/* styles.css - Giao diện tươi sáng: Xanh - Trắng - Hồng cao cấp (Bright Blue - Crisp White - Pastel Rose) */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;700&family=Noto+Serif+SC:wght@600;700&display=swap');

:root {
  /* Bảng màu Tươi Sáng: Xanh - Trắng - Hồng */
  --bg-main: #f8fafc;
  --bg-gradient: linear-gradient(135deg, #f0f7ff 0%, #ffffff 45%, #fff1f4 100%);
  --bg-card: #ffffff;
  --bg-card-glass: rgba(255, 255, 255, 0.92);
  --bg-card-subtle: #f9fbfe;

  --color-primary-blue: #2563eb;
  --color-blue-light: #60a5fa;
  --color-blue-subtle: #eff6ff;
  --color-blue-border: #bfdbfe;

  --color-primary-pink: #ec4899;
  --color-pink-light: #f472b6;
  --color-pink-subtle: #fdf2f8;
  --color-pink-border: #fbcfe8;

  --color-accent-rose: #f43f5e;
  --color-accent-sky: #0ea5e9;

  --color-text-title: #0f172a;
  --color-text-body: #334155;
  --color-text-muted: #64748b;
  --color-text-subtle: #94a3b8;

  --color-success: #10b981;
  --color-success-bg: #ecfdf5;
  --color-success-border: #a7f3d0;

  --color-warning: #f59e0b;
  --color-warning-bg: #fffbeb;
  --color-warning-border: #fde68a;

  --color-error: #ef4444;
  --color-error-bg: #fef2f2;
  --color-error-border: #fecaca;

  --shadow-sm: 0 2px 8px rgba(37, 99, 235, 0.04);
  --shadow-md: 0 8px 24px -4px rgba(37, 99, 235, 0.08), 0 6px 16px -6px rgba(236, 72, 153, 0.08);
  --shadow-lg: 0 16px 36px -6px rgba(37, 99, 235, 0.1), 0 12px 24px -6px rgba(236, 72, 153, 0.12);
  --shadow-glow: 0 0 20px rgba(236, 72, 153, 0.25);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-hanzi: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-serif-hanzi: 'Noto Serif SC', 'Songti SC', serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--color-text-body);
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Container chính */
.app-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}

/* Header thương hiệu */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 28px;
  background: var(--bg-card-glass);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.8);
  box-shadow: var(--shadow-md);
  border-radius: var(--radius-lg);
  margin-bottom: 28px;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand-logo-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #2563eb 0%, #ec4899 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 24px;
  font-weight: 800;
  box-shadow: 0 6px 16px rgba(236, 72, 153, 0.35);
  font-family: var(--font-serif-hanzi);
}

.brand-title h1 {
  font-size: 22px;
  font-weight: 800;
  color: var(--color-text-title);
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-badge {
  font-size: 11px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--color-blue-subtle), var(--color-pink-subtle));
  color: var(--color-primary-pink);
  border: 1px solid var(--color-pink-border);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.brand-tagline {
  font-size: 13px;
  color: var(--color-text-muted);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Nút bấm thẩm mỹ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  border: none;
  outline: none;
  font-family: var(--font-sans);
}

.btn-primary {
  background: linear-gradient(135deg, #2563eb 0%, #ec4899 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.25), 0 3px 8px rgba(236, 72, 153, 0.25);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.35), 0 6px 14px rgba(236, 72, 153, 0.35);
}

.btn-pink {
  background: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(236, 72, 153, 0.25);
}

.btn-pink:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(236, 72, 153, 0.35);
}

.btn-blue {
  background: linear-gradient(135deg, #0ea5e9 0%, #2563eb 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(14, 165, 233, 0.25);
}

.btn-blue:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.35);
}

.btn-outline {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  color: var(--color-text-body);
}

.btn-outline:hover {
  background: var(--color-blue-subtle);
  border-color: var(--color-blue-border);
  color: var(--color-primary-blue);
}

.btn-outline-pink {
  background: #ffffff;
  border: 1px solid var(--color-pink-border);
  color: var(--color-primary-pink);
}

.btn-outline-pink:hover {
  background: var(--color-pink-subtle);
  border-color: var(--color-primary-pink);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-muted);
}

.btn-ghost:hover {
  background: rgba(0, 0, 0, 0.04);
  color: var(--color-text-title);
}

.btn-lg {
  padding: 14px 28px;
  font-size: 16px;
  border-radius: var(--radius-lg);
}

