/* ============================================================
   Hạc Giấy 2026 — Landing page styles
   Design tokens + page components. Plain CSS, no build step.
   ============================================================ */
@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;500;600;700;800&display=swap');

:root {
  /* Brand */
  --hg-red: #c0272b;
  --hg-red-dark: #8e1c1f;
  --hg-red-deep: #a61010;
  --hg-red-bright: #cb0000;
  --hg-red-grad: linear-gradient(180deg, #cb0000, #7e0000);
  --hg-ink: #201e1d;
  --hg-bg: #fdfbf7;
  --hg-cream: #f4f0e6;
  --hg-divider: #ece3d8;
  --hg-teal: #206b6a;

  --font: "Montserrat", system-ui, -apple-system, sans-serif;

  --shadow-sm: 0 1px 2px rgba(45, 43, 43, .14);
  --shadow-md: 0 3px 10px rgba(45, 43, 43, .16);
  --shadow-lg: 0 12px 32px rgba(45, 43, 43, .22);

  --radius: 15px;
  --header-h: 80px;
  --maxw: 1360px;
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
/* Form controls don't inherit font-family by default → force Montserrat
   (otherwise button text falls back to the UA font, e.g. Arial on Windows). */
button, input, select, textarea, optgroup { font-family: inherit; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--hg-ink);
  background: var(--hg-bg);
  overflow-x: hidden;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { font-family: var(--font); margin: 0; line-height: 1.2; }
:focus-visible { outline: 2px solid var(--hg-red); outline-offset: 2px; }
::selection { background: rgba(192, 39, 43, .28); }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(20px, 5vw, 56px); }
.section { padding: clamp(64px, 9vw, 120px) 0; scroll-margin-top: 90px; }
.section-title {
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 800;
  text-transform: uppercase;
  text-align: center;
  color: var(--hg-red-bright);
  margin: 0 0 12px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: var(--font); font-weight: 800; font-size: 15px; line-height: 1.2;
  padding: 13px 24px; border-radius: 999px; border: none; cursor: pointer;
  transition: background .25s ease, transform .25s ease, box-shadow .25s ease;
}
.btn-primary { background: var(--hg-red); color: #fff; }
.btn-primary:hover { background: var(--hg-red-dark); }
.btn-solid { background: #c80b0b; color: #fff; }
.btn-solid:hover { background: var(--hg-red-dark); }

/* ============================================================
   Header / navigation
   ============================================================ */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 60;
  height: var(--header-h);
  background: rgba(253, 251, 247, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--hg-divider);
  transition: transform .3s ease, height .3s ease, box-shadow .3s ease;
}
.site-header.is-scrolled { box-shadow: var(--shadow-sm); }
.site-header .container {
  height: 100%; display: flex; align-items: center; gap: clamp(16px, 3vw, 40px);
}
.brand { display: flex; align-items: center; gap: 10px; flex: none; }
.brand img { width: 99px; height: 46px; object-fit: contain; }
.main-nav { display: flex; gap: clamp(14px, 2vw, 28px); margin-left: 8px; }
.main-nav a {
  font-size: 15px; font-weight: 600; color: var(--hg-ink);
  padding-bottom: 4px; border-bottom: 2px solid transparent;
  transition: color .25s ease, border-color .25s ease;
}
.main-nav a:hover, .main-nav a.is-active {
  color: var(--hg-red); border-color: var(--hg-red); font-weight: 700;
}
.header-cta { margin-left: auto; flex: none; }
.nav-toggle {
  display: none; margin-left: auto; background: none; border: none;
  cursor: pointer; padding: 6px; color: var(--hg-ink);
}

/* Mobile drawer */
.mobile-nav {
  position: fixed; inset: var(--header-h) 0 auto 0; z-index: 55;
  background: var(--hg-bg); border-bottom: 1px solid var(--hg-divider);
  box-shadow: var(--shadow-md);
  display: none; flex-direction: column; padding: 12px clamp(20px, 5vw, 56px) 24px;
}
.mobile-nav.is-open { display: flex; }
.mobile-nav a { font-size: 17px; font-weight: 600; padding: 14px 0; border-bottom: 1px solid var(--hg-divider); }
.mobile-nav a:last-child { border-bottom: none; }
.mobile-nav .btn { margin-top: 16px; }

