* {
  box-sizing: border-box
}

:root {
  --ink: #13241f;
  --muted: #71807b;
  --line: #dce6e1;
  --paper: #f6f8f5;
  --white: #fff;
  --mint: #b9efdc;
  --mint-strong: #3b9578;
  --orange: #ee8f43;
  --orange-soft: #fff0e2;
  --yellow: #f7d36e;
  --red: #dc6b61;
  --serif: Georgia, 'Times New Roman', serif;
  --mono: 'DM Mono', monospace;
  --sans: 'Noto Sans SC', sans-serif;
  --ease-out: cubic-bezier(.16, 1, .3, 1);
  --ease-spring: cubic-bezier(.34, 1.56, .64, 1);
  --ease-smooth: cubic-bezier(.4, 0, .2, 1)
}

html,
body {
  margin: 0;
  min-height: 100%;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper)
}

button {
  font: inherit;
  cursor: pointer;
  border: 0
}

.app-shell {
  display: flex;
  min-height: 100vh
}

.sidebar {
  width: 244px;
  flex: none;
  background: var(--ink);
  color: #eef8f3;
  padding: 31px 20px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  z-index: 5
}

.brand-mark {
  font-family: var(--serif);
  font-size: 29px;
  letter-spacing: -1.5px;
  display: grid;
  grid-template-columns: 16px auto;
  align-items: center;
  line-height: 1
}

.brand-mark small {
  grid-column: 2;
  font: 10px var(--mono);
  letter-spacing: 1.2px;
  color: #92a8a0;
  margin-top: 8px
}

.brand-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--mint);
  display: inline-block;
  box-shadow: 0 0 0 5px rgba(185, 239, 220, .12)
}

.main-nav {
  margin-top: 78px;
  display: grid;
  gap: 7px
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 14px 11px;
  background: transparent;
  color: #9cafaa;
  text-align: left;
  border-radius: 4px;
  font-weight: 600;
  font-size: 13px;
  transition: .2s
}

.nav-item:hover,
.nav-item.active {
  background: #243c34;
  color: #f5fffb
}

.nav-item.active {
  box-shadow: inset 3px 0 0 var(--mint)
}

.nav-index {
  font: 11px var(--mono);
  color: #779188
}

.nav-item.active .nav-index {
  color: var(--mint)
}

.sidebar-footer {
  margin-top: auto;
  border-top: 1px solid #2e4740;
  padding: 18px 9px 0;
  display: flex;
  gap: 9px;
  align-items: center;
  color: #bfcec8;
  font-size: 11px
}

.sidebar-footer small {
  display: block;
  color: #718981;
  font: 9px var(--mono);
  margin-top: 6px
}

.sync-dot {
  width: 7px;
  height: 7px;
  background: var(--mint);
  border-radius: 50%
}

.main-content {
  flex: 1;
  min-width: 0
}

.topbar {
  height: 78px;
  background: var(--white);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 4.2vw
}

.crumb {
  font: 12px var(--mono);
  color: #93a19c
}

.crumb b {
  padding: 0 11px;
  color: #c2cdc9
}

.crumb strong {
  font-family: var(--sans);
  font-weight: 600;
  color: var(--ink)
}

.top-actions {
  display: flex;
  gap: 20px;
  align-items: center
}

.day-chip {
  font: 11px var(--mono);
  color: var(--muted);
  padding: 9px 11px;
  border: 1px solid var(--line);
  border-radius: 3px
}

.day-chip b {
  color: var(--mint-strong)
}

.reset-btn {
  font: 11px var(--mono);
  color: #8c9995;
  background: none;
  text-decoration: underline;
  text-underline-offset: 3px
}

.menu-toggle,
.mobile-close {
  display: none
}

.view {
  display: none;
  padding: 42px 4.2vw 74px;
  max-width: 1400px;
  margin: auto
}

.active-view {
  display: block
}

.eyebrow {
  font: 11px var(--mono);
  letter-spacing: 1.6px;
  color: var(--mint-strong);
  text-transform: uppercase
}

.hero-title {
  font: 800 clamp(36px, 5vw, 72px);
  letter-spacing: -4px;
  line-height: 1.04;
  margin: 13px 0 17px;
  max-width: 780px
}

.hero-title em {
  font: normal 1em var(--serif);
  letter-spacing: -3px
}

.lede {
  max-width: 620px;
  color: #61706b;
  line-height: 1.8;
  font-size: 14px
}

