/* TKC Website V1.0 — Coding Alpha 3
   Interaction enhancements layered after Alpha 1/2 styling.
   Original corporate palette, typography and content remain unchanged. */

:root { --tkc-nav-sticky-height: 76px; }

/* Navigation follows the viewport. The original top strip scrolls away. */
.tkc-nav {
  position: sticky;
  top: 0;
  z-index: 1100;
  background: rgba(255,255,255,.985);
  transition: box-shadow 200ms ease, background-color 200ms ease;
}
.tkc-nav.tkc-nav--scrolled {
  box-shadow: 0 8px 26px rgba(8,35,50,.12);
}
html { scroll-padding-top: calc(var(--tkc-nav-sticky-height) + 14px); }
main section[id] { scroll-margin-top: calc(var(--tkc-nav-sticky-height) + 14px); }

/* Each navigation item clearly communicates hover and current section. */
.tkc-links .tkc-link {
  position: relative;
  padding-inline: 4px;
  transition: color 180ms ease;
}
.tkc-links .tkc-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: #f5b817;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 210ms cubic-bezier(.2,.7,.2,1);
}
.tkc-links .tkc-link:hover,
.tkc-links .tkc-link:focus-visible,
.tkc-links .tkc-link[aria-current="location"] {
  color: #0b2535;
}
.tkc-links .tkc-link:hover::after,
.tkc-links .tkc-link:focus-visible::after,
.tkc-links .tkc-link[aria-current="location"]::after {
  transform: scaleX(1);
}
.tkc-links .tkc-link[aria-current="location"] { box-shadow: none; }
.tkc-links .tkc-link.tkc-link-active { box-shadow: none; }
.tkc-mobile-menu-link:hover,
.tkc-mobile-menu-link:focus-visible {
  background: #dce8ee;
  box-shadow: inset 3px 0 0 #f5b817;
}
.tkc-contact-fab:focus-visible,
.tkc-service-carousel-arrow:focus-visible,
.tkc-service-carousel-viewport:focus-visible,
.tkc-project-card:focus-visible,
.tkc-project-modal-close:focus-visible {
  outline: 3px solid #f5b817;
  outline-offset: 3px;
}

/* Continuous loop of TKC service highlights; the first four cards
   retain their visual design. JS adds two aria-hidden copies. */
.tkc-service-carousel {
  max-width: none;
  width: 100%;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 82px;
  align-items: stretch;
  margin-inline: auto;
  padding: 0 8px;
}
.tkc-service-carousel-viewport {
  min-width: 0;
  overflow-x: auto;
  overflow-y: hidden;
  overscroll-behavior-x: contain;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  scroll-behavior: auto;
  cursor: grab;
  touch-action: pan-x;
}
.tkc-service-carousel-viewport::-webkit-scrollbar { display: none; }
.tkc-service-carousel-viewport.tkc-service-is-dragging {
  cursor: grabbing;
  user-select: none;
}
.tkc-service-carousel .tkc-service-track.tkc-service-grid {
  display: flex;
  width: max-content;
  max-width: none;
  grid-template-columns: none;
  gap: 0;
  align-items: stretch;
}
.tkc-service-carousel .tkc-service-card {
  flex: 0 0 var(--tkc-service-card-width, clamp(245px, 25vw, 440px));
  width: var(--tkc-service-card-width, clamp(245px, 25vw, 440px));
  box-sizing: border-box;
  min-width: 0;
}
.tkc-service-carousel-controls {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 7px;
  border-left: 1px solid #35505e;
  background: #0b2535;
}
.tkc-service-carousel-arrow {
  display: grid;
  place-items: center;
  width: 42px;
  height: 35px;
  background: #17394b;
  color: #fff;
  border: 1px solid #426071;
  border-radius: 3px;
  font-size: 18px;
  line-height: 1;
  transition: background-color 180ms ease, color 180ms ease;
}
.tkc-service-carousel-arrow:hover {
  background: #f5b817;
  border-color: #f5b817;
  color: #10212b;
}

/* Whole project tile opens details, with a small visual affordance. */
.tkc-project-card[role="button"] {
  cursor: pointer;
  position: relative;
  outline-offset: 3px;
}
.tkc-project-card .tkc-project-view {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  padding: 0 24px 20px;
  color: #0d394e;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .025em;
}
.tkc-project-view > span { color: #bd8a06; font-size: 17px; }
.tkc-project-card:hover .tkc-project-view,
.tkc-project-card:focus-visible .tkc-project-view {
  color: #b28000;
}

