/* ========== Hero ========== */
.srf-hero {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 460px;
  height: clamp(400px, 48vw, 560px);
  overflow: hidden;
  background: #0d2133;
}

.srf-hero__bg {
  position: absolute;
  inset: 0;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
}

.srf-hero__overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.62);
}

.srf-hero__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 920px;
  padding: 48px 24px;
  text-align: center;
}

.srf-hero__eyebrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 14px;
  font-size: 16px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.8);
}

.srf-hero__accent {
  display: inline-flex;
  line-height: 0;
}

.srf-hero__title {
  margin-bottom: 18px;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-white);
}

.srf-hero__desc {
  max-width: 760px;
  margin: 0 auto 28px;
  font-size: 16px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.94);
}

/* ========== Buttons ========== */
.srf-btn {
  display: inline-block;
  padding: 11px 32px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-align: center;
  border: 1px solid transparent;
  border-radius: 4px;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}

.srf-btn--ghost-light {
  color: var(--color-white);
  border-color: var(--color-white);
  background: transparent;
}

.srf-btn--ghost-light:hover,
.srf-btn--ghost-light:focus-visible {
  color: var(--color-primary);
  background: var(--color-white);
}

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

.srf-btn--primary:hover,
.srf-btn--primary:focus-visible {
  background: #004270;
  border-color: #004270;
}

.srf-btn:focus-visible {
  outline: 2px solid var(--color-white);
  outline-offset: 3px;
}

.page-main--retrofit-landing03 {
  background: var(--color-bg-light);
}

/* ========== Feature Cards Stack ========== */
.srf-stack {
  padding: 48px 0 64px;
}

.srf-stack--hardware {
  padding-top: 0;
  padding-bottom: 64px;
}

.srf-stack--modules {
  padding-top: 60px;
}

.srf-stack__inner {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.srf-card {
  position: relative;
  overflow: hidden;
  border-radius: 0;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12), 0 4px 16px rgba(0, 0, 0, 0.08);
}

.srf-card__bg {
  position: absolute;
  inset: 0;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  opacity: 0.38;
  transform: scale(1.06);
}

.srf-card__overlay {
  position: absolute;
  inset: 0;
}

.srf-card__inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 44%);
  gap: 40px;
  align-items: center;
  min-height: 360px;
  padding: 48px 40px;
}

.srf-card__title {
  margin-bottom: 16px;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.35;
}

.srf-card__text {
  margin-bottom: 0;
  font-size: 16px;
  line-height: 1.75;
}

.srf-card__content .srf-btn {
  margin-top: 24px;
}

.srf-card__media img {
  display: block;
  width: 100%;
  max-height: 340px;
  height: auto;
  margin: 0 auto;
  object-fit: contain;
}

/* Blue feature card */
.srf-card--blue {
  color: var(--color-white);
  background-color: var(--color-primary);
}

.srf-card--blue .srf-card__overlay {
  background: rgba(0, 83, 135, 0.8);
}

.srf-card--blue .srf-card__title,
.srf-card--blue .srf-card__text {
  color: var(--color-white);
}

/* Light overview card */
.srf-card--light .srf-card__overlay {
  background: rgba(255, 255, 255, 0.8);
}

.srf-card--light .srf-card__title,
.srf-card--light .srf-card__text {
  color: var(--color-text);
}

.srf-card--light .srf-checklist__icon {
  color: var(--color-primary);
}

.srf-card--light .srf-checklist__text {
  color: var(--color-text);
}

.srf-card__note {
  margin-top: 20px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.6;
  color: var(--color-primary);
}

/* Hardware checklist */
.srf-checklist {
  margin: 20px 0 28px;
  padding: 0;
  list-style: none;
}

.srf-checklist__item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 14px;
}

.srf-checklist__item:last-child {
  margin-bottom: 0;
}

.srf-checklist__icon {
  flex-shrink: 0;
  margin-top: 2px;
  line-height: 0;
  color: var(--color-white);
}

.srf-checklist__text {
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-white);
}

/* ========== Key Features Accordion ========== */
.srf-features {
  padding: 56px 0 48px;
  background: var(--color-white);
}

.srf-features__head {
  margin-bottom: 36px;
  text-align: center;
}

.srf-features__title {
  margin-bottom: 12px;
  font-size: 28px;
  font-weight: 700;
  color: var(--color-primary);
}

.srf-features__line {
  display: block;
  width: 56px;
  height: 3px;
  margin: 0 auto;
  background: #2aa8c8;
}