/* ============================================================
   Hero
   ============================================================ */
.hero { background: var(--hg-cream); padding-top: var(--header-h); }
.hero-banner {
  width: 100%; aspect-ratio: 1893 / 689; object-fit: cover; display: block;
}
.hero-cta {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 16px;
  padding: clamp(28px, 4vw, 40px) clamp(20px, 5vw, 56px);
  background: var(--hg-red-grad);
}
.hero-cta .btn {
  background: #c80b0b; color: #fff; border: 1px solid rgba(255, 255, 255, .5);
  font-weight: 800; text-transform: uppercase;
}
.hero-cta .btn:hover { background: #fff; color: var(--hg-red); }

/* ============================================================
   About / intro (tabs + collage)
   ============================================================ */
.about-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(min(340px, 100%), 1fr));
  gap: clamp(32px, 5vw, 64px); align-items: center;
}
.kicker {
  font-size: 12px; letter-spacing: .12em; text-transform: uppercase;
  color: var(--hg-red-dark); font-weight: 800; margin-bottom: 12px;
}
.about h2 { font-size: clamp(30px, 4vw, 44px); color: var(--hg-red-bright); margin-bottom: 20px; }
.tab-list { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 24px; }
.tab-btn {
  border: 1.5px solid var(--hg-red-dark); background: var(--hg-bg); color: var(--hg-red-dark);
  padding: 10px 18px; border-radius: 999px; font-family: var(--font);
  font-weight: 700; font-size: 14px; cursor: pointer; transition: all .2s ease;
}
.tab-btn:hover { background: rgba(192, 39, 43, .08); }
.tab-btn.is-active { background: var(--hg-red-dark); color: #fff; }
.tab-panel { display: none; }
.tab-panel.is-active { display: block; animation: hg-fadeup .4s ease both; }
.tab-panel h3 { font-size: clamp(16px, 1.8vw, 20px); font-weight: 600; color: #2d2b2b; margin-bottom: 20px; }
.tab-panel p { font-size: 18px; line-height: 1.8; color: #2d2b2b; font-weight: 500; margin: 0 0 16px; max-width: 56ch; }
.tab-panel strong { font-weight: 800; }
.about-hr { height: 2px; border: 0; background: var(--hg-divider); max-width: 120px; margin: 28px 0 0; }

.collage {
  display: grid; grid-template-columns: repeat(4, 1fr); grid-template-rows: repeat(4, 1fr);
  gap: 8px; aspect-ratio: 1 / 1;
}
.collage img { width: 100%; height: 100%; object-fit: cover; border-radius: 8px; }
/* Collage layouts */
.collage-1 img { grid-area: 1 / 1 / 5 / 5; }
.collage-3 img:nth-child(1) { grid-area: 1 / 1 / 5 / 3; }
.collage-3 img:nth-child(2) { grid-area: 1 / 3 / 3 / 5; }
.collage-3 img:nth-child(3) { grid-area: 3 / 3 / 5 / 5; }
.collage-8 img:nth-child(1) { grid-area: 1 / 1 / 3 / 3; }
.collage-8 img:nth-child(2) { grid-area: 1 / 3 / 3 / 5; }
.collage-8 img:nth-child(3) { grid-area: 3 / 1 / 4 / 2; }
.collage-8 img:nth-child(4) { grid-area: 3 / 2 / 4 / 3; }
.collage-8 img:nth-child(5) { grid-area: 3 / 3 / 4 / 4; }
.collage-8 img:nth-child(6) { grid-area: 3 / 4 / 4 / 5; }
.collage-8 img:nth-child(7) { grid-area: 4 / 1 / 5 / 3; }
.collage-8 img:nth-child(8) { grid-area: 4 / 3 / 5 / 5; }

