/* ============================================
   BrickAndMotorLabs - Design System & Styles
   Build. Learn. Engineer the Future.
   ============================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* --- CSS Variables --- */
:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --accent: #ff6d00;
  --accent-dark: #e05e00;
  --dark: #202124;
  --dark-light: #3c4043;
  --gray: #5f6368;
  --gray-light: #dadce0;
  --light: #f8f9fa;
  --white: #ffffff;
  --success: #0d904f;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition: 0.3s ease;
  --max-width: 1200px;
  --nav-height: 70px;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  color: var(--dark);
  background: var(--white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition);
}

ul {
  list-style: none;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.2;
  font-weight: 700;
}

h1 { font-size: clamp(2rem, 5vw, 3.2rem); }
h2 { font-size: clamp(1.6rem, 4vw, 2.4rem); }
h3 { font-size: clamp(1.2rem, 3vw, 1.5rem); }

p {
  margin-bottom: 1rem;
  color: var(--gray);
}

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* --- Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--white);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.navbar__logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.navbar__logo span {
  color: var(--accent);
}

.navbar__menu {
  display: flex;
  align-items: center;
  gap: 32px;
}

.navbar__link {
  font-weight: 500;
  color: var(--dark-light);
  position: relative;
  padding: 4px 0;
}

.navbar__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition);
}

.navbar__link:hover::after,
.navbar__link--active::after {
  width: 100%;
}

.navbar__link:hover,
.navbar__link--active {
  color: var(--primary);
}

.navbar__cta {
  background: var(--accent);
  color: var(--white) !important;
  padding: 10px 24px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
  transition: background var(--transition), transform var(--transition);
}

.navbar__cta::after {
  display: none;
}

.navbar__cta:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
}

/* Hamburger */
.navbar__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 5px;
}

.navbar__hamburger span {
  width: 25px;
  height: 3px;
  background: var(--dark);
  border-radius: 2px;
  transition: var(--transition);
}

/* --- Hero Section --- */
.hero {
  margin-top: var(--nav-height);
  padding: 80px 0 100px;
  background: linear-gradient(135deg, #e8f0fe 0%, #f8f9fa 50%, #fef7e0 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(26, 115, 232, 0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(255, 109, 0, 0.06) 0%, transparent 70%);
  border-radius: 50%;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero__content {
  max-width: 560px;
}

.hero__badge {
  display: inline-block;
  background: rgba(26, 115, 232, 0.1);
  color: var(--primary);
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.hero__title {
  margin-bottom: 20px;
  color: var(--dark);
}

.hero__title span {
  color: var(--accent);
}

.hero__description {
  font-size: 1.15rem;
  margin-bottom: 32px;
  color: var(--gray);
}

.hero__buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
}

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

.btn--primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.btn--outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero__video-wrapper {
  width: 100%;
  max-width: 500px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  background: var(--white);
  aspect-ratio: 16 / 9;
}

.hero__video-wrapper iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* --- Section Base --- */
.section {
  padding: 80px 0;
}

.section--light {
  background: var(--light);
}

.section--dark {
  background: var(--dark);
  color: var(--white);
}

.section__header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 50px;
}

.section__subtitle {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 12px;
}

.section__title {
  margin-bottom: 16px;
}

.section--dark .section__subtitle {
  color: var(--accent);
}

.section--dark .section__title {
  color: var(--white);
}

.section--dark .section__description {
  color: rgba(255, 255, 255, 0.7);
}

/* --- Age Filter --- */
.filter-bar {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 10px 24px;
  border: 2px solid var(--gray-light);
  border-radius: 50px;
  background: var(--white);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--gray);
  cursor: pointer;
  transition: all var(--transition);
}

.filter-btn:hover,
.filter-btn--active {
  border-color: var(--primary);
  color: var(--primary);
  background: rgba(26, 115, 232, 0.05);
}

.sort-select {
  padding: 10px 20px;
  border: 2px solid var(--gray-light);
  border-radius: 50px;
  background: var(--white);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--gray);
  cursor: pointer;
  transition: all var(--transition);
}

.sort-select:hover,
.sort-select:focus {
  border-color: var(--primary);
  color: var(--primary);
  outline: none;
}

/* --- Product Grid --- */
.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.product-card {
  background: var(--white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  border: 1px solid var(--gray-light);
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.product-card__image {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: var(--light);
}

.product-card__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.product-card__body {
  padding: 24px;
}