.dashboard-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 39px
}

.quick-stats {
  display: flex;
  gap: 10px
}

.stat-card {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 16px 17px;
  min-width: 130px
}

.stat-card .stat-number {
  font: 29px var(--serif);
  display: block
}

.stat-card .stat-label {
  font-size: 11px;
  color: var(--muted);
  display: block;
  margin-top: 4px
}

.stat-card.accent {
  background: var(--mint);
  border-color: var(--mint)
}

.subject-switch {
  display: flex;
  border-bottom: 1px solid var(--line);
  margin-bottom: 0
}

.subject-tab {
  padding: 14px 21px 13px;
  background: none;
  color: var(--muted);
  font-size: 13px;
  position: relative
}

.subject-tab.active {
  color: var(--ink);
  font-weight: 800
}

.subject-tab.active:after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 14px;
  right: 14px;
  height: 3px;
  background: var(--mint-strong)
}

.subject-tab.orange.active:after {
  background: var(--orange)
}

.subject-panel {
  padding-top: 24px
}

.topic-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px
}

.topic-header h2 {
  font-size: 17px;
  margin: 0
}

.topic-header p {
  font-size: 12px;
  color: var(--muted);
  margin: 0
}

.topic-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 11px
}

.topic-card {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 19px 19px 16px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
  transition: .2s;
  position: relative
}

.topic-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px #18372b0c;
  border-color: #9cb8ad
}

.topic-icon {
  width: 35px;
  height: 35px;
  background: #edf6f1;
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-size: 18px;
  flex: none
}

.topic-card.orange .topic-icon {
  background: var(--orange-soft)
}

.topic-copy {
  min-width: 0;
  flex: 1
}

.topic-copy h3 {
  font-size: 14px;
  margin: 0 0 7px
}

.topic-copy p {
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
  margin: 0
}

.topic-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 15px;
  font: 10px var(--mono);
  color: #98a8a1
}

.priority {
  font: 10px var(--mono);
  padding: 3px 7px;
  border-radius: 2px
}

.priority.high {
  color: #c85d52;
  background: #fff0ee
}

.priority.medium {
  color: #af7a17;
  background: #fff8dc
}

.priority.low {
  color: #4e9a80;
  background: #eaf9f3
}

.progress-line {
  height: 4px;
  background: #edf1ef;
  margin-top: 11px
}

.progress-line span {
  display: block;
  height: 100%;
  background: var(--mint-strong)
}

.orange .progress-line span {
  background: var(--orange)
}

.section-label {
  font: 11px var(--mono);
  letter-spacing: 1.5px;
  color: #8e9a96;
  margin: 40px 0 15px
}

.split-grid {
  display: grid;
  grid-template-columns: 1.35fr .65fr;
  gap: 15px;
  margin-top: 18px
}

.paper-panel {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 23px
}

.paper-panel h3 {
  font-size: 16px;
  margin: 0
}

.paper-panel p {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.8
}

.plan-list {
  margin-top: 15px
}

.plan-row {
  display: grid;
  grid-template-columns: 58px 1fr 65px;
  gap: 13px;
  align-items: center;
  border-top: 1px solid #edf1ef;
  padding: 13px 0
}

.plan-row:first-child {
  border-top: 0
}

.plan-day {
  font: 12px var(--mono);
  color: var(--mint-strong)
}

.plan-row strong {
  font-size: 12px
}

.plan-row small {
  display: block;
  color: var(--muted);
  margin-top: 4px;
  font-size: 11px
}

.plan-hours {
  text-align: right;
  font: 11px var(--mono);
  color: #7c8c85
}

.day-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 8px;
  margin-top: 19px
}

.day-block {
  border: 1px solid var(--line);
  padding: 13px 10px;
  min-height: 100px;
  cursor: pointer
}

.day-block.active {
  border: 2px solid var(--mint-strong);
  padding: 12px 9px;
  background: #f5fffb
}

.day-block.done {
  background: #e8f8f1
}

.day-block b {
  font: 11px var(--mono);
  color: var(--mint-strong)
}

.day-block strong {
  display: block;
  font-size: 12px;
  margin-top: 15px
}

.day-block small {
  display: block;
  color: var(--muted);
  font-size: 10px;
  margin-top: 7px;
  line-height: 1.4
}

.detail-hero {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: flex-start;
  border-bottom: 1px solid var(--line);
  padding-bottom: 31px
}

