/* ==========================================================================
   E-INK OPTIMIZED STYLESHEET FOR KINDLE & E-PAPER DEVICES
   High Contrast • Crisp Typography • Zero Heavy Transitions • Pure Monochrome
   ========================================================================== */

:root {
  --bg-color: #ffffff;
  --text-color: #000000;
  --border-color: #000000;
  --card-bg: #ffffff;
  --highlight-bg: #f0f0f0;
  --muted-text: #333333;
  --badge-bg: #e0e0e0;
  --btn-bg: #ffffff;
  --btn-active-bg: #000000;
  --btn-active-text: #ffffff;

  --base-font-size: 15px;
  --kanji-hero-size: 68px;
  --meaning-size: 20px;
  --japanese-font-stack: "Hiragino Mincho ProN", "Yu Mincho", "MS Mincho", "Sawarabi Mincho", "Noto Serif CJK JP", "Noto Serif JP", Georgia, serif;
}

/* Dark / Inverted Mode */
body.theme-dark {
  --bg-color: #000000;
  --text-color: #ffffff;
  --border-color: #ffffff;
  --card-bg: #000000;
  --highlight-bg: #1a1a1a;
  --muted-text: #cccccc;
  --badge-bg: #333333;
  --btn-bg: #000000;
  --btn-active-bg: #ffffff;
  --btn-active-text: #000000;
}

/* Font Size Modifiers */
body.font-large {
  --base-font-size: 16px;
  --kanji-hero-size: 74px;
  --meaning-size: 22px;
}

body.font-xl {
  --base-font-size: 18px;
  --kanji-hero-size: 82px;
  --meaning-size: 24px;
}

/* Font Family Toggles */
body.font-sans {
  --japanese-font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
}

/* Furigana Hidden Modifier */
body.furigana-hide rt {
  display: none !important;
}

/* Base Reset & E-ink rules */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
  /* Disable animations and transitions for crisp instant e-ink redrawing */
  transition: none !important;
  animation: none !important;
  text-rendering: optimizeLegibility;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--japanese-font-stack);
  font-size: var(--base-font-size);
  line-height: 1.4;
  padding: 4px 6px;
  min-height: 100vh;
}

/* App Container */
.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 0;
}

/* ==========================================================================
   Header & Status Elements
   ========================================================================== */
.header {
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 4px;
  margin-bottom: 6px;
}

.header-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82em;
  font-weight: bold;
}

.date-badge {
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.status-counters {
  display: flex;
  gap: 6px;
}

.badge {
  display: inline-block;
  padding: 2px 6px;
  border: 1px solid var(--border-color);
  font-size: 0.8em;
  font-weight: bold;
  border-radius: 2px;
}

.badge-inverse {
  background-color: var(--btn-active-bg);
  color: var(--btn-active-text);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Battery Status */
.battery-status {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.85em;
  font-weight: bold;
  margin-right: 2px;
}

.battery-icon-border {
  display: inline-block;
  width: 15px;
  height: 9px;
  border: 1.5px solid var(--border-color);
  border-radius: 1px;
  position: relative;
  vertical-align: middle;
  box-sizing: border-box;
}

.battery-icon-border::after {
  content: '';
  position: absolute;
  right: -3px;
  top: 1.5px;
  width: 1.5px;
  height: 3px;
  background-color: var(--border-color);
}

.battery-fill {
  display: block;
  height: 100%;
  width: 100%;
  background-color: var(--border-color);
}

/* ==========================================================================
   Buttons & Navigation
   ========================================================================== */
.btn {
  background-color: var(--btn-bg);
  color: var(--text-color);
  border: 2px solid var(--border-color);
  padding: 5px 10px;
  font-family: inherit;
  font-size: 0.9em;
  font-weight: bold;
  cursor: pointer;
  border-radius: 3px;
  text-align: center;
  user-select: none;
}

.btn:active, .btn.active {
  background-color: var(--btn-active-bg);
  color: var(--btn-active-text);
}

.btn-sm {
  padding: 2px 6px;
  font-size: 0.78em;
}

.btn-lg {
  padding: 10px 20px;
  font-size: 1.1em;
}

.nav-bar {
  display: flex;
  justify-content: space-between;
  gap: 6px;
  margin-top: 6px;
}

.nav-btn {
  flex: 1;
  padding: 10px 4px;
  font-size: 1em;
}

.btn-today {
  flex: 1.2;
}

/* ==========================================================================
   Main Card & Hero Section
   ========================================================================== */
.main-card {
  border: 2px solid var(--border-color);
  padding: 6px 8px;
  background-color: var(--card-bg);
  position: relative;
}

.kanji-hero-grid {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 8px;
  align-items: center;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 6px;
  margin-bottom: 6px;
}

@media (max-width: 480px) {
  .kanji-hero-grid {
    grid-template-columns: 84px 1fr;
    gap: 6px;
  }
}

.kanji-box {
  width: 100%;
  aspect-ratio: 1 / 1;
  border: 2px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--bg-color);
}

.kanji-character {
  font-size: var(--kanji-hero-size);
  font-weight: 900;
  line-height: 1;
  user-select: none;
}

.kanji-summary {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.meanings-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
}

.meaning-text {
  font-size: var(--meaning-size);
  font-weight: bold;
  line-height: 1.15;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.meta-radical {
  font-size: 0.8em;
  white-space: nowrap;
}

.meta-radical .meta-label {
  color: var(--muted-text);
  font-weight: bold;
}

.meta-radical .meta-val {
  font-weight: bold;
}

.meta-row {
  display: flex;
  gap: 10px;
  font-size: 0.85em;
  margin-top: 2px;
}

