/* 基础重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
  color: #1a202c;
  line-height: 1.6;
  min-height: 100vh;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 顶部导航 */
.header {
  background: linear-gradient(135deg, #1a365d 0%, #2c5282 100%);
  color: white;
  box-shadow: 0 4px 20px rgba(0,0,0,0.15);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.logo-title {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.3;
}

.logo-sub {
  font-size: 0.75rem;
  opacity: 0.8;
}

.nav {
  display: flex;
  gap: 28px;
}

.nav a {
  color: rgba(255,255,255,0.8);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 6px 0;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
}

.nav a:hover,
.nav a.active {
  color: white;
  border-bottom-color: #63b3ed;
}

/* 账号与数据面板 */
.account-bar {
  background: #ffffff;
  border-bottom: 1px solid #e2e8f0;
}

.account-grid {
  padding-top: 14px;
  padding-bottom: 14px;
}

.auth-card {
  display: grid;
  gap: 12px;
}

.auth-status {
  font-size: 0.9rem;
  color: #2d3748;
}

.auth-forms {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.auth-form {
  display: grid;
  grid-template-columns: minmax(120px, 1fr) minmax(160px, 1fr) minmax(160px, 1fr) auto;
  gap: 8px;
}

.auth-form input,
.note-input,
.admin-select {
  border: 1px solid #cbd5e0;
  border-radius: 6px;
  color: #1a202c;
  font: inherit;
  padding: 9px 10px;
}

.auth-form button,
.account-actions button,
.panel-header button,
.data-action-btn,
.admin-action-btn {
  background: #1a365d;
  border: none;
  border-radius: 6px;
  color: white;
  cursor: pointer;
  font: inherit;
  font-weight: 600;
  padding: 9px 14px;
}

.auth-form button:hover,
.account-actions button:hover,
.panel-header button:hover,
.data-action-btn:hover,
.admin-action-btn:hover {
  background: #2c5282;
}

.account-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.data-panel {
  background: #f7fafc;
  border-bottom: 1px solid #e2e8f0;
  padding: 24px 0;
}

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

.panel-header h2 {
  color: #1a365d;
  font-size: 1.2rem;
}

.data-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.data-box {
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  padding: 16px;
}

.data-box h3 {
  color: #1a365d;
  font-size: 1rem;
  margin-bottom: 10px;
}

.data-box ul {
  list-style: none;
}

.data-box li {
  border-bottom: 1px solid #edf2f7;
  color: #4a5568;
  font-size: 0.85rem;
  padding: 8px 0;
}

.data-box li:last-child {
  border-bottom: none;
}

.section-user-tools {
  border-left: 4px solid var(--course-color);
}

.tool-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 12px 0;
}

.note-input {
  min-height: 90px;
  resize: vertical;
  width: 100%;
}

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

.admin-table {
  background: white;
  border-collapse: collapse;
  min-width: 820px;
  width: 100%;
}

.admin-table th,
.admin-table td {
  border-bottom: 1px solid #e2e8f0;
  font-size: 0.85rem;
  padding: 10px;
  text-align: left;
}

.admin-table th {
  background: #edf2f7;
  color: #1a365d;
}

/* 横幅区域 */
.hero-section {
  background: linear-gradient(135deg, #1a365d 0%, #2c5282 50%, #2b6cb0 100%);
  padding: 60px 0 50px;
  color: white;
  text-align: center;
}

.hero-section h1 {
  font-size: 2.2rem;
  font-weight: 600;
  margin-bottom: 16px;
  line-height: 1.4;
}

.hero-section p {
  font-size: 1rem;
  opacity: 0.9;
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-search {
  max-width: 600px;
  margin: 0 auto;
  display: flex;
  gap: 0;
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

.hero-search input {
  flex: 1;
  padding: 14px 20px;
  border: none;
  font-size: 1rem;
  outline: none;
  color: #1a202c;
}

.hero-search input::placeholder {
  color: #a0aec0;
}

.hero-search button {
  padding: 14px 28px;
  background: #c53030;
  color: white;
  border: none;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: background 0.2s;
}

.hero-search button:hover {
  background: #9b2c2c;
}

/* 课程区域 */
.courses-section {
  padding: 48px 0 64px;
}

.section-header {
  text-align: center;
  margin-bottom: 36px;
}

.section-header h2 {
  font-size: 1.5rem;
  color: #1a365d;
  margin-bottom: 8px;
}

.section-header p {
  color: #718096;
  font-size: 0.95rem;
}

.course-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.course-card {
  background: white;
  border-radius: 16px;
  padding: 28px 24px;
  text-align: center;
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  border: 2px solid transparent;
  position: relative;
  overflow: hidden;
}

