:root {
  --ink: #17202a;
  --muted: #667085;
  --line: #d9e2ec;
  --paper: #f6f8fb;
  --white: #ffffff;
  --teal: #0b6670;
  --teal-soft: #e6f5f6;
  --amber: #f3a712;
  --red: #c94c5f;
  --shadow: 0 18px 45px rgba(23, 32, 42, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.7;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 18px 7%;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 900;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 8px;
  background: var(--teal);
  color: var(--white);
  font-weight: 900;
}

.brand small {
  display: block;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  margin-top: -4px;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  color: #344054;
  font-weight: 800;
}

.site-nav a {
  padding: 8px 0;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--teal);
  border-bottom-color: var(--teal);
}

main {
  padding: 0 7% 72px;
}

.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 42px;
  align-items: center;
  min-height: 560px;
  margin: 0 -7%;
  padding: 78px 7%;
  background:
    radial-gradient(circle at 86% 22%, rgba(243, 167, 18, 0.22), transparent 28%),
    linear-gradient(120deg, #edf9fa 0%, #ffffff 58%, #fff7e8 100%);
}

.hero-content {
  max-width: 780px;
}

.page-title {
  margin: 0 -7% 48px;
  padding: 70px 7%;
  background: linear-gradient(120deg, #edf9fa, #ffffff 60%, #fff7e8);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 820px;
  margin-bottom: 20px;
  font-size: clamp(40px, 6vw, 68px);
  line-height: 1.08;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.18;
}

h3 {
  margin-bottom: 10px;
  font-size: 22px;
  line-height: 1.25;
}

.hero p,
.page-title p,
.section-head p {
  max-width: 760px;
  color: #425466;
  font-size: 18px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 900;
}

.button.primary {
  background: var(--teal);
  color: var(--white);
}

.button.secondary {
  background: var(--white);
  border: 1px solid var(--line);
  color: var(--ink);
}

.hero-card,
.card,
.question,
.note-box,
.status-panel,
.resource {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.hero-card {
  padding: 28px;
}

.status-panel {
  display: grid;
  gap: 0;
  overflow: hidden;
}

.panel-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 26px;
  border-bottom: 1px solid var(--line);
}

.panel-row:last-child {
  border-bottom: 0;
}

.panel-row span {
  color: var(--muted);
  font-weight: 800;
}

.panel-row strong {
  text-align: right;
  font-size: 18px;
}

.hero-card strong {
  display: block;
  margin-bottom: 12px;
  font-size: 20px;
}

.hero-card ul {
  margin: 0;
  padding-left: 22px;
  color: var(--muted);
}

.section {
  margin-bottom: 76px;
}

.section-head {
  margin-bottom: 28px;
}

.grid {
  display: grid;
  gap: 18px;
}

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

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

.course-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.course-option {
  display: flex;
  min-height: 245px;
  flex-direction: column;
  padding: 26px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.course-option.available {
  border-top: 4px solid var(--teal);
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.course-option.available:hover,
.course-option.available:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 22px 50px rgba(23, 32, 42, 0.14);
}

.course-family {
  margin-bottom: 16px;
  color: var(--red);
  font-size: 13px;
  font-weight: 900;
}

.course-option h3 {
  overflow-wrap: anywhere;
}

.course-option p {
  color: var(--muted);
}

.course-status {
  margin-top: auto;
  padding-top: 18px;
  color: var(--teal);
  font-weight: 900;
}

.course-status.soon {
  color: var(--muted);
}

.course-content {
  scroll-margin-top: 130px;
}

.course-summary {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  margin-bottom: 22px;
  padding: 18px 22px;
  background: #243442;
  border-radius: 8px;
  color: rgba(255, 255, 255, 0.78);
}

.course-summary strong {
  color: var(--white);
}

.curriculum-list {
  display: grid;
  gap: 12px;
}

.unit-block {
  margin-top: 0;
  padding: 0;
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: none;
}

.unit-block summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 76px;
  padding: 18px 22px;
  color: var(--ink);
  list-style: none;
}

.unit-block summary::-webkit-details-marker {
  display: none;
}

.unit-block summary::after {
  content: "+";
  flex: 0 0 auto;
  color: var(--teal);
  font-size: 24px;
  line-height: 1;
}