.product-card__age {
  display: inline-block;
  background: rgba(255, 109, 0, 0.1);
  color: var(--accent);
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.product-card__title {
  font-size: 1.15rem;
  margin-bottom: 8px;
  color: var(--dark);
}

.product-card__description {
  font-size: 0.9rem;
  color: var(--gray);
  margin-bottom: 16px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.product-card__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 16px;
  border-top: 1px solid var(--gray-light);
}

.product-card__price {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary);
}

.product-card__price.product-card__pay {
  text-decoration: none;
  border-bottom: 2px dotted var(--primary);
  cursor: pointer;
  background: none;
  border-top: none;
  border-right: none;
  border-left: none;
  padding: 0;
  font-family: inherit;
  text-align: left;
}

.product-card__price.product-card__pay:hover {
  color: var(--primary-dark);
  border-bottom-style: solid;
}

.product-card__price.product-card__pay:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: 2px;
}

/* --- Payment Modal --- */
.pay-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.pay-modal[hidden] {
  display: none;
}

.pay-modal__overlay {
  position: absolute;
  inset: 0;
  background: rgba(32, 33, 36, 0.6);
}

.pay-modal__card {
  position: relative;
  background: var(--white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-width: 440px;
  width: 100%;
  padding: 32px;
  text-align: center;
}

.pay-modal__close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  font-size: 1.7rem;
  line-height: 1;
  color: var(--gray);
  cursor: pointer;
}

.pay-modal__close:hover {
  color: var(--dark);
}

.pay-modal__title {
  font-size: 1.3rem;
  margin: 0 0 6px;
  color: var(--dark);
}

.pay-modal__price {
  font-size: 1.9rem;
  font-weight: 700;
  color: var(--primary);
  margin: 0 0 14px;
}

.pay-modal__text {
  color: var(--gray);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

.pay-modal__btn {
  display: inline-flex;
  width: 100%;
  justify-content: center;
  margin-bottom: 14px;
}

.pay-modal__alt {
  font-size: 0.85rem;
  color: var(--gray);
  margin: 0;
}

.pay-modal__alt a {
  color: var(--primary);
  font-weight: 600;
}

.product-card__link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.9rem;
}

.product-card__link:hover {
  color: var(--accent-dark);
}

.product-card__parts {
  font-size: 0.8rem;
  color: var(--gray);
  margin-top: 4px;
}

/* --- About Section --- */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about__image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

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

.about__content h2 {
  margin-bottom: 20px;
}

.about__content p {
  margin-bottom: 16px;
}

.founders {
  display: flex;
  gap: 24px;
  margin-top: 30px;
}

.founder {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.founder__avatar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.founder__info strong {
  display: block;
  color: var(--dark);
}

.founder__info span {
  font-size: 0.85rem;
  color: var(--gray);
}

/* --- Features --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
  margin-top: 50px;
}

.feature-card {
  text-align: center;
  padding: 30px 20px;
  background: var(--white);
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-light);
  transition: all var(--transition);
}

.feature-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.feature-card__icon {
  width: 60px;
  height: 60px;
  margin: 0 auto 16px;
  background: rgba(26, 115, 232, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.feature-card__title {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.feature-card__description {
  font-size: 0.9rem;
}

/* --- Events --- */
.events-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
  max-width: 800px;
  margin: 0 auto;
}

.event-card {
  display: flex;
  gap: 24px;
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--gray-light);
  transition: all var(--transition);
}

.event-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.event-card__date {
  text-align: center;
  min-width: 70px;
  padding: 12px;
  background: var(--primary);
  color: var(--white);
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.event-card__day {
  font-size: 1.8rem;
  font-weight: 800;
  line-height: 1;
}

.event-card__month {
  font-size: 0.85rem;
  text-transform: uppercase;
  font-weight: 600;
}

.event-card__content h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.event-card__content p {
  font-size: 0.9rem;
  margin-bottom: 8px;
}

.events-empty {
  text-align: center;
  max-width: 620px;
  margin: 0 auto;
  background: var(--white);
  border: 1px dashed var(--gray-light);
  border-radius: var(--radius-md);
  padding: 48px 32px;
}

.events-empty__icon {
  font-size: 3rem;
  margin-bottom: 12px;
}

.events-empty h3 {
  font-size: 1.4rem;
  margin-bottom: 12px;
}

.events-empty p {
  color: var(--gray);
  line-height: 1.6;
  margin-bottom: 12px;
}

