/* ===== CSS VARIABLES ===== */
:root {
  --bg: #f5f0e8;
  --bg2: #ece6d8;
  --surface: #ffffff;
  --surface2: #f9f5ed;
  --border: #d4c9b0;
  --text: #1a1208;
  --text2: #6b5e42;
  --text3: #9e8f72;
  --accent: #c0392b;
  --accent2: #e74c3c;
  --accent-soft: rgba(192,57,43,.1);
  --ink: #1a1208;
  --gold: #b8860b;
  --gold-soft: rgba(184,134,11,.15);
  --shadow: 0 4px 24px rgba(26,18,8,.08);
  --shadow-lg: 0 12px 48px rgba(26,18,8,.14);
  --radius: 12px;
  --radius-sm: 6px;
  --transition: .25s cubic-bezier(.4,0,.2,1);
}

[data-theme="dark"] {
  --bg: #0f0d0a;
  --bg2: #1a1710;
  --surface: #1e1b14;
  --surface2: #252119;
  --border: #3a3526;
  --text: #f0e8d4;
  --text2: #b8a98a;
  --text3: #7a6e56;
  --accent: #e05a4d;
  --accent2: #f07060;
  --accent-soft: rgba(224,90,77,.12);
  --gold: #d4a843;
  --gold-soft: rgba(212,168,67,.12);
  --shadow: 0 4px 24px rgba(0,0,0,.4);
  --shadow-lg: 0 12px 48px rgba(0,0,0,.6);
}

/* ===== RESET ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Noto Sans KR', 'Noto Sans JP', sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background var(--transition), color var(--transition);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ===== TOPBAR ===== */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 2rem;
  height: 60px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
}

.topbar-brand {
  display: flex; align-items: center; gap: .5rem;
}
.brand-kanji {
  font-family: 'Shippori Mincho', serif;
  font-size: 1.6rem;
  color: var(--accent);
  line-height: 1;
}
.brand-text {
  font-family: 'Space Mono', monospace;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: .15em;
  color: var(--text);
}

.topbar-actions {
  display: flex; align-items: center; gap: .5rem;
}

.icon-btn {
  width: 40px; height: 40px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface2);
  color: var(--text2);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition);
  position: relative;
}
.icon-btn svg { width: 18px; height: 18px; }
.icon-btn:hover {
  color: var(--accent); border-color: var(--accent);
  background: var(--accent-soft);
  transform: translateY(-1px);
}
.icon-btn.accent {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.icon-btn.accent:hover {
  background: var(--accent2); border-color: var(--accent2); color: #fff;
  transform: translateY(-1px) scale(1.05);
}

/* theme icons */
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

/* ===== HERO ===== */
.hero {
  margin-top: 60px;
  position: relative;
  overflow: hidden;
  padding: 5rem 2rem 3rem;
  text-align: center;
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
}

.hero-deco {
  position: absolute; inset: 0; pointer-events: none;
}
.deco-char {
  font-family: 'Shippori Mincho', serif;
  font-size: clamp(80px,12vw,160px);
  font-weight: 700;
  color: var(--border);
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(calc(-50% + var(--x)), calc(-50% + var(--y)));
  animation: floatChar 6s ease-in-out infinite;
  animation-delay: var(--d);
  opacity: .5;
  user-select: none;
}
@keyframes floatChar {
  0%,100% { transform: translate(calc(-50% + var(--x)), calc(-50% + var(--y))); }
  50% { transform: translate(calc(-50% + var(--x)), calc(-50% + var(--y) - 12px)); }
}

.hero-content { position: relative; z-index: 1; }
.hero-date {
  font-family: 'Space Mono', monospace;
  font-size: .8rem;
  letter-spacing: .2em;
  color: var(--text3);
  text-transform: uppercase;
  margin-bottom: .75rem;
}
.hero-title {
  font-family: 'Shippori Mincho', serif;
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
  margin-bottom: .5rem;
}
.hero-sub {
  font-size: .95rem;
  color: var(--text2);
}