.back-btn {
  background: none;
  color: var(--muted);
  font: 11px var(--mono);
  padding: 6px 0
}

.detail-title {
  font-size: clamp(29px, 4vw, 52px);
  letter-spacing: -2px;
  margin: 20px 0 11px
}

.detail-label {
  display: inline-block;
  font: 10px var(--mono);
  color: var(--mint-strong);
  background: #e8f8f1;
  padding: 6px 8px
}

.detail-progress {
  width: 190px;
  text-align: right
}

.detail-progress span {
  display: block;
  font: 12px var(--mono);
  color: var(--muted);
  margin-bottom: 8px
}

.detail-progress .progress-line {
  margin: 0
}

.lesson-layout {
  display: grid;
  grid-template-columns: 1.5fr .7fr;
  gap: 34px;
  padding-top: 33px
}

.lesson-main h2 {
  font-size: 20px;
  margin: 0 0 14px
}

.lesson-main p {
  font-size: 14px;
  line-height: 2;
  color: #4e5e58
}

.lesson-main ul {
  padding-left: 19px;
  color: #4e5e58;
  font-size: 14px;
  line-height: 2.1
}

.callout {
  background: var(--mint);
  padding: 19px 22px;
  margin: 24px 0;
  border-left: 4px solid var(--mint-strong)
}

.callout b {
  display: block;
  font-size: 13px;
  margin-bottom: 8px
}

.callout p {
  margin: 0;
  font-size: 13px;
  line-height: 1.8
}

.formula {
  background: #1c342c;
  color: #ecfff6;
  font: 18px var(--mono);
  padding: 23px;
  text-align: center;
  margin: 22px 0
}

.visual-figure {
  border: 1px solid var(--line);
  padding: 17px;
  background: #fbfcfb
}

.visual-figure svg {
  width: 100%;
  height: auto;
  display: block
}

.visual-figure figcaption {
  font-size: 11px;
  color: var(--muted);
  line-height: 1.6;
  margin-top: 10px
}

.quiz-panel {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 21px;
  align-self: start;
  position: sticky;
  top: 20px
}

.quiz-panel h3 {
  font-size: 14px;
  margin: 0 0 17px
}

.question {
  font-size: 13px;
  line-height: 1.7;
  margin: 0 0 15px
}

.answer-option {
  width: 100%;
  background: #f5f8f6;
  border: 1px solid transparent;
  padding: 11px;
  text-align: left;
  font-size: 12px;
  margin: 5px 0;
  color: var(--ink);
  transition: .2s
}

.answer-option:hover {
  border-color: var(--mint-strong)
}

.answer-option.correct {
  background: #e3f8ee;
  border-color: var(--mint-strong)
}

.answer-option.wrong {
  background: #fff0ee;
  border-color: var(--red)
}

.quiz-result {
  font-size: 12px;
  line-height: 1.6;
  margin: 13px 0 0;
  color: var(--muted)
}

.complete-btn {
  width: 100%;
  padding: 12px;
  background: var(--ink);
  color: #fff;
  font-size: 12px;
  margin-top: 17px
}

.complete-btn:disabled {
  background: #c7d2cd
}

.exam-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 30px
}

.exam-card {
  background: #fff;
  border: 1px solid var(--line);
  padding: 24px
}

.exam-card h3 {
  margin: 0;
  font-size: 16px
}

.exam-card .big {
  font: 45px var(--serif);
  margin: 20px 0 4px
}

.exam-card p {
  font-size: 12px;
  line-height: 1.8;
  color: var(--muted)
}

.type-bars {
  margin-top: 20px
}

.type-bar {
  display: grid;
  grid-template-columns: 80px 1fr 35px;
  align-items: center;
  gap: 9px;
  font-size: 11px;
  margin: 12px 0
}

.bar {
  height: 8px;
  background: #edf2ef
}

.bar i {
  height: 100%;
  background: var(--mint-strong);
  display: block
}

.bar.orange i {
  background: var(--orange)
}

.toast {
  position: fixed;
  right: 24px;
  bottom: 24px;
  background: var(--ink);
  color: #fff;
  font-size: 12px;
  padding: 12px 15px;
  transform: translateY(90px);
  opacity: 0;
  transition: .25s;
  z-index: 20
}

