/* ============================================================
   CSS Custom Properties
   ============================================================ */
:root {
  --bg: #f0f4ff;
  --bg-card: #ffffff;
  --bg-card-hover: #f8f9ff;
  --bg-input: #ffffff;
  --border: #e2e8f0;
  --border-focus: #6366f1;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,.1), 0 4px 10px rgba(0,0,0,.05);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --font: 'Inter', sans-serif;
  --font-code: 'Fira Code', monospace;
  --brand-from: #6366f1;
  --brand-to: #8b5cf6;
  --blue: #3b82f6;
  --blue-light: #eff6ff;
  --blue-border: #bfdbfe;
  --purple: #8b5cf6;
  --purple-light: #f5f3ff;
  --purple-border: #ddd6fe;
  --green: #10b981;
  --green-light: #ecfdf5;
  --green-border: #a7f3d0;
  --red: #ef4444;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #263245;
  --bg-input: #1e293b;
  --border: #334155;
  --border-focus: #818cf8;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,.3);
  --shadow-lg: 0 10px 30px rgba(0,0,0,.4);
  --blue-light: #1e3a5f;
  --blue-border: #1d4ed8;
  --purple-light: #2e1065;
  --purple-border: #6d28d9;
  --green-light: #064e3b;
  --green-border: #065f46;
}

/* ============================================================
   Reset & Base
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
  min-height: 100vh;
}

/* ============================================================
   Header
   ============================================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(135deg, var(--brand-from), var(--brand-to));
  box-shadow: 0 2px 20px rgba(99,102,241,.3);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo { display: flex; align-items: center; gap: 10px; }

.logo-icon {
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,0.2);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 800;
  color: white;
  backdrop-filter: blur(4px);
}

.logo-text {
  font-size: 20px;
  font-weight: 800;
  color: white;
  letter-spacing: -0.3px;
}

.header-actions { display: flex; align-items: center; gap: 10px; }

.header-lang-info {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,.18);
  border: 1px solid rgba(255,255,255,.28);
  padding: 5px 12px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
  color: white;
}

.theme-toggle {
  background: rgba(255,255,255,0.2);
  border: none;
  border-radius: 50%;
  width: 40px; height: 40px;
  cursor: pointer;
  font-size: 18px;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.2s, transform 0.2s;
}
.theme-toggle:hover { background: rgba(255,255,255,0.3); transform: rotate(15deg); }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  background: linear-gradient(160deg, #6366f1 0%, #8b5cf6 50%, #a78bfa 100%);
  padding: 52px 24px 72px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  width: 600px; height: 600px;
  border-radius: 50%;
  background: rgba(255,255,255,.06);
  top: -200px; right: -100px;
  pointer-events: none;
}
.hero::after {
  content: '';
  position: absolute;
  width: 400px; height: 400px;
  border-radius: 50%;
  background: rgba(255,255,255,.04);
  bottom: -150px; left: -80px;
  pointer-events: none;
}

.hero-content {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,.18);
  border: 1px solid rgba(255,255,255,.3);
  color: white;
  font-size: 13px;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 18px;
  backdrop-filter: blur(6px);
}

.hero-title {
  font-size: clamp(28px, 4.5vw, 48px);
  font-weight: 800;
  color: white;
  line-height: 1.15;
  margin-bottom: 14px;
  letter-spacing: -0.8px;
}

.gradient-text {
  background: linear-gradient(to right, #fde68a, #fbbf24);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 16px;
  color: rgba(255,255,255,.85);
  max-width: 580px;
  margin-bottom: 28px;
  line-height: 1.7;
}

/* ============================================================
   Language Selector — Dropdown
   ============================================================ */
.lang-section {
  margin-bottom: 24px;
}

.lang-dropdown-row {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.lang-dropdown-label {
  font-size: 14px;
  font-weight: 700;
  color: white;
  white-space: nowrap;
}