/* Stepper Tabs Thanh tiến trình */
.stepper-nav {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 28px;
}

.step-card {
  background: var(--bg-card);
  border: 1.5px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 14px 18px;
  display: flex;
  align-items: center;
  gap: 14px;
  cursor: pointer;
  transition: all 0.25s ease;
  position: relative;
  overflow: hidden;
}

.step-card:hover {
  border-color: var(--color-blue-light);
  transform: translateY(-1px);
}

.step-card.active {
  border-color: var(--color-primary-pink);
  background: linear-gradient(135deg, #ffffff 60%, var(--color-pink-subtle) 100%);
  box-shadow: 0 6px 18px rgba(236, 72, 153, 0.12);
}

.step-card.completed {
  border-color: var(--color-success-border);
  background: #ffffff;
}

.step-num {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-full);
  background: #f1f5f9;
  color: var(--color-text-muted);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  flex-shrink: 0;
  transition: all 0.2s ease;
}

.step-card.active .step-num {
  background: linear-gradient(135deg, var(--color-primary-blue), var(--color-primary-pink));
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(236, 72, 153, 0.3);
}

.step-card.completed .step-num {
  background: var(--color-success);
  color: #ffffff;
}

.step-info {
  display: flex;
  flex-direction: column;
}

.step-info .step-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text-title);
}

.step-info .step-desc {
  font-size: 12px;
  color: var(--color-text-muted);
}

/* Các View màn hình */
.step-view {
  display: none;
  animation: fadeIn 0.3s ease;
}

.step-view.active-view {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Bố cục thẻ Card tiêu chuẩn */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(226, 232, 240, 0.8);
  box-shadow: var(--shadow-md);
  padding: 24px;
  margin-bottom: 24px;
}

.card-header-flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid #f1f5f9;
}

.card-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text-title);
  display: flex;
  align-items: center;
  gap: 10px;
}

.card-title i {
  color: var(--color-primary-pink);
}

/* Form inputs & Level Selector */
.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text-title);
  margin-bottom: 8px;
}

.form-helper {
  font-size: 12px;
  color: var(--color-text-muted);
  margin-top: 5px;
}

.input-text, .textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: 15px;
  font-family: var(--font-sans);
  border: 1.5px solid #cbd5e1;
  border-radius: var(--radius-md);
  background: #ffffff;
  color: var(--color-text-title);
  transition: all 0.2s ease;
}

.input-text:focus, .textarea:focus {
  outline: none;
  border-color: var(--color-primary-blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.hsk-level-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 10px;
  margin-bottom: 18px;
}

.hsk-level-btn {
  background: #ffffff;
  border: 1.5px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 12px 8px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.hsk-level-btn:hover {
  border-color: var(--color-primary-blue);
  background: var(--color-blue-subtle);
}

.hsk-level-btn.selected {
  border-color: var(--color-primary-pink);
  background: linear-gradient(135deg, var(--color-blue-subtle), var(--color-pink-subtle));
  box-shadow: 0 4px 12px rgba(236, 72, 153, 0.2);
}

.hsk-level-btn .lvl-name {
  font-size: 15px;
  font-weight: 800;
  color: var(--color-primary-blue);
  display: block;
}

.hsk-level-btn.selected .lvl-name {
  color: var(--color-primary-pink);
}

.hsk-level-btn .lvl-words {
  font-size: 11px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* Preset Topic Badges */
.topic-presets-container {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 10px;
}

.topic-preset-chip {
  padding: 8px 14px;
  border-radius: var(--radius-full);
  background: var(--color-blue-subtle);
  border: 1px solid var(--color-blue-border);
  color: var(--color-primary-blue);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.topic-preset-chip:hover {
  background: var(--color-pink-subtle);
  border-color: var(--color-pink-border);
  color: var(--color-primary-pink);
  transform: translateY(-1px);
}

/* THƯ VIỆN 54 CHỦ ĐỀ GIÁO TRÌNH PHÁT TRIỂN HÁN NGỮ */
.fazhan-library-card {
  margin-top: 14px;
  background: #ffffff;
  border: 1.5px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 16px 18px;
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.04);
}

.fazhan-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  flex-wrap: wrap;
  gap: 8px;
}

.fazhan-card-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14.5px;
  font-weight: 800;
  color: var(--color-text-title);
}

.fazhan-path-badge {
  font-size: 11.5px;
  background: #f1f5f9;
  border: 1px solid #cbd5e1;
  color: #475569;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-family: monospace;
}

