/* ===== Fonts ===== */
@font-face {
  font-family: "Atyp Display";
  src: url("../assets/fonts/AtypDisplay-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Atyp Display";
  src: url("../assets/fonts/AtypDisplay-Bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

/* ===== Tokens ===== */
:root {
  /* brand colors */
  --blue: #2e47e0;
  --blue-deep: #1d2bb0;
  --blue-night: #101a6b;
  --orange: #ff6500;
  --orange-2: #f35a00;
  --green: #1c8c3c;
  --cream: #ece7da;
  --cream-2: #f4f1e8;
  --ink: #0c1559;
  --white: #ffffff;

  /* spacing scale (4/8) */
  --s2: 8px;
  --s3: 12px;
  --s4: 16px;
  --s5: 24px;
  --s6: 32px;
  --s8: 48px;
  --s10: 64px;
  --section-y: clamp(64px, 9vw, 112px);
  --card-pad: clamp(24px, 3vw, 32px);
  --card-gap: clamp(16px, 2vw, 24px);

  /* type scale */
  --fs-eyebrow: 0.8rem;
  --ls-eyebrow: 0.14em;
  --fs-body: 1.0625rem;
  --fs-lead: clamp(1.125rem, 1.5vw, 1.35rem);
  --fs-h3: 1.5rem;
  --fs-h2: clamp(2rem, 5vw, 3.6rem);
  --fs-display: clamp(2.5rem, 6vw, 5rem);
  --fs-num: clamp(2.5rem, 4vw, 3.75rem);
  --lh-display: 0.95;
  --lh-tight: 1.1;
  --lh-body: 1.55;

  /* layout */
  --maxw: 1200px;
  --gutter: clamp(20px, 5vw, 56px);
  --radius: 16px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: "Atyp Display", "Segoe UI", system-ui, -apple-system, sans-serif;
  color: var(--white);
  background: var(--blue);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, p { margin: 0; }

/* unified visible focus for interactive elements */
a:focus-visible, button:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 3px;
  border-radius: 6px;
}

.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding-inline: var(--gutter); }

/* Display type */
.display {
  font-weight: 700;
  text-transform: uppercase;
  line-height: var(--lh-display);
  letter-spacing: -0.01em;
}
.accent { color: var(--orange); }

/* shared eyebrow */
.eyebrow, .card-eyebrow, .area .n {
  font-size: var(--fs-eyebrow);
  font-weight: 700;
  letter-spacing: var(--ls-eyebrow);
  text-transform: uppercase;
}

/* ===== Background ===== */
.bg-blue {
  position: relative;
  min-height: 100%;
  background:
    linear-gradient(180deg, rgba(16, 26, 107, 0.25), rgba(46, 71, 224, 0.0) 30%),
    var(--blue);
}
.bg-blue::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("../assets/img/bg.jpg");
  background-size: cover;
  background-position: center;
  opacity: 0.35;
  mix-blend-mode: screen;
  pointer-events: none;
  z-index: 0;
}
.bg-blue > * { position: relative; z-index: 1; }

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
  background: rgba(29, 43, 176, 0.92);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s4);
  padding-block: var(--s5);
}
.logo { height: 76px; width: auto; }

.header-meta {
  margin: 0 0 0 auto;
  font-family: "Atyp Display", "Segoe UI", system-ui, sans-serif;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: rgba(255, 255, 255, 0.92);
  text-align: right;
}
@media (max-width: 900px) {
  .header-meta { display: none; }
}

/* Language switch */
.lang {
  display: inline-flex;
  border: 1.5px solid rgba(255, 255, 255, 0.4);
  border-radius: 999px;
  overflow: hidden;
  font-size: 0.875rem;
  font-weight: 700;
}
.lang button {
  appearance: none;
  background: transparent;
  border: 0;
  color: var(--white);
  min-height: 44px;
  padding: 0 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  letter-spacing: 0.04em;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
  font-family: inherit;
}
.lang button[aria-pressed="true"] { background: var(--orange); color: var(--white); }

/* ===== Floating seeds (JS-driven field) ===== */
.seed-field {
  position: absolute;
  inset: 0;
  z-index: 1;
  overflow: hidden;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.9s ease;
}
.seed-field.ready { opacity: 1; }
.seed {
  position: absolute;
  top: 0;
  left: 0;
  filter: drop-shadow(0 14px 24px rgba(0, 0, 0, 0.18));
  will-change: transform;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  padding-block: var(--section-y);
  overflow: hidden;
}
.hero .wrap { position: relative; z-index: 3; text-align: center; }
.hero h1 {
  font-size: var(--fs-display);
  max-width: 22ch;
  margin-inline: auto;
}
.hero .sub {
  margin: var(--s5) auto 0;
  max-width: 52ch;
  font-size: var(--fs-lead);
  font-weight: 400;
  color: rgba(255, 255, 255, 0.92);
}
.hero .date-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--s3);
  margin-bottom: var(--s5);
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--orange);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.hero-tree {
  position: absolute;
  right: -5%;
  bottom: -14%;
  width: clamp(190px, 27vw, 440px);
  z-index: 1;
  pointer-events: none;
  filter: drop-shadow(0 30px 40px rgba(0, 0, 0, 0.25));
}