.toast.show {
  transform: translateY(0);
  opacity: 1
}

@media(max-width:900px) {
  .sidebar {
    position: fixed;
    left: -260px;
    top: 0;
    bottom: 0;
    transition: .25s
  }

  .sidebar.open {
    left: 0
  }

  .scrim {
    display: none;
    position: fixed;
    inset: 0;
    background: #10231c88;
    z-index: 4
  }

  .scrim.show {
    display: block
  }

  .mobile-close,
  .menu-toggle {
    display: block
  }

  .mobile-close {
    position: absolute;
    right: 17px;
    top: 23px;
    background: none;
    color: #b8ccc4;
    font-size: 24px
  }

  .menu-toggle {
    background: none;
    font-size: 22px;
    color: var(--ink);
    margin-right: 14px
  }

  .topbar {
    justify-content: flex-start
  }

  .top-actions {
    margin-left: auto
  }

  .view {
    padding-left: 5vw;
    padding-right: 5vw
  }

  .dashboard-head {
    display: block
  }

  .quick-stats {
    margin-top: 27px
  }

  .lesson-layout,
  .split-grid {
    grid-template-columns: 1fr
  }

  .quiz-panel {
    position: static
  }

  .detail-progress {
    width: 150px
  }

  .day-grid {
    grid-template-columns: repeat(4, 1fr)
  }
}

@media(max-width:560px) {
  .topbar {
    height: 68px;
    padding: 0 18px
  }

  .crumb span,
  .crumb b {
    display: none
  }

  .top-actions {
    gap: 8px
  }

  .reset-btn {
    display: none
  }

  .day-chip {
    padding: 8px 7px
  }

  .view {
    padding: 29px 18px 55px
  }

  .hero-title {
    font-size: 42px;
    letter-spacing: -2.5px
  }

  .lede {
    font-size: 13px
  }

  .quick-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 6px
  }

  .stat-card {
    min-width: 0;
    padding: 12px 10px
  }

  .stat-card .stat-number {
    font-size: 24px
  }

  .stat-card .stat-label {
    font-size: 10px
  }

  .subject-tab {
    padding: 13px 12px;
    font-size: 12px
  }

  .topic-list {
    grid-template-columns: 1fr
  }

  .topic-card {
    padding: 16px
  }

  .split-grid {
    margin-top: 17px
  }

  .paper-panel {
    padding: 18px
  }

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

  .detail-hero {
    display: block
  }

  .detail-progress {
    width: 100%;
    text-align: left;
    margin-top: 24px
  }

  .lesson-main p,
  .lesson-main ul {
    font-size: 13px
  }

  .exam-grid {
    grid-template-columns: 1fr
  }

  .hero-title em {
    letter-spacing: -2px
  }
}

.resource-grid {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 12px;
  margin-top: 24px
}

.resource-panel {
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 3px solid var(--yellow);
  padding: 18px 20px
}

.resource-panel p {
  font-size: 12px;
  line-height: 1.9;
  color: #4e5e58;
  margin: 10px 0 0
}

.resource-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px
}

.resource-link {
  font: 11px var(--mono);
  color: var(--mint-strong);
  background: #e8f8f1;
  border: 1px solid #cdeadd;
  padding: 7px 10px;
  text-decoration: none;
  transition: .2s
}

.resource-link:hover {
  background: var(--mint)
}

.resource-hint {
  font-size: 11px !important;
  color: var(--muted) !important
}

.doc-resource {
  display: grid;
  grid-template-columns: 48px 1fr 24px;
  align-items: center;
  gap: 12px;
  width: 100%;
  margin-top: 14px;
  padding: 12px 14px;
  color: var(--ink);
  background: #f7fbf8;
  border: 1px solid #cdeadd;
  text-decoration: none;
  transition: all .28s var(--ease-out)
}

.doc-resource:hover {
  transform: translateY(-2px);
  background: #e8f8f1;
  border-color: var(--mint-strong);
  box-shadow: 0 10px 24px #18372b12
}

.doc-resource.orange {
  background: #fff8f1;
  border-color: #f4cfaa
}

.doc-resource.orange:hover {
  background: var(--orange-soft);
  border-color: var(--orange)
}

.doc-resource-icon {
  display: grid;
  place-items: center;
  min-height: 32px;
  color: var(--mint-strong);
  border: 1px solid currentColor;
  font: 10px var(--mono);
  letter-spacing: .4px
}

