@import url('./tokens.css');
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Outfit:wght@600;700;800&family=JetBrains+Mono:wght@500;700&display=swap');

/* ===================================================================
   BASE & RESET
   =================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--text-primary);
  background-color: var(--surface-base);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}

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

.wrap {
  width: var(--wrap-width);
  margin: auto;
}

/* ===================================================================
   NAVIGATION
   =================================================================== */
nav {
  height: 74px;
  border-bottom: 1px solid var(--border-light);
  background: rgba(255, 255, 255, 0.95);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-family: var(--font-heading);
  font-size: 25px;
  font-weight: 800;
  letter-spacing: 0.13em;
  color: var(--text-primary);
  display: inline-flex;
  align-items: baseline;
}

.logo b {
  color: var(--cyan);
}

.links {
  display: flex;
  gap: 30px;
  font-size: var(--text-small);
  font-weight: 700;
  color: var(--text-secondary);
}

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

.navcta, .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--text-primary);
  padding: 11px 20px;
  font-size: var(--text-small);
  font-weight: 700;
  font-family: var(--font-body);
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.navcta:hover, .btn.dark:hover {
  background: var(--text-primary);
  color: var(--white);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(16, 35, 48, 0.15);
}

.btn.dark {
  background: var(--text-primary);
  color: var(--white);
}

.btn.light {
  background: var(--white);
  color: var(--text-primary);
  border-color: var(--border-light);
}

.btn.light:hover {
  background: var(--surface-subtle);
  border-color: var(--text-primary);
}

/* ===================================================================
   HERO SECTION
   =================================================================== */
.hero {
  background: linear-gradient(120deg, #f5f8fa 0%, #eaf5f7 100%);
  padding: var(--hero-pad-y) 0;
  border-bottom: 1px solid var(--border-light);
}

.heroGrid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 72px;
  align-items: center;
}

.eyebrow, .kicker {
  font-family: var(--font-mono);
  font-size: var(--text-mono-eyebrow);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: 800;
  color: var(--text-link);
  display: inline-block;
}

h1 {
  font-family: var(--font-heading);
  font-size: var(--text-hero-h1);
  line-height: 1.05;
  letter-spacing: -0.045em;
  margin: 18px 0 25px;
  color: var(--text-primary);
  font-weight: 700;
}

h2 {
  font-family: var(--font-heading);
  font-size: var(--text-section-h2);
  line-height: 1.1;
  letter-spacing: -0.035em;
  margin: 10px 0 16px;
  color: var(--text-primary);
  font-weight: 700;
}

.hero p {
  font-size: var(--text-body-lg);
  color: var(--text-secondary);
  max-width: 650px;
  line-height: 1.6;
}

.actions {
  display: flex;
  gap: 14px;
  margin-top: 32px;
}

.visual {
  height: 425px;
  background: var(--surface-dark-card);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-visual-refined);
  border: 1px solid rgba(22, 174, 200, 0.25);
  border-radius: var(--radius-sm);
}

.visual img {
  width: 91%;
  height: 365px;
  object-fit: cover;
  opacity: 0.82;
  transition: opacity var(--transition-smooth);
}

.visual label {
  position: absolute;
  left: 20px;
  bottom: 17px;
  color: var(--white);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  background: rgba(10, 23, 33, 0.85);
  backdrop-filter: blur(4px);
  padding: 5px 9px;
  border-radius: 2px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

/* ===================================================================
   SECTION: SOLUTIONS & CARDS
   =================================================================== */
section {
  padding: var(--section-pad-y) 0;
}

.intro {
  max-width: 770px;
  margin-bottom: 45px;
}

.intro p {
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.6;
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  align-items: stretch;
}

.card {
  background: var(--white);
  padding: 30px;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth), border-color var(--transition-fast), background var(--transition-fast);
  position: relative;
}

.card:hover {
  background: #fafcfd;
  border-color: #cbdbe3;
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(16, 35, 48, 0.06);
}

.card.is-active-source {
  border-color: var(--cyan);
  background: #f7fcfe;
  box-shadow: 0 0 0 1px var(--cyan), 0 8px 24px rgba(22, 174, 200, 0.12);
}

.card-main {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.card img.card-thumb {
  width: calc(100% + 60px);
  height: 175px;
  object-fit: cover;
  margin: -30px -30px 25px;
  border-bottom: 1px solid var(--border-light);
}

.card h3 {
  font-family: var(--font-heading);
  font-size: var(--text-card-h3);
  margin: 0 0 10px;
  color: var(--text-primary);
}

.card p {
  font-size: 14.5px;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* Explore Toggle Button */
.arrow-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: none;
  border: none;
  padding: 0;
  margin-top: 22px;
  color: var(--text-link);
  font-family: var(--font-body);
  font-weight: 800;
  font-size: var(--text-small);
  cursor: pointer;
  align-self: flex-start;
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.arrow-btn:hover {
  color: var(--cyan);
}

.arrow-btn .btn-icon {
  display: inline-block;
  transition: transform var(--transition-smooth);
}