/* ============================================================
   Activities
   ============================================================ */
.activities { background: var(--hg-red-grad); border-radius: 20px; padding-top: clamp(40px, 5vw, 64px); padding-bottom: clamp(40px, 5vw, 64px); }
.activities .section-title { color: #fff; }
.activities .subtitle { text-align: center; font-size: 22px; color: #f8f4f4; font-style: italic; margin-bottom: 54px; }
.activities .subtitle b { font-size: 18px; }
.activity-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr)); gap: 24px; }
.activity-card {
  display: flex; flex-direction: column; overflow: hidden; border-radius: var(--radius);
  background: var(--hg-bg); box-shadow: var(--shadow-sm); transition: transform .3s ease;
}
.activity-card:hover { transform: translateY(-10px); }
.activity-card .thumb { aspect-ratio: 4 / 3; overflow: hidden; cursor: pointer; }
.activity-card .thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s ease; }
.activity-card:hover .thumb img { transform: scale(1.04); }
.activity-card .body { display: flex; flex-direction: column; gap: 10px; padding: 24px; }
.activity-card h3 { font-size: 19px; color: #b52f1d; }
.activity-card .btn { align-self: flex-start; margin-top: 6px; }

/* ============================================================
   Modal
   ============================================================ */
.modal-backdrop {
  position: fixed; inset: 0; z-index: 200; display: none;
  place-items: center; padding: 16px;
  background: rgba(45, 43, 43, .5);
}
.modal-backdrop.is-open { display: grid; }
.modal {
  width: min(960px, 100%); max-height: 90vh; overflow: auto; position: relative;
  display: grid; grid-template-columns: 1.15fr 1fr; align-items: stretch;
  background: var(--hg-bg); border-radius: 20px; box-shadow: var(--shadow-lg);
}
.modal-close {
  position: absolute; top: 16px; right: 16px; width: 36px; height: 36px;
  border-radius: 50%; border: none; background: var(--hg-bg); box-shadow: var(--shadow-sm);
  cursor: pointer; display: flex; align-items: center; justify-content: center; z-index: 2;
}
.modal-text { padding: clamp(28px, 4vw, 48px); display: flex; flex-direction: column; gap: 16px; }
.modal-text h3 { font-weight: 800; font-size: 22px; color: var(--hg-red-dark); }
.modal-text p { margin: 0; font-size: 15px; line-height: 1.8; }
.modal-meta { display: flex; flex-direction: column; gap: 8px; }
.modal-meta div { font-size: 14.5px; }
.modal-meta strong { color: var(--hg-red-dark); }
.modal-note { font-size: 14.5px; color: var(--hg-red-dark); font-weight: 600; }
.modal-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 8px; }
.modal-img { position: relative; min-height: 280px; overflow: hidden; background: #f8f4f4; }
.modal-img img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }

/* ============================================================
   Schedule (accordion)
   ============================================================ */
.schedule {
  background: url("../images/bg-schedule.webp") center / cover no-repeat;
  padding: clamp(64px, 9vw, 120px) 0;
}
.schedule .accordion {
  max-width: 900px; margin: 0 auto;
  border: 2px solid var(--hg-divider); border-radius: 20px; background: var(--hg-bg);
  padding: 8px clamp(16px, 3vw, 32px); box-shadow: var(--shadow-sm);
}
.acc-item { border-bottom: 2px solid var(--hg-divider); }
.acc-item:last-child { border-bottom: none; }
.acc-header {
  width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 16px;
  background: none; border: none; cursor: pointer; padding: 24px 4px; text-align: left;
  color: var(--hg-ink);
}
.acc-title { display: flex; flex-direction: column; gap: 8px; min-width: 0; }
.acc-month {
  align-self: flex-start; font-weight: 800; font-size: 13px; letter-spacing: .08em;
  text-transform: uppercase; color: #fff; background: var(--hg-red-dark);
  border-radius: 999px; padding: 4px 14px;
}
.acc-name { font-weight: 800; font-size: clamp(17px, 2.2vw, 21px); line-height: 1.4; }
.acc-chevron { flex: none; color: var(--hg-red-dark); transition: transform .3s ease; }
.acc-item.is-open .acc-chevron { transform: rotate(180deg); }
.acc-body { overflow: hidden; max-height: 0; opacity: 0; transition: max-height .35s ease, opacity .3s ease; }
.acc-item.is-open .acc-body { max-height: 600px; opacity: 1; }
.acc-body-inner { padding: 0 4px 28px; }
.acc-body-inner > p { margin: 0 0 20px; font-size: 16.5px; line-height: 1.75; color: rgba(32, 30, 29, .78); font-weight: 500; }
.acc-sub { font-weight: 800; font-size: 13px; letter-spacing: .06em; text-transform: uppercase; color: var(--hg-red-dark); margin-bottom: 12px; }
.acc-acts { display: flex; flex-direction: column; gap: 12px; background: rgba(192, 39, 43, .05); border-radius: 14px; padding: 16px 18px; }
.acc-acts p { margin: 0; font-size: 15.5px; line-height: 1.65; font-weight: 500; }
.acc-acts strong { font-weight: 700; color: #2d2b2b; }