.srf-features__list {
  max-width: 1200px;
  margin: 0 auto;
}

.srf-features__item {
  margin-bottom: 10px;
  border: 1px solid var(--color-border);
  border-radius: 0;
  background: #f7f8f9;
  overflow: hidden;
}

.srf-features__item:last-child {
  margin-bottom: 0;
}

.srf-features__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 22px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
}

.srf-features__trigger::-webkit-details-marker {
  display: none;
}

.srf-features__item[open] .srf-features__trigger {
  color: var(--color-primary);
}

.srf-features__chevron {
  flex-shrink: 0;
  color: var(--color-primary);
  line-height: 0;
  transition: transform var(--transition);
}

.srf-features__item[open] .srf-features__chevron {
  transform: rotate(180deg);
}

.srf-features__panel {
  padding: 0 22px 20px;
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-muted);
}

/* ========== WRM Module ========== */
.srf-wrm {
  padding: 64px 0 72px;
  background: var(--color-white);
}

.srf-wrm__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 48px 56px;
  align-items: center;
  margin-bottom: 72px;
}

.srf-wrm__row:last-child {
  margin-bottom: 0;
}

.srf-wrm__row--reverse .srf-wrm__content {
  order: 2;
}

.srf-wrm__row--reverse .srf-wrm__media {
  order: 1;
}

.srf-wrm__title {
  margin-bottom: 16px;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-text);
}

.srf-wrm__lead {
  margin-bottom: 18px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.6;
  color: #2aa8c8;
}

.srf-wrm__text {
  margin: 20px 0 16px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
}

.srf-wrm__text:last-child {
  margin-bottom: 0;
}

.srf-wrm-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.srf-wrm-list__item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.srf-wrm-list__item:last-child {
  margin-bottom: 0;
}

.srf-wrm-list__icon {
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--color-primary);
  line-height: 0;
}

.srf-wrm-list__text {
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-text);
}

.srf-wrm__carousel {
  display: flex;
  align-items: center;
  gap: 12px;
}

.srf-wrm-swiper {
  flex: 1;
  min-width: 0;
  overflow: hidden;
}

.srf-wrm-swiper .swiper-slide {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 280px;
}

.srf-wrm-swiper img {
  display: block;
  width: 100%;
  max-width: 420px;
  max-height: 300px;
  height: auto;
  margin: 0 auto;
  object-fit: contain;
}

.srf-wrm__nav {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  padding: 0;
  color: #b8bcc4;
  background: transparent;
  border: 0;
  cursor: pointer;
  transition: color var(--transition);
}

.srf-wrm__nav:hover,
.srf-wrm__nav:focus-visible {
  color: var(--color-primary);
}

.srf-wrm__nav:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.srf-wrm__nav.swiper-button-disabled {
  opacity: 0.35;
  cursor: default;
}

/* ========== Product Image ========== */
.srf-product {
  padding: 0 0 64px;
  background: var(--color-white);
}

.srf-product-swiper {
  overflow: hidden;
}

.srf-product-swiper .swiper-slide {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 300px;
}

.srf-product-swiper img {
  display: block;
  width: auto;
  max-width: 100%;
  max-height: 300px;
  height: auto;
  margin: 0 auto;
  object-fit: contain;
}

/* ========== Ultrasonic Sensors ========== */
.srf-sensors {
  padding: 64px 0;
  background: var(--color-bg-light);
}

.srf-sensors__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 48px 56px;
  align-items: center;
}

.srf-sensors__title {
  margin-bottom: 16px;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-text);
}

.srf-sensors__text {
  margin-bottom: 16px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
}

.srf-sensors__text:last-child {
  margin-bottom: 0;
}

.srf-sensors__media {
  margin: 0;
  text-align: center;
}

.srf-sensors__media img {
  display: block;
  width: 100%;
  max-width: 520px;
  height: auto;
  margin: 0 auto;
  object-fit: contain;
}

/* ========== Key Benefits Accordion ========== */
.srf-benefits {
  padding: 56px 0 64px;
  background: var(--color-white);
}

.srf-benefits__head {
  margin-bottom: 36px;
  text-align: center;
}

.srf-benefits__title {
  margin-bottom: 12px;
  font-size: 28px;
  font-weight: 700;
  color: var(--color-primary);
}

.srf-benefits__line {
  display: block;
  width: 56px;
  height: 3px;
  margin: 0 auto;
  background: #2aa8c8;
}