.unit-block[open] summary::after {
  content: "−";
}

.unit-block[open] summary {
  border-bottom: 1px solid var(--line);
}

.unit-heading {
  display: flex;
  align-items: center;
  gap: 18px;
  min-width: 0;
}

.unit-heading strong {
  overflow-wrap: anywhere;
  font-size: 20px;
}

.unit-number {
  flex: 0 0 auto;
  min-width: 72px;
  color: var(--red);
  font-size: 13px;
  font-weight: 900;
}

.lesson-count {
  margin-left: auto;
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}

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

.lesson-list li {
  display: grid;
  grid-template-columns: 90px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  padding: 17px 22px;
  border-bottom: 1px solid var(--line);
}

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

.lesson-number,
.lesson-state {
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.lesson-title {
  display: grid;
  gap: 2px;
  min-width: 0;
}

.lesson-title strong {
  overflow-wrap: anywhere;
}

.lesson-title span {
  color: var(--muted);
  font-size: 14px;
}

.lesson-state {
  padding: 4px 9px;
  background: var(--paper);
  border-radius: 4px;
  white-space: nowrap;
}

.card {
  min-height: 210px;
  padding: 26px;
}

.tag {
  display: inline-block;
  margin-bottom: 14px;
  color: var(--red);
  font-size: 13px;
  font-weight: 900;
}

.card p,
.resource p,
.question p,
.note-box p {
  color: var(--muted);
  margin-bottom: 0;
}

.text-link {
  display: inline-block;
  margin-top: 18px;
  color: var(--teal);
  font-weight: 900;
}

.highlight {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 32px;
  background: #243442;
  color: var(--white);
  border-radius: 8px;
}

.highlight p {
  color: rgba(255, 255, 255, 0.76);
  margin-bottom: 0;
}

.notice {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 30px;
  padding: 34px;
  background: #243442;
  color: var(--white);
  border-radius: 8px;
}

.notice p {
  color: rgba(255, 255, 255, 0.76);
  margin-bottom: 0;
}

.notice-list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding-left: 22px;
  color: rgba(255, 255, 255, 0.86);
}

.resource-list {
  display: grid;
  gap: 14px;
}

.resource {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 24px;
  box-shadow: none;
}

.resource strong {
  display: block;
  margin-bottom: 4px;
  font-size: 18px;
}

.question-list {
  display: grid;
  gap: 18px;
}

.question {
  padding: 26px;
}

.question-bank-layout {
  display: grid;
  grid-template-columns: minmax(240px, 320px) minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

.question-filters {
  position: sticky;
  top: 112px;
  display: grid;
  gap: 16px;
  padding: 24px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.filter-heading h2 {
  margin-bottom: 0;
  font-size: 28px;
}

.filter-field {
  display: grid;
  gap: 6px;
  color: #344054;
  font-size: 14px;
  font-weight: 800;
}

.filter-field select,
.filter-field input {
  width: 100%;
  min-height: 44px;
  padding: 9px 11px;
  background: var(--white);
  border: 1px solid #b8c4d1;
  border-radius: 6px;
  color: var(--ink);
  font: inherit;
  font-weight: 500;
}

.filter-field select:focus,
.filter-field input:focus {
  border-color: var(--teal);
  outline: 3px solid rgba(11, 102, 112, 0.14);
}

.filter-button {
  width: 100%;
  border: 0;
  cursor: pointer;
  font: inherit;
}

.filter-summary {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.question-workspace {
  min-width: 0;
}

.question-state {
  padding: 42px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  text-align: center;
}

.question-practice {
  scroll-margin-top: 112px;
}

.question-topline {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 26px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.question-taxonomy {
  color: var(--muted);
  font-size: 14px;
}

.question-position {
  flex: 0 0 auto;
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.question-stem {
  margin-bottom: 24px;
  color: var(--ink);
  font-size: 18px;
}

.question-stimulus {
  margin-bottom: 24px;
  padding: 20px;
  background: #f4f7fa;
  border: 1px solid var(--line);
  border-left: 4px solid var(--amber);
  border-radius: 8px;
  color: #344054;
}