/* Decorative trees across the page */
.deco-tree {
  position: absolute;
  z-index: 0;
  pointer-events: none;
  filter: drop-shadow(0 20px 30px rgba(0, 0, 0, 0.2));
}
.tree-hero-left { left: -5%; bottom: -8%; width: clamp(140px, 19vw, 320px); opacity: 0.92; z-index: 1; }
.tree-event { right: -3%; bottom: -7%; width: clamp(140px, 18vw, 300px); opacity: 0.9; }
.tree-pisa-left { left: -4%; bottom: -6%; width: clamp(120px, 15vw, 240px); opacity: 0.85; }
.tree-footer { right: 2%; bottom: -12%; width: clamp(110px, 13vw, 200px); opacity: 0.85; }

/* Scroll-down indicator */
.scroll-down {
  position: absolute;
  left: 50%;
  bottom: var(--s5);
  transform: translateX(-50%);
  z-index: 3;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1.5px solid rgba(255, 255, 255, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  background: rgba(29, 43, 176, 0.35);
  backdrop-filter: blur(4px);
  animation: bob 1.8s ease-in-out infinite;
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease);
}
.scroll-down:hover { background: var(--orange); border-color: var(--orange); }
.scroll-down svg { width: 22px; height: 22px; }
@keyframes bob {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, 8px); }
}
@media (prefers-reduced-motion: reduce) {
  .scroll-down { animation: none; }
}

/* ===== Stats ===== */
.stats { padding-block: var(--section-y); }
.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--card-gap);
}
.flip {
  perspective: 1200px;
  height: 270px;
  cursor: pointer;
  outline: none;
}
.flip:focus-visible { outline: 3px solid #fff; outline-offset: 3px; border-radius: var(--radius); }
.flip-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.7s var(--ease);
  transform-style: preserve-3d;
}
.flip:hover .flip-inner,
.flip.is-flipped .flip-inner { transform: rotateY(180deg); }

.flip-face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: var(--card-pad);
  border-radius: var(--radius);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  overflow: hidden;
  box-shadow: 0 18px 40px rgba(12, 21, 89, 0.18);
}
.flip-back { transform: rotateY(180deg); justify-content: center; }

/* card colors */
.c-orange { background: var(--orange); color: #fff; }
.c-white { background: #fff; color: var(--ink); }
.c-blue { background: var(--blue-deep); color: #fff; }
.c-green { background: var(--green); color: #fff; }
.c-white .card-num { color: var(--orange); }

.card-eyebrow { opacity: 0.85; }
.card-main { display: flex; flex-direction: column; gap: var(--s2); }
.card-num {
  font-weight: 700;
  font-size: var(--fs-num);
  line-height: var(--lh-display);
}
.card-num.sm { font-size: clamp(2rem, 3.1vw, 2.8rem); }
.card-cap {
  font-size: var(--fs-body);
  font-weight: 600;
  line-height: 1.25;
  opacity: 0.9;
  max-width: 24ch;
}
.card-flip {
  align-self: flex-end;
  font-size: 1.5rem;
  line-height: 1;
  opacity: 0.5;
}
.card-lbl {
  margin: 0;
  font-size: var(--fs-lead);
  font-weight: 600;
  line-height: 1.35;
}

@media (prefers-reduced-motion: reduce) {
  .flip-inner { transition: none; }
}

/* ===== Generic section ===== */
.section { position: relative; padding-block: var(--section-y); overflow: hidden; }
.section > .wrap { position: relative; z-index: 1; }
.section .eyebrow {
  display: inline-block;
  color: var(--orange);
  margin-bottom: var(--s4);
}
.section h2 {
  font-size: var(--fs-h2);
  max-width: 18ch;
}
.section .lead {
  margin-top: var(--s5);
  max-width: 60ch;
  font-size: var(--fs-lead);
  font-weight: 400;
}

/* Light variants */
.section.light { background: var(--cream); color: var(--ink); }
.section.light .eyebrow { color: var(--orange-2); }

