:root {
  color-scheme: light;
  --blue-950: #08245e;
  --blue-900: #0a347f;
  --blue-800: #0b4cc4;
  --blue-700: #0b63f6;
  --blue-600: #2176ff;
  --blue-100: #dceaff;
  --blue-50: #f0f6ff;
  --cyan: #32c7e6;
  --green: #20a968;
  --green-soft: #eafaf2;
  --amber: #e99312;
  --amber-soft: #fff7df;
  --red: #df4b55;
  --red-soft: #fff0f1;
  --purple: #7257da;
  --ink: #14213d;
  --muted: #64728b;
  --paper: #ffffff;
  --surface: #f7f9fc;
  --surface-strong: #edf2f8;
  --line: #dce4ef;
  --shadow-sm: 0 8px 24px rgba(25, 58, 112, 0.08);
  --shadow-md: 0 22px 60px rgba(25, 58, 112, 0.13);
  --shadow-lg: 0 28px 80px rgba(25, 58, 112, 0.18);
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --radius-sm: 14px;
  --radius-md: 22px;
  --radius-lg: 32px;
  --font-scale: 1;
  --sidebar-width: 308px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 92px;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 0 0, rgba(50, 199, 230, 0.09), transparent 28rem),
    linear-gradient(180deg, #f8fbff 0, #f2f6fb 100%);
  color: var(--ink);
  font-family: Inter, "Segoe UI", Arial, sans-serif;
  font-size: calc(16px * var(--font-scale));
  line-height: 1.72;
  transition: background 0.25s ease, color 0.25s ease;
}

body::before {
  position: fixed;
  z-index: -1;
  inset: 0;
  background-image: radial-gradient(rgba(11, 99, 246, 0.08) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: linear-gradient(to bottom, black, transparent 70%);
  content: "";
  pointer-events: none;
}

body.panel-open,
body.sidebar-open {
  overflow: hidden;
}

a {
  color: var(--blue-800);
  text-decoration: none;
}

button,
input,
textarea {
  font: inherit;
}

button {
  position: relative;
  overflow: hidden;
  color: inherit;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible,
summary:focus-visible {
  outline: 3px solid rgba(11, 99, 246, 0.28);
  outline-offset: 3px;
}

img {
  max-width: 100%;
}

::selection {
  background: rgba(50, 199, 230, 0.28);
  color: var(--blue-950);
}

.tap-ripple {
  position: absolute;
  z-index: 0;
  width: 14px;
  height: 14px;
  border-radius: 999px;
  background: currentColor;
  opacity: 0.18;
  pointer-events: none;
  transform: translate(-50%, -50%) scale(0);
  animation: tapRipple 0.58s var(--ease-out);
}

@keyframes tapRipple {
  to {
    opacity: 0;
    transform: translate(-50%, -50%) scale(18);
  }
}

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

.screenonly {
  display: initial;
}

.printonly {
  display: none;
}

.reading-progress {
  position: fixed;
  z-index: 100;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: rgba(11, 99, 246, 0.08);
}

.reading-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan), var(--blue-700), #7c58e8);
  transition: width 0.08s linear;
}

.topbar {
  position: sticky;
  z-index: 50;
  top: 0;
  display: flex;
  min-height: 72px;
  padding: 10px clamp(16px, 4vw, 54px);
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid rgba(220, 228, 239, 0.85);
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 6px 30px rgba(25, 58, 112, 0.06);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 11px;
  color: var(--ink);
}

.brand:hover {
  text-decoration: none;
}

.brand img {
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 13px;
  box-shadow: var(--shadow-sm);
}

.brand span {
  display: grid;
  line-height: 1.1;
}

.brand strong {
  color: var(--blue-900);
  font-size: 1.18rem;
  letter-spacing: -0.02em;
}

.brand small {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.71rem;
  font-weight: 650;
}

.top-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
}

.icon-btn,
.primary-btn,
.secondary-btn {
  min-height: 42px;
  border: 0;
  border-radius: 13px;
  cursor: pointer;
  font-weight: 750;
  isolation: isolate;
  transition: transform 0.18s var(--ease-out), background 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.icon-btn {
  display: inline-flex;
  padding: 0 13px;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
}

.icon-btn:hover,
.secondary-btn:hover {
  border-color: #b9c9df;
  background: var(--blue-50);
  transform: translateY(-1px);
  box-shadow: 0 10px 24px rgba(25, 58, 112, 0.09);
}

.icon-btn kbd {
  padding: 2px 6px;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 0.7rem;
}

.primary-btn {
  padding: 0 17px;
  background: linear-gradient(135deg, var(--blue-700), var(--blue-800));
  color: #fff;
  box-shadow: 0 10px 24px rgba(11, 99, 246, 0.22);
}

.primary-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 13px 30px rgba(11, 99, 246, 0.3);
}

.icon-btn:active,
.primary-btn:active,
.secondary-btn:active,
.cover-primary:active,
.cover-secondary:active {
  transform: translateY(1px) scale(0.98);
}

.secondary-btn {
  padding: 0 17px;
  border: 1px solid var(--line);
  background: var(--paper);
}

.mobile-menu {
  display: none;
}

.layout {
  display: grid;
  max-width: 1510px;
  padding: 24px clamp(14px, 2vw, 30px) 80px;
  margin: 0 auto;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  gap: 28px;
}

.sidebar {
  position: sticky;
  top: 96px;
  height: calc(100vh - 120px);
  padding: 20px;
  overflow: auto;
  border: 1px solid rgba(220, 228, 239, 0.9);
  border-radius: 26px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: var(--shadow-sm);
  scrollbar-width: thin;
}

.sidebar-head {
  padding: 3px 2px 15px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  display: inline-block;
  color: var(--blue-700);
  font-size: 0.73rem;
  font-weight: 850;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.sidebar-title {
  display: flex;
  margin: 3px 0 10px;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.sidebar-title h2 {
  margin: 0;
  color: var(--blue-950);
  font-size: 1.18rem;
}