.stimulus-title {
  margin-bottom: 10px;
  color: var(--red);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

.question-figure {
  margin: 18px 0;
  text-align: center;
}

.question-figure img {
  width: auto;
  max-width: 100%;
  max-height: 620px;
  object-fit: contain;
}

.question-table-wrap {
  max-width: 100%;
  margin: 14px 0;
  overflow-x: auto;
}

.question-table {
  width: 100%;
  border-collapse: collapse;
  color: #344054;
  font-size: 15px;
}

.question-table td {
  padding: 9px 12px;
  border: 1px solid var(--line);
  vertical-align: top;
}

.graphic-choice-label {
  color: #344054;
  font-weight: 800;
}

.question-practice fieldset {
  margin: 0;
  padding: 0;
  border: 0;
}

.practice-choices {
  display: grid;
  gap: 12px;
}

.practice-choice {
  display: grid;
  grid-template-columns: auto auto minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 14px 16px;
  background: #fbfcfe;
  border: 1px solid var(--line);
  border-radius: 8px;
  cursor: pointer;
  transition: border-color 140ms ease, background 140ms ease;
}

.practice-choice:hover,
.practice-choice:focus-within {
  background: var(--teal-soft);
  border-color: var(--teal);
}

.practice-choice input {
  width: 18px;
  height: 18px;
  margin-top: 4px;
  accent-color: var(--teal);
}

.choice-marker {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  margin-top: -1px;
  background: #e9eef4;
  border-radius: 50%;
  font-weight: 900;
}

.choice-content {
  min-width: 0;
}

.practice-choice.is-correct {
  background: #eaf8ee;
  border-color: #3a9a5b;
}

.practice-choice.is-incorrect {
  background: #fff0f2;
  border-color: var(--red);
}

.answer-actions,
.question-navigation {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.answer-actions .button,
.question-navigation .button {
  border: 1px solid var(--line);
  cursor: pointer;
  font: inherit;
}

.answer-actions .primary {
  border-color: var(--teal);
}

.answer-feedback {
  margin-top: 20px;
  padding: 14px 16px;
  border-radius: 8px;
  font-weight: 800;
}

.answer-feedback.correct {
  background: #eaf8ee;
  color: #24713e;
}

.answer-feedback.incorrect,
.answer-feedback.needs-answer {
  background: #fff0f2;
  color: #9f3043;
}

.solution-panel {
  margin-top: 16px;
}

.solution-content {
  margin-top: 14px;
  color: #344054;
}

.question-navigation {
  justify-content: space-between;
}

.question-navigation button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.pilot-note {
  margin-left: calc(320px + 28px);
}

.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;
}

.question-meta {
  margin-bottom: 10px;
  color: var(--red);
  font-size: 13px;
  font-weight: 900;
}

.question ol {
  color: #425466;
}

details {
  margin-top: 16px;
  padding: 14px 16px;
  background: var(--teal-soft);
  border-radius: 8px;
}

summary {
  cursor: pointer;
  color: var(--teal);
  font-weight: 900;
}

.note-box {
  padding: 28px;
  box-shadow: none;
}

.contact-layout {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 26px 7%;
  background: var(--white);
  border-top: 1px solid var(--line);
  color: var(--muted);
}

@media (max-width: 900px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero,
  .grid.three,
  .grid.two,
  .course-grid,
  .contact-layout,
  .notice,
  .question-bank-layout {
    grid-template-columns: 1fr;
  }

  .question-filters {
    position: static;
  }

  .pilot-note {
    margin-left: 0;
  }

  .hero {
    min-height: auto;
    padding-top: 58px;
  }

  .highlight,
  .resource,
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .panel-row {
    align-items: flex-start;
    flex-direction: column;
    gap: 6px;
  }

  .panel-row strong {
    text-align: left;
  }

  .unit-block summary {
    align-items: flex-start;
  }

  .unit-heading {
    align-items: flex-start;
    flex-direction: column;
    gap: 4px;
  }

  .lesson-count {
    display: none;
  }

  .lesson-list li {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .lesson-state {
    justify-self: start;
    margin-top: 5px;
  }
}