/* ==========================================================================
   EasyKit Hub (201866.xyz) - Global Stylesheet & Print Engine (V2)
   ========================================================================== */

:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-kaiti: "Kaiti", "STKaiti", "KaiTi_GB2312", "楷体", "BiauKai", serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Color Palette - Light Mode */
  --bg-primary: #F8FAF9;
  --bg-surface: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-subtle: #F1F5F3;
  --border-color: #E2E8E5;
  --border-strong: #CBD5D0;
  --text-primary: #1A202C;
  --text-secondary: #4A5568;
  --text-muted: #718096;

  /* Brand Accents */
  --brand-primary: #0D9488;
  --brand-primary-hover: #0F766E;
  --brand-light: rgba(13, 148, 136, 0.1);
  --brand-ring: rgba(13, 148, 136, 0.25);

  /* Calligraphy Grid Themes */
  --grid-vermilion: #DC2626;
  --grid-vermilion-dash: rgba(220, 38, 38, 0.45);
  --grid-vermilion-diag: rgba(220, 38, 38, 0.25);
  --grid-green: #059669;
  --grid-green-dash: rgba(5, 150, 105, 0.45);
  --grid-green-diag: rgba(5, 150, 105, 0.25);
  --grid-gray: #64748B;
  --grid-gray-dash: rgba(100, 116, 139, 0.45);
  --grid-gray-diag: rgba(100, 116, 139, 0.2);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.08);
}

[data-theme="dark"] {
  --bg-primary: #0F171E;
  --bg-surface: #18222C;
  --bg-card: #18222C;
  --bg-subtle: #202D3A;
  --border-color: #2D3D4E;
  --border-strong: #3D5064;
  --text-primary: #F1F5F9;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --brand-primary: #14B8A6;
  --brand-primary-hover: #2DD4BF;
  --brand-light: rgba(20, 184, 166, 0.15);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.25);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.4);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   Header & Navbar
   ========================================================================== */
.site-header {
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.brand-icon {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, #0D9488 0%, #065F46 100%);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 800;
  box-shadow: 0 2px 8px rgba(13, 148, 136, 0.3);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-link:hover, .nav-link.active {
  color: var(--brand-primary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.icon-btn {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.icon-btn:hover {
  background: var(--border-color);
  color: var(--text-primary);
}

/* ==========================================================================
   Hero & Search Section
   ========================================================================== */
.hero-section {
  padding: 3rem 1.25rem 2rem;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-surface) 0%, var(--bg-primary) 100%);
  border-bottom: 1px solid var(--border-color);
}

.hero-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto 2rem;
}

.search-box-wrap {
  max-width: 580px;
  margin: 0 auto;
  position: relative;
}

.search-input-group {
  display: flex;
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-md);
  padding: 6px;
  box-shadow: var(--shadow-md);
  transition: all 0.2s ease;
}

.search-input-group:focus-within {
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 4px var(--brand-ring);
}

.search-input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  padding: 0.6rem 1rem;
  font-size: 1.1rem;
  color: var(--text-primary);
  font-family: inherit;
}

.search-btn {
  background: var(--brand-primary);
  color: #FFFFFF;
  border: none;
  padding: 0.7rem 1.4rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.search-btn:hover {
  background: var(--brand-primary-hover);
}

.quick-tags {
  margin-top: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.tag-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 4px 10px;
  border-radius: 99px;
  color: var(--text-secondary);
  cursor: pointer;
  font-weight: 500;
  font-size: 0.85rem;
  transition: all 0.15s ease;
}

.tag-btn:hover {
  border-color: var(--brand-primary);
  color: var(--brand-primary);
}

/* ==========================================================================
   Main Content Layout
   ========================================================================== */
.main-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.25rem;
  flex: 1;
  width: 100%;
}

.app-grid {
  display: grid;
  grid-template-columns: 460px 1fr;
  gap: 2rem;
  align-items: start;
}

@media (max-width: 960px) {
  .app-grid {
    grid-template-columns: 1fr;
  }
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
}