.sidebar-title span {
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--blue-50);
  color: var(--blue-800);
  font-size: 0.75rem;
  font-weight: 800;
}

.mini-progress {
  height: 7px;
  overflow: hidden;
  border-radius: 99px;
  background: #e4ebf4;
}

.mini-progress span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--cyan), var(--blue-700));
  transition: width 0.35s ease;
}

.search-box {
  position: relative;
  display: block;
  margin: 16px 0 10px;
}

.search-box::before {
  position: absolute;
  top: 50%;
  left: 13px;
  width: 13px;
  height: 13px;
  border: 2px solid var(--muted);
  border-radius: 50%;
  content: "";
  transform: translateY(-60%);
}

.search-box::after {
  position: absolute;
  top: calc(50% + 5px);
  left: 25px;
  width: 6px;
  height: 2px;
  background: var(--muted);
  content: "";
  transform: rotate(45deg);
}

.search-box input,
#globalSearchInput,
.calculator-display input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface);
  color: var(--ink);
}

.search-box input {
  height: 44px;
  padding: 0 12px 0 39px;
  font-size: 0.86rem;
}

.sidebar-filter {
  display: flex;
  margin-bottom: 11px;
  gap: 6px;
  overflow-x: auto;
}

.filter-chip {
  padding: 6px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 0.68rem;
  font-weight: 800;
  white-space: nowrap;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

.filter-chip.active {
  border-color: var(--blue-700);
  background: var(--blue-700);
  color: #fff;
}

.filter-chip:hover {
  border-color: #abc2e2;
  background: var(--blue-50);
  color: var(--blue-800);
  transform: translateY(-1px);
}

.filter-chip.active:hover {
  border-color: var(--blue-700);
  background: var(--blue-700);
  color: #fff;
}

.toc-hint {
  display: block;
  margin: 0 2px 8px;
  color: var(--muted);
  font-size: 0.72rem;
}

.sidebar ol {
  padding: 0;
  margin: 0;
  list-style: none;
  counter-reset: chapter;
}

.sidebar li {
  position: relative;
  margin: 2px 0;
}

.sidebar li::before {
  position: absolute;
  z-index: 2;
  top: 12px;
  left: 10px;
  display: grid;
  width: 22px;
  height: 22px;
  border-radius: 8px;
  background: var(--surface-strong);
  color: var(--muted);
  content: counter(chapter, decimal-leading-zero);
  counter-increment: chapter;
  font-size: 0.58rem;
  font-weight: 850;
  place-items: center;
  pointer-events: none;
}

.sidebar li.completed::before {
  background: var(--green);
  color: #fff;
  content: "OK";
}

.sidebar li.bookmarked a::after {
  position: absolute;
  top: 50%;
  right: 10px;
  width: 7px;
  height: 10px;
  border-radius: 2px 2px 4px 4px;
  background: var(--amber);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 72%, 0 100%);
  content: "";
  transform: translateY(-50%);
}

.sidebar li a {
  position: relative;
  display: block;
  padding: 10px 24px 10px 42px;
  border-radius: 11px;
  color: #4b5a72;
  font-size: 0.78rem;
  font-weight: 680;
  line-height: 1.35;
  transition: background 0.16s ease, color 0.16s ease, transform 0.16s var(--ease-out), box-shadow 0.16s ease;
}

.sidebar li a:hover,
.sidebar li.active a {
  background: var(--blue-50);
  color: var(--blue-800);
  text-decoration: none;
}

.sidebar li.active a {
  box-shadow: inset 3px 0 var(--blue-700);
}

.sidebar li a:hover {
  transform: translateX(2px);
  box-shadow: 0 8px 18px rgba(25, 58, 112, 0.07);
}

.sidebar li[hidden] {
  display: none;
}

main {
  min-width: 0;
}

.cover {
  position: relative;
  display: grid;
  min-height: 680px;
  padding: clamp(34px, 5vw, 72px);
  overflow: hidden;
  border-radius: 38px;
  background:
    radial-gradient(circle at var(--cover-glow-x, 78%) var(--cover-glow-y, 23%), rgba(50, 199, 230, 0.38), transparent 23rem),
    radial-gradient(circle at 18% 100%, rgba(122, 87, 218, 0.35), transparent 30rem),
    linear-gradient(135deg, #071c4a, #0a3a91 45%, #0b63f6);
  color: #fff;
  box-shadow: 0 30px 80px rgba(5, 38, 97, 0.28);
  grid-template-columns: minmax(0, 1.08fr) minmax(330px, 0.92fr);
  align-items: center;
  isolation: isolate;
  transition: box-shadow 0.24s ease;
}

.cover:hover {
  box-shadow: 0 36px 95px rgba(5, 38, 97, 0.34);
}

.cover::before,
.cover::after {
  position: absolute;
  z-index: -1;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 50%;
  content: "";
}

.cover::before {
  top: -150px;
  right: -60px;
  width: 530px;
  height: 530px;
}

.cover::after {
  right: 110px;
  bottom: -310px;
  width: 620px;
  height: 620px;
}

.cover-copy {
  position: relative;
  z-index: 2;
}

.pill,
.kicker {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  font-size: 0.76rem;
  font-weight: 850;
  letter-spacing: 0.05em;
}

.pill {
  padding: 8px 13px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(255, 255, 255, 0.1);
  color: #dff5ff;
  text-transform: uppercase;
}

.cover-brand {
  display: flex;
  margin-top: 22px;
  align-items: center;
  gap: 12px;
  color: #fff;
  font-size: 1.45rem;
  font-weight: 900;
}

.cover-brand img {
  width: 54px;
  height: 54px;
  border-radius: 16px;
  box-shadow: 0 14px 35px rgba(2, 17, 48, 0.3);
}

.cover h1 {
  max-width: 720px;
  margin: 23px 0 20px;
  font-size: clamp(3rem, 5.5vw, 5.7rem);
  letter-spacing: -0.065em;
  line-height: 0.98;
}