.fazhan-tabs-nav {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  border-bottom: 1px dashed #e2e8f0;
}

.fazhan-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius-full);
  border: 1px solid #e2e8f0;
  background: #f8fafc;
  color: #475569;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s ease;
}

.fazhan-tab-btn:hover {
  background: #ffffff;
  border-color: var(--color-pink-border);
  color: var(--color-primary-pink);
}

.fazhan-tab-btn.active {
  background: linear-gradient(135deg, var(--color-primary-blue) 0%, #3b82f6 100%);
  color: #ffffff;
  border-color: transparent;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.fazhan-search-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 12px 0 10px 0;
}

.fazhan-search-wrap {
  position: relative;
  flex: 1;
}

.fazhan-search-wrap .search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: #94a3b8;
  font-size: 13px;
}

#fazhan-search-input {
  width: 100%;
  padding: 8px 34px 8px 34px;
  border-radius: 8px;
  border: 1.5px solid #cbd5e1;
  font-size: 13px;
  outline: none;
  transition: all 0.2s ease;
}

#fazhan-search-input:focus {
  border-color: var(--color-primary-blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.btn-clear-search {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  font-size: 16px;
  color: #94a3b8;
  cursor: pointer;
  display: none;
}

.fazhan-stats-badge {
  font-size: 12px;
  font-weight: 700;
  color: #64748b;
  white-space: nowrap;
}

.fazhan-topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 10px;
  max-height: 290px;
  overflow-y: auto;
  padding: 4px;
}

.fazhan-topic-card {
  background: #ffffff;
  border: 1.5px solid #e2e8f0;
  border-radius: 10px;
  padding: 10px 12px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.fazhan-topic-card:hover {
  border-color: var(--color-primary-pink);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(236, 72, 153, 0.1);
}

.fazhan-topic-card.selected {
  border-color: var(--color-primary-blue);
  background: #f0f7ff;
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2);
}

.ft-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 4px;
}

.ft-lesson-tag {
  font-size: 11px;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 4px;
  background: #dbeafe;
  color: #1e40af;
}

.ft-genre-tag {
  font-size: 11px;
  color: #64748b;
}

.ft-hanzi-title {
  font-family: var(--font-hanzi);
  font-size: 14.5px;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 2px;
}

.ft-vietnamese {
  font-size: 12px;
  color: #475569;
  line-height: 1.35;
  margin-bottom: 8px;
}

.ft-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 11px;
  color: #64748b;
  border-top: 1px dashed #f1f5f9;
  padding-top: 6px;
}

.ft-level-badge {
  font-weight: 700;
  color: var(--color-primary-pink);
}

.ft-words-badge {
  background: #f8fafc;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid #e2e8f0;
}

/* Step 2: Dàn ý & Gợi ý ngữ pháp SONG NGỮ VIỆT - TRUNG */
.guide-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 24px;
}

.bilingual-toggle-bar {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.outline-box {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 18px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}

.outline-part-title {
  font-size: 16px;
  font-weight: 800;
  color: var(--color-primary-blue);
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px dashed #e2e8f0;
}

.outline-part-title span {
  font-size: 11.5px;
  background: var(--color-blue-subtle);
  padding: 3px 10px;
  border-radius: var(--radius-full);
  color: var(--color-primary-blue);
  font-weight: 700;
}

.outline-purpose-vi {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 14px;
  line-height: 1.5;
  background: #f8fafc;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-primary-blue);
}

/* Thẻ ý tưởng triển khai Song Ngữ */
.bilingual-idea-item {
  background: #fdfdfe;
  border: 1px solid #f1f5f9;
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin-bottom: 10px;
  position: relative;
  transition: all 0.2s ease;
}

.bilingual-idea-item:hover {
  border-color: var(--color-pink-border);
  background: #ffffff;
  box-shadow: 0 4px 12px rgba(236, 72, 153, 0.06);
}

.bi-hanzi {
  font-family: var(--font-hanzi);
  font-size: 15.5px;
  font-weight: 700;
  color: #1e3a8a;
  line-height: 1.6;
}

.bi-pinyin {
  font-size: 12px;
  color: var(--color-primary-pink);
  margin: 2px 0 4px;
  font-weight: 500;
}

.bi-vietnamese {
  font-size: 13px;
  color: var(--color-text-body);
  line-height: 1.5;
}