.doc-resource.orange .doc-resource-icon {
  color: var(--orange)
}

.doc-resource-copy {
  min-width: 0
}

.doc-resource-copy strong,
.doc-resource-copy small {
  display: block
}

.doc-resource-copy strong {
  overflow: hidden;
  font-size: 12px;
  line-height: 1.45;
  text-overflow: ellipsis;
  white-space: nowrap
}

.doc-resource-copy small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.5
}

.doc-resource-arrow {
  color: var(--mint-strong);
  font-size: 18px;
  text-align: center
}

.doc-resource.orange .doc-resource-arrow {
  color: var(--orange)
}

.dashboard-resources,
.plan-resources,
.kp-resources {
  margin-top: 16px
}

.doc-resource-panel {
  border-left-color: var(--mint-strong)
}

.doc-resource-panel:has(.doc-resource.orange) {
  border-left-color: var(--orange)
}

.goal-card {
  background: #1c342c;
  color: #ecfff6;
  padding: 20px 22px;
  margin-bottom: 28px
}

.goal-card b {
  font: 11px var(--mono);
  letter-spacing: 1.5px;
  color: var(--mint)
}

.goal-card p {
  font-size: 15px !important;
  line-height: 1.9 !important;
  color: #f2fbf6 !important;
  margin: 10px 0
}

.goal-card small {
  display: block;
  font-size: 11px;
  line-height: 1.7;
  color: #9db8ad
}

.step-list {
  list-style: none;
  padding: 0 !important;
  margin: 0 0 8px
}

.step-list li {
  display: flex;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px dashed var(--line)
}

.step-list li:last-child {
  border-bottom: 0
}

.step-no {
  flex: none;
  font: 12px var(--mono);
  color: var(--orange);
  padding-top: 3px
}

.step-list p {
  margin: 0;
  font-size: 13px !important
}

.pitfall-list {
  list-style: none;
  padding: 0 !important
}

.pitfall-list li {
  background: #fff0ee;
  border-left: 3px solid var(--red);
  padding: 11px 14px;
  margin: 8px 0;
  font-size: 12px !important;
  line-height: 1.8
}

.mindmap-figure {
  background: #f3f8f5
}

.mindmap-svg {
  width: 100%;
  height: auto;
  display: block
}

.lesson-aside {
  align-self: start;
  position: sticky;
  top: 20px
}

.task-panel,
.lesson-aside .quiz-panel {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 21px;
  margin-bottom: 14px
}

.lesson-aside .quiz-panel {
  position: static
}

.task-panel h3 {
  font-size: 14px;
  margin: 6px 0 4px
}

.task-progress-text {
  font: 11px var(--mono);
  color: var(--muted);
  margin: 0 0 12px
}

.task-item {
  display: flex;
  align-items: center;
  gap: 10px;
  border: 1px solid #edf1ef;
  background: #fbfdfc;
  padding: 10px 12px;
  margin: 6px 0;
  transition: .2s
}

.task-item label {
  display: flex;
  flex: 1;
  gap: 10px;
  align-items: flex-start;
  cursor: pointer
}

.task-item input {
  margin-top: 3px;
  accent-color: var(--mint-strong)
}

.task-item span {
  font-size: 12px;
  line-height: 1.7;
  color: #4e5e58
}

.task-item.done {
  background: #f0faf5;
  border-color: #cdeadd
}

.task-item.done span {
  text-decoration: line-through;
  color: #8ba39a
}

.task-link {
  flex: none;
  background: none;
  font: 11px var(--mono);
  color: var(--mint-strong);
  text-decoration: underline;
  text-underline-offset: 3px;
  padding: 2px 0
}

.task-link:hover {
  color: var(--ink)
}

.daily-tasks {
  margin-top: 14px
}

@media(max-width:900px) {
  .resource-grid {
    grid-template-columns: 1fr
  }

  .doc-resource-copy strong {
    white-space: normal
  }

  .lesson-aside {
    position: static
  }
}

.kp-layout {
  display: grid;
  grid-template-columns: 270px 1fr;
  gap: 0;
  border: 1px solid var(--line);
  background: var(--white);
  min-height: 70vh
}

.kp-tree {
  background: #f9fbf9;
  border-right: 1px solid var(--line);
  padding: 16px 10px;
  position: sticky;
  top: 0;
  align-self: start;
  max-height: calc(100vh - 100px);
  overflow-y: auto
}