.cover h1 em {
  color: #8fe8ff;
  font-style: normal;
}

.cover-copy > p {
  max-width: 670px;
  margin: 0;
  color: #dceaff;
  font-size: clamp(1rem, 1.5vw, 1.2rem);
}

.cover-actions {
  display: flex;
  margin: 30px 0;
  flex-wrap: wrap;
  gap: 10px;
}

.cover-primary,
.cover-secondary {
  position: relative;
  display: inline-flex;
  min-height: 50px;
  padding: 0 20px;
  border-radius: 14px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-weight: 800;
  isolation: isolate;
  transition: transform 0.18s var(--ease-out), background 0.18s ease, box-shadow 0.18s ease;
}

.cover-primary {
  background: #fff;
  color: var(--blue-900);
  box-shadow: 0 13px 30px rgba(2, 17, 48, 0.22);
}

.cover-primary:hover {
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 18px 34px rgba(2, 17, 48, 0.28);
}

.cover-secondary {
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.cover-secondary:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateY(-1px);
}

.cover-stats {
  display: flex;
  max-width: 590px;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  gap: clamp(24px, 4vw, 54px);
}

.cover-stats div {
  display: grid;
}

.cover-stats strong {
  font-size: 1.55rem;
  line-height: 1.1;
}

.cover-stats span {
  color: #bdcfef;
  font-size: 0.75rem;
  font-weight: 650;
}

.cover-visual {
  position: relative;
  z-index: 1;
  align-self: end;
  min-height: 580px;
}

.cover-visual > img {
  position: absolute;
  right: -4%;
  bottom: -6%;
  width: min(590px, 118%);
  max-width: none;
  filter: drop-shadow(0 35px 38px rgba(2, 17, 48, 0.34));
  animation: mascotFloat 5s ease-in-out infinite;
}

@keyframes mascotFloat {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.mascot-bubble {
  position: absolute;
  z-index: 3;
  top: 70px;
  right: 0;
  display: grid;
  max-width: 220px;
  padding: 14px 17px;
  border-radius: 18px 18px 4px 18px;
  background: #fff;
  color: var(--ink);
  box-shadow: var(--shadow-md);
  line-height: 1.4;
}

.mascot-bubble b {
  color: var(--blue-800);
}

.mascot-bubble span {
  color: var(--muted);
  font-size: 0.78rem;
}

.orbit {
  position: absolute;
  z-index: 3;
  display: grid;
  --orbit-rotate: 0deg;
  width: 48px;
  height: 48px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.13);
  color: #fff;
  font-weight: 900;
  place-items: center;
  backdrop-filter: blur(8px);
  transform: rotate(var(--orbit-rotate));
  animation: orbitFloat 6.5s ease-in-out infinite;
}

.orbit-one {
  top: 25%;
  left: 3%;
  --orbit-rotate: -8deg;
}

.orbit-two {
  top: 13%;
  left: 31%;
  --orbit-rotate: 10deg;
  animation-delay: -2s;
}

.orbit-three {
  top: 46%;
  right: -1%;
  --orbit-rotate: 7deg;
  animation-delay: -4s;
}

@keyframes orbitFloat {
  0%,
  100% {
    transform: translateY(0) rotate(var(--orbit-rotate));
  }
  50% {
    transform: translateY(-9px) rotate(calc(var(--orbit-rotate) + 3deg));
  }
}

.learning-home {
  margin: 28px 0;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.88);
  box-shadow: var(--shadow-sm);
}

.dashboard-copy {
  display: grid;
  grid-template-columns: 1fr minmax(280px, 0.55fr);
  column-gap: 30px;
  align-items: end;
}

.dashboard-copy .eyebrow {
  grid-column: 1 / -1;
}

.dashboard-copy h2 {
  margin: 5px 0 0;
  color: var(--blue-950);
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  letter-spacing: -0.045em;
  line-height: 1.08;
}

.dashboard-copy p {
  margin: 0;
  color: var(--muted);
  font-size: 0.91rem;
}

.dashboard-grid {
  display: grid;
  margin-top: 22px;
  grid-template-columns: 1.2fr 0.8fr 0.8fr 1.2fr;
  gap: 12px;
}

.stat-card {
  position: relative;
  min-height: 154px;
  padding: 19px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
}

.stat-card::after {
  position: absolute;
  right: -42px;
  bottom: -54px;
  width: 116px;
  height: 116px;
  border-radius: 50%;
  background: rgba(50, 199, 230, 0.11);
  content: "";
  pointer-events: none;
}

.stat-card > span {
  display: block;
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 800;
}

.stat-card > strong {
  display: block;
  margin: 7px 0 9px;
  color: var(--blue-950);
  font-size: 2rem;
  line-height: 1;
}

.stat-card small {
  color: var(--muted);
  font-size: 0.7rem;
}

.primary-stat {
  background: linear-gradient(135deg, var(--blue-50), #f5f1ff);
}

.quick-actions {
  display: grid;
  margin-top: 11px;
  gap: 7px;
}

.quick-actions button {
  padding: 8px 11px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper);
  cursor: pointer;
  color: var(--blue-800);
  font-size: 0.75rem;
  font-weight: 780;
  text-align: left;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, border-color 0.16s ease;
}

.quick-actions button:hover {
  border-color: #aac4ee;
  background: var(--blue-50);
  transform: translateY(-1px);
}

.chapter {
  position: relative;
  padding: clamp(24px, 4vw, 46px);
  margin: 28px 0;
  border: 1px solid rgba(220, 228, 239, 0.92);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--shadow-sm);
  scroll-margin-top: 95px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s var(--ease-out), opacity 0.2s ease;
}

.chapter.current-chapter {
  border-color: rgba(11, 99, 246, 0.35);
  box-shadow: 0 24px 65px rgba(25, 58, 112, 0.14);
}

.chapter-meter {
  position: absolute;
  top: 0;
  left: clamp(24px, 4vw, 46px);
  right: clamp(24px, 4vw, 46px);
  height: 4px;
  overflow: hidden;
  border-radius: 0 0 999px 999px;
  background: rgba(11, 99, 246, 0.08);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.chapter-meter span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--cyan), var(--blue-700), var(--purple));
  transition: width 0.12s linear;
}