/* Khối câu mẫu song ngữ kèm nút chèn vào bài */
.bilingual-sample-card {
  background: linear-gradient(135deg, #ffffff 60%, var(--color-pink-subtle) 100%);
  border: 1px solid var(--color-pink-border);
  border-left: 4px solid var(--color-primary-pink);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  margin-top: 10px;
  margin-bottom: 12px;
  position: relative;
}

.sample-type-badge {
  font-size: 11px;
  font-weight: 800;
  color: var(--color-primary-pink);
  text-transform: uppercase;
  margin-bottom: 6px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.btn-insert-sentence {
  background: #ffffff;
  border: 1px solid var(--color-pink-border);
  color: var(--color-primary-pink);
  font-size: 11.5px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.btn-insert-sentence:hover {
  background: var(--color-primary-pink);
  color: #ffffff;
  transform: translateY(-1px);
}

/* Luận điểm thân bài Song Ngữ */
.argument-box {
  background: #ffffff;
  border: 1.5px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 14px 16px;
  margin-bottom: 14px;
}

.arg-heading-vi {
  font-size: 13.5px;
  font-weight: 800;
  color: var(--color-primary-blue);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Thẻ Từ vựng Song Ngữ Chi Tiết */
.vocab-bilingual-card {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 14px;
  margin-bottom: 12px;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.vocab-bilingual-card:hover {
  border-color: var(--color-primary-pink);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.vocab-top-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 6px;
}

.vocab-collocation-chip {
  background: var(--color-blue-subtle);
  border: 1px solid var(--color-blue-border);
  border-radius: var(--radius-sm);
  padding: 4px 8px;
  font-size: 12px;
  color: var(--color-primary-blue);
  margin: 6px 0;
  display: inline-block;
  font-family: var(--font-hanzi);
}

/* Thẻ Ngữ Pháp Song Ngữ */
.grammar-card {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 16px;
  margin-bottom: 14px;
  border-left: 4px solid var(--color-primary-blue);
}

.grammar-pattern {
  font-family: var(--font-hanzi);
  font-size: 15.5px;
  font-weight: 800;
  color: var(--color-primary-blue);
  margin-bottom: 6px;
}

.grammar-desc {
  font-size: 13px;
  color: var(--color-text-body);
  margin-bottom: 8px;
  line-height: 1.5;
}

.grammar-example {
  background: #f8fafc;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid #f1f5f9;
}

/* Ẩn hiện Pinyin toggle */
.hide-pinyin .bi-pinyin,
.hide-pinyin .pinyin {
  display: none !important;
}

/* Step 3: Studio Viết & OCR */
.studio-layout {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 24px;
}

.editor-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 18px;
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-bottom: none;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.editor-symbols {
  display: flex;
  gap: 6px;
}

.sym-btn {
  background: #ffffff;
  border: 1px solid #cbd5e1;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: var(--font-hanzi);
  cursor: pointer;
  transition: all 0.2s ease;
}

.sym-btn:hover {
  background: var(--color-blue-subtle);
  border-color: var(--color-primary-blue);
  color: var(--color-primary-blue);
}

.editor-textarea {
  width: 100%;
  height: 380px;
  padding: 20px;
  font-family: var(--font-hanzi);
  font-size: 18px;
  line-height: 2;
  border: 1px solid #cbd5e1;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  resize: vertical;
  color: #1e293b;
  background: #ffffff;
}

.editor-textarea:focus {
  outline: none;
  border-color: var(--color-primary-blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.writing-stats-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 18px;
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: var(--radius-md);
  margin-top: 14px;
}

.char-counter-stat {
  display: flex;
  align-items: center;
  gap: 12px;
}

.count-badge {
  font-size: 20px;
  font-weight: 800;
  color: var(--color-primary-blue);
}

.count-badge.target-met {
  color: var(--color-success);
}

.count-badge.target-short {
  color: var(--color-warning);
}

.count-badge.target-over {
  color: var(--color-error);
}

/* OCR Section */
.ocr-box {
  background: linear-gradient(135deg, var(--color-blue-subtle) 0%, var(--color-pink-subtle) 100%);
  border: 2px dashed var(--color-pink-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
  cursor: pointer;
  transition: all 0.25s ease;
  margin-bottom: 20px;
}

.ocr-box:hover, .ocr-box.dragover {
  border-color: var(--color-primary-pink);
  background: #ffffff;
  box-shadow: 0 8px 24px rgba(236, 72, 153, 0.15);
}

.ocr-icon-circle {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 12px;
  font-size: 24px;
  color: var(--color-primary-pink);
  box-shadow: var(--shadow-sm);
}

.ocr-preview-modal-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  max-height: 500px;
}