/* ============================================================
   Journey (year timeline)
   ============================================================ */
.journey .section-title { color: var(--hg-red-bright); margin-bottom: 56px; }
.journey-years { position: relative; display: flex; justify-content: space-between; gap: 8px; margin-bottom: 48px; }
.journey-years::before { content: ""; position: absolute; left: 0; right: 0; top: 11px; height: 2px; background: var(--hg-divider); z-index: 0; }
.year-btn {
  position: relative; z-index: 1; display: flex; flex-direction: column; align-items: center; gap: 12px;
  background: none; border: none; cursor: pointer; padding: 0; flex: 1;
}
.year-dot { width: 12px; height: 12px; border-radius: 50%; background: #d7d3d3; border: 3px solid var(--hg-bg); transition: all .25s ease; }
.year-label { font-weight: 600; font-size: 17px; color: var(--hg-ink); transition: all .25s ease; }
.year-btn.is-active .year-dot { width: 18px; height: 18px; background: var(--hg-red-dark); box-shadow: 0 0 0 2px rgba(174, 24, 0, .25); }
.year-btn.is-active .year-label { font-weight: 800; font-size: 22px; color: var(--hg-red-dark); }
.journey-detail { display: grid; grid-template-columns: min(320px, 40%) 1fr; gap: clamp(24px, 3vw, 40px); align-items: center; }
.journey-photo { position: relative; aspect-ratio: 4 / 5; overflow: hidden; border-radius: 20px; background: #2d2b2b; }
.journey-photo img { width: 100%; height: 100%; object-fit: cover; }
.stop-tags { display: flex; flex-wrap: wrap; gap: 12px; }
.stop-tag {
  border: 1px solid var(--hg-divider); background: #f8f4f4; color: var(--hg-ink);
  border-radius: 999px; padding: 10px 20px; font-size: 15px; cursor: pointer; transition: all .2s ease;
}
.stop-tag.is-active { background: var(--hg-red-dark); color: #fff; }
.stop-detail { margin-top: 24px; padding: 20px 24px; background: #f8f4f4; border-radius: 16px; border: 1px solid var(--hg-divider); animation: hg-fadeup .4s ease both; }
.stop-detail .place { font-weight: 800; color: var(--hg-red-dark); margin-bottom: 8px; }
.stop-detail p { margin: 0 0 16px; font-size: 15px; line-height: 1.7; }