.events-empty .btn {
  margin-top: 12px;
}

.event-card__tag {
  display: inline-block;
  background: rgba(26, 115, 232, 0.1);
  color: var(--primary);
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
}

/* --- Contact --- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: start;
}

.contact-info h2 {
  margin-bottom: 16px;
}

.contact-info p {
  margin-bottom: 30px;
}

.contact-detail {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 24px;
}

.contact-detail__icon {
  width: 48px;
  height: 48px;
  background: rgba(26, 115, 232, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.2rem;
}

.contact-detail__text strong {
  display: block;
  color: var(--dark);
  margin-bottom: 2px;
}

.contact-detail__text span {
  font-size: 0.9rem;
  color: var(--gray);
}

.social-links {
  display: flex;
  gap: 12px;
  margin-top: 30px;
}

.social-link {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: all var(--transition);
  border: 1px solid var(--gray-light);
}

.social-link:hover {
  background: var(--primary);
  color: var(--white);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.contact-form-wrapper {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 30px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--gray-light);
}

.contact-form-wrapper h3 {
  margin-bottom: 20px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  font-size: 0.9rem;
  color: var(--dark);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--gray-light);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-family: inherit;
  transition: border-color var(--transition);
  background: var(--white);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.form-alert {
  margin-top: 16px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  line-height: 1.5;
}

.form-alert--success {
  background: #e6f4ea;
  border: 1px solid var(--success);
  color: var(--success);
}

.form-alert--error {
  background: #fce8e6;
  border: 1px solid #c5221f;
  color: #c5221f;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* --- Build Guide Page --- */
.build-hero {
  margin-top: var(--nav-height);
  padding: 60px 0;
  background: linear-gradient(135deg, #e8f0fe 0%, #fef7e0 100%);
  text-align: center;
}

.build-hero__product {
  max-width: 500px;
  margin: 0 auto 30px;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.build-hero__product img {
  width: 100%;
}

.build-hero h1 {
  margin-bottom: 8px;
}

.build-hero__meta {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.build-hero__meta span {
  background: var(--white);
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--gray);
}

.build-content {
  padding: 60px 0;
}

.build-content__section {
  margin-bottom: 40px;
}

.build-content__section h2 {
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--gray-light);
}

.build-content__section p {
  margin-bottom: 12px;
}

.build-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
}

.build-item {
  background: var(--light);
  border-radius: var(--radius-sm);
  padding: 20px;
  border: 1px solid var(--gray-light);
}

.build-item h4 {
  margin-bottom: 8px;
  color: var(--primary);
}

.build-item p {
  font-size: 0.9rem;
  margin-bottom: 0;
}

.build-cta {
  text-align: center;
  padding: 40px 0;
  background: var(--light);
}

/* --- YouTube Section --- */
.youtube-section {
  padding: 60px 0;
}

.youtube-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.youtube-card {
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-light);
  transition: all var(--transition);
}

.youtube-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.youtube-card iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: none;
}

.youtube-card__footer {
  padding: 16px;
  background: var(--white);
}

.youtube-card__footer h4 {
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.youtube-card__footer span {
  font-size: 0.8rem;
  color: var(--gray);
}

.youtube-cta {
  text-align: center;
  margin-top: 40px;
}

/* --- Footer --- */
.footer {
  background: var(--dark);
  color: rgba(255, 255, 255, 0.7);
  padding: 60px 0 30px;
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer__brand p {
  margin-top: 12px;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.5);
}

.footer__logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--white);
}

.footer__logo span {
  color: var(--accent);
}

.footer__heading {
  color: var(--white);
  font-size: 1rem;
  margin-bottom: 20px;
}

.footer__links li {
  margin-bottom: 10px;
}

.footer__links a {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--transition);
}

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

.footer__bottom {
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.4);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .product-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer__grid {
    grid-template-columns: 1fr 1fr;
  }

  .youtube-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .navbar__menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px;
    gap: 0;
    box-shadow: var(--shadow-md);
    transform: translateY(-120%);
    transition: transform var(--transition);
    z-index: 999;
  }

  .navbar__menu--open {
    transform: translateY(0);
  }

  .navbar__link {
    padding: 14px 0;
    width: 100%;
    border-bottom: 1px solid var(--gray-light);
  }

  .navbar__link::after {
    display: none;
  }

  .navbar__cta {
    margin-top: 10px;
    text-align: center;
    justify-content: center;
  }

  .navbar__hamburger {
    display: flex;
  }

  .navbar__hamburger--active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 6px);
  }