.srf-benefits__list {
  max-width: 1200px;
  margin: 0 auto;
}

.srf-benefits__item {
  margin-bottom: 10px;
  border: 1px solid var(--color-border);
  border-radius: 0;
  background: #f7f8f9;
  overflow: hidden;
}

.srf-benefits__item:last-child {
  margin-bottom: 0;
}

.srf-benefits__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 22px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
}

.srf-benefits__trigger::-webkit-details-marker {
  display: none;
}

.srf-benefits__item[open] .srf-benefits__trigger {
  color: var(--color-primary);
}

.srf-benefits__chevron {
  flex-shrink: 0;
  color: var(--color-primary);
  line-height: 0;
  transition: transform var(--transition);
}

.srf-benefits__item[open] .srf-benefits__chevron {
  transform: rotate(180deg);
}

.srf-benefits__panel {
  padding: 0 22px 20px;
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-muted);
}

.srf-benefits__panel ul {
  margin: 0;
  padding-left: 1.1em;
  list-style: disc;
}

.srf-benefits__panel li {
  margin-bottom: 8px;
}

.srf-benefits__panel li:last-child {
  margin-bottom: 0;
}

/* ========== Download ========== */
.srf-download {
  padding: 72px 0 88px;
  background: var(--color-white);
}

.srf-download__head {
  max-width: 760px;
  margin: 0 auto 36px;
  text-align: center;
}

.srf-download__title {
  margin-bottom: 12px;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-primary);
}

.srf-download__line {
  display: block;
  width: 56px;
  height: 3px;
  margin: 0 auto;
  background: var(--color-primary);
}

.srf-download__media {
  margin: 0 auto 32px;
  text-align: center;
}

.srf-download__media img {
  display: inline-block;
  width: 60%;
  max-width: 480px;
  height: auto;
}

.srf-download__action {
  text-align: center;
}

/* ========== Video ========== */
.srf-video {
  position: relative;
  padding: 72px 0 88px;
  overflow: hidden;
  background: var(--color-primary);
}

.srf-video__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
}

.srf-video__overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: rgba(0, 83, 135, 0.62);
}

.srf-video__inner {
  position: relative;
  z-index: 2;
}

.srf-video__frame {
  max-width: 960px;
  margin: 0 auto;
  padding: 14px;
  background: var(--color-white);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.24);
}

.srf-video__frame-border {
  padding: 4px;
  border: 2px solid var(--color-primary);
  background: var(--color-primary);
}

.srf-video__player {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  vertical-align: middle;
  background: #000000;
  object-fit: cover;
  border: 0;
}

.srf-video__player--youtube {
  object-fit: unset;
}

/* ========== Tablet ========== */
@media (max-width: 960px) {
  .srf-card__inner {
    grid-template-columns: 1fr;
    gap: 32px;
    min-height: auto;
    padding: 40px 32px;
  }

  .srf-wrm__row,
  .srf-wrm__row--reverse {
    grid-template-columns: 1fr;
    gap: 32px;
    margin-bottom: 56px;
  }

  .srf-features__list,
  .srf-benefits__list {
    max-width: 100%;
  }

  .srf-sensors__inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

/* ========== Mobile ========== */
@media (max-width: 768px) {
  .srf-hero__inner {
    padding: 40px 24px;
  }

  .srf-stack {
    padding: 32px 0 48px;
  }

  .srf-stack__inner {
    gap: 24px;
  }

  .srf-card__inner {
    padding: 32px 24px;
  }

  .srf-features {
    padding: 48px 0 56px;
  }

  .srf-wrm {
    padding: 48px 0 56px;
  }

  .srf-sensors {
    padding: 48px 0;
  }

  .srf-benefits {
    padding: 48px 0 56px;
  }

  .srf-download,
  .srf-video {
    padding: 48px 0 64px;
  }

  .srf-download__media img {
    width: 80%;
  }

  .srf-video__frame {
    padding: 10px;
  }

  .srf-wrm-swiper .swiper-slide {
    min-height: 220px;
  }

  .srf-wrm__nav {
    width: 32px;
    height: 32px;
  }
}

@media (max-width: 640px) {
  .srf-hero__title,
  .srf-card__title,
  .srf-features__title,
  .srf-wrm__title,
  .srf-sensors__title,
  .srf-benefits__title,
  .srf-download__title {
    font-size: 24px;
  }

  .srf-download__media img {
    width: 100%;
  }
}