.lang-section-hint {
  font-size: 12px;
  color: rgba(255,255,255,.6);
}

.lang-dropdown-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.lang-dropdown {
  appearance: none;
  -webkit-appearance: none;
  background: rgba(255,255,255,.15);
  border: 1.5px solid rgba(255,255,255,.35);
  border-radius: var(--radius-sm);
  color: white;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 600;
  padding: 9px 40px 9px 14px;
  cursor: pointer;
  outline: none;
  backdrop-filter: blur(6px);
  min-width: 220px;
  transition: background 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.lang-dropdown:focus {
  background: rgba(255,255,255,.22);
  border-color: rgba(255,255,255,.7);
  box-shadow: 0 0 0 3px rgba(255,255,255,.15);
}

.lang-dropdown option {
  background: #1e293b;
  color: #f1f5f9;
  font-size: 14px;
}

.lang-dropdown-arrow {
  position: absolute;
  right: 12px;
  font-size: 13px;
  color: rgba(255,255,255,.8);
  pointer-events: none;
  line-height: 1;
}

/* ============================================================
   Search Card
   ============================================================ */
.search-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-lg), 0 0 0 1px rgba(0,0,0,.06);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.search-inputs {
  display: grid;
  grid-template-columns: 2fr 1fr 2fr;
  gap: 14px;
}

.input-group { display: flex; flex-direction: column; gap: 5px; }
.input-label { font-size: 12px; font-weight: 700; color: var(--text-secondary); text-transform: uppercase; letter-spacing: .5px; }
.required { color: var(--red); }
.optional { color: var(--text-muted); font-weight: 400; text-transform: none; font-size: 11px; }

.input-wrapper { position: relative; }
.input-icon { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); font-size: 15px; pointer-events: none; z-index: 1; }

.text-input {
  width: 100%;
  padding: 11px 13px 11px 38px;
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 15px;
  font-weight: 500;
  background: var(--bg-input);
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  -webkit-appearance: none;
  appearance: none;
}
.select-input { cursor: pointer; }
.text-input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 4px rgba(99,102,241,.12);
}
.text-input::placeholder { color: var(--text-muted); font-weight: 400; }

.autocomplete-list {
  position: absolute;
  top: calc(100% + 6px);
  left: 0; right: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  z-index: 50;
  max-height: 200px;
  overflow-y: auto;
  display: none;
}
.autocomplete-list.open { display: block; }
.autocomplete-item {
  padding: 10px 14px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
  transition: background 0.15s;
}
.autocomplete-item:hover, .autocomplete-item.selected { background: var(--blue-light); color: var(--blue); }

.btn-search {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  background: linear-gradient(135deg, var(--brand-from), var(--brand-to));
  color: white;
  font-family: var(--font);
  font-size: 16px;
  font-weight: 700;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s, box-shadow 0.2s;
  box-shadow: 0 4px 14px rgba(99,102,241,.4);
  width: 100%;
}
.btn-search:hover { opacity: .92; transform: translateY(-1px); box-shadow: 0 6px 20px rgba(99,102,241,.5); }
.btn-search:active { transform: translateY(0); }
.btn-search:disabled { opacity: .6; cursor: not-allowed; transform: none; }
.btn-icon { font-size: 18px; }

/* Popular Verbs */
.popular-verbs { display: flex; align-items: center; gap: 10px; margin-top: 18px; flex-wrap: wrap; }
.popular-label { font-size: 13px; font-weight: 600; color: rgba(255,255,255,.7); white-space: nowrap; }
.verb-chips { display: flex; gap: 8px; flex-wrap: wrap; }
.verb-chip {
  background: rgba(255,255,255,.15);
  border: 1px solid rgba(255,255,255,.25);
  color: white;
  font-size: 13px;
  font-weight: 600;
  padding: 5px 14px;
  border-radius: 100px;
  cursor: pointer;
  transition: background 0.2s;
  font-family: var(--font-code);
  backdrop-filter: blur(4px);
}
.verb-chip:hover { background: rgba(255,255,255,.28); }