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

  .navbar__hamburger--active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -6px);
  }

  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero__content {
    max-width: 100%;
  }

  .hero__buttons {
    justify-content: center;
  }

  .hero__video-wrapper {
    max-width: 100%;
  }

  .product-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin: 0 auto;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  .event-card {
    flex-direction: column;
    text-align: center;
  }

  .founders {
    flex-direction: column;
  }

  .footer__grid {
    grid-template-columns: 1fr;
  }

  .footer__bottom {
    flex-direction: column;
    text-align: center;
  }

  .youtube-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 60px 0;
  }
}

/* ─── Product Card Placeholder ─────────────────────────────────── */
.product-card__placeholder {
  width: 100%;
  aspect-ratio: 4 / 3;
  background: linear-gradient(135deg, #e8f0fe 0%, #fef7e0 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.5rem;
  border-bottom: 1px solid var(--gray-light);
}

/* ─── Hero Channel Card ─────────────────────────────────────────── */
.hero__channel-card {
  background: var(--dark);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 500px;
}

.channel-card__link {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--white);
}

.channel-card__thumb {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity var(--transition);
}

.channel-card__link:hover .channel-card__thumb {
  opacity: 0.85;
}

.channel-card__icon {
  width: 72px;
  height: 72px;
  background: #ff0000;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  color: var(--white);
  box-shadow: 0 0 40px rgba(255, 0, 0, 0.35);
  transition: transform var(--transition), box-shadow var(--transition);
}

.channel-card__link:hover .channel-card__icon {
  transform: scale(1.1);
  box-shadow: 0 0 60px rgba(255, 0, 0, 0.5);
}

.channel-card__info {
  padding: 20px 24px;
  background: rgba(255,255,255,0.05);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.channel-card__info strong {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--white);
}

.channel-card__info span {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.6);
}

/* ─── YouTube Clickable Cards ───────────────────────────────────── */
.youtube-card--link .youtube-card__thumb-link {
  display: block;
  text-decoration: none;
}

.youtube-card__thumb-placeholder {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, #1a1a2e 0%, #0f3460 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: opacity var(--transition);
}

.youtube-card__thumb-link:hover .youtube-card__thumb-placeholder {
  opacity: 0.8;
}

.youtube-card__thumb-placeholder span {
  width: 56px;
  height: 56px;
  background: #ff0000;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  color: var(--white);
  box-shadow: 0 0 30px rgba(255, 0, 0, 0.4);
  transition: transform var(--transition);
}

.youtube-card__thumb-link:hover .youtube-card__thumb-placeholder span {
  transform: scale(1.15);
}

/* ─── Build Page Navigation ─────────────────────────────────────── */
.build-nav {
  padding: 32px 0 60px;
  background: var(--white);
  border-top: 1px solid var(--gray-light);
}

.build-nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.build-nav__btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all var(--transition);
  text-decoration: none;
  white-space: nowrap;
}

.build-nav__btn--prev,
.build-nav__btn--next {
  background: var(--white);
  border: 2px solid var(--gray-light);
  color: var(--dark);
}

.build-nav__btn--prev:hover,
.build-nav__btn--next:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: rgba(26, 115, 232, 0.04);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.build-nav__btn--disabled {
  background: var(--light);
  border: 2px solid var(--gray-light);
  color: var(--gray-light);
  cursor: not-allowed;
  padding: 12px 24px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
}

.build-nav__count {
  font-size: 0.85rem;
  color: var(--gray);
  font-weight: 500;
  text-align: center;
}

/* ─── About Page Placeholder ────────────────────────────────────── */
.about__placeholder {
  width: 100%;
  height: 100%;
  min-height: 320px;
  background: linear-gradient(135deg, #e8f0fe 0%, #fef7e0 100%);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 40px;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.about__placeholder span {
  font-size: 4rem;
}

.about__placeholder p {
  font-size: 1rem;
  font-weight: 600;
  color: var(--dark);
  margin: 0;
}

/* ─── Build Nav Responsive ──────────────────────────────────────── */
@media (max-width: 600px) {
  .build-nav .container {
    flex-direction: column;
    text-align: center;
  }

  .build-nav__btn,
  .build-nav__btn--disabled {
    width: 100%;
    justify-content: center;
    order: 1;
  }

  .build-nav__btn--prev { order: 2; }
  .build-nav__btn--next { order: 0; }
  .build-nav__count     { order: 3; }
}