:root {
  color-scheme: light;
  --bg-1: #e7f3ff;
  --bg-2: #f7efe4;
  --bg-3: #d6ebdf;
  --ink: #1d2430;
  --ink-soft: #4a5564;
  --panel: rgba(255, 255, 255, 0.74);
  --panel-border: rgba(255, 255, 255, 0.65);
  --shadow: 0 14px 42px rgba(20, 32, 47, 0.15);
  --accent: #155a80;
  --accent-soft: rgba(21, 90, 128, 0.14);
  --safe-top: max(14px, env(safe-area-inset-top));
  --safe-right: max(14px, env(safe-area-inset-right));
  --safe-bottom: max(16px, env(safe-area-inset-bottom));
  --safe-left: max(14px, env(safe-area-inset-left));
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  color: var(--ink);
  font-family: "Trebuchet MS", "Avenir Next", "Segoe UI", sans-serif;
}

body {
  background:
    radial-gradient(130% 120% at 8% 8%, rgba(255, 255, 255, 0.7) 0%, rgba(255, 255, 255, 0) 55%),
    radial-gradient(110% 105% at 96% 12%, rgba(255, 245, 217, 0.62) 0%, rgba(255, 245, 217, 0) 56%),
    linear-gradient(148deg, var(--bg-1), var(--bg-2) 52%, var(--bg-3));
  position: relative;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    repeating-linear-gradient(
      24deg,
      rgba(255, 255, 255, 0.11) 0,
      rgba(255, 255, 255, 0.11) 1px,
      rgba(255, 255, 255, 0) 1px,
      rgba(255, 255, 255, 0) 11px
    ),
    repeating-linear-gradient(
      -20deg,
      rgba(10, 24, 42, 0.025) 0,
      rgba(10, 24, 42, 0.025) 1px,
      rgba(10, 24, 42, 0) 1px,
      rgba(10, 24, 42, 0) 13px
    );
}

h1,
h2,
h3,
p,
ul {
  margin: 0;
}

button,
a {
  font: inherit;
}

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

/* Landing */

.site-shell {
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: calc(var(--safe-top) + 1.4rem) calc(var(--safe-right) + 1rem) calc(var(--safe-bottom) + 1.2rem) calc(var(--safe-left) + 1rem);
}

.landing-main {
  width: min(560px, 100%);
  padding: clamp(1.15rem, 3.2vw, 1.9rem);
  border-radius: 1.25rem;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: var(--shadow);
  backdrop-filter: blur(6px);
}

.landing-main h1 {
  font-size: clamp(1.65rem, 6.3vw, 2.5rem);
  letter-spacing: 0.01em;
}

.landing-main p {
  margin-top: 0.6rem;
  font-size: clamp(1rem, 3.3vw, 1.12rem);
  color: var(--ink-soft);
}

.language-grid {
  margin-top: 1rem;
  display: grid;
  gap: 0.65rem;
}

.lang-link {
  display: block;
  width: 100%;
  text-align: center;
  text-decoration: none;
  padding: 0.9rem 1rem;
  border-radius: 0.9rem;
  border: 1px solid rgba(21, 90, 128, 0.2);
  background: rgba(255, 255, 255, 0.72);
  color: var(--ink);
  font-size: clamp(1.03rem, 3.1vw, 1.16rem);
  font-weight: 700;
}

.lang-link:hover,
.lang-link:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.lang-link.suggested {
  border-color: var(--accent);
  background: rgba(255, 255, 255, 0.9);
}

.helper-text {
  margin-top: 0.75rem;
  min-height: 1.2em;
  font-size: 0.92rem;
  color: var(--ink-soft);
}

.continue-wrap {
  margin-top: 0.55rem;
}

.continue-link {
  display: inline-block;
  text-decoration: none;
  font-size: 0.91rem;
  color: var(--accent);
  border-bottom: 1px solid rgba(21, 90, 128, 0.45);
}

/* Reader */

body[data-page="reader"] {
  overflow: hidden;
}

.reader-shell {
  position: relative;
  width: 100vw;
  height: 100svh;
  overflow: hidden;
}

.booklet {
  width: 100vw;
  height: 100svh;
  display: flex;
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.booklet::-webkit-scrollbar {
  display: none;
}