/* ===== SENTENCES ===== */
.sentences-container {
  max-width: 840px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
  display: flex; flex-direction: column; gap: 1rem;
}

/* loading */
.loading-state {
  display: flex; flex-direction: column; align-items: center; gap: 1.5rem;
  padding: 4rem 0; color: var(--text2);
}
.loader-ring {
  width: 48px; height: 48px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* sentence card */
.sentence-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow var(--transition), border-color var(--transition);
  cursor: pointer;
  animation: slideUp .4s ease both;
}
.sentence-card:hover {
  box-shadow: var(--shadow);
  border-color: var(--gold);
}
.sentence-card.active {
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

.card-num {
  display: inline-block;
  font-family: 'Space Mono', monospace;
  font-size: .7rem; font-weight: 700;
  letter-spacing: .1em;
  color: var(--accent);
  background: var(--accent-soft);
  padding: .2rem .55rem;
  border-radius: 4px;
  margin-bottom: .5rem;
}

.card-main {
  padding: 1.25rem 1.5rem;
}

.japanese-line {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.japanese-text {
  font-family: 'Shippori Mincho', 'Noto Sans JP', serif;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.5;
  flex: 1;
}
.korean-text {
  font-size: .9rem;
  color: var(--text2);
  margin-top: .4rem;
  line-height: 1.5;
}

/* audio buttons */
.audio-btns {
  display: flex; gap: .4rem; flex-shrink: 0;
}
.audio-btn {
  display: flex; align-items: center; gap: .3rem;
  font-size: .72rem; font-weight: 700; letter-spacing: .05em;
  padding: .3rem .6rem;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border);
  background: var(--surface2);
  color: var(--text2);
  cursor: pointer;
  transition: all var(--transition);
}
.audio-btn svg { width: 13px; height: 13px; }
.audio-btn.jp:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.audio-btn.kr:hover { border-color: var(--gold); color: var(--gold); background: var(--gold-soft); }
.audio-btn.playing { animation: pulse .6s ease infinite alternate; }
@keyframes pulse { from { opacity: 1; } to { opacity: .5; } }

/* vocabulary panel */
.vocab-panel {
  border-top: 1px solid var(--border);
  background: var(--surface2);
  overflow: hidden;
  max-height: 0;
  transition: max-height .4s cubic-bezier(.4,0,.2,1);
}
.vocab-panel.open { max-height: 600px; }

.vocab-inner { padding: 1rem 1.5rem 1.25rem; }
.vocab-title {
  font-family: 'Space Mono', monospace;
  font-size: .7rem; letter-spacing: .15em;
  text-transform: uppercase;
  color: var(--text3);
  margin-bottom: .75rem;
}
.vocab-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: .5rem;
}
.vocab-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: .6rem .8rem;
  transition: border-color var(--transition);
}
.vocab-item:hover { border-color: var(--accent); }
.vocab-word {
  font-family: 'Shippori Mincho', serif;
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent);
}
.vocab-reading {
  font-size: .75rem;
  color: var(--text3);
  margin: .1rem 0;
}
.vocab-meaning {
  font-size: .8rem;
  color: var(--text2);
}

/* ===== STUDY MODAL ===== */
.modal-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,.6);
  backdrop-filter: blur(6px);
  display: flex; align-items: center; justify-content: center;
  padding: 1rem;
  opacity: 0; pointer-events: none;
  transition: opacity var(--transition);
}
.modal-overlay.open {
  opacity: 1; pointer-events: all;
}