.meta-item {
  display: flex;
  flex-direction: column;
}

.meta-label {
  font-size: 0.72em;
  text-transform: uppercase;
  color: var(--muted-text);
  font-weight: bold;
}

.meta-val {
  font-weight: bold;
  font-size: 0.95em;
}

.quick-tools {
  display: flex;
  gap: 6px;
  margin-top: 4px;
}

.btn-master {
  flex: 1;
}

/* ==========================================================================
   Content Sections
   ========================================================================== */
.content-section {
  margin-top: 6px;
  padding-top: 4px;
  border-top: 1px solid var(--border-color);
}

.section-heading {
  font-size: 0.78em;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
  padding-bottom: 1px;
  border-bottom: 1px dotted var(--border-color);
  display: flex;
  justify-content: space-between;
}

/* Readings Box */
.readings-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

@media (max-width: 480px) {
  .readings-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.reading-box {
  border: 1px solid var(--border-color);
  padding: 3px 6px;
  background-color: var(--highlight-bg);
}

.reading-type {
  font-size: 0.65em;
  font-weight: bold;
  text-transform: uppercase;
  margin-bottom: 1px;
}

.reading-kana {
  font-size: 1.05em;
  font-weight: bold;
  line-height: 1.2;
}

.reading-romaji {
  font-size: 0.72em;
  color: var(--muted-text);
  font-family: monospace, sans-serif;
}

/* Mnemonic */
.mnemonic-text {
  font-size: 0.88em;
  line-height: 1.35;
  padding: 3px 6px;
  border-left: 3px solid var(--border-color);
  background-color: var(--highlight-bg);
}

/* Vocabulary Grid */
.vocab-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5px;
}

.vocab-card {
  border: 1px solid var(--border-color);
  padding: 3px 6px;
  background-color: var(--bg-color);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 6px;
  min-height: 28px;
}

.vocab-word {
  font-size: 1.05em;
  font-weight: bold;
  line-height: 1.2;
  white-space: nowrap;
}

.vocab-meaning {
  font-size: 0.82em;
  color: var(--muted-text);
  text-align: right;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-weight: 500;
}

/* Example Sentences */
.sentences-list {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.sentence-item {
  border: 1px solid var(--border-color);
  padding: 4px 6px;
  background-color: var(--bg-color);
}

.sentence-ja {
  font-size: 1.05em;
  line-height: 1.4;
  font-weight: 500;
}

.sentence-en {
  font-size: 0.82em;
  margin-top: 2px;
  color: var(--muted-text);
  font-style: italic;
  border-top: 1px dotted var(--border-color);
  padding-top: 2px;
}

/* ==========================================================================
   Ruby / Furigana Styles
   ========================================================================== */
ruby {
  ruby-align: center;
}

rt {
  font-size: 0.55em;
  font-weight: normal;
  line-height: 1;
  user-select: none;
  color: inherit;
}

/* ==========================================================================
   Modals (All Kanji List & Settings)
   ========================================================================== */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 10px;
  z-index: 1000;
}

.modal.hidden {
  display: none !important;
}

.modal-content {
  background-color: var(--bg-color);
  color: var(--text-color);
  border: 3px solid var(--border-color);
  width: 100%;
  max-width: 680px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  padding: 14px;
  overflow: hidden;
}

.modal-content-sm {
  max-width: 480px;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 8px;
  margin-bottom: 10px;
}

.modal-search {
  margin-bottom: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.search-box {
  width: 100%;
  padding: 8px;
  border: 2px solid var(--border-color);
  font-family: inherit;
  font-size: 0.95em;
  background-color: var(--bg-color);
  color: var(--text-color);
}

.filter-pills {
  display: flex;
  gap: 6px;
}

.pill {
  background-color: var(--bg-color);
  color: var(--text-color);
  border: 1px solid var(--border-color);
  padding: 4px 8px;
  font-size: 0.8em;
  cursor: pointer;
}

.pill.active {
  background-color: var(--btn-active-bg);
  color: var(--btn-active-text);
}

.kanji-table-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(64px, 1fr));
  gap: 6px;
  overflow-y: auto;
  padding: 4px;
  border: 1px solid var(--border-color);
}

.kanji-grid-item {
  aspect-ratio: 1 / 1;
  border: 2px solid var(--border-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  background-color: var(--bg-color);
  position: relative;
  user-select: none;
}

.kanji-grid-item:active, .kanji-grid-item.active {
  background-color: var(--btn-active-bg);
  color: var(--btn-active-text);
}

.kanji-grid-item.learned::after {
  content: "★";
  position: absolute;
  top: 1px;
  right: 2px;
  font-size: 0.65em;
}

.grid-kanji {
  font-size: 1.6em;
  font-weight: bold;
  line-height: 1;
}

.grid-sub {
  font-size: 0.65em;
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 90%;
}

/* Settings elements */
.settings-body {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 6px 0;
}

.setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
}

.setting-row label {
  font-size: 0.9em;
  font-weight: bold;
}

.select-box {
  padding: 6px;
  border: 2px solid var(--border-color);
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: inherit;
  font-size: 0.9em;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
  margin-top: 14px;
  padding-top: 8px;
  border-top: 2px solid var(--border-color);
  font-size: 0.75em;
  color: var(--muted-text);
  text-align: center;
}

.footer-row {
  display: flex;
  justify-content: space-between;
}

@media (max-width: 480px) {
  .footer-row {
    flex-direction: column;
    gap: 4px;
  }
}