.ocr-img-preview-pane {
  background: #0f172a;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  max-height: 480px;
}

.ocr-img-preview-pane img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.ocr-text-edit-pane {
  display: flex;
  flex-direction: column;
}

.ocr-text-edit-pane textarea {
  flex: 1;
  min-height: 380px;
  font-family: var(--font-hanzi);
  font-size: 16px;
  line-height: 1.8;
  padding: 16px;
  border: 1.5px solid #cbd5e1;
  border-radius: var(--radius-md);
}

/* Step 4: BÁO CÁO LEXIBOT HSK 3.0 (CỰC KỲ CHI TIẾT) */
.lexibot-report-container {
  background: #ffffff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border: 1px solid #e2e8f0;
  overflow: hidden;
}

/* Banner điểm tổng quan */
.report-hero-header {
  background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 50%, #ec4899 100%);
  color: #ffffff;
  padding: 36px 32px;
  position: relative;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.report-hero-left h2 {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 6px;
}

.report-hero-subtitle {
  font-size: 14px;
  opacity: 0.9;
  display: flex;
  align-items: center;
  gap: 8px;
}

.report-score-capsule {
  display: flex;
  align-items: center;
  gap: 24px;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(12px);
  padding: 16px 28px;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.score-big-number {
  font-size: 54px;
  font-weight: 800;
  line-height: 1;
  text-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.score-details {
  display: flex;
  flex-direction: column;
}

.score-hsk-badge {
  background: #ffffff;
  color: var(--color-primary-blue);
  font-weight: 800;
  font-size: 13px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 6px;
  display: inline-block;
  text-align: center;
}

.score-cefr-badge {
  font-size: 12px;
  opacity: 0.95;
}

/* 4 Trụ cột điểm (Radar/Pillar Cards) */
.report-pillars-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding: 24px 32px;
  background: #f8fafc;
  border-bottom: 1px solid #e2e8f0;
}

.pillar-card {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 16px;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

.pillar-card:hover {
  transform: translateY(-2px);
  border-color: var(--color-blue-light);
  box-shadow: var(--shadow-md);
}

.pillar-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--color-text-muted);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.pillar-score-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 8px;
}

.pillar-score-val {
  font-size: 24px;
  font-weight: 800;
  color: var(--color-primary-blue);
}

.pillar-status {
  font-size: 12px;
  font-weight: 700;
  color: var(--color-success);
}

.pillar-bar-track {
  width: 100%;
  height: 6px;
  background: #e2e8f0;
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: 8px;
}

.pillar-bar-fill {
  height: 100%;
  border-radius: var(--radius-full);
  background: linear-gradient(90deg, var(--color-primary-blue), var(--color-primary-pink));
}

.pillar-desc {
  font-size: 12px;
  color: var(--color-text-body);
  line-height: 1.4;
}

/* Bố cục nội dung báo cáo */
.report-body-padding {
  padding: 32px;
}

/* Executive Summary Box */
.summary-quote-box {
  background: linear-gradient(135deg, var(--color-blue-subtle) 0%, var(--color-pink-subtle) 100%);
  border-left: 5px solid var(--color-primary-pink);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 20px 24px;
  margin-bottom: 32px;
  position: relative;
}

.summary-quote-title {
  font-size: 15px;
  font-weight: 800;
  color: var(--color-text-title);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.summary-quote-text {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--color-text-body);
}

/* Phân tích từ vựng chuẩn HSK 3.0 */
.vocab-distrib-section {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 32px;
}

.distrib-bars-row {
  display: flex;
  gap: 12px;
  margin-top: 16px;
}

.distrib-col {
  flex: 1;
  text-align: center;
  padding: 12px 8px;
  background: #f8fafc;
  border-radius: var(--radius-sm);
  border: 1px solid #f1f5f9;
}

.distrib-lvl-name {
  font-size: 13px;
  font-weight: 700;
  color: var(--color-text-title);
}

.distrib-percent {
  font-size: 18px;
  font-weight: 800;
  color: var(--color-primary-blue);
  margin: 6px 0;
}

/* Bảng chữa câu chi tiết chuẩn LexiBot */
.sentence-diagnostics-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.sentence-card {
  background: #ffffff;
  border: 1.5px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 20px;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.sentence-card.is-error {
  border-left: 5px solid var(--color-error);
}

.sentence-card.is-warning {
  border-left: 5px solid var(--color-warning);
}

.sentence-card.is-success {
  border-left: 5px solid var(--color-success);
}

.sentence-card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.sentence-index-badge {
  font-size: 12px;
  font-weight: 800;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: #f1f5f9;
  color: var(--color-text-title);
}

