/* ============================================
   TOTE & CO — Style Sheet
   Tokyo minimal apparel × magazine lookbook
   ============================================ */

/* ----- CSS Custom Properties ----- */
:root {
  --color-white: #FFFFFF;
  --color-ink: #1A1A1A;
  --color-gray: #E8E8E8;
  --color-vermillion: #C8412C;

  --font-display: 'Italiana', serif;
  --font-body: 'Manrope', sans-serif;
  --font-jp: 'Zen Kaku Gothic New', sans-serif;

  --max-width: 1200px;
  --header-height: 64px;
  --transition: 0.3s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  color: var(--color-ink);
  background-color: var(--color-white);
  line-height: 1.7;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ----- Utility ----- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ============================================
   Header
   ============================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-gray);
  height: var(--header-height);
}

.header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header__logo {
  font-family: var(--font-display);
  font-size: 1.5rem;
  letter-spacing: 0.12em;
  color: var(--color-ink);
  transition: opacity var(--transition);
}

.header__logo:hover {
  opacity: 0.7;
}

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

.header__nav-link {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-ink);
  transition: opacity var(--transition);
}

.header__nav-link:hover {
  opacity: 0.6;
}

.header__nav-link--cart {
  display: flex;
  align-items: center;
}

/* ============================================
   Main
   ============================================ */
.main {
  padding-top: 40px;
}

/* ============================================
   Product Section
   ============================================ */
.product {
  padding: 0 24px 80px;
}

.product__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

/* ----- Product Gallery ----- */
.product__gallery {
  position: sticky;
  top: calc(var(--header-height) + 24px);
}

.product__main-image {
  width: 100%;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  background-color: var(--color-gray);
  margin-bottom: 12px;
}

.product__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: opacity var(--transition);
}

.product__thumbnails {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
}

.product__thumb {
  aspect-ratio: 1 / 1;
  overflow: hidden;
  border: 2px solid transparent;
  padding: 0;
  transition: border-color var(--transition);
  cursor: pointer;
}

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

.product__thumb:hover {
  border-color: var(--color-ink);
}

.product__thumb--active {
  border-color: var(--color-ink);
}

/* ----- Product Info ----- */
.product__info {
  padding-top: 8px;
}

.product__category {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #888;
  margin-bottom: 8px;
}

.product__name {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  line-height: 1.3;
  margin-bottom: 16px;
}

.product__price {
  font-family: var(--font-body);
  font-size: 1.375rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 32px;
}

.product__price-tax {
  font-size: 0.75rem;
  font-weight: 400;
  color: #888;
  margin-left: 4px;
}

/* ----- Color Swatches ----- */
.product__colors {
  margin-bottom: 28px;
}

.product__label {
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  margin-bottom: 12px;
}

.product__color-list {
  display: flex;
  gap: 12px;
  margin-bottom: 8px;
}

.product__color-swatch {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 2px solid transparent;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
  cursor: pointer;
}

.product__color-swatch:hover {
  box-shadow: 0 0 0 2px var(--color-gray);
}

.product__color-swatch--active {
  border-color: var(--color-ink);
  box-shadow: 0 0 0 2px var(--color-white), 0 0 0 4px var(--color-ink);
}

.product__color-name {
  font-size: 0.75rem;
  color: #888;
  letter-spacing: 0.02em;
}

/* ----- Size Selector ----- */
.product__sizes {
  margin-bottom: 32px;
}

.product__size-list {
  display: flex;
  gap: 8px;
}

.product__size-btn {
  width: 52px;
  height: 44px;
  border: 1px solid var(--color-gray);
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--color-ink);
  background-color: var(--color-white);
  transition: background-color var(--transition), border-color var(--transition), color var(--transition);
}

.product__size-btn:hover {
  border-color: var(--color-ink);
}

.product__size-btn--active {
  background-color: var(--color-ink);
  border-color: var(--color-ink);
  color: var(--color-white);
}

/* ----- Add to Cart Button ----- */
.product__cart-btn {
  width: 100%;
  height: 52px;
  background-color: var(--color-vermillion);
  color: var(--color-white);
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: none;
  border-radius: 9999px;
  cursor: pointer;
  transition: background-color var(--transition), transform var(--transition);
  margin-bottom: 32px;
}