.course-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--course-color);
}

.course-card::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: radial-gradient(circle, rgba(0,0,0,0.05) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  transition: width 0.4s, height 0.4s;
}

.course-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 20px 40px rgba(0,0,0,0.15);
  border-color: rgba(0,0,0,0.1);
}

.course-card:hover::after {
  width: 300px;
  height: 300px;
}

.course-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 1.6rem;
  font-weight: 700;
  color: white;
  box-shadow: 0 4px 15px rgba(0,0,0,0.2);
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  position: relative;
}

.course-card:hover .course-icon {
  transform: scale(1.15);
  box-shadow: 0 8px 25px rgba(0,0,0,0.3);
}

.course-icon::after {
  content: '';
  position: absolute;
  top: -3px;
  left: -3px;
  right: -3px;
  bottom: -3px;
  border-radius: 50%;
  background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.3) 50%, transparent 70%);
  background-size: 200% 200%;
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { background-position: -200% -200%; }
  100% { background-position: 200% 200%; }
}

.course-short {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.course-name {
  font-size: 0.95rem;
  color: #4a5568;
  margin-bottom: 12px;
  line-height: 1.5;
  min-height: 2.8em;
}

.course-chapters {
  font-size: 0.8rem;
  color: #718096;
  padding: 4px 12px;
  background: #f7fafc;
  border-radius: 12px;
  display: inline-block;
}

/* 课程详情页 */
.course-header {
  background: var(--course-color);
  color: white;
  padding: 40px 0 32px;
}

.course-header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

.course-header h1 {
  font-size: 1.6rem;
  margin-bottom: 8px;
}

.course-header p {
  opacity: 0.9;
  font-size: 0.95rem;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  font-size: 0.85rem;
  opacity: 0.85;
}

.breadcrumb a {
  color: white;
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

/* 章节列表 */
.chapter-list {
  padding: 32px 0;
}

.chapter-item {
  background: white;
  border-radius: 10px;
  margin-bottom: 16px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  transition: box-shadow 0.2s;
}

.chapter-item:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.chapter-title-bar {
  padding: 18px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  background: #fafafa;
  border-left: 4px solid var(--course-color);
}

.chapter-title-bar h3 {
  font-size: 1.05rem;
  color: #1a202c;
}

.chapter-toggle {
  color: #718096;
  transition: transform 0.2s;
}

.chapter-item.expanded .chapter-toggle {
  transform: rotate(180deg);
}

.chapter-sections {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s, padding 0.3s;
}

.chapter-item.expanded .chapter-sections {
  padding: 12px 24px 20px;
  max-height: 600px;
}

.section-item {
  padding: 14px 16px;
  border-bottom: 1px solid #edf2f7;
  cursor: pointer;
  border-radius: 6px;
  transition: background 0.2s;
}

.section-item:last-child {
  border-bottom: none;
}

.section-item:hover {
  background: #f7fafc;
}

.section-item h4 {
  font-size: 0.95rem;
  color: #2d3748;
  margin-bottom: 8px;
}

.section-keypoints {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.keypoint-tag {
  font-size: 0.75rem;
  padding: 3px 10px;
  border-radius: 4px;
  background: #edf2f7;
  color: #4a5568;
}

/* 章节学习页 */
.chapter-header {
  background: linear-gradient(135deg, #1a365d 0%, #2c5282 100%);
  color: white;
  padding: 36px 0 28px;
}

.chapter-header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

.chapter-header h1 {
  font-size: 1.4rem;
  margin-bottom: 6px;
}

.chapter-header .course-tag {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(255,255,255,0.2);
  border-radius: 4px;
  font-size: 0.8rem;
  margin-bottom: 8px;
}

.section-detail {
  background: white;
  border-radius: 10px;
  padding: 28px;
  margin-bottom: 16px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

.section-detail h3 {
  font-size: 1.1rem;
  color: #1a365d;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid #e2e8f0;
}

.section-detail h4 {
  font-size: 0.95rem;
  color: #2d3748;
  margin: 16px 0 8px;
}

.section-detail p {
  font-size: 0.9rem;
  color: #4a5568;
  line-height: 1.7;
}

.keypoints-list {
  list-style: none;
  padding: 0;
}

.keypoints-list li {
  padding: 10px 0 10px 28px;
  position: relative;
  font-size: 0.9rem;
  color: #4a5568;
  border-bottom: 1px solid #f0f0f0;
}

.keypoints-list li:last-child {
  border-bottom: none;
}

.keypoints-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 16px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--course-color);
}