.modal-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) * 1.5);
  width: 100%; max-width: 580px;
  box-shadow: var(--shadow-lg);
  position: relative;
  transform: translateY(20px) scale(.97);
  transition: transform .3s cubic-bezier(.34,1.56,.64,1);
  overflow: hidden;
}
.modal-overlay.open .modal-box {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute; top: 1rem; right: 1rem;
  width: 34px; height: 34px;
  border-radius: 50%;
  border: 1.5px solid var(--border);
  background: var(--surface2);
  color: var(--text2);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition);
  z-index: 2;
}
.modal-close:hover { background: var(--accent); border-color: var(--accent); color: #fff; transform: rotate(90deg); }
.modal-close svg { width: 16px; height: 16px; }

.modal-header {
  padding: 1.25rem 1.5rem .75rem;
  display: flex; align-items: center; gap: .75rem;
  border-bottom: 1px solid var(--border);
}
.modal-badge {
  font-family: 'Space Mono', monospace;
  font-size: .65rem; font-weight: 700;
  letter-spacing: .15em; text-transform: uppercase;
  background: var(--accent); color: #fff;
  padding: .25rem .6rem; border-radius: 4px;
  flex-shrink: 0;
}
.modal-progress-wrap {
  flex: 1;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}
.modal-progress-bar {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width .4s ease;
  width: 10%;
}
.modal-counter {
  font-family: 'Space Mono', monospace;
  font-size: .75rem;
  color: var(--text3);
  flex-shrink: 0;
}

.modal-body {
  padding: 2rem 2rem 1.5rem;
  min-height: 180px;
}

.study-sentence {
  font-family: 'Shippori Mincho', serif;
  font-size: 1.4rem;
  line-height: 2;
  color: var(--text);
  display: flex; flex-wrap: wrap; align-items: center; gap: .4rem;
}

.blank-box {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 60px; height: 36px;
  background: var(--bg2);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  color: transparent;
  transition: all var(--transition);
  padding: 0 .5rem;
  font-family: 'Shippori Mincho', serif;
}
.blank-box.revealed {
  background: var(--gold-soft);
  border-color: var(--gold);
  color: var(--gold);
  border-style: solid;
}

.modal-actions {
  display: flex; gap: .75rem;
  padding: 0 1.5rem 1.5rem;
}

.btn-modal {
  flex: 1;
  display: flex; align-items: center; justify-content: center; gap: .4rem;
  padding: .75rem .5rem;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border);
  font-size: .85rem; font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  font-family: 'Noto Sans KR', sans-serif;
}
.btn-modal svg { width: 16px; height: 16px; flex-shrink: 0; }

.btn-modal.play {
  background: var(--surface2); color: var(--text2);
}
.btn-modal.play:hover {
  background: var(--accent-soft); border-color: var(--accent); color: var(--accent);
}
.btn-modal.answer {
  background: var(--surface2); color: var(--text2);
}
.btn-modal.answer:hover {
  background: var(--gold-soft); border-color: var(--gold); color: var(--gold);
}
.btn-modal.next {
  background: var(--accent); border-color: var(--accent); color: #fff;
}
.btn-modal.next:hover {
  background: var(--accent2); border-color: var(--accent2);
  transform: translateX(2px);
}
.btn-modal.finish {
  background: var(--gold); border-color: var(--gold); color: #fff;
}
.btn-modal.finish:hover {
  filter: brightness(1.1);
}

/* ===== FOOTER ===== */
.site-footer {
  text-align: center;
  padding: 2rem;
  font-family: 'Space Mono', monospace;
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--text3);
  border-top: 1px solid var(--border);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 600px) {
  .topbar { padding: 0 1rem; }
  .hero { padding: 3.5rem 1rem 2rem; }
  .sentences-container { padding: 1.5rem 1rem 3rem; }
  .japanese-text { font-size: 1.1rem; }
  .study-sentence { font-size: 1.15rem; }
  .modal-actions { flex-wrap: wrap; }
  .btn-modal { flex: 1 1 calc(50% - .4rem); }
  .btn-modal.next { flex: 1 1 100%; }
  .vocab-grid { grid-template-columns: 1fr 1fr; }
}