/* ==========================================
   1. VARIABLES & RESET
   ========================================== */
:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --bg-color: #f8fafc;
  --card-bg: #ffffff;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1);
  --radius: 8px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
}

.hidden {
  display: none !important;
}

/* ==========================================
   2. HEADER & SEARCH BAR
   ========================================== */
.app-header {
  background-color: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
  padding: 1rem;
}

.header-container {
  max-width: 1000px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: center;
}

.app-title {
  font-size: 1.5rem;
  color: var(--primary-color);
}

.search-box {
  position: relative;
  width: 100%;
  max-width: 500px;
}

.search-box input {
  width: 100%;
  padding: 0.75rem 2.5rem 0.75rem 1rem;
  font-size: 1rem;
  border: 2px solid var(--border-color);
  border-radius: 25px;
  outline: none;
  transition: border-color 0.2s;
}

.search-box input:focus {
  border-color: var(--primary-color);
}

#clear-search-btn {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--text-muted);
  cursor: pointer;
}

.status-bar {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ==========================================
   3. MAIN CONTENT & GRID LAYOUT
   ========================================== */
.main-content {
  max-width: 1000px;
  margin: 1.5rem auto;
  padding: 0 1rem;
}

.kanji-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 0.75rem;
}

/* Card Kanji */
.kanji-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: var(--shadow-sm);
}

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

.kanji-card .char {
  font-size: 2.2rem;
  font-weight: 500;
  line-height: 1.2;
}

.kanji-card .mean {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
  text-align: center;
  font-weight: 500;
}

.load-more-container {
  display: flex;
  justify-content: center;
  margin: 2rem 0;
}

/* Buttons */
.btn {
  padding: 0.6rem 1.2rem;
  border-radius: 6px;
  border: none;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s;
}

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

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

.btn-secondary {
  background-color: #f1f5f9;
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: #e2e8f0;
}

/* ==========================================
   4. MODAL POPUP
   ========================================== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 1rem;
}

.modal-content {
  background-color: var(--card-bg);
  border-radius: var(--radius);
  width: 100%;
  max-width: 700px;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  box-shadow: var(--shadow-lg);
  padding: 1.5rem;
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  font-size: 1.8rem;
  cursor: pointer;
  color: var(--text-muted);
}

.modal-body {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 1.5rem;
  margin-top: 0.5rem;
}

/* Modal Cột Trái (SVG) */
.modal-left {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.svg-container {
  width: 180px;
  height: 180px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  background-color: #fafafa;
  display: flex;
  align-items: center;
  justify-content: center;
}

.svg-container svg {
  width: 100%;
  height: 100%;
}

.animator-controls {
  display: flex;
  gap: 0.5rem;
  width: 100%;
}

.animator-controls .btn {
  flex: 1;
  font-size: 0.8rem;
  padding: 0.4rem;
}

/* Modal Cột Phải (Thông tin) */
.kanji-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
  margin-bottom: 1rem;
}

.modal-kanji {
  font-size: 2.5rem;
  display: inline-block;
  margin-right: 0.5rem;
}

.modal-main-meta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.modal-mean {
  font-size: 1.25rem;
  font-weight: bold;
  color: var(--primary-color);
}

.badge {
  font-size: 0.75rem;
  padding: 0.2rem 0.5rem;
  border-radius: 12px;
  font-weight: 600;
}

.badge-level {
  background-color: #dbeafe;
  color: #1e40af;
}

.meta-grid {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1rem;
}

.meta-label {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.meta-value {
  font-weight: 600;
}

.section-block {
  margin-bottom: 1rem;
}

.section-block h3 {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.comp-tags-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.comp-tag {
  background-color: #f1f5f9;
  border: 1px solid var(--border-color);
  padding: 0.25rem 0.6rem;
  border-radius: 4px;
  font-size: 0.85rem;
}

.detail-text {
  font-size: 0.95rem;
  line-height: 1.6;
}

.detail-text p {
  margin-bottom: 0.4rem;
}

/* ==========================================
   5. SPINNER & EMPTY STATE
   ========================================== */
.spinner-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem 0;
  color: var(--text-muted);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--border-color);
  border-top-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-bottom: 1rem;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.empty-result {
  text-align: center;
  padding: 3rem 0;
  color: var(--text-muted);
}

/* Responsive cho Mobile */
@media (max-width: 600px) {
  .modal-body {
    grid-template-columns: 1fr;
  }
  
  .modal-left {
    margin-bottom: 1rem;
  }
}