.chapter.current-chapter .chapter-meter {
  opacity: 1;
}

.chapter.completed-chapter::after {
  position: absolute;
  top: 0;
  right: 34px;
  width: 13px;
  height: 30px;
  border-radius: 0 0 6px 6px;
  background: var(--green);
  content: "";
}

.chapter h1 {
  max-width: 850px;
  margin: 7px 0 10px;
  color: var(--blue-950);
  font-size: clamp(1.9rem, 3.2vw, 3rem);
  letter-spacing: -0.045em;
  line-height: 1.08;
}

.chapter h2 {
  margin: 30px 0 12px;
  color: var(--blue-950);
  font-size: 1.35rem;
  letter-spacing: -0.02em;
}

.chapter h3 {
  line-height: 1.3;
}

.kicker {
  padding: 6px 11px;
  background: var(--blue-50);
  color: var(--blue-700);
}

.intro {
  max-width: 900px;
  color: #506079;
  font-size: 1.04rem;
}

.chapter-actions {
  display: flex;
  margin: 14px 0 22px;
  flex-wrap: wrap;
  gap: 8px;
}

.chapter-action {
  display: inline-flex;
  min-height: 38px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 11px;
  align-items: center;
  gap: 7px;
  background: var(--paper);
  color: var(--muted);
  cursor: pointer;
  font-size: 0.75rem;
  font-weight: 800;
  isolation: isolate;
  transition: transform 0.16s var(--ease-out), border-color 0.16s ease, background 0.16s ease, color 0.16s ease, box-shadow 0.16s ease;
}

.chapter-action:hover {
  border-color: #b8cce6;
  background: var(--blue-50);
  color: var(--blue-800);
  transform: translateY(-1px);
  box-shadow: 0 9px 20px rgba(25, 58, 112, 0.08);
}

.chapter-action::before {
  display: inline-block;
  width: 10px;
  height: 10px;
  border: 2px solid currentColor;
  border-radius: 4px;
  content: "";
}

.chapter-action.complete.active {
  border-color: #b6e8cf;
  background: var(--green-soft);
  color: #14794b;
}

.chapter-action.complete.active::before {
  border-color: var(--green);
  background: var(--green);
  box-shadow: inset 0 0 0 2px var(--green-soft);
}

.chapter-action.bookmark.active {
  border-color: #f2d38f;
  background: var(--amber-soft);
  color: #9a6109;
}

.chapter-action.bookmark::before {
  border: 0;
  border-radius: 2px 2px 4px 4px;
  background: currentColor;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 72%, 0 100%);
}

.chapter-action.note::before {
  border-radius: 2px;
  background: linear-gradient(to bottom, transparent 30%, currentColor 31%, currentColor 42%, transparent 43%, transparent 62%, currentColor 63%, currentColor 74%, transparent 75%);
}

.chapter-action.note.active {
  border-color: #cbd8ff;
  background: var(--blue-50);
  color: var(--blue-800);
}

.grid2,
.grid3,
.challenge-grid {
  display: grid;
  gap: 15px;
}

.grid2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.interactive-surface {
  transition: transform 0.22s var(--ease-out), border-color 0.22s ease, box-shadow 0.22s ease, background 0.22s ease, opacity 0.22s ease;
  will-change: transform;
}

.reveal-ready .reveal-item {
  opacity: 0;
  transform: translateY(16px);
}

.reveal-ready .reveal-item.in-view {
  opacity: 1;
  transform: translateY(0);
}

@media (hover: hover) and (pointer: fine) {
  .interactive-surface.in-view:hover,
  .interactive-surface:not(.reveal-item):hover {
    border-color: rgba(11, 99, 246, 0.28);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
  }

  .quiz.interactive-surface.in-view:hover,
  .solution.interactive-surface.in-view:hover,
  .example.interactive-surface.in-view:hover,
  .tip.interactive-surface.in-view:hover,
  .mistake.interactive-surface.in-view:hover {
    transform: translateY(-2px);
  }
}

.card h3 {
  margin: 0 0 8px;
  color: var(--blue-950);
}

.card p:last-child {
  margin-bottom: 0;
}

.card.blue {
  border-color: #c9dcff;
  background: #f0f6ff;
}

.card.yellow {
  border-color: #f4dda2;
  background: #fff9e9;
}

.card.green {
  border-color: #c5ebd8;
  background: #f0fbf5;
}

.card.purple {
  border-color: #ddd3ff;
  background: #f7f4ff;
}

.card.pink {
  border-color: #f3cfe1;
  background: #fff4f9;
}

.card.cyan {
  border-color: #bdebf4;
  background: #f0fbfd;
}

.card.red {
  border-color: #f3c7cb;
  background: var(--red-soft);
}

.formula {
  padding: 18px 20px;
  margin: 12px 0;
  overflow-x: auto;
  border: 1px solid #254378;
  border-radius: 17px;
  background:
    linear-gradient(135deg, rgba(35, 119, 255, 0.13), transparent),
    #091b3a;
  color: #e8f1ff;
  font-family: "Cascadia Code", Consolas, monospace;
  font-size: 0.9rem;
  line-height: 1.8;
  white-space: pre-line;
}

.formula .tag {
  color: #ffe08b;
  font-weight: 850;
}

.example,
.solution,
.mistake,
.tip {
  padding: 17px 19px;
  margin: 16px 0;
  border: 1px solid;
  border-left-width: 5px;
  border-radius: 4px 17px 17px 4px;
}

.example {
  border-color: #bcd4ff;
  border-left-color: var(--blue-700);
  background: var(--blue-50);
}

.example h3 {
  margin: 0 0 7px;
  color: var(--blue-900);
}

.solution {
  border-color: #bce8d2;
  border-left-color: var(--green);
  background: var(--green-soft);
}