/* ============================================================
   Stats / impact
   ============================================================ */
.impact { background: var(--hg-red-deep); color: #fff; }
.impact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(340px, 100%), 1fr)); gap: clamp(32px, 5vw, 64px); align-items: center; }
.impact h2 { font-size: clamp(26px, 3.4vw, 38px); margin-bottom: 16px; }
.impact > .impact-grid p { font-size: 18px; line-height: 1.8; font-weight: 600; margin: 0 0 40px; max-width: 52ch; }
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(150px, 100%), 1fr)); gap: 20px; }
.stat { background: #fff; padding: 22px 16px; border: 1px solid rgba(255, 255, 255, .25); transition: box-shadow .3s ease; }
.stat:hover { box-shadow: 0 0 0 1px #ff9783; }
.stat-num { font-weight: 800; font-size: clamp(30px, 4vw, 42px); color: var(--hg-red-deep); line-height: 1; white-space: nowrap; }
.stat-label { font-size: 16px; color: #000; margin-top: 8px; font-weight: 800; line-height: 1.3; }
.impact-photo { aspect-ratio: 4 / 5; border-radius: 20px; overflow: hidden; border: 1px solid rgba(255, 255, 255, .25); }
.impact-photo img { width: 100%; height: 100%; object-fit: cover; }

/* ============================================================
   Donate
   ============================================================ */
.donate {
  position: relative; display: flex; justify-content: center;
  background: url("../images/bg-donate.webp") center / cover no-repeat;
  padding: clamp(64px, 9vw, 120px) clamp(20px, 5vw, 56px);
  scroll-margin-top: 90px;
}
.donate-card {
  position: relative; max-width: 820px; width: 100%; background: var(--hg-bg);
  border: 2px solid var(--hg-ink); border-radius: var(--radius);
  padding: clamp(28px, 4vw, 48px); box-shadow: var(--shadow-lg);
}
.donate-card .eyebrow { font-size: clamp(26px, 4vw, 40px); text-transform: uppercase; color: var(--hg-red-dark); font-weight: 800; text-align: center; }
.donate-card h2 { font-size: 20px; margin: 0 0 20px; text-align: center; font-weight: 500; }
.donate-body { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(220px, 100%), 1fr)); gap: 32px; align-items: center; }
.bank-info { display: flex; flex-direction: column; gap: 10px; text-align: center; }
.bank-row { border-radius: 20px; padding: 12px 24px; color: #fff; background: var(--hg-teal); }
.bank-row:nth-child(even) { background: #2e6a69; }
.bank-row span { font-size: 16px; font-weight: 500; }
.bank-info .btn { margin-top: 12px; background: var(--hg-red-deep); color: #fff; white-space: normal; line-height: 1.3; }
.donate-qr { width: 320px; max-width: 100%; aspect-ratio: 1 / 1; margin: 0 auto; object-fit: contain; }
.donate-note { margin: 24px 0 0; font-size: 13.5px; line-height: 1.6; color: #605d5d; text-align: center; font-style: italic; }

/* ============================================================
   Footer
   ============================================================ */
.site-footer { background: #8f0000; color: #fff; padding: clamp(48px, 6vw, 80px) 0 32px; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(220px, 100%), 1fr)); gap: 40px; }
.site-footer h4 { font-weight: 800; font-size: 18px; letter-spacing: .08em; text-transform: uppercase; margin-bottom: 12px; }
.footer-brand strong { font-size: 22px; }
.site-footer p { font-size: 16px; line-height: 1.7; margin: 0; max-width: 32ch; }
.footer-contact div, .footer-social a { display: flex; gap: 10px; align-items: flex-start; font-size: 16px; line-height: 1.5; margin-bottom: 10px; }
.footer-contact svg, .footer-social svg { flex-shrink: 0; margin-top: 3px; }
.footer-social a:hover { color: #ff9783; }
.footer-hr { height: 1px; border: 0; background: rgba(255, 255, 255, .22); margin: 32px 0 20px; }
.footer-copy { font-size: 12px; }

/* ============================================================
   Animations & responsive
   ============================================================ */
@keyframes hg-fadeup { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes hg-bounce { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(6px); } }

@media (max-width: 800px) {
  .main-nav, .header-cta { display: none; }
  .nav-toggle { display: block; }
  .modal { grid-template-columns: 1fr; }
  .modal-img { min-height: 220px; order: -1; }
  .journey-detail { grid-template-columns: 1fr; }
  .journey-photo { max-width: 320px; margin: 0 auto; }
  .year-label { font-size: 14px; }
  .year-btn.is-active .year-label { font-size: 17px; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
}