/* Character Canvas Card */
.canvas-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hanzi-box-outer {
  width: 320px;
  height: 320px;
  position: relative;
  background: #FFFDFC;
  border: 2px solid var(--grid-vermilion);
  border-radius: 4px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.06);
  overflow: hidden;
  margin-bottom: 1.25rem;
}

.grid-lines {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  pointer-events: none;
}

.grid-lines.vermilion {
  --line-main: var(--grid-vermilion);
  --line-dash: var(--grid-vermilion-dash);
  --line-diag: var(--grid-vermilion-diag);
}

.grid-lines.green {
  --line-main: var(--grid-green);
  --line-dash: var(--grid-green-dash);
  --line-diag: var(--grid-green-diag);
}

.grid-lines.gray {
  --line-main: var(--grid-gray);
  --line-dash: var(--grid-gray-dash);
  --line-diag: var(--grid-gray-diag);
}

#hanzi-target {
  width: 320px;
  height: 320px;
  position: relative;
  z-index: 2;
}

.canvas-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  width: 100%;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.55rem 1rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--brand-primary);
  color: #FFFFFF;
}

.btn-primary:hover {
  background: var(--brand-primary-hover);
}

.btn-secondary {
  background: var(--bg-subtle);
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: var(--border-color);
}

.btn-outline {
  background: transparent;
  border-color: var(--brand-primary);
  color: var(--brand-primary);
}

.btn-outline:hover {
  background: var(--brand-light);
}

/* Character Info & Metadata Card */
.char-meta-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1rem;
  margin-bottom: 1.25rem;
}

.meta-char-display {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}

.current-char {
  font-family: var(--font-kaiti);
  font-size: 3rem;
  font-weight: 700;
  line-height: 1;
  color: var(--text-primary);
}

.current-pinyin {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--brand-primary);
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.info-item {
  background: var(--bg-subtle);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.info-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.info-value {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.section-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Progressive Stroke Steps Gallery */
.stroke-steps-container {
  display: flex;
  gap: 0.75rem;
  overflow-x: auto;
  padding: 0.5rem 0 1rem;
  margin-bottom: 1.5rem;
}

.stroke-step-card {
  width: 76px;
  flex-shrink: 0;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 6px;
  text-align: center;
}

.stroke-step-canvas {
  width: 64px;
  height: 64px;
  background: #FFFFFF;
  border: 1px solid var(--border-color);
  border-radius: 4px;
}

.stroke-step-num {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Practice Banner */
.practice-cta-card {
  background: linear-gradient(135deg, rgba(13,148,136,0.12) 0%, rgba(15,118,110,0.05) 100%);
  border: 1px solid rgba(13, 148, 136, 0.25);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 1.5rem;
}

.cta-text h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--brand-primary);
  margin-bottom: 0.2rem;
}

.cta-text p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Printable Worksheet Generator (worksheet.html) Styles
   ========================================================================== */
.worksheet-layout {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 2rem;
}

@media (max-width: 960px) {
  .worksheet-layout {
    grid-template-columns: 1fr;
  }
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.form-control {
  width: 100%;
  padding: 0.6rem 0.85rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
}

.form-control:focus {
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 3px var(--brand-ring);
}

/* Paper Preview (A4 Dimensions) */
.paper-preview-container {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  display: flex;
  justify-content: center;
  overflow-x: auto;
}

@media (max-width: 768px) {
  .paper-preview-container {
    padding: 0.5rem;
    overflow-x: scroll;
  }
}

.a4-sheet {
  width: 210mm;
  min-height: 297mm;
  background: #FFFFFF !important;
  color: #000000 !important;
  box-shadow: 0 10px 30px rgba(0,0,0,0.15);
  padding: 12mm 15mm;
  position: relative;
  box-sizing: border-box;
}

.sheet-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  border-bottom: 1.5px solid #1E293B;
  padding-bottom: 6px;
  margin-bottom: 12px;
}

