/* ==========================================================================
   NusTherm™ — Glass Heat Reduction Coating | A Nusfun product line
   Design tokens derived from official NusTherm brand artwork
   ========================================================================== */

:root {
  /* Brand palette (sampled from official NusTherm marketing artwork) */
  --nt-navy: #0B3D74;
  --nt-navy-dark: #082B54;
  --nt-navy-tint: #EAF1F8;
  --nt-green: #6FAE3C;
  --nt-green-dark: #558A2C;
  --nt-green-tint: #EEF6E7;
  --nt-blue-accent: #2C6FD1;

  --nt-bg: #FFFFFF;
  --nt-bg-alt: #F6F8FA;
  --nt-text: #1B2733;
  --nt-text-muted: #5B6B7A;
  --nt-border: #E3E8ED;

  --nt-font-display: "Poppins", "Segoe UI", -apple-system, BlinkMacSystemFont, sans-serif;
  --nt-font-body: "Inter", "Segoe UI", -apple-system, BlinkMacSystemFont, sans-serif;

  --nt-radius: 14px;
  --nt-radius-sm: 8px;
  --nt-shadow: 0 4px 24px rgba(11, 61, 116, 0.08);
  --nt-shadow-lg: 0 12px 40px rgba(11, 61, 116, 0.14);

  --nt-container: 1200px;
  --nt-container-wide: 1240px;
  --nt-container-xwide: 1280px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  font-family: var(--nt-font-body);
  color: var(--nt-text);
  background: var(--nt-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; object-fit: contain; }

.container {
  max-width: var(--nt-container);
  margin: 0 auto;
  padding: 0 24px;
}
.container--wide { max-width: var(--nt-container-wide); }
.container--xwide { max-width: var(--nt-container-xwide); }

h1, h2, h3, h4 {
  font-family: var(--nt-font-display);
  color: var(--nt-navy);
  line-height: 1.2;
  margin: 0 0 0.5em;
}

h1 { font-size: clamp(2rem, 4vw, 3.1rem); font-weight: 700; }
h2 { font-size: clamp(1.6rem, 3vw, 2.3rem); font-weight: 600; }
h3 { font-size: 1.25rem; font-weight: 600; }

p { margin: 0 0 1em; color: var(--nt-text-muted); }

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

.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--nt-green-dark);
  background: var(--nt-green-tint);
  padding: 5px 14px;
  border-radius: 100px;
  margin-bottom: 14px;
}

.section-head {
  max-width: 720px;
  margin: 0 auto 40px;
  text-align: center;
}
.section-head h2 { margin-bottom: 16px; }
.section-head p { font-size: 1.05rem; margin-bottom: 0; }

section { padding: 72px 0; }
.section-alt { background: var(--nt-bg-alt); }

@media (max-width: 768px) {
  .container, .container--wide, .container--xwide { padding: 0 16px; }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--nt-font-display);
  font-weight: 600;
  font-size: 0.98rem;
  padding: 14px 28px;
  border-radius: 100px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, color 0.18s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--nt-navy), var(--nt-blue-accent));
  color: #fff;
  box-shadow: var(--nt-shadow);
}
.btn-primary:hover { box-shadow: var(--nt-shadow-lg); }
.btn-secondary {
  background: transparent;
  border-color: var(--nt-navy);
  color: var(--nt-navy);
}
.btn-secondary:hover { background: var(--nt-navy); color: #fff; }
.btn-green {
  background: linear-gradient(135deg, var(--nt-green), var(--nt-green-dark));
  color: #fff;
  box-shadow: 0 4px 20px rgba(111, 174, 60, 0.3);
}

/* ==========================================================================
   Header / Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--nt-border);
}

.nav-wrap {
  max-width: var(--nt-container);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  font-family: var(--nt-font-display);
  font-weight: 700;
  font-size: 1.4rem;
  color: var(--nt-navy);
  white-space: nowrap;
}
.brand span { color: var(--nt-green); }
.brand sup { font-size: 0.55em; top: -0.9em; }

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2vw, 26px);
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  font-size: 0.93rem;
  font-weight: 500;
  color: var(--nt-text);
  transition: color 0.15s ease;
  white-space: nowrap;
}
.nav-links a:hover { color: var(--nt-navy); }

.nav-right {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nusfun-link {
  display: flex;
  align-items: center;
  gap: 8px;
  border-left: 1px solid var(--nt-border);
  padding-left: 20px;
}
.nusfun-link img { height: 38px; width: auto; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--nt-navy);
  margin: 5px 0;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

@media (max-width: 1130px) {
  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 8px 24px 16px;
    border-bottom: 1px solid var(--nt-border);
    box-shadow: var(--nt-shadow);
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.2s ease, opacity 0.2s ease;
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 12px 0; border-bottom: 1px solid var(--nt-border); }
  .nav-toggle { display: block; }
  .nav-right { gap: 10px; }
}