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 6px;
  color: #4a5568;
  font-size: 0.9rem;
  cursor: pointer;
  margin: 24px 0 40px;
  transition: all 0.2s;
}

.back-btn:hover {
  background: #f7fafc;
  border-color: #cbd5e0;
}

/* 检索页 */
.search-header {
  background: linear-gradient(135deg, #1a365d 0%, #2c5282 100%);
  color: white;
  padding: 40px 0 32px;
}

.search-header h2 {
  font-size: 1.5rem;
  margin-bottom: 20px;
}

.search-box-inline {
  max-width: 500px;
  display: flex;
  background: white;
  border-radius: 8px;
  overflow: hidden;
}

.search-box-inline input {
  flex: 1;
  padding: 12px 16px;
  border: none;
  font-size: 0.95rem;
  outline: none;
}

.search-box-inline button {
  padding: 12px 24px;
  background: #c53030;
  color: white;
  border: none;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.2s;
}

.search-box-inline button:hover {
  background: #9b2c2c;
}

/* 检索结果 */
.search-results {
  padding: 32px 0;
}

.result-count {
  font-size: 0.9rem;
  color: #718096;
  margin-bottom: 20px;
}

.result-count span {
  color: #c53030;
  font-weight: 600;
}

.result-item {
  background: white;
  border-radius: 10px;
  padding: 20px 24px;
  margin-bottom: 12px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  cursor: pointer;
  transition: all 0.2s;
  border-left: 3px solid var(--result-color);
}

.result-item:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.result-course {
  font-size: 0.8rem;
  color: var(--result-color);
  font-weight: 600;
  margin-bottom: 6px;
}

.result-title {
  font-size: 1rem;
  font-weight: 600;
  color: #1a202c;
  margin-bottom: 8px;
}

.result-keywords {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.result-keyword {
  font-size: 0.75rem;
  padding: 3px 10px;
  background: #f7fafc;
  border-radius: 4px;
  color: #4a5568;
}

.result-keyword.highlight {
  background: #fff5f5;
  color: #c53030;
}

.no-results {
  text-align: center;
  padding: 60px 20px;
  color: #a0aec0;
}

.no-results svg {
  margin-bottom: 16px;
}

/* 章节总览 */
.all-chapters {
  padding: 32px 0;
}

.course-group {
  margin-bottom: 32px;
}

.course-group-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--course-color);
}

.course-group-header h3 {
  font-size: 1.1rem;
  color: var(--course-color);
}

.course-group-header .badge {
  font-size: 0.75rem;
  padding: 3px 10px;
  background: var(--course-color);
  color: white;
  border-radius: 4px;
}

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 12px;
}

.chapter-grid-item {
  background: white;
  border-radius: 8px;
  padding: 16px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
  cursor: pointer;
  transition: all 0.2s;
  border-left: 3px solid var(--course-color);
}

.chapter-grid-item:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.chapter-grid-item h4 {
  font-size: 0.9rem;
  color: #2d3748;
  margin-bottom: 8px;
}

.chapter-grid-item .sections-count {
  font-size: 0.8rem;
  color: #718096;
}

/* 页脚 */
.footer {
  background: #1a202c;
  color: #a0aec0;
  padding: 28px 0;
  text-align: center;
  font-size: 0.8rem;
}

.footer p {
  margin-bottom: 4px;
}

.footer p:first-child {
  color: #e2e8f0;
  font-weight: 500;
}

/* 响应式 */
@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    height: auto;
    padding: 12px 16px;
    gap: 10px;
  }

  .nav {
    gap: 16px;
  }

  .hero-section {
    padding: 40px 0 32px;
  }

  .hero-section h1 {
    font-size: 1.6rem;
  }

  .hero-search {
    flex-direction: column;
    margin: 0 16px;
  }

  .hero-search button {
    justify-content: center;
  }

  .course-cards {
    grid-template-columns: 1fr;
  }

  .auth-forms,
  .auth-form {
    grid-template-columns: 1fr;
  }

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

  .section-detail {
    padding: 20px;
  }
}

/* 功能按钮 */
.function-buttons {
  display: flex;
  gap: 16px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.func-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 24px;
  background: white;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  color: #4a5568;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  position: relative;
  overflow: hidden;
}

.func-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0,0,0,0.05), transparent);
  transition: left 0.5s;
}

.func-btn:hover::before {
  left: 100%;
}

.func-btn:hover {
  background: #f7fafc;
  border-color: var(--course-color);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.12);
}

