/* ==========================================================================
   Site layout — Di sản văn hóa Phường Đông Hòa
   Shared variables, header, footer, page shell
   ========================================================================== */

:root {
  --color-cream: #faf7f2;
  --color-beige: #e8dfd4;
  --color-beige-deep: #d4c4b0;
  --color-brown: #4a3f35;
  --color-brown-soft: #6b5d4f;
  --color-footer-bg: #4a3728;
  --color-ivory: #f5f0e8;
  --color-ivory-muted: rgba(245, 240, 232, 0.78);
  --color-brass: #c9a962;
  --color-brass-dark: #a8864a;
  --color-white: #ffffff;
  --color-overlay-beige: rgba(232, 223, 212, 0.45);
  --color-overlay-dark: rgba(45, 38, 32, 0.55);

  --font-serif-display: "Playfair Display", "Cormorant Garamond", Georgia, serif;
  --font-serif-logo: "Cormorant Garamond", "Playfair Display", Georgia, serif;
  --font-sans: "Source Sans 3", "Segoe UI", system-ui, sans-serif;

  --header-height: 4.5rem;
  --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-soft: 0 4px 24px rgba(74, 63, 53, 0.08);
  --shadow-header: 0 2px 20px rgba(74, 63, 53, 0.06);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body.site-body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-brown);
  background-color: var(--color-cream);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

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

.site-main {
  flex: 1 0 auto;
}

.site-main--flush {
  padding-top: 0;
}

.site-main--padded {
  padding-top: var(--header-height);
}

/* -------------------------------------------------------------------------- */
/* Header                                                                     */
/* -------------------------------------------------------------------------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(1.25rem, 4vw, 3rem);
  background: var(--color-white);
  border-bottom: 1px solid rgba(212, 196, 176, 0.35);
  transition: box-shadow var(--transition-smooth), background var(--transition-smooth);
}

.site-header.is-scrolled {
  box-shadow: var(--shadow-header);
}

.site-header__logo {
  flex-shrink: 0;
  font-family: var(--font-serif-logo);
  font-size: clamp(1.25rem, 2.5vw, 1.65rem);
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--color-brown);
  transition: color var(--transition-smooth);
}

.site-header__logo:hover {
  color: var(--color-brass-dark);
}

.site-header__nav {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

.site-header__menu {
  display: flex;
  align-items: center;
  gap: clamp(1.5rem, 3vw, 2.75rem);
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-header__link {
  position: relative;
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-brown-soft);
  padding: 0.35rem 0;
  transition: color var(--transition-smooth);
}

.site-header__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: var(--color-brass);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--transition-smooth);
}

.site-header__link:hover {
  color: var(--color-brown);
}

.site-header__link:hover::after {
  transform: scaleX(1);
}

.site-header__link.is-active {
  color: var(--color-brown);
}

.site-header__link.is-active::after {
  transform: scaleX(1);
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.site-header__icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  color: var(--color-brown);
  transition: color var(--transition-smooth), background var(--transition-smooth);
}

.site-header__icon-btn:hover {
  color: var(--color-brass-dark);
  background: rgba(201, 169, 98, 0.12);
}

.site-header__icon-btn svg {
  width: 1.25rem;
  height: 1.25rem;
}

.site-header__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0.5rem;
  border-radius: 4px;
  transition: background var(--transition-smooth);
}

.site-header__toggle:hover {
  background: rgba(201, 169, 98, 0.12);
}

.site-header__toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-brown);
  border-radius: 1px;
  transition: transform var(--transition-smooth), opacity var(--transition-smooth);
}

.site-header.is-menu-open .site-header__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header.is-menu-open .site-header__toggle-bar:nth-child(2) {
  opacity: 0;
}

.site-header.is-menu-open .site-header__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* -------------------------------------------------------------------------- */
/* Footer                                                                     */
/* -------------------------------------------------------------------------- */

.site-footer {
  flex-shrink: 0;
  background: var(--color-footer-bg);
  color: var(--color-ivory);
  border-top: 2px solid var(--color-brass);
}