/* Event cards */
.event-cards {
  margin-top: var(--s8);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--card-gap);
}
.ev-card {
  display: flex;
  flex-direction: column;
  gap: var(--s4);
  padding: var(--card-pad);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.16);
  transition: transform 0.3s var(--ease), background 0.3s var(--ease);
}
.ev-card:hover { transform: translateY(-6px); background: rgba(255, 255, 255, 0.14); }
.ev-n {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--orange);
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
}
.ev-card p { margin: 0; font-size: var(--fs-lead); font-weight: 600; line-height: 1.35; }

/* What is PISA - areas */
.statement {
  font-size: var(--fs-h2);
  max-width: 16ch;
}
.areas {
  margin-top: var(--s8);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--card-gap);
}
.area {
  background: var(--blue);
  color: var(--white);
  border-radius: var(--radius);
  padding: var(--card-pad);
  position: relative;
  overflow: hidden;
}
.area .n { color: var(--orange); }
.area h3 { margin-top: var(--s2); font-size: var(--fs-h3); text-transform: uppercase; }
.area p { margin-top: var(--s3); font-weight: 400; font-size: var(--fs-body); color: rgba(255,255,255,0.85); }
.area-new { background: var(--orange); }
.area-new .n { color: #fff; }
.area-new p { color: rgba(255, 255, 255, 0.92); }

.pisa-tree { position: absolute; right: -3%; bottom: -5%; width: clamp(160px, 22vw, 320px); opacity: 0.95; pointer-events: none; }

/* ===== Invited countries (horizontal marquee) ===== */
.country-marquee {
  margin-top: var(--s6);
  display: flex;
  flex-direction: column;
  gap: var(--s3);
  /* fade edges */
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
}
.marquee-row { overflow: hidden; }
.marquee-track {
  display: flex;
  gap: var(--s3);
  width: max-content;
  will-change: transform;
  animation: marquee 42s linear infinite;
}
.marquee-track.dir-1 { animation-direction: reverse; }
.marquee-row:nth-child(1) .marquee-track { animation-duration: 38s; }
.marquee-row:nth-child(2) .marquee-track { animation-duration: 50s; }
.marquee-row:nth-child(3) .marquee-track { animation-duration: 44s; }
.country-marquee:hover .marquee-track { animation-play-state: paused; }
@keyframes marquee {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}
.country-chip {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: var(--s2);
  padding: 12px 18px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.16);
  white-space: nowrap;
}
.country-chip.is-org { background: rgba(255, 101, 0, 0.16); border-color: rgba(255, 101, 0, 0.45); }
.country-chip.is-host { background: rgba(255, 255, 255, 0.16); border-color: rgba(255, 255, 255, 0.55); }
.country-chip.is-host .c-tag { color: var(--orange); }
.country-chip .c-name { font-size: 1rem; font-weight: 700; }
.country-chip .c-tag { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: rgba(255, 255, 255, 0.8); }
@media (prefers-reduced-motion: reduce) {
  .marquee-track { animation: none; }
  .marquee-row { overflow-x: auto; }
}

/* ===== More about PISA (links) ===== */
.more-links { margin-top: var(--s8); }
.more-links .eyebrow { color: var(--orange-2); }
.link-row { margin-top: var(--s4); display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--card-gap); max-width: 720px; }
.more-link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: var(--s5);
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid rgba(12, 21, 89, 0.12);
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.more-link:hover { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(12, 21, 89, 0.12); }
.more-link-t { font-weight: 700; font-size: 1.25rem; color: var(--ink); }
.more-link-t::after { content: " \2197"; color: var(--orange-2); }
.more-link-d { font-size: 0.95rem; font-weight: 500; color: rgba(12, 21, 89, 0.65); }

/* ===== Footer ===== */
.site-footer { position: relative; overflow: hidden; padding-block: var(--s10); border-top: 1px solid rgba(255,255,255,0.1); }
.site-footer .wrap { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: var(--s5); align-items: center; justify-content: space-between; }
.site-footer .logo { height: 60px; }
.site-footer .meta { font-weight: 400; color: rgba(255,255,255,0.85); font-size: 0.95rem; }

/* ===== Responsive ===== */
@media (max-width: 1000px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .areas { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 820px) {
  .event-cards { grid-template-columns: 1fr; }
  .hero-tree { width: clamp(180px, 60vw, 340px); right: -10%; bottom: -2%; opacity: 0.9; }
  .hero .sub { background: rgba(29, 43, 176, 0.5); border-radius: 12px; padding: var(--s3) var(--s4); backdrop-filter: blur(2px); }
}
@media (max-width: 560px) {
  .stats-grid { grid-template-columns: 1fr; }
  .areas { grid-template-columns: 1fr; }
  .link-row { grid-template-columns: 1fr; }
}
@media (max-height: 620px) {
  .scroll-down { display: none; }
}