.error-category-tag {
  font-size: 12px;
  font-weight: 700;
  padding: 3px 12px;
  border-radius: var(--radius-full);
  background: var(--color-pink-subtle);
  color: var(--color-primary-pink);
  border: 1px solid var(--color-pink-border);
}

/* So sánh câu gốc vs câu sửa chuẩn (Diff Visuals) */
.sentence-diff-block {
  background: #fdfdfe;
  border: 1px solid #f1f5f9;
  border-radius: var(--radius-sm);
  padding: 14px;
  margin-bottom: 12px;
}

.diff-row {
  margin-bottom: 10px;
  font-size: 15px;
  line-height: 1.7;
  font-family: var(--font-hanzi);
}

.diff-row:last-child {
  margin-bottom: 0;
}

.diff-label {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 800;
  text-transform: uppercase;
  padding: 2px 6px;
  border-radius: 4px;
  margin-right: 8px;
  letter-spacing: 0.5px;
}

.label-orig {
  background: var(--color-error-bg);
  color: var(--color-error);
  border: 1px solid var(--color-error-border);
}

.label-corr {
  background: var(--color-success-bg);
  color: var(--color-success);
  border: 1px solid var(--color-success-border);
}

.label-native {
  background: var(--color-blue-subtle);
  color: var(--color-primary-blue);
  border: 1px solid var(--color-blue-border);
}

.explanation-box {
  background: #f8fafc;
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 13.5px;
  color: var(--color-text-body);
  border-left: 3px solid #cbd5e1;
  white-space: pre-line;
  margin-bottom: 12px;
}

.native-polish-box {
  background: linear-gradient(135deg, #ffffff 0%, var(--color-blue-subtle) 100%);
  border: 1px solid var(--color-blue-border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-family: var(--font-hanzi);
}

.native-polish-title {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 800;
  color: var(--color-primary-blue);
  text-transform: uppercase;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.native-polish-hanzi {
  font-size: 15px;
  font-weight: 600;
  color: #1e3a8a;
}

.native-polish-pinyin {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--color-primary-pink);
  margin-top: 4px;
}

/* Full Polished Essay Versions */
.full-versions-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 32px;
}

.version-card {
  background: #ffffff;
  border: 1.5px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.version-card.clean {
  border-top: 4px solid var(--color-primary-blue);
}

.version-card.advanced {
  border-top: 4px solid var(--color-primary-pink);
  background: linear-gradient(180deg, #ffffff 60%, var(--color-pink-subtle) 100%);
}

.version-card-title {
  font-size: 16px;
  font-weight: 800;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.version-essay-content {
  font-family: var(--font-hanzi);
  font-size: 15.5px;
  line-height: 2;
  color: #1e293b;
  white-space: pre-wrap;
  margin-bottom: 16px;
}

.version-translation-box {
  background: #f8fafc;
  padding: 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--color-text-body);
  line-height: 1.6;
}

/* Modal API Key & Settings */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  backdrop-filter: blur(6px);
  z-index: 1000;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-overlay.open {
  display: flex;
}

.modal-card {
  background: #ffffff;
  border-radius: var(--radius-lg);
  max-width: 580px;
  width: 100%;
  padding: 28px;
  box-shadow: var(--shadow-lg);
  animation: modalPop 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalPop {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid #e2e8f0;
}

/* Print Stylesheet cho xuất PDF/In Báo cáo LexiBot */
@media print {
  body {
    background: #ffffff;
    color: #000000;
  }
  .app-header, .stepper-nav, .header-actions, .btn, .modal-overlay {
    display: none !important;
  }
  .lexibot-report-container {
    box-shadow: none !important;
    border: none !important;
  }
  .report-hero-header {
    background: #2563eb !important;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }
}

/* Responsive */
@media (max-width: 992px) {
  .guide-grid, .studio-layout, .full-versions-grid, .ocr-preview-modal-body {
    grid-template-columns: 1fr;
  }
  .stepper-nav {
    grid-template-columns: repeat(2, 1fr);
  }
  .report-pillars-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hsk-level-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media (max-width: 640px) {
  .stepper-nav {
    grid-template-columns: 1fr;
  }
  .report-pillars-grid {
    grid-template-columns: 1fr;
  }
  .report-hero-header {
    flex-direction: column;
    gap: 20px;
    text-align: center;
  }
  .hsk-level-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}