.kp-tree-all {
  width: 100%;
  text-align: left;
  padding: 11px 13px;
  color: var(--ink);
  font-size: 12.5px;
  font-weight: 700;
  border-radius: 4px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: .15s
}

.kp-tree-all:hover,
.kp-tree-all.active {
  background: var(--mint)
}

.kp-tree-all span {
  font: 10px var(--mono);
  color: var(--muted)
}

.kp-tree-cat {
  margin-top: 5px
}

.kp-tree-cat-head {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 10px 13px;
  color: var(--ink);
  font-size: 12.5px;
  font-weight: 600;
  text-align: left;
  border-radius: 4px;
  transition: .15s
}

.kp-tree-cat-head:hover {
  background: #edf6f1
}

.kp-tree-cat-head span:nth-child(2) {
  flex: 1;
  line-height: 1.4
}

.kp-tree-cat-head small {
  display: block;
  font: 9px var(--mono);
  color: var(--muted);
  letter-spacing: 1px;
  margin-top: 3px
}

.kp-arrow {
  font: 8px var(--mono);
  color: var(--muted);
  transition: .2s;
  flex: none
}

.kp-tree-cat.open .kp-arrow {
  transform: rotate(90deg)
}

.kp-cnt {
  font: 10px var(--mono);
  color: #a8b8b2;
  flex: none
}

.kp-tree-items {
  display: none;
  padding: 3px 4px 8px 20px
}

.kp-tree-cat.open .kp-tree-items {
  display: block
}

.kp-tree-item {
  display: block;
  width: 100%;
  text-align: left;
  padding: 8px 11px;
  font-size: 11.5px;
  line-height: 1.5;
  color: var(--muted);
  border-left: 2px solid var(--line);
  transition: .15s;
  background: none
}

.kp-tree-item:hover {
  color: var(--ink);
  border-left-color: var(--mint-strong)
}

.kp-tree-item.active {
  color: var(--mint-strong);
  border-left-color: var(--mint-strong);
  background: #e8f8f1;
  font-weight: 600
}

.kp-content {
  padding: 26px 28px;
  min-width: 0
}

.kp-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 11px;
  margin-bottom: 20px
}

.kp-card {
  background: #fbfcfb;
  border: 1px solid var(--line);
  padding: 17px 18px 14px;
  text-align: left;
  transition: .2s;
  position: relative
}

.kp-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px #18372b12;
  border-color: #9cb8ad
}

.kp-idx {
  font: 10px var(--mono);
  color: var(--mint-strong);
  letter-spacing: 1px
}

.kp-card h3 {
  font-size: 13.5px;
  margin: 8px 0 7px;
  line-height: 1.5
}

.kp-card p {
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
  margin: 0
}

.kp-go {
  display: inline-block;
  margin-top: 12px;
  font: 11px var(--mono);
  color: var(--mint-strong)
}

.kp-detail-hero {
  border-bottom: 1px solid var(--line);
  padding-bottom: 20px;
  margin-bottom: 24px
}

.kp-detail-hero h2 {
  font-size: clamp(22px, 3vw, 36px);
  letter-spacing: -1.5px;
  margin: 14px 0 8px
}

.kp-sec {
  margin-bottom: 24px
}

.kp-sec-head {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-bottom: 12px
}

.kp-no {
  font: 11px var(--mono);
  color: var(--orange)
}

.kp-sec-head h3 {
  font-size: 16px;
  margin: 0
}

.kp-concept {
  background: var(--ink);
  color: #eef8f3;
  padding: 20px 22px;
  border-left: 4px solid var(--mint-strong)
}

.kp-concept p {
  margin: 0;
  font-size: 14px;
  line-height: 2
}

.kp-explain {
  list-style: none;
  margin: 0;
  padding: 0
}

.kp-explain li {
  display: flex;
  gap: 13px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 13px;
  line-height: 1.9;
  color: #4e5e58
}

.kp-explain li:last-child {
  border-bottom: 0
}

.kp-dot {
  flex: none;
  width: 7px;
  height: 7px;
  background: var(--mint-strong);
  border-radius: 50%;
  margin-top: 8px
}

.kp-exam {
  background: #fbfcfb;
  border: 1px solid var(--line)
}

.kp-exam-q {
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
  background: var(--orange-soft)
}

.kp-exam-q b {
  font: 10px var(--mono);
  letter-spacing: 1.4px;
  color: var(--orange);
  display: block;
  margin-bottom: 7px
}