.func-btn.active {
  background: linear-gradient(135deg, var(--course-color) 0%, color-mix(in srgb, var(--course-color) 80%, white) 100%);
  border-color: var(--course-color);
  color: white;
  box-shadow: 0 6px 20px rgba(0,0,0,0.18);
  transform: translateY(-2px);
}

.func-btn svg {
  transition: transform 0.3s;
}

.func-btn:hover svg,
.func-btn.active svg {
  transform: scale(1.1);
}

/* 考点区域 */
.exam-section {
  border-left: 4px solid var(--course-color);
}

.exam-points-list {
  list-style: none;
  padding: 0;
}

.exam-points-list li {
  padding: 12px 0 12px 32px;
  position: relative;
  font-size: 0.9rem;
  color: #2d3748;
  border-bottom: 1px solid #f0f0f0;
  line-height: 1.6;
}

.exam-points-list li:last-child {
  border-bottom: none;
}

.exam-points-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 18px;
  width: 10px;
  height: 10px;
  background: var(--course-color);
  border-radius: 50%;
}

.point-num {
  font-weight: 600;
  color: var(--course-color);
  margin-right: 8px;
}

/* 选择题区域 */
.question-section {
  border-left: 4px solid var(--course-color);
}

.question-text {
  font-size: 0.95rem;
  color: #2d3748;
  margin-bottom: 16px;
  line-height: 1.6;
}

.options-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.option-item {
  display: flex;
  align-items: center;
  padding: 16px 20px;
  background: white;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  border: 2px solid #e2e8f0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  position: relative;
  overflow: hidden;
}

.option-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--course-color);
  transform: scaleY(0);
  transition: transform 0.3s;
}

.option-item:hover {
  background: #f7fafc;
  border-color: var(--course-color);
  transform: translateX(4px);
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.option-item:hover::before {
  transform: scaleY(1);
}

.option-item.selected {
  border-color: var(--course-color);
  background: rgba(0,0,0,0.02);
  transform: translateX(4px);
}

.option-item.correct {
  background: linear-gradient(135deg, #c6f6d5 0%, #aeffc5 100%);
  border-color: #38a169;
  animation: correctPulse 0.5s ease-out;
}

.option-item.wrong {
  background: linear-gradient(135deg, #fed7d7 0%, #ffb3b3 100%);
  border-color: #fc8181;
  animation: shake 0.5s ease-out;
}

@keyframes correctPulse {
  0% { transform: scale(0.98); }
  50% { transform: scale(1.02); }
  100% { transform: scale(1); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

.option-letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: white;
  border-radius: 50%;
  font-weight: 600;
  color: #4a5568;
  margin-right: 12px;
  font-size: 0.85rem;
  box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.option-item.correct .option-letter {
  background: #38a169;
  color: white;
}

.option-item.wrong .option-letter {
  background: #fc8181;
  color: white;
}

.option-text {
  flex: 1;
  font-size: 0.9rem;
  color: #4a5568;
}

.option-status {
  font-size: 1.1rem;
  font-weight: bold;
  margin-left: 8px;
}

.option-item.correct .option-status {
  color: #38a169;
}

.option-item.wrong .option-status {
  color: #fc8181;
}

/* 解析区域 */
.question-analysis {
  margin-top: 20px;
  padding: 20px;
  background: linear-gradient(135deg, #ebf8ff 0%, #e6fffa 100%);
  border-radius: 12px;
  border-left: 4px solid #3182ce;
  box-shadow: 0 4px 15px rgba(49, 130, 206, 0.15);
  animation: fadeInUp 0.4s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.analysis-title {
  font-weight: 600;
  color: #2c5282;
  margin-bottom: 8px;
  font-size: 0.9rem;
}

.analysis-content {
  font-size: 0.85rem;
  color: #4a5568;
  line-height: 1.6;
}

/* 大题区域 */
.essay-section {
  border-left: 4px solid var(--course-color);
}

.answer-container {
  margin-top: 20px;
}

.show-answer-btn {
  padding: 14px 28px;
  background: linear-gradient(135deg, var(--course-color) 0%, color-mix(in srgb, var(--course-color) 80%, white) 100%);
  color: white;
  border: none;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  box-shadow: 0 4px 15px rgba(0,0,0,0.15);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.show-answer-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.2);
}

.show-answer-btn:active {
  transform: translateY(0);
}

.essay-answer {
  margin-top: 20px;
  padding: 24px;
  background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
  border-radius: 12px;
  font-size: 0.95rem;
  color: #2d3748;
  line-height: 1.9;
  border-left: 4px solid var(--course-color);
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
  animation: fadeInUp 0.4s ease-out;
}