.solution summary {
  cursor: pointer;
  color: #126f45;
  font-weight: 850;
}

.solution[open] summary {
  margin-bottom: 9px;
}

.mistake {
  border-color: #f0c5ca;
  border-left-color: var(--red);
  background: var(--red-soft);
}

.tip {
  border-color: #f3dba2;
  border-left-color: var(--amber);
  background: var(--amber-soft);
}

.level {
  display: flex;
  margin-bottom: 13px;
  flex-wrap: wrap;
  gap: 7px;
}

.badge {
  padding: 5px 9px;
  border-radius: 999px;
  font-size: 0.7rem;
  font-weight: 850;
}

.b1 {
  background: #dceaff;
  color: #174f9e;
}

.b2 {
  background: #dff7eb;
  color: #14794b;
}

.b3 {
  background: #fff0c7;
  color: #96600d;
}

.b4 {
  background: #fce2ee;
  color: #9b3566;
}

.b5 {
  background: #ebe4ff;
  color: #5b42b0;
}

.svgbox {
  padding: 18px;
  margin: 16px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--paper);
  text-align: center;
}

.svgbox svg {
  width: min(100%, 760px);
  height: auto;
}

.svgbox small {
  display: block;
  margin-top: 7px;
  color: var(--muted);
}

.quiz {
  position: relative;
  padding: 22px;
  margin: 20px 0;
  overflow: hidden;
  border: 1px solid #bed6ff;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #f4f8ff, #f8f6ff);
}

.quiz::before {
  position: absolute;
  top: 0;
  right: 0;
  padding: 6px 12px;
  border-radius: 0 0 0 12px;
  background: var(--blue-100);
  color: var(--blue-800);
  content: "Cek pemahaman";
  font-size: 0.65rem;
  font-weight: 850;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.quiz h3 {
  margin: 0 0 8px;
  color: var(--blue-950);
}

.quiz button {
  position: relative;
  display: block;
  width: 100%;
  min-height: 44px;
  padding: 10px 46px 10px 13px;
  margin: 8px 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
  cursor: pointer;
  font-weight: 700;
  text-align: left;
  transition: border 0.15s ease, background 0.15s ease, transform 0.15s ease;
}

.quiz button::after {
  position: absolute;
  top: 50%;
  right: 13px;
  display: grid;
  width: 24px;
  height: 24px;
  border-radius: 999px;
  background: var(--surface-strong);
  color: var(--muted);
  content: "";
  font-size: 0.62rem;
  font-weight: 900;
  line-height: 1;
  opacity: 0;
  transform: translateY(-50%) scale(0.7);
  place-items: center;
  transition: opacity 0.16s ease, transform 0.16s var(--ease-out), background 0.16s ease, color 0.16s ease;
}

.quiz button:hover:not(:disabled) {
  border-color: #9dbfff;
  transform: translateX(2px);
}

.quiz button.correct {
  border-color: #7ed0a6;
  background: var(--green-soft);
  color: #126f45;
}

.quiz button.correct::after {
  background: var(--green);
  color: #fff;
  content: "OK";
  opacity: 1;
  transform: translateY(-50%) scale(1);
}

.quiz button.wrong {
  border-color: #eba6ae;
  background: var(--red-soft);
  color: #a5313c;
}

.quiz button.wrong::after {
  background: var(--red);
  color: #fff;
  content: "!";
  opacity: 1;
  transform: translateY(-50%) scale(1);
}

.quiz button:disabled {
  cursor: default;
}

.quiz .feedback {
  min-height: 24px;
  margin: 12px 0 0;
  font-size: 0.82rem;
  font-weight: 800;
}

.practice li {
  margin: 8px 0;
  padding-left: 4px;
}

.callout {
  display: grid;
  min-height: 156px;
  padding: 19px 22px 19px 10px;
  overflow: hidden;
  border: 1px solid #c8d9f9;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--blue-50), #f7f3ff);
  grid-template-columns: 130px 1fr;
  align-items: center;
  gap: 12px;
}

.callout-mascot {
  width: 150px;
  margin: -15px 0 -37px -5px;
}

.chapter-note {
  margin: 18px 0 0;
  padding: 16px;
  border: 1px solid #d6dff0;
  border-radius: 17px;
  background: #fbfcff;
}

.chapter-note[hidden] {
  display: none;
}

.chapter-note label {
  display: flex;
  margin-bottom: 8px;
  align-items: center;
  justify-content: space-between;
  color: var(--blue-950);
  font-size: 0.8rem;
  font-weight: 850;
}

.chapter-note label span {
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 650;
}

.chapter-note textarea {
  width: 100%;
  min-height: 120px;
  padding: 13px;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.55;
}

.note-area {
  min-height: 92px;
  padding: 14px;
  border: 2px dashed #bfd1e9;
  border-radius: 15px;
  background: var(--paper);
  color: var(--muted);
}

.table-wrap {
  overflow-x: auto;
}

.tbl {
  width: 100%;
  margin: 12px 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-collapse: separate;
  border-radius: 17px;
  background: var(--paper);
  border-spacing: 0;
}

.tbl th,
.tbl td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.tbl th {
  background: var(--blue-50);
  color: var(--blue-900);
  font-size: 0.78rem;
}

.tbl tr:last-child td {
  border-bottom: 0;
}

.checklist label {
  display: block;
  padding: 11px 13px;
  margin: 8px 0;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--paper);
}

.checklist input {
  margin-right: 8px;
  accent-color: var(--blue-700);
}

.footer-nav {
  display: flex;
  margin-top: 26px;
  justify-content: space-between;
  gap: 10px;
}

.footer-nav a {
  position: relative;
  overflow: hidden;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper);
  color: var(--blue-800);
  font-size: 0.75rem;
  font-weight: 800;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, border-color 0.16s ease, box-shadow 0.16s ease;
}

.footer-nav a:hover {
  border-color: #aac4ee;
  background: var(--blue-50);
  box-shadow: 0 8px 18px rgba(25, 58, 112, 0.08);
  text-decoration: none;
  transform: translateY(-1px);
}