.kp-exam-q p {
  margin: 0;
  font-size: 14px;
  line-height: 1.9;
  font-weight: 600
}

.kp-exam-steps {
  padding: 15px 20px
}

.kp-exam-steps b {
  font: 10px var(--mono);
  letter-spacing: 1.4px;
  color: var(--muted);
  display: block;
  margin-bottom: 9px
}

.kp-exam-steps ol {
  margin: 0;
  padding-left: 0;
  list-style: none;
  counter-reset: st
}

.kp-exam-steps li {
  counter-increment: st;
  display: flex;
  gap: 11px;
  padding: 6px 0;
  font-size: 13px;
  line-height: 1.8;
  color: #4e5e58
}

.kp-exam-steps li:before {
  content: counter(st, decimal-leading-zero);
  font: 11px var(--mono);
  color: var(--mint-strong);
  flex: none;
  padding-top: 2px
}

.kp-exam-answer {
  padding: 15px 20px;
  background: #e8f8f1;
  border-top: 1px solid #cdeadd
}

.kp-exam-answer b {
  font: 10px var(--mono);
  letter-spacing: 1.4px;
  color: var(--mint-strong);
  display: block;
  margin-bottom: 6px
}

.kp-exam-answer p {
  margin: 0;
  font-size: 13px;
  line-height: 1.9
}

.kp-detail-nav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 30px;
  border-top: 1px solid var(--line);
  padding-top: 18px
}

.kp-detail-nav button {
  font: 12px var(--mono);
  color: var(--mint-strong);
  text-align: left;
  max-width: 45%;
  background: none
}

.kp-detail-nav button span {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-top: 4px;
  font-family: var(--sans)
}

.kp-detail-nav button:hover {
  color: var(--ink)
}

.kp-nav-r {
  text-align: right !important
}

@media(max-width:900px) {
  .kp-layout {
    grid-template-columns: 1fr
  }

  .kp-tree {
    position: static;
    max-height: none;
    border-right: 0;
    border-bottom: 1px solid var(--line)
  }

  .kp-list {
    grid-template-columns: 1fr
  }

  .kp-content {
    padding: 18px 16px
  }
}

/* ==================== Animation System ==================== */
html {
  scroll-behavior: smooth
}

/* GPU hint for animated elements */
.topic-card,
.kp-card,
.day-block,
.nav-item,
.answer-option,
.complete-btn,
.subject-tab,
.kp-tree-item,
.kp-tree-cat-head,
.resource-link,
.doc-resource,
.task-item,
.toast,
.progress-line span,
.kp-arrow {
  will-change: transform, opacity
}

/* View entrance */
.active-view {
  animation: viewIn .42s var(--ease-out) both
}

@keyframes viewIn {
  from {
    opacity: 0;
    transform: translateY(14px)
  }

  to {
    opacity: 1;
    transform: translateY(0)
  }
}

/* Card stagger entrance */
.topic-card,
.kp-card,
.stat-card,
.exam-card,
.day-block,
.paper-panel {
  animation: cardIn .5s var(--ease-out) backwards
}

.topic-card:nth-child(1),
.kp-card:nth-child(1),
.stat-card:nth-child(1) {
  animation-delay: .04s
}

.topic-card:nth-child(2),
.kp-card:nth-child(2),
.stat-card:nth-child(2) {
  animation-delay: .09s
}

.topic-card:nth-child(3),
.kp-card:nth-child(3) {
  animation-delay: .14s
}

.topic-card:nth-child(4),
.kp-card:nth-child(4) {
  animation-delay: .19s
}

.topic-card:nth-child(5),
.kp-card:nth-child(5) {
  animation-delay: .24s
}

.topic-card:nth-child(6),
.kp-card:nth-child(6) {
  animation-delay: .29s
}

@keyframes cardIn {
  from {
    opacity: 0;
    transform: translateY(22px) scale(.98)
  }

  to {
    opacity: 1;
    transform: translateY(0) scale(1)
  }
}

/* Detail section cascade */
.kp-sec,
.lesson-main>*,
.goal-card,
.resource-panel,
.step-list li,
.kp-exam,
.kp-detail-hero,
.detail-hero,
.callout,
.visual-figure {
  animation: fadeUp .5s var(--ease-out) backwards
}

