIAL
   ============================================================ */

.testimonial {
  padding: clamp(var(--space-16), 8vw, var(--space-32)) 0;
  background: var(--color-bg);
}

.testimonial-inner {
  max-width: var(--content-default);
  margin-inline: auto;
  display: flex;
  gap: var(--space-8);
}

.testimonial-accent {
  width: 4px;
  flex-shrink: 0;
  background: var(--color-accent);
  border-radius: var(--radius-full);
}

.testimonial-content {
  flex: 1;
}

.testimonial blockquote {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.45;
  letter-spacing: -0.015em;
  margin-bottom: var(--space-6);
}

.testimonial blockquote::before {
  content: '\201C';
  display: inline;
}

.testimonial blockquote::after {
  content: '\201D';
  display: inline;
}

.testimonial-attribution {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-weight: 500;
}

.testimonial-attribution span {
  color: var(--color-accent);
  font-weight: 600;
}

/* ============================================================
   CTA SECTION
   ============================================================ */

.cta-section {
  padding: clamp(var(--space-16), 8vw, var(--space-32)) 0;
  background: var(--color-surface);
  text-align: center;
}

.cta-inner {
  max-width: 640px;
  margin-inline: auto;
}

.cta-section h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.025em;
  margin-bottom: var(--space-5);
}

.cta-section p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-8);
  margin-inline: auto;
}

.cta-section .btn-primary {
  font-size: var(--text-base);
  padding: 0.85em 2.5em;
}

/* ============================================================
   FOOTER
   ============================================================ */

.site-footer {
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-16) 0 var(--space-8);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}

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

.footer-brand-desc {
  font-size: var(--text-sm);
  line-height: 1.7;
  max-width: 280px;
  margin-top: var(--space-4);
}

.footer-column h4 {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-4);
  letter-spacing: -0.01em;
}

.footer-column ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-column a {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.5);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-column a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-6);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
}

.footer-copyright {
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.35);
}

.footer-part-of {
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.35);
}

.footer-part-of a {
  text-decoration: none;
}

.footer-part-of span {
  color: var(--color-accent);
  transition: opacity var(--transition-fast);
}

.footer-initiative {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
}

.footer-initiative img {
  height: 32px;
  width: auto;
}

.footer-initiative-text {
  font-size: var(--text-xs);
  font-weight: 600;
  color: rgba(255, 255, 255, 0.4);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-part-of a:hover span {
  opacity: 0.8;
}



/* ============================================================
   SCROLL REVEAL ANIMATIONS
   ============================================================ */

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ============================================================
   RESPONSIVE REFINEMENTS
   ============================================================ */

@media (max-width: 767px) {
  .hero { min-height: 80vh; }
  .hero-content { padding: var(--space-24) 0 var(--space-12); }
  .hero h1 { font-size: clamp(2rem, 8vw, 3rem); }
  .hero-subtitle { font-size: var(--text-base); }

  .about-grid { gap: var(--space-8); }
  .about h2 { font-size: clamp(1.5rem, 5vw, 2.25rem); }

  .testimonial-inner { flex-direction: column; gap: 0; }
  .testimonial-accent {
    width: 100%;
    height: 4px;
    margin-bottom: var(--space-6);
  }
  .testimonial blockquote { font-size: var(--text-lg); }
}

/* Ensure images don't break layout */
img {
  max-width: 100%;
  height: auto;
}