.card.is-active-source .arrow-btn {
  color: var(--cyan);
}

.card.is-active-source .arrow-btn .btn-icon {
  transform: rotate(90deg);
}

/* ===================================================================
   FULL-WIDTH EXPANSION PANEL
   =================================================================== */
.card-expand {
  grid-column: 1 / -1;
  order: 10; /* Always below all cards on desktop */
  display: grid;
  grid-template-rows: 0fr;
  opacity: 0;
  visibility: hidden;
  transition: grid-template-rows 0.45s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.35s ease, visibility 0.45s;
  background: var(--surface-subtle);
  border: 0 solid var(--border-light);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-top: 0;
}

.card-expand.is-open {
  grid-template-rows: 1fr;
  opacity: 1;
  visibility: visible;
  border-width: 1px;
  margin-top: 8px;
  box-shadow: 0 16px 36px rgba(11, 24, 34, 0.08);
}

.expand-inner {
  overflow: hidden;
  min-height: 0;
  padding: 0 36px;
  transition: padding 0.45s ease;
}

.card-expand.is-open .expand-inner {
  padding: 32px 36px 36px;
}

/* Panel Header */
.expand-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 18px;
  margin-bottom: 24px;
}

.expand-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
  display: block;
  margin-bottom: 4px;
}

.expand-header h3 {
  font-family: var(--font-heading);
  font-size: 22px;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.expand-close-btn {
  background: transparent;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 6px 14px;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.expand-close-btn:hover {
  background: var(--white);
  border-color: var(--text-primary);
  color: var(--text-primary);
}

/* Dynamic Item Distribution Grid */
.expand-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 22px;
}

/* 1.5x Scaled Sub-Item Card */
.expand-item {
  display: flex;
  flex-direction: column;
  background: var(--white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: 0 3px 10px rgba(11, 24, 34, 0.03);
  transition: all var(--transition-fast);
}

.expand-item:hover {
  border-color: var(--cyan);
  transform: translateY(-3px);
  box-shadow: 0 10px 22px rgba(16, 35, 48, 0.08);
}

/* 1.5x scaled image dimensions (prominent hero visual inside item) */
.expand-item .item-img {
  width: 100%;
  height: 160px;
  object-fit: cover;
  border-bottom: 1px solid var(--border-light);
  transition: transform 0.35s ease;
}

.expand-item:hover .item-img {
  transform: scale(1.03);
}

.expand-item-info {
  padding: 20px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.expand-item h4 {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 6px;
}

.expand-item .item-desc {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
  flex-grow: 1;
}

.expand-item .know-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 700;
  color: var(--text-link);
  letter-spacing: 0.01em;
  align-self: flex-start;
  transition: gap var(--transition-fast), color var(--transition-fast);
}

.expand-item .know-more:hover {
  color: var(--cyan);
  gap: 10px;
}

/* ===================================================================
   SECTION: CUSTOM CONTROLLERS & SCALABLE CONTROL SYSTEMS
   =================================================================== */
.custom-control,
.ac {
  background: var(--surface-subtle);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.custom-controlGrid,
.acGrid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 70px;
  align-items: center;
}

.custom-controlVisual,
.acVisual {
  height: 470px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-visual-refined);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
}

.custom-controlVisual img,
.acVisual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.75);
}

.overlay {
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: 20px;
  background: rgba(11, 24, 34, 0.92);
  color: var(--white);
  padding: 20px;
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-sm);
}

.overlay strong {
  font-family: var(--font-heading);
  font-size: 19px;
  letter-spacing: -0.01em;
}

.overlay span {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-inverse-secondary);
  display: inline-block;
  margin-top: 4px;
}

/* 2x2 Capability Grid */
.features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px 24px;
  margin-top: 24px;
  border-top: 1px solid var(--border-light);
  padding-top: 22px;
}

.feature {
  display: flex;
  flex-direction: column;
}

.feature b {
  display: block;
  font-family: var(--font-heading);
  font-size: 15.5px;
  color: var(--text-primary);
  margin-bottom: 5px;
  line-height: 1.3;
}

.feature span {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===================================================================
   SECTION: TECHNOLOGY (DARK)
   =================================================================== */
.dark {
  background: var(--surface-dark);
  color: var(--white);
}

.dark h2, .dark h3 {
  color: var(--white);
}

.dark .intro p {
  color: var(--text-inverse-secondary);
}

.dark .kicker {
  color: var(--text-dark-accent);
}

.capgrid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border-dark);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.cap {
  background: var(--surface-dark);
  padding: 38px;
  transition: background var(--transition-fast);
}

.cap:hover {
  background: var(--surface-dark-card);
}

.num {
  font-family: var(--font-mono);
  color: var(--text-dark-accent);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.14em;
  margin-bottom: 18px;
}

.cap h3 {
  font-family: var(--font-heading);
  font-size: var(--text-card-h3);
  margin-bottom: 8px;
}

.cap p {
  font-size: 14px;
  color: var(--text-inverse-secondary);
  line-height: 1.6;
}