.site-footer__inner {
  max-width: 72rem;
  margin: 0 auto;
  padding: clamp(2.5rem, 5vw, 4rem) clamp(1.5rem, 4vw, 3rem) clamp(1.5rem, 3vw, 2rem);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.35fr 0.85fr 0.85fr;
  gap: clamp(2rem, 4vw, 3.5rem);
}

.site-footer__logo {
  display: inline-block;
  margin: 0 0 1rem;
  font-family: var(--font-serif-logo);
  font-size: clamp(1.35rem, 2.5vw, 1.75rem);
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--color-ivory);
  transition: color var(--transition-smooth);
}

.site-footer__logo:hover {
  color: var(--color-brass);
}

.site-footer__about {
  margin: 0 0 1.5rem;
  max-width: 22rem;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--color-ivory-muted);
}

.site-footer__social {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  border: 1px solid rgba(201, 169, 98, 0.35);
  color: var(--color-ivory);
  transition: color var(--transition-smooth), border-color var(--transition-smooth),
    background var(--transition-smooth), transform var(--transition-smooth);
}

.site-footer__social-link:hover {
  color: var(--color-brass);
  border-color: var(--color-brass);
  background: rgba(201, 169, 98, 0.12);
  transform: translateY(-2px);
}

.site-footer__social-link svg {
  width: 1.1rem;
  height: 1.1rem;
}

.site-footer__heading {
  margin: 0 0 1.25rem;
  font-family: var(--font-serif-display);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-brass);
}

.site-footer__links {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer__links li + li {
  margin-top: 0.65rem;
}

.site-footer__link {
  font-size: 0.9375rem;
  color: var(--color-ivory-muted);
  transition: color var(--transition-smooth);
}

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

.site-footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: clamp(2rem, 4vw, 2.75rem);
  padding-top: 1.5rem;
  border-top: 1px solid rgba(245, 240, 232, 0.15);
  font-size: 0.8125rem;
  color: var(--color-ivory-muted);
}

.site-footer__credit {
  transition: color var(--transition-smooth);
}

.site-footer__credit:hover {
  color: var(--color-brass);
}

/* -------------------------------------------------------------------------- */
/* Generic inner page                                                         */
/* -------------------------------------------------------------------------- */

.page-section {
  padding: clamp(2rem, 4vw, 3rem) clamp(1.25rem, 4vw, 3rem);
}

.page-section__title {
  margin: 0 0 1rem;
  font-family: var(--font-serif-display);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 600;
  color: var(--color-brown);
}

.page-section__lead {
  margin: 0;
  color: var(--color-brown-soft);
  max-width: 40rem;
}

.page-anchor {
  scroll-margin-top: var(--header-height);
}

/* -------------------------------------------------------------------------- */
/* Responsive — header & footer                                               */
/* -------------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .site-header__link::after,
  .site-footer__social-link,
  .site-footer__link,
  .site-footer__logo {
    transition: none;
  }
}

@media (max-width: 1024px) {
  .site-header__nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    transform: none;
    padding: 0;
    max-height: 0;
    overflow: hidden;
    background: var(--color-white);
    border-bottom: 1px solid transparent;
    transition: max-height var(--transition-smooth), border-color var(--transition-smooth);
  }

  .site-header.is-menu-open .site-header__nav {
    max-height: 20rem;
    border-bottom-color: rgba(212, 196, 176, 0.35);
    box-shadow: var(--shadow-soft);
  }

  .site-header__menu {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 1rem 1.5rem 1.5rem;
  }

  .site-header__link {
    padding: 0.85rem 0;
    border-bottom: 1px solid rgba(212, 196, 176, 0.25);
  }

  .site-header__link:last-child {
    border-bottom: none;
  }

  .site-header__toggle {
    display: flex;
  }

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

  .site-footer__brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  .site-footer__grid {
    grid-template-columns: 1fr;
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
  }
}