.challenge-bank {
  background:
    radial-gradient(circle at 100% 0, rgba(50, 199, 230, 0.08), transparent 25rem),
    var(--paper);
}

.challenge-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.challenge-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.challenge-card > span {
  color: var(--blue-700);
  font-size: 0.68rem;
  font-weight: 850;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.challenge-card h3 {
  margin: 5px 0 7px;
  color: var(--blue-950);
}

.challenge-card .solution {
  margin-bottom: 0;
  padding: 12px 14px;
}

.tool-dock {
  position: fixed;
  z-index: 45;
  right: 22px;
  bottom: 22px;
  display: flex;
  padding: 7px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: var(--shadow-md);
  gap: 5px;
  backdrop-filter: blur(14px);
}

.tool-dock button {
  display: flex;
  min-height: 45px;
  padding: 0 12px;
  border: 0;
  border-radius: 12px;
  align-items: center;
  gap: 6px;
  background: transparent;
  cursor: pointer;
  color: var(--blue-900);
  font-size: 0.72rem;
  font-weight: 850;
  isolation: isolate;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, box-shadow 0.16s ease;
}

.tool-dock button:hover {
  background: var(--blue-50);
  transform: translateY(-2px);
  box-shadow: 0 10px 22px rgba(25, 58, 112, 0.09);
}

.tool-dock img {
  width: 32px;
  height: 32px;
  object-fit: contain;
}

.panel-backdrop {
  position: fixed;
  z-index: 70;
  inset: 0;
  background: rgba(4, 18, 48, 0.36);
  backdrop-filter: blur(3px);
}

.panel-backdrop[hidden] {
  display: none;
}

.utility-panel {
  position: fixed;
  z-index: 80;
  top: 0;
  right: 0;
  width: min(430px, 94vw);
  height: 100vh;
  padding: 28px;
  overflow-y: auto;
  border-left: 1px solid var(--line);
  background: var(--paper);
  box-shadow: -25px 0 70px rgba(5, 38, 97, 0.18);
  opacity: 0.98;
  transform: translateX(105%) scale(0.98);
  transition: transform 0.26s var(--ease-out), opacity 0.26s ease;
}

.utility-panel.open {
  opacity: 1;
  transform: translateX(0) scale(1);
}

.panel-head,
.dialog-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 15px;
}

.panel-head h2,
.dialog-head h2 {
  margin: 1px 0 0;
  color: var(--blue-950);
  font-size: 1.7rem;
  letter-spacing: -0.04em;
}

.panel-close,
.dialog-head button {
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  cursor: pointer;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

.panel-close:hover,
.dialog-head button:hover {
  border-color: #aac4ee;
  background: var(--blue-50);
  color: var(--blue-800);
  transform: translateY(-1px);
}

.assistant-hero {
  display: grid;
  min-height: 195px;
  padding: 12px 16px 12px 0;
  margin: 24px 0 16px;
  overflow: hidden;
  border: 1px solid #c9dcff;
  border-radius: 22px;
  background: linear-gradient(135deg, var(--blue-50), #f8f4ff);
  grid-template-columns: 140px 1fr;
  align-items: center;
}

.assistant-hero img {
  width: 165px;
  margin: -5px 0 -35px -18px;
  animation: mascotFloat 5.4s ease-in-out infinite;
}

.assistant-hero p {
  color: #41516b;
  font-size: 0.86rem;
}

.assistant-options {
  display: grid;
  gap: 8px;
}

.assistant-options button {
  min-height: 46px;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  cursor: pointer;
  color: var(--blue-900);
  font-weight: 780;
  text-align: left;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, border-color 0.16s ease;
}

.assistant-options button:hover {
  border-color: #a9c5f4;
  background: var(--blue-50);
  transform: translateX(2px);
}

.assistant-context {
  padding-top: 15px;
  margin-top: 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.74rem;
}

.calculator-display {
  display: block;
  margin: 26px 0 10px;
}

.calculator-display input {
  height: 58px;
  padding: 0 15px;
  font-family: "Cascadia Code", Consolas, monospace;
  font-size: 1.05rem;
}

.calculator-result {
  min-height: 54px;
  padding: 14px;
  border-radius: 12px;
  background: var(--blue-50);
  color: var(--blue-900);
  font-weight: 850;
  text-align: right;
}

.calculator-grid {
  display: grid;
  margin-top: 12px;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.calculator-grid button {
  min-height: 52px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  cursor: pointer;
  font-weight: 800;
  transition: transform 0.14s var(--ease-out), background 0.14s ease, border-color 0.14s ease, box-shadow 0.14s ease;
}

.calculator-grid button:hover {
  background: var(--blue-50);
  transform: translateY(-1px);
  box-shadow: 0 8px 16px rgba(25, 58, 112, 0.08);
}

.calculator-grid .calc-clear {
  grid-column: span 2;
  color: var(--red);
}

.calculator-grid .calc-equals {
  grid-column: span 2;
  border-color: var(--blue-700);
  background: var(--blue-700);
  color: #fff;
}

.panel-note {
  color: var(--muted);
  font-size: 0.75rem;
}

.timer-ring {
  display: grid;
  width: 230px;
  height: 230px;
  margin: 34px auto 24px;
  border: 12px solid var(--blue-100);
  border-radius: 50%;
  background: radial-gradient(circle, var(--paper), var(--blue-50));
  box-shadow: inset 0 0 0 2px #c7d9f7;
  place-content: center;
  text-align: center;
  transition: box-shadow 0.2s ease, transform 0.2s var(--ease-out);
}

body.timer-running .timer-ring {
  box-shadow: inset 0 0 0 2px #c7d9f7, 0 0 0 12px rgba(50, 199, 230, 0.1);
  transform: scale(1.02);
  animation: focusPulse 1.5s ease-in-out infinite;
}

@keyframes focusPulse {
  0%,
  100% {
    box-shadow: inset 0 0 0 2px #c7d9f7, 0 0 0 7px rgba(50, 199, 230, 0.08);
  }
  50% {
    box-shadow: inset 0 0 0 2px #c7d9f7, 0 0 0 16px rgba(50, 199, 230, 0.16);
  }
}