.sheet-title {
  font-size: 16pt;
  font-weight: 700;
  color: #0F172A;
  letter-spacing: 2px;
}

.sheet-meta {
  display: flex;
  gap: 18px;
  font-size: 9.5pt;
  color: #475569;
}

.worksheet-row-wrapper {
  margin-bottom: 6px;
  page-break-inside: avoid;
  break-inside: avoid;
}

/* Pinyin Row */
.worksheet-pinyin-row {
  display: flex;
  margin-bottom: 1px;
}

.pinyin-cell {
  width: 16mm;
  height: 5.5mm;
  border: 0.75px solid rgba(220, 38, 38, 0.35);
  border-bottom: none;
  font-family: var(--font-sans);
  font-size: 3.5mm;
  font-weight: 600;
  color: #475569;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  background: #FFFDFD;
  box-sizing: border-box;
}

/* Character Tianzige & Mige Row */
.worksheet-grid-row {
  display: flex;
}

.grid-cell {
  width: 16mm;
  height: 16mm;
  border: 1px solid #DC2626;
  position: relative;
  box-sizing: border-box;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-kaiti);
  font-size: 12.5mm;
  line-height: 1;
  background: #FFFFFF;
}

.grid-cell-tianzige::before {
  content: '';
  position: absolute;
  top: 50%; left: 0; right: 0;
  border-top: 1px dashed rgba(220, 38, 38, 0.45);
}

.grid-cell-tianzige::after {
  content: '';
  position: absolute;
  left: 50%; top: 0; bottom: 0;
  border-left: 1px dashed rgba(220, 38, 38, 0.45);
}

.grid-cell-mige {
  background-image: 
    linear-gradient(to bottom, transparent calc(50% - 0.5px), rgba(220, 38, 38, 0.4) 50%, transparent calc(50% + 0.5px)),
    linear-gradient(to right, transparent calc(50% - 0.5px), rgba(220, 38, 38, 0.4) 50%, transparent calc(50% + 0.5px)),
    linear-gradient(45deg, transparent calc(50% - 0.5px), rgba(220, 38, 38, 0.25) 50%, transparent calc(50% + 0.5px)),
    linear-gradient(-45deg, transparent calc(50% - 0.5px), rgba(220, 38, 38, 0.25) 50%, transparent calc(50% + 0.5px));
}

.cell-char-solid {
  color: #1E293B;
  position: relative;
  z-index: 2;
}

/* Cognitive Fading Scaffolding */
.cell-char-fading-1 {
  color: #64748B;
  position: relative;
  z-index: 2;
}

.cell-char-fading-2 {
  color: #94A3B8;
  position: relative;
  z-index: 2;
}

.cell-char-trace {
  color: #CBD5E1;
  position: relative;
  z-index: 2;
}

/* ==========================================================================
   Footer & Legal Information
   ========================================================================== */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  padding: 3rem 1.25rem 2rem;
  margin-top: 4rem;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}

@media (max-width: 768px) {
  .footer-container {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 0.75rem;
  max-width: 400px;
}

.footer-links h5 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.footer-links ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: var(--brand-primary);
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ==========================================================================
   CSS Print Engine (A4 Vector Quality)
   ========================================================================== */
@media print {
  @page {
    size: A4 portrait;
    margin: 10mm 12mm;
  }

  body {
    background: #FFFFFF !important;
    color: #000000 !important;
    padding: 0 !important;
    margin: 0 !important;
  }

  .site-header,
  .site-footer,
  .hero-section,
  .worksheet-config-card,
  .no-print {
    display: none !important;
  }

  .main-container, .worksheet-layout, .paper-preview-container {
    padding: 0 !important;
    margin: 0 !important;
    display: block !important;
    border: none !important;
    background: transparent !important;
    box-shadow: none !important;
  }

  .a4-sheet {
    box-shadow: none !important;
    border: none !important;
    width: 100% !important;
    padding: 0 !important;
    margin: 0 !important;
  }

  * {
    -webkit-print-color-adjust: exact !important;
    print-color-adjust: exact !important;
  }
}