/* ===================================================================
   SECTION: OEM DEVELOPMENT PROCESS
   =================================================================== */
.process {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.step {
  padding: 32px 24px;
  border-right: 1px solid var(--border-light);
  background: var(--white);
}

.step:last-child {
  border-right: 0;
}

.stepNum {
  font-family: var(--font-mono);
  color: var(--text-link);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.13em;
}

.step h3 {
  font-family: var(--font-heading);
  font-size: 19px;
  margin-top: 16px;
  margin-bottom: 8px;
}

.step p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.55;
}


/* ===================================================================
   SECTION: CONTACT & INQUIRIES (Merged with CTA)
   =================================================================== */
.contact-section {
  background: var(--surface-base);
  padding: var(--section-pad-y) 0;
  border-top: 1px solid var(--border-light);
}

.contact-grid {
  display: grid;
  grid-template-columns: 5fr 7fr;
  gap: 60px;
  align-items: flex-start;
}

.contact-info {
  display: flex;
  flex-direction: column;
}

.contact-info h2 {
  font-family: var(--font-heading);
  font-size: var(--text-section-h2);
  line-height: 1.15;
  margin-bottom: 20px;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.contact-info p {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 36px;
}

.contact-direct {
  margin-top: auto;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.contact-direct-label {
  font-family: var(--font-mono);
  font-size: var(--text-mono-eyebrow);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--text-secondary);
  font-weight: 700;
}

.contact-direct-email {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.contact-direct-email:hover {
  color: var(--cyan);
}

/* Contact Form Box */
.contact-card {
  background: var(--surface-subtle);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 36px;
  box-shadow: 0 4px 18px rgba(16, 35, 48, 0.04);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

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

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

.form-group label {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 4px;
}

.form-group label .req {
  color: var(--cyan);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  background: var(--white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
}

/* Custom Specification Dynamic Field */
.custom-spec-group {
  display: none;
  flex-direction: column;
  gap: 8px;
  animation: fadeInDown 0.25s ease forwards;
}

.custom-spec-group.is-visible {
  display: flex;
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--text-secondary);
  opacity: 0.7;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(22, 174, 200, 0.15);
}

/* Custom Specification Dynamic Field */
.custom-spec-group {
  display: none;
  flex-direction: column;
  gap: 8px;
  animation: fadeInDown 0.25s ease forwards;
}

.custom-spec-group.is-visible {
  display: flex;
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.form-group textarea {
  resize: vertical;
  min-height: 105px;
}

.btn-submit {
  width: 100%;
  background: var(--ink);
  color: var(--white);
  border: none;
  border-radius: var(--radius-sm);
  padding: 15px 24px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 6px;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.btn-submit:hover {
  background: var(--blue);
  transform: translateY(-1px);
}


/* ===================================================================
   FOOTER
   =================================================================== */
footer {
  background: var(--surface-dark);
  color: var(--text-inverse-secondary);
  padding: 40px 0;
  border-top: 1px solid var(--border-dark);
}

.foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.foot strong {
  font-family: var(--font-heading);
  color: var(--white);
  letter-spacing: 0.13em;
  font-size: 14px;
}

.foot small {
  font-size: 11px;
}

/* ===================================================================
   RESPONSIVE DESIGN
   =================================================================== */
@media (max-width: 850px) {
  .links {
    display: none;
  }
  .heroGrid, .custom-controlGrid, .acGrid, .contact-grid {
    grid-template-columns: 1fr;
    gap: 45px;
  }
  .cards, .capgrid {
    grid-template-columns: 1fr;
  }

  /* Responsive order positioning on mobile so each expander opens directly below its parent card */
  #card-cooling { order: 1; }
  #expand-cooling { order: 2; }
  #card-air-quality { order: 3; }
  #expand-air-quality { order: 4; }
  #card-heating { order: 5; }
  #expand-heating { order: 6; }

  .expand-inner {
    padding: 0 20px;
  }

  .card-expand.is-open .expand-inner {
    padding: 24px 20px 24px;
  }

  .expand-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .expand-close-btn {
    align-self: flex-end;
  }

  .process {
    grid-template-columns: 1fr 1fr;
  }
  .step:nth-child(2) {
    border-right: 0;
  }
  .step {
    border-bottom: 1px solid var(--border-light);
  }
  .ctaGrid {
    display: block;
  }
  .cta .btn {
    display: inline-block;
    margin-top: 20px;
  }
}

@media (max-width: 520px) {
  h1 {
    font-size: 40px;
  }
  h2 {
    font-size: 32px;
  }
  .actions {
    flex-direction: column;
  }
  .btn {
    text-align: center;
  }
  .process {
    grid-template-columns: 1fr;
  }
  .step {
    border-right: 0;
  }
  .form-row {
    grid-template-columns: 1fr;
  }
  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .contact-card {
    padding: 24px 18px;
  }
  .foot {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
  .expand-grid {
    grid-template-columns: 1fr;
  }
  .expand-item .item-img {
    height: 150px;
  }
  .expand-item-info {
    padding: 16px;
  }
  .expand-item h4 {
    font-size: 16px;
  }
}