.timer-ring span {
  color: var(--blue-950);
  font-size: 3rem;
  font-weight: 900;
  letter-spacing: -0.06em;
  line-height: 1;
}

.timer-ring small {
  margin-top: 8px;
  color: var(--muted);
}

.timer-presets,
.timer-actions {
  display: flex;
  justify-content: center;
  gap: 8px;
}

.timer-presets button {
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  cursor: pointer;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

.timer-presets button:hover {
  border-color: #aac4ee;
  background: var(--blue-50);
  color: var(--blue-800);
  transform: translateY(-1px);
}

.timer-presets button.active {
  border-color: var(--blue-700);
  background: var(--blue-50);
  color: var(--blue-800);
}

.timer-actions {
  margin: 18px 0;
}

.search-dialog,
.challenge-dialog {
  width: min(760px, calc(100vw - 28px));
  max-height: min(720px, calc(100vh - 40px));
  padding: 24px;
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: 25px;
  background: var(--paper);
  color: var(--ink);
  box-shadow: 0 30px 100px rgba(5, 38, 97, 0.26);
}

.search-dialog[open],
.challenge-dialog[open] {
  animation: dialogEnter 0.22s var(--ease-out);
}

@keyframes dialogEnter {
  from {
    opacity: 0;
    transform: translateY(12px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.search-dialog::backdrop,
.challenge-dialog::backdrop {
  background: rgba(4, 18, 48, 0.42);
  backdrop-filter: blur(4px);
}

#globalSearchInput {
  height: 54px;
  padding: 0 16px;
  margin: 20px 0 12px;
}

.search-results {
  display: grid;
  gap: 8px;
}

.search-result {
  position: relative;
  display: block;
  padding: 13px 14px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface);
  color: var(--ink);
  transition: transform 0.16s var(--ease-out), background 0.16s ease, border-color 0.16s ease, box-shadow 0.16s ease;
}

.search-result:hover {
  border-color: #abc6f2;
  background: var(--blue-50);
  box-shadow: 0 9px 20px rgba(25, 58, 112, 0.08);
  text-decoration: none;
  transform: translateY(-1px);
}

.search-result strong {
  display: block;
  color: var(--blue-900);
}

.search-result small {
  display: block;
  margin-top: 3px;
  color: var(--muted);
}

.random-question {
  padding: 20px;
  margin-top: 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
}

.random-question h3 {
  margin-top: 0;
  color: var(--blue-950);
}

.display-settings {
  position: fixed;
  z-index: 44;
  left: max(18px, calc(50% - 735px));
  bottom: 22px;
  display: flex;
  padding: 6px;
  border: 1px solid var(--line);
  border-radius: 15px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: var(--shadow-md);
  transform: none;
  backdrop-filter: blur(14px);
}

.display-settings button,
.display-settings span {
  display: grid;
  min-height: 38px;
  padding: 0 10px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  place-items: center;
  font-size: 0.68rem;
  font-weight: 800;
}

.display-settings button {
  cursor: pointer;
  transition: transform 0.16s var(--ease-out), background 0.16s ease, color 0.16s ease;
}

.display-settings button:hover {
  background: var(--blue-50);
  color: var(--blue-800);
  transform: translateY(-1px);
}

.display-settings span {
  color: var(--muted);
}

.toast {
  position: fixed;
  z-index: 120;
  top: 86px;
  left: 50%;
  max-width: min(430px, calc(100vw - 28px));
  padding: 11px 15px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--blue-950);
  color: #fff;
  box-shadow: var(--shadow-md);
  font-size: 0.78rem;
  font-weight: 750;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, -15px);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

body.focus-mode .sidebar {
  display: none;
}

body.focus-mode .layout {
  max-width: 1050px;
  grid-template-columns: 1fr;
}

body.focus-mode .learning-home,
body.focus-mode .cover {
  display: none;
}

body.focus-mode .chapter:not(.current-chapter) {
  opacity: 0.42;
}

body.dark-mode {
  color-scheme: dark;
  --ink: #edf4ff;
  --muted: #aebbd0;
  --paper: #101b2f;
  --surface: #14223a;
  --surface-strong: #1b2d49;
  --line: #293d5d;
  --blue-950: #eef5ff;
  --blue-900: #b9d5ff;
  --blue-800: #8cbcff;
  --blue-50: #152b4e;
  --blue-100: #1a3764;
  --green-soft: #133126;
  --amber-soft: #352b14;
  --red-soft: #351a21;
  background: #091323;
}

body.dark-mode::before {
  opacity: 0.35;
}

body.dark-mode .topbar,
body.dark-mode .sidebar,
body.dark-mode .learning-home,
body.dark-mode .chapter,
body.dark-mode .tool-dock,
body.dark-mode .display-settings {
  background: rgba(16, 27, 47, 0.95);
}

body.dark-mode .intro,
body.dark-mode .dashboard-copy p {
  color: #b6c2d4;
}

body.dark-mode .card.blue,
body.dark-mode .card.yellow,
body.dark-mode .card.green,
body.dark-mode .card.purple,
body.dark-mode .card.pink,
body.dark-mode .card.cyan,
body.dark-mode .quiz,
body.dark-mode .callout {
  background: var(--surface);
  border-color: var(--line);
}

body.dark-mode .svgbox,
body.dark-mode .quiz button,
body.dark-mode .chapter-action,
body.dark-mode .footer-nav a,
body.dark-mode .checklist label,
body.dark-mode .chapter-note textarea {
  background: #0d182a;
}

body.dark-mode .cover {
  background:
    radial-gradient(circle at var(--cover-glow-x, 78%) var(--cover-glow-y, 23%), rgba(50, 199, 230, 0.25), transparent 23rem),
    linear-gradient(135deg, #06132f, #092b67 48%, #084cbf);
}

body.dark-mode .stat-card::after {
  background: rgba(50, 199, 230, 0.08);
}

body.dark-mode .interactive-surface:hover {
  box-shadow: 0 24px 65px rgba(0, 0, 0, 0.22);
}

body.dark-mode .utility-panel,
body.dark-mode .search-dialog,
body.dark-mode .challenge-dialog {
  background: var(--paper);
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }

  .reveal-ready .reveal-item {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 1180px) {
  .top-actions .icon-btn span {
    display: none;
  }

  .top-actions .icon-btn kbd {
    display: none;
  }

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

  .cover {
    grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.8fr);
  }

  .cover-visual > img {
    right: -18%;
  }

  .display-settings {
    left: 20px;
    transform: none;
  }
}

@media (max-width: 900px) {
  html {
    scroll-padding-top: 78px;
  }

  .topbar {
    min-height: 66px;
    padding: 9px 13px;
  }

  .brand small,
  .top-actions #focusButton,
  .top-actions #themeButton {
    display: none;
  }

  .brand img {
    width: 40px;
    height: 40px;
  }

  .mobile-menu {
    display: inline-flex;
  }

  .top-actions .mobile-menu span,
  .top-actions #searchButton span {
    display: inline;
  }

  .top-actions .primary-btn {
    display: none;
  }

  .layout {
    display: block;
    padding: 13px 12px 85px;
  }

  .sidebar {
    position: fixed;
    z-index: 65;
    top: 0;
    left: 0;
    width: min(350px, 92vw);
    height: 100vh;
    border-radius: 0 24px 24px 0;
    transform: translateX(-105%);
    transition: transform 0.22s ease;
  }

  body.sidebar-open .sidebar {
    transform: translateX(0);
  }

  body.sidebar-open::after {
    position: fixed;
    z-index: 60;
    inset: 0;
    background: rgba(4, 18, 48, 0.36);
    content: "";
    backdrop-filter: blur(3px);
  }

  .cover {
    min-height: auto;
    padding: 32px 25px 0;
    border-radius: 26px;
    grid-template-columns: 1fr;
  }

  .cover h1 {
    font-size: clamp(2.8rem, 13vw, 4.5rem);
  }

  .cover-stats {
    gap: 23px;
  }

  .cover-visual {
    min-height: 430px;
  }

  .cover-visual > img {
    right: 50%;
    bottom: -12%;
    width: 500px;
    transform: translateX(50%);
    animation: none;
  }

  .mascot-bubble {
    top: 45px;
    right: 0;
  }

  .orbit-one {
    top: 25%;
    left: 5%;
  }

  .orbit-two {
    top: 9%;
    left: 26%;
  }

  .dashboard-copy {
    display: block;
  }

  .dashboard-copy p {
    margin-top: 9px;
  }

  .grid2,
  .grid3,
  .challenge-grid {
    grid-template-columns: 1fr;
  }

  .chapter {
    padding: 25px 20px;
    border-radius: 24px;
  }

  .chapter-meter {
    left: 20px;
    right: 20px;
  }

  .tool-dock {
    right: 10px;
    bottom: 10px;
  }

  .tool-dock button:not(:first-child) {
    display: none;
  }

  .tool-dock button span {
    display: none;
  }

  .display-settings {
    display: none;
  }
}

@media (max-width: 620px) {
  .brand strong {
    font-size: 1rem;
  }

  .top-actions {
    gap: 5px;
  }

  .top-actions .icon-btn {
    padding: 0 9px;
    font-size: 0.72rem;
  }

  .cover {
    padding-right: 19px;
    padding-left: 19px;
  }

  .cover-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
  }

  .cover-stats strong {
    font-size: 1.28rem;
  }

  .cover-stats span {
    font-size: 0.62rem;
  }

  .cover-actions > * {
    width: 100%;
  }

  .mascot-bubble {
    max-width: 190px;
  }

  .learning-home {
    padding: 21px 17px;
    border-radius: 24px;
  }

  .dashboard-grid {
    grid-template-columns: 1fr 1fr;
  }

  .stat-card {
    min-height: 138px;
    padding: 15px;
  }

  .primary-stat,
  .quick-card {
    grid-column: 1 / -1;
  }

  .callout {
    padding: 14px;
    grid-template-columns: 1fr;
  }

  .callout-mascot {
    width: 120px;
    margin: -10px auto -35px;
  }

  .footer-nav {
    flex-wrap: wrap;
  }

}

@page {
  size: A4;
  margin: 15mm 13mm 17mm;
}

@media print {
  :root {
    --ink: #172033;
    --muted: #526071;
    --paper: #fff;
    --surface: #f8fafc;
    --line: #dbe3ed;
    --blue-950: #08245e;
  }

  body {
    background: #fff;
    color: var(--ink);
    font-size: 10.5pt;
  }

  body::before,
  .topbar,
  .sidebar,
  .learning-home,
  .footer-nav,
  .chapter-actions,
  .chapter-note,
  .tool-dock,
  .display-settings,
  .screenonly,
  .reading-progress {
    display: none !important;
  }

  .printonly {
    display: block;
  }

  .layout {
    display: block;
    max-width: none;
    padding: 0;
  }

  .cover {
    min-height: 255mm;
    padding: 22mm 16mm;
    border-radius: 0;
    box-shadow: none;
    break-after: page;
  }

  .cover h1 {
    font-size: 39pt;
  }

  .cover-visual {
    min-height: 120mm;
  }

  .cover-visual > img {
    width: 120mm;
  }

  .chapter {
    padding: 11mm;
    margin: 0 0 10mm;
    border-radius: 4mm;
    box-shadow: none;
  }

  .chapter h1 {
    font-size: 21pt;
  }

  .grid2,
  .grid3 {
    grid-template-columns: 1fr 1fr;
  }

  .card,
  .example,
  .solution,
  .tip,
  .mistake,
  .quiz,
  .svgbox {
    break-inside: avoid;
  }

  .quiz button {
    display: none;
  }

  .formula {
    white-space: pre-wrap;
  }
}