/* Engineering project detail modal. No unverified project facts. */
body.tkc-dialog-open { overflow: hidden; }
.tkc-project-modal {
  position: fixed;
  inset: 0;
  z-index: 2500;
  padding: 30px 18px;
  display: flex;
  justify-content: center;
  align-items: center;
  background: rgba(3,22,34,.82);
  backdrop-filter: blur(5px);
  overflow-y: auto;
}
.tkc-project-modal[hidden] { display: none !important; }
.tkc-project-modal-panel {
  width: min(1020px,100%);
  max-height: min(92vh,920px);
  position: relative;
  display: grid;
  grid-template-columns: minmax(0,44%) minmax(0,56%);
  background: #fff;
  box-shadow: 0 24px 60px rgba(0,0,0,.35);
  color: #10212b;
  overflow-y: auto;
  border-top: 4px solid #f5b817;
}
.tkc-project-modal-close {
  position: absolute;
  top: 10px;
  right: 10px;
  z-index: 2;
  width: 44px;
  height: 44px;
  border: 1px solid #d7e0e5;
  background: #fff;
  color: #152e3c;
  font-size: 28px;
  line-height: 1;
  display: grid;
  place-items: center;
  cursor: pointer;
  border-radius: 2px;
}
.tkc-project-modal-close:hover { background: #f5b817; }
.tkc-project-modal-media {
  position: relative;
  background: #102b3a;
  min-height: 460px;
  overflow: hidden;
}
.tkc-project-modal-media img {
  width: 100%;
  height: 100%;
  position: absolute;
  inset: 0;
  object-fit: cover;
}
.tkc-project-modal-body { padding: 43px 40px 34px; min-width: 0; }
.tkc-project-modal-eyebrow {
  display: block;
  margin-bottom: 13px;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .16em;
  color: #a77904;
}
.tkc-project-modal-body h2 {
  margin: 0 50px 22px 0;
  font-size: clamp(23px,3vw,32px);
  line-height: 1.14;
  overflow-wrap: anywhere;
}
.tkc-project-modal-client {
  display: flex;
  gap: 16px;
  align-items: baseline;
  padding-bottom: 15px;
  border-bottom: 1px solid #d9e2e6;
}
.tkc-project-modal-client span,
.tkc-project-modal-fields h3 {
  color: #778992;
  font-size: 10px;
  letter-spacing: .08em;
  font-weight: 800;
}
.tkc-project-modal-client strong { font-size: 13px; color: #213b49; }
.tkc-project-modal-description {
  margin: 19px 0 22px;
  line-height: 1.6;
  color: #4f6470;
  font-size: 13px;
}
.tkc-project-modal-fields {
  display: grid;
  grid-template-columns: repeat(2,minmax(0,1fr));
  gap: 14px;
}
.tkc-project-modal-fields section {
  padding: 15px 16px;
  background: #f3f6f8;
  border-left: 3px solid #d6e1e6;
  min-width: 0;
}
.tkc-project-modal-fields h3 { margin: 0 0 8px; }
.tkc-project-modal-fields p {
  margin: 0;
  color: #526775;
  font-size: 12px;
  line-height: 1.5;
}
.tkc-project-modal-footnote {
  margin: 22px 0 0;
  color: #7a8b94;
  font-size: 11px;
  line-height: 1.5;
}