.kp-sec:nth-child(1) {
  animation-delay: .06s
}

.kp-sec:nth-child(2) {
  animation-delay: .14s
}

.kp-sec:nth-child(3) {
  animation-delay: .22s
}

.kp-sec:nth-child(4) {
  animation-delay: .30s
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(16px)
  }

  to {
    opacity: 1;
    transform: translateY(0)
  }
}

/* Upgraded transition curves */
.nav-item,
.topic-card,
.kp-card,
.answer-option,
.resource-link,
.task-item,
.kp-tree-all,
.kp-tree-cat-head,
.kp-tree-item,
.day-block,
.subject-tab,
.complete-btn,
.task-link,
.kp-detail-nav button,
.back-btn,
.reset-btn {
  transition: all .28s var(--ease-out)
}

/* Button press feedback */
.topic-card:active,
.kp-card:active,
.nav-item:active,
.complete-btn:active,
.answer-option:active,
.day-block:active,
.subject-tab:active,
.kp-tree-item:active,
.kp-tree-cat-head:active,
.kp-tree-all:active,
.kp-detail-nav button:active,
.back-btn:active {
  transform: scale(.97) !important;
  transition-duration: .08s !important
}

/* Card hover lift */
.topic-card:hover,
.kp-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 32px #18372b14;
  border-color: var(--mint-strong)
}

.kp-card:hover {
  border-color: #9cb8ad
}

/* Day block hover */
.day-block:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px #18372b10;
  border-color: var(--mint-strong)
}

/* Nav item slide */
.nav-item:hover {
  transform: translateX(3px)
}

/* Answer option press */
.answer-option:hover {
  transform: translateX(4px)
}

.answer-option.correct {
  animation: pulseGreen .4s var(--ease-spring)
}

.answer-option.wrong {
  animation: shake .35s var(--ease-smooth)
}

@keyframes pulseGreen {
  0% {
    transform: scale(1)
  }

  50% {
    transform: scale(1.03)
  }

  100% {
    transform: scale(1)
  }
}

@keyframes shake {

  0%,
  100% {
    transform: translateX(0)
  }

  25% {
    transform: translateX(-5px)
  }

  75% {
    transform: translateX(5px)
  }
}

/* Subject tab underline grow */
.subject-tab::after {
  transition: all .3s var(--ease-out)
}

/* Progress bar smooth fill */
.progress-line span {
  transition: width .6s var(--ease-out)
}

/* Toast spring entrance */
.toast {
  transform: translateY(90px) scale(.9);
  opacity: 0;
  transition: transform .35s var(--ease-spring), opacity .25s var(--ease-smooth)
}

.toast.show {
  transform: translateY(0) scale(1);
  opacity: 1
}

/* Tree expand smooth */
.kp-tree-items {
  overflow: hidden;
  animation: treeExpand .28s var(--ease-smooth)
}

@keyframes treeExpand {
  from {
    opacity: 0;
    max-height: 0
  }

  to {
    opacity: 1;
    max-height: 500px
  }
}

/* Tree item stagger */
.kp-tree-item {
  animation: slideIn .3s var(--ease-out) backwards
}

.kp-tree-item:nth-child(1) {
  animation-delay: .02s
}

.kp-tree-item:nth-child(2) {
  animation-delay: .05s
}

.kp-tree-item:nth-child(3) {
  animation-delay: .08s
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-8px)
  }

  to {
    opacity: 1;
    transform: translateX(0)
  }
}

/* Task checkbox toggle */
.task-item {
  transition: all .25s var(--ease-out)
}

.task-item.done {
  animation: checkPop .3s var(--ease-spring)
}

@keyframes checkPop {
  0% {
    transform: scale(1)
  }

  50% {
    transform: scale(1.02)
  }

  100% {
    transform: scale(1)
  }
}

/* Mindmap draw-in */
.mindmap-svg {
  animation: drawIn .8s var(--ease-out) both
}

@keyframes drawIn {
  from {
    opacity: 0;
    transform: scale(.96)
  }

  to {
    opacity: 1;
    transform: scale(1)
  }
}

/* Focus ring */
button:focus-visible,
a:focus-visible,
input:focus-visible {
  outline: 2px solid var(--mint-strong);
  outline-offset: 2px;
  border-radius: 2px
}

/* Sidebar slide (mobile) */
.sidebar {
  transition: left .28s var(--ease-smooth)
}

.scrim {
  transition: opacity .28s var(--ease-smooth)
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important
  }
}