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  padding: 72px 0 60px;
  background: linear-gradient(180deg, var(--nt-navy-tint) 0%, #fff 70%);
  overflow: hidden;
}
.hero .container { max-width: 1400px; }
.hero-grid {
  display: grid;
  grid-template-columns: 45fr 55fr;
  gap: 56px;
  align-items: center;
}
.hero-visual { max-width: 760px; }
.hero-copy .eyebrow { }
.hero-copy p.lead {
  font-size: 1.15rem;
  color: var(--nt-text-muted);
  max-width: 540px;
}
.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
}
.hero-tags li {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--nt-navy);
  background: #fff;
  border: 1px solid #D7E3F0;
  padding: 7px 14px;
  border-radius: 100px;
}
.hero-cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 24px;
}
.hero-visual img {
  border-radius: var(--nt-radius);
  box-shadow: var(--nt-shadow-lg);
}

@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .hero { padding: 48px 0 40px; }
  .hero-visual { max-width: 100%; }
}

@media (max-width: 768px) {
  .nusfun-link img { height: 32px; }
}

/* ==========================================================================
   About
   ========================================================================== */
.about-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
  align-items: start;
}
@media (max-width: 800px) {
  .about-grid { grid-template-columns: 1fr; }
}
.about-card {
  background: var(--nt-bg-alt);
  border: 1px solid var(--nt-border);
  border-radius: var(--nt-radius);
  padding: 32px;
}

/* ==========================================================================
   Benefit cards
   ========================================================================== */
.benefit-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
@media (max-width: 1000px) {
  .benefit-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 560px) {
  .benefit-grid { grid-template-columns: 1fr; }
}
.benefit-card {
  background: #fff;
  border: 1px solid var(--nt-border);
  border-radius: var(--nt-radius);
  padding: 28px 24px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.benefit-card:hover { transform: translateY(-4px); box-shadow: var(--nt-shadow); }
.benefit-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--nt-green-tint);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--nt-green-dark);
}
.benefit-card h3 { font-size: 1.05rem; }
.benefit-card p { font-size: 0.94rem; margin-bottom: 0; }

/* ==========================================================================
   How it works / technology
   ========================================================================== */
.tech-copy { max-width: 760px; margin: 0 auto 40px; text-align: center; }
.tech-image { border-radius: var(--nt-radius); overflow: hidden; box-shadow: var(--nt-shadow-lg); }

.process-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  counter-reset: process;
}
.process-list li {
  counter-increment: process;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.86rem;
  font-weight: 500;
  color: var(--nt-text-muted);
  background: var(--nt-bg-alt);
  border: 1px solid var(--nt-border);
  padding: 8px 16px 8px 10px;
  border-radius: 100px;
}
.process-list li::before {
  content: counter(process);
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--nt-navy);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ==========================================================================
   Applications
   ========================================================================== */
.app-image { border-radius: var(--nt-radius); overflow: hidden; box-shadow: var(--nt-shadow-lg); }

.app-list {
  display: grid;
  grid-template-columns: repeat(3, auto);
  justify-content: center;
  gap: 10px 28px;
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  text-align: center;
}
.app-list li {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--nt-navy);
  position: relative;
  padding-left: 18px;
}
.app-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--nt-green);
}
@media (max-width: 700px) {
  .app-list { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 420px) {
  .app-list { grid-template-columns: 1fr; }
}

/* ==========================================================================
   Illustrative example
   ========================================================================== */
.example-image { border-radius: var(--nt-radius); overflow: hidden; box-shadow: var(--nt-shadow-lg); margin-bottom: 24px; }
.disclaimer-box {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: var(--nt-navy-tint);
  border: 1px solid #CBD9E8;
  border-radius: var(--nt-radius-sm);
  padding: 16px 20px;
  max-width: 760px;
  margin: 0 auto;
}
.disclaimer-box svg { flex-shrink: 0; margin-top: 3px; color: var(--nt-navy); }
.disclaimer-box p { margin: 0; font-size: 0.92rem; color: var(--nt-navy-dark); }

/* ==========================================================================
   Project pathway
   ========================================================================== */
.pathway-layout {
  display: flex;
  flex-direction: column;
  gap: 40px;
}
.pathway-image { border-radius: var(--nt-radius); overflow: hidden; box-shadow: var(--nt-shadow-lg); max-width: 1100px; margin: 0 auto; width: 100%; }

.pathway-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: step;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
@media (max-width: 900px) {
  .pathway-steps { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 560px) {
  .pathway-steps { grid-template-columns: 1fr; }
}
.pathway-steps li {
  position: relative;
  background: #fff;
  border: 1px solid var(--nt-border);
  border-radius: var(--nt-radius-sm);
  padding: 24px 20px 20px;
}
.pathway-steps li::before {
  counter-increment: step;
  content: counter(step);
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--nt-navy);
  color: #fff;
  font-family: var(--nt-font-display);
  font-weight: 600;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
}
.pathway-steps h4 { margin: 0 0 6px; font-size: 1rem; color: var(--nt-navy); }
.pathway-steps p { margin: 0; font-size: 0.92rem; }