/* Floating WhatsApp-style contact shortcut. The destination is
   TKC's on-page Contact section, not an external WhatsApp number. */
.tkc-contact-fab {
  position: fixed;
  bottom: max(22px, env(safe-area-inset-bottom));
  right: 22px;
  z-index: 1250;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 54px;
  padding: 10px 15px 10px 12px;
  border-radius: 100px;
  background: #1eac5d;
  color: #fff;
  border: 2px solid #eaf8ef;
  box-shadow: 0 9px 26px rgba(4,43,23,.29);
  font-weight: 800;
  font-size: 12px;
  text-decoration: none;
  transition: transform 180ms ease, background-color 180ms ease, box-shadow 180ms ease;
}
.tkc-contact-fab:hover {
  transform: translateY(-3px);
  background: #168c4a;
  box-shadow: 0 13px 28px rgba(4,43,23,.32);
}
.tkc-contact-fab-label { white-space: nowrap; }
body.tkc-dialog-open .tkc-contact-fab { visibility: hidden; }
@media (max-width: 991px) {
  :root { --tkc-nav-sticky-height: 68px; }
  .tkc-service-carousel {
    grid-template-columns: minmax(0,1fr) 70px;
    padding: 0 6px;
  }
  .tkc-service-carousel .tkc-service-card {
    --tkc-service-card-width: clamp(240px,40vw,330px);
  }
  .tkc-project-modal-panel {
    grid-template-columns: minmax(0,40%) minmax(0,60%);
  }
  .tkc-project-modal-body { padding: 34px 23px 28px; }
}
@media (max-width: 767px) {
  .tkc-service-carousel .tkc-service-card {
    --tkc-service-card-width: min(78vw,320px);
  }
  .tkc-project-modal { align-items: flex-start; padding: 18px 12px; }
  .tkc-project-modal-panel { display: block; max-height: calc(100dvh - 36px); }
  .tkc-project-modal-media { min-height: 0; height: 235px; }
  .tkc-project-modal-body { padding: 24px 20px 28px; }
  .tkc-project-modal-body h2 { margin-right: 37px; }
  .tkc-contact-fab-label { display: none; }
  .tkc-contact-fab {
    width: 54px;
    height: 54px;
    padding: 0;
    justify-content: center;
    right: 16px;
    bottom: max(16px, env(safe-area-inset-bottom));
  }
}
@media (max-width: 479px) {
  :root { --tkc-nav-sticky-height: 62px; }
  .tkc-project-card .tkc-project-view { padding: 0 19px 18px; }
  .tkc-project-modal-fields { grid-template-columns: minmax(0,1fr); }
  .tkc-service-carousel { grid-template-columns: minmax(0,1fr) 54px; }
  .tkc-service-carousel-arrow { width: 38px; height: 34px; }
  .tkc-service-carousel .tkc-service-card { --tkc-service-card-width: min(78vw,290px); }
}
@media (prefers-reduced-motion: reduce) {
  .tkc-links .tkc-link,
  .tkc-links .tkc-link::after,
  .tkc-contact-fab,
  .tkc-service-carousel-arrow {
    transition: none !important;
  }
  .tkc-contact-fab:hover { transform: none; }
}

/* Acceptance corrections: uninterrupted carousel without previous/next arrows.
   Autoplay resumes automatically after direct manual interaction; hover alone
   does not stop it. Pausing explicitly remains possible for accessibility. */
.tkc-service-carousel {
  position: relative;
  display: block;
  width: 100%;
  grid-template-columns: none;
  padding: 0;
}
.tkc-service-carousel-viewport {
  width: 100%;
  touch-action: auto;
}
.tkc-service-carousel-pause {
  position: absolute;
  z-index: 5;
  right: 12px;
  top: 8px;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1px solid rgba(219,237,244,.35);
  border-radius: 4px;
  color: #fff;
  background: rgba(7,35,51,.88);
  cursor: pointer;
  font-size: 18px;
  line-height: 1;
  transition: background-color .2s ease, border-color .2s ease;
}
.tkc-service-carousel-pause:hover {
  background-color: #19465d;
  border-color: #f5b817;
}
.tkc-service-carousel-pause:focus-visible {
  outline: 3px solid #f5b817;
  outline-offset: 2px;
}
@media (max-width: 991px) {
  .tkc-service-carousel { display: block; grid-template-columns: none; padding: 0; }
}
@media (max-width: 479px) {
  .tkc-service-carousel { display: block; grid-template-columns: none; padding: 0; }
  .tkc-service-carousel-pause { right: 8px; top: 7px; width: 32px; height: 32px; }
}
@media (prefers-reduced-motion: reduce) {
  .tkc-service-carousel-pause { display: none; }
}

/* Hide template-only project details when a project has a concise verified summary. */
.tkc-project-modal-fields[hidden],
.tkc-project-modal-footnote[hidden],
.tkc-project-modal-client[hidden] { display: none !important; }

/* TKC portfolio: preserve the full Yamaha tire assembly machine portrait. */
.tkc-project-media-portrait .tkc-project-image { object-fit: contain; background: #e5e9e9; }
.tkc-project-modal-media.tkc-project-modal-media-portrait img { object-fit: contain; background: #102b3a; }
@media (min-width: 992px) {
  .tkc-projects-grid > .tkc-project-card:last-child:nth-child(3n + 1) { grid-column: 2; }
}