.page {
  flex: 0 0 100vw;
  width: 100vw;
  height: 100svh;
  scroll-snap-align: start;
  padding:
    calc(var(--safe-top) + 2.4rem)
    calc(var(--safe-right) + 1rem)
    calc(var(--safe-bottom) + 3.2rem)
    calc(var(--safe-left) + 1rem);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.page-inner {
  width: min(860px, 100%);
  max-height: 100%;
  padding: clamp(0.9rem, 2.4vw, 1.55rem);
  border-radius: 1.15rem;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: clamp(0.6rem, 1.5vw, 0.9rem);
  overflow: hidden;
}

.page-kicker {
  font-size: 0.79rem;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.page h1,
.page h2 {
  line-height: 1.07;
  letter-spacing: -0.01em;
}

.page h1 {
  font-size: clamp(1.58rem, 6vw, 2.75rem);
}

.page h2 {
  font-size: clamp(1.34rem, 5vw, 2.15rem);
}

.page p,
.page li {
  font-size: clamp(0.98rem, 2.95vw, 1.15rem);
  line-height: 1.39;
  color: var(--ink);
}

.page ul {
  padding-left: 1.15rem;
  display: grid;
  gap: 0.35rem;
}

.image-placeholder {
  width: 100%;
  height: clamp(102px, 17svh, 158px);
  border: 1px dashed rgba(21, 90, 128, 0.34);
  border-radius: 0.8rem;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.74), rgba(228, 238, 250, 0.67));
  display: grid;
  place-items: center;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.chrome-btn {
  position: fixed;
  top: calc(var(--safe-top) + 0.45rem);
  right: calc(var(--safe-right) + 0.45rem);
  z-index: 25;
  width: 2rem;
  height: 2rem;
  border: 1px solid rgba(21, 90, 128, 0.35);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.85);
  display: grid;
  place-items: center;
  font-size: 1rem;
  line-height: 1;
}

.chrome-btn:hover,
.chrome-btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.page-indicator {
  position: fixed;
  z-index: 20;
  left: 50%;
  transform: translateX(-50%);
  bottom: calc(var(--safe-bottom) + 0.55rem);
  min-width: 4.6rem;
  text-align: center;
  font-size: 0.86rem;
  letter-spacing: 0.04em;
  color: var(--ink-soft);
  background: rgba(255, 255, 255, 0.8);
  border-radius: 999px;
  padding: 0.2rem 0.58rem;
  border: 1px solid rgba(21, 90, 128, 0.2);
}

.edge-zone {
  position: fixed;
  top: 0;
  bottom: 0;
  z-index: 18;
  width: clamp(54px, 15vw, 190px);
  border: 0;
  background: transparent;
  color: transparent;
  cursor: pointer;
}

.edge-zone:focus-visible {
  outline: none;
  box-shadow: inset 0 0 0 3px var(--accent-soft);
}

.edge-left {
  left: 0;
}

.edge-right {
  right: 0;
}

/* Language overlay */

.lang-modal {
  position: fixed;
  inset: 0;
  z-index: 40;
  background: rgba(19, 31, 44, 0.36);
  display: grid;
  place-items: center;
  padding: 1rem;
}

.lang-card {
  width: min(360px, 92vw);
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--shadow);
  border: 1px solid rgba(21, 90, 128, 0.2);
  padding: 1rem;
  display: grid;
  gap: 0.62rem;
}

.lang-card h2 {
  font-size: 1.15rem;
}

.lang-actions {
  display: grid;
  gap: 0.5rem;
}

.lang-choice,
.close-modal {
  width: 100%;
  padding: 0.58rem 0.72rem;
  border-radius: 0.75rem;
  border: 1px solid rgba(21, 90, 128, 0.32);
  background: rgba(255, 255, 255, 0.95);
  color: var(--ink);
  text-align: center;
}

.lang-choice:hover,
.lang-choice:focus-visible,
.close-modal:hover,
.close-modal:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--accent-soft);
}

@media (orientation: landscape) {
  .page {
    padding-top: calc(var(--safe-top) + 2rem);
    padding-bottom: calc(var(--safe-bottom) + 2.6rem);
  }

  .page h1 {
    font-size: clamp(1.36rem, 3.8vw, 2.45rem);
  }

  .page h2 {
    font-size: clamp(1.2rem, 3.3vw, 1.9rem);
  }

  .page p,
  .page li {
    font-size: clamp(0.9rem, 1.62vw, 1.04rem);
  }

  .two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    align-items: start;
  }
}

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