.product__cart-btn:hover {
  background-color: #A93622;
}

.product__cart-btn:active {
  transform: scale(0.98);
}

/* ----- Description ----- */
.product__description {
  font-family: var(--font-jp);
  font-size: 0.875rem;
  font-weight: 400;
  line-height: 1.9;
  color: #555;
  margin-bottom: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-gray);
}

/* ============================================
   Accordion
   ============================================ */
.accordion {
  border-top: 1px solid var(--color-gray);
}

.accordion__item {
  border-bottom: 1px solid var(--color-gray);
}

.accordion__trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  font-family: var(--font-jp);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-ink);
  background: none;
  border: none;
  cursor: pointer;
  transition: opacity var(--transition);
}

.accordion__trigger:hover {
  opacity: 0.6;
}

.accordion__icon {
  font-size: 1.125rem;
  font-weight: 300;
  line-height: 1;
  transition: transform var(--transition);
}

.accordion__trigger[aria-expanded="true"] .accordion__icon {
  transform: rotate(45deg);
}

.accordion__content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.accordion__content--open {
  max-height: 300px;
  padding-bottom: 18px;
}

.accordion__list {
  font-family: var(--font-jp);
  font-size: 0.8125rem;
  font-weight: 400;
  color: #555;
  line-height: 2;
  padding-left: 0;
}

.accordion__list li {
  position: relative;
  padding-left: 16px;
}

.accordion__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background-color: var(--color-gray);
}

/* ============================================
   Related Products
   ============================================ */
.related {
  padding: 64px 24px 80px;
  background-color: #FAFAFA;
}

.related__inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.related__title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-align: center;
  margin-bottom: 48px;
}

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

.related__card {
  display: block;
  transition: opacity var(--transition);
}

.related__card:hover {
  opacity: 0.8;
}

.related__card-image {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  background-color: var(--color-gray);
  margin-bottom: 16px;
}

.related__card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.related__card:hover .related__card-image img {
  transform: scale(1.03);
}

.related__card-body {
  text-align: center;
}

.related__card-name {
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  margin-bottom: 4px;
}

.related__card-price {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 400;
  color: #888;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  padding: 48px 24px;
  border-top: 1px solid var(--color-gray);
  text-align: center;
}

.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer__logo {
  font-family: var(--font-display);
  font-size: 1.125rem;
  letter-spacing: 0.12em;
  margin-bottom: 20px;
}

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

.footer__link {
  font-size: 0.75rem;
  font-weight: 400;
  color: #888;
  letter-spacing: 0.02em;
  transition: color var(--transition);
}

.footer__link:hover {
  color: var(--color-ink);
}

.footer__copy {
  font-size: 0.6875rem;
  color: #AAA;
  letter-spacing: 0.02em;
}

/* ============================================
   Media Queries — Tablet (768px)
   ============================================ */
@media (max-width: 768px) {
  .product__inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .product__gallery {
    position: static;
  }

  .product__name {
    font-size: 1.625rem;
  }

  .product__price {
    font-size: 1.25rem;
    margin-bottom: 24px;
  }

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

  .related__grid .related__card:last-child {
    display: none;
  }

  .header__nav-list {
    gap: 20px;
  }
}

/* ============================================
   Media Queries — Mobile (480px)
   ============================================ */
@media (max-width: 480px) {
  :root {
    --header-height: 56px;
  }

  .header__inner {
    padding: 0 16px;
  }

  .header__logo {
    font-size: 1.25rem;
  }

  .header__nav-list {
    gap: 16px;
  }

  .header__nav-link {
    font-size: 0.75rem;
  }

  .main {
    padding-top: 24px;
  }

  .product {
    padding: 0 16px 48px;
  }

  .product__thumbnails {
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
  }

  .product__name {
    font-size: 1.375rem;
  }

  .product__size-btn {
    width: 44px;
    height: 40px;
    font-size: 0.75rem;
  }

  .product__cart-btn {
    height: 48px;
    font-size: 0.8125rem;
  }

  .related {
    padding: 48px 16px 56px;
  }

  .related__title {
    font-size: 1.25rem;
    margin-bottom: 32px;
  }

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

  .related__grid .related__card:last-child {
    display: block;
  }

  .related__card-image {
    aspect-ratio: 4 / 3;
  }

  .footer {
    padding: 32px 16px;
  }

  .footer__nav {
    gap: 16px;
  }

  .footer__link {
    font-size: 0.6875rem;
  }
}