/* ==========================================================================
   Partners
   ========================================================================== */
.partner-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}
.partner-image { border-radius: var(--nt-radius); overflow: hidden; box-shadow: var(--nt-shadow-lg); }
.partner-copy { max-width: 760px; margin: 0 auto; text-align: center; }
.partner-types {
  display: grid;
  grid-template-columns: repeat(2, auto);
  justify-content: center;
  gap: 8px 24px;
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  text-align: left;
}
.partner-types li {
  font-size: 0.88rem;
  color: var(--nt-text-muted);
  position: relative;
  padding-left: 16px;
}
.partner-types li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--nt-navy);
}
@media (max-width: 560px) {
  .partner-types { grid-template-columns: 1fr; justify-items: start; }
}

.partner-tags {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 20px;
}
.partner-tags span {
  background: var(--nt-green-tint);
  color: var(--nt-green-dark);
  font-size: 0.86rem;
  font-weight: 600;
  padding: 8px 16px;
  border-radius: 100px;
}

/* ==========================================================================
   Contact
   ========================================================================== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
}
@media (max-width: 900px) {
  .contact-grid { grid-template-columns: 1fr; }
}
.contact-info {
  background: var(--nt-navy);
  color: #fff;
  border-radius: var(--nt-radius);
  padding: 36px 32px;
}
.contact-info h3 { color: #fff; }
.contact-info p { color: #C9DAEC; }
.contact-info ul { list-style: none; padding: 0; margin: 20px 0 0; }
.contact-info li {
  display: flex;
  gap: 12px;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid rgba(255,255,255,0.12);
  font-size: 0.95rem;
  color: #fff;
}
.contact-info li:last-child { border-bottom: none; }
.contact-info a { color: #fff; }
.contact-info svg { flex-shrink: 0; color: var(--nt-green); }

.form-card {
  background: #fff;
  border: 1px solid var(--nt-border);
  border-radius: var(--nt-radius);
  padding: 32px;
  box-shadow: var(--nt-shadow);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 560px) { .form-row { grid-template-columns: 1fr; } }
.field { margin-bottom: 18px; }
.field label {
  display: block;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--nt-navy);
  margin-bottom: 6px;
}
.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--nt-border);
  border-radius: var(--nt-radius-sm);
  font-family: var(--nt-font-body);
  font-size: 0.96rem;
  color: var(--nt-text);
  background: #fcfdfe;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--nt-navy);
  box-shadow: 0 0 0 3px rgba(11, 61, 116, 0.12);
}
.field textarea { resize: vertical; min-height: 110px; }
.form-note { font-size: 0.84rem; color: var(--nt-text-muted); margin-top: 14px; }

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: var(--nt-navy-dark);
  color: #C9DAEC;
  padding: 48px 0 28px;
}
.footer-grid {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
  padding-bottom: 28px;
  border-bottom: 1px solid rgba(255,255,255,0.14);
}
.footer-brand { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.footer-brand img { height: 34px; width: auto; }
.footer-tagline {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
  padding-left: 16px;
  border-left: 1px solid rgba(255,255,255,0.18);
}
.footer-tagline strong { color: #fff; font-family: var(--nt-font-display); font-size: 1rem; }
.footer-tagline span { font-size: 0.82rem; color: #9FB6CC; }
.footer-links { display: flex; gap: 24px; flex-wrap: wrap; }
.footer-links a { color: #C9DAEC; font-size: 0.92rem; }
.footer-links a:hover { color: #fff; }
.footer-meta {
  padding-top: 22px;
  font-size: 0.86rem;
  color: #9FB6CC;
  text-align: center;
}
.footer-meta a { color: #C9DAEC; }

/* ==========================================================================
   Reveal-on-scroll (subtle, respects reduced motion)
   ========================================================================== */
.reveal { opacity: 1; transform: none; transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.reveal-pending { opacity: 0; transform: translateY(18px); }
.reveal.in-view { opacity: 1; transform: translateY(0); }

/* Focus visibility for accessibility */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 3px solid var(--nt-blue-accent);
  outline-offset: 2px;
}

/* ==========================================================================
   Zoomable info-graphics (click / tap to enlarge)
   ========================================================================== */
img.zoomable { cursor: zoom-in; }

.zoom-hint {
  display: none;
  text-align: center;
  font-size: 0.82rem;
  color: var(--nt-text-muted);
  margin-top: 10px;
}
@media (max-width: 768px) {
  .zoom-hint { display: block; }
}

.lightbox-overlay {
  position: fixed;
  inset: 0;
  background: rgba(11, 20, 30, 0.86);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  z-index: 2000;
  cursor: zoom-out;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}
.lightbox-overlay.open { opacity: 1; pointer-events: auto; }
.lightbox-overlay img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
  border-radius: 8px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.4);
}
.lightbox-close {
  position: absolute;
  top: 20px;
  right: 24px;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255,255,255,0.12);
  border: none;
  color: #fff;
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}