/* ============================================================
   Loading & Error
   ============================================================ */
.loading-overlay {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 60px 24px;
  color: var(--text-secondary);
  font-weight: 500;
}
.loading-spinner {
  width: 44px; height: 44px;
  border: 3px solid var(--border);
  border-top-color: var(--brand-from);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.error-banner {
  max-width: 900px;
  margin: 16px auto 0;
  padding: 14px 20px;
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: var(--radius-sm);
  color: var(--red);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 10px;
}
[data-theme="dark"] .error-banner { background: #450a0a; border-color: #7f1d1d; }
.error-close { margin-left: auto; background: none; border: none; cursor: pointer; color: var(--red); font-size: 16px; }

/* ============================================================
   Results
   ============================================================ */
.results { max-width: 1100px; margin: 0 auto; padding: 36px 24px 80px; }
.results-inner { display: flex; flex-direction: column; gap: 22px; }

/* Verb Forms Card */
.verb-forms-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border);
  animation: fadeUp 0.4s ease;
}
.vf-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; margin-bottom: 22px; }
.vf-title { font-size: 21px; font-weight: 800; color: var(--text-primary); }
.vf-badges { display: flex; gap: 8px; margin-top: 6px; flex-wrap: wrap; }
.badge { display: inline-flex; align-items: center; padding: 4px 12px; border-radius: 100px; font-size: 12px; font-weight: 700; letter-spacing: .3px; text-transform: uppercase; }
.badge-irregular { background: #fef3c7; color: #92400e; border: 1px solid #fde68a; }
.badge-regular   { background: #d1fae5; color: #065f46; border: 1px solid #a7f3d0; }
[data-theme="dark"] .badge-irregular { background: #451a03; color: #fbbf24; border-color: #78350f; }
[data-theme="dark"] .badge-regular   { background: #064e3b; color: #6ee7b7; border-color: #065f46; }

.vf-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 12px; }

.vf-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  cursor: pointer;
  transition: box-shadow 0.2s, transform 0.2s;
}
.vf-item:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.vf-item-label { font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: var(--text-muted); margin-bottom: 5px; }
.vf-item-value { font-family: var(--font-code); font-size: 19px; font-weight: 600; color: var(--brand-from); word-break: break-word; }
[data-theme="dark"] .vf-item-value { color: #a5b4fc; }

.btn-copy-all {
  display: flex; align-items: center; gap: 6px;
  padding: 8px 16px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font); font-size: 13px; font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.2s;
  white-space: nowrap;
}
.btn-copy-all:hover { background: var(--blue-light); color: var(--blue); border-color: var(--blue); }

/* Translation Banner */
.translation-banner {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 20px;
  box-shadow: var(--shadow-sm);
  animation: fadeUp 0.3s ease;
  flex-wrap: wrap;
}
.tb-flag { font-size: 26px; }
.tb-text { font-size: 14px; font-weight: 700; color: var(--text-primary); }
.tb-spinner {
  width: 18px; height: 18px;
  border: 2px solid var(--border);
  border-top-color: var(--brand-from);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
.tb-status { font-size: 13px; color: var(--text-muted); }
.tb-change {
  margin-left: auto;
  background: none;
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 5px 14px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.2s;
  font-family: var(--font);
}
.tb-change:hover { background: var(--bg); color: var(--brand-from); border-color: var(--brand-from); }

/* ============================================================
   Tabs
   ============================================================ */
.tabs-nav {
  display: flex;
  gap: 6px;
  background: var(--bg-card);
  padding: 5px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  animation: fadeUp 0.4s ease 0.08s both;
}
.tab-btn {
  flex: 1;
  display: flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 18px;
  border-radius: calc(var(--radius-md) - 2px);
  font-family: var(--font); font-size: 14px; font-weight: 700;
  border: none; cursor: pointer;
  color: var(--text-secondary);
  background: transparent;
  transition: all 0.2s;
}
.tab-btn.active {
  background: linear-gradient(135deg, var(--brand-from), var(--brand-to));
  color: white;
  box-shadow: 0 4px 12px rgba(99,102,241,.3);
}
.tab-btn:not(.active):hover { background: var(--bg); color: var(--text-primary); }
.tab-count {
  background: rgba(255,255,255,.25);
  border-radius: 100px;
  padding: 2px 7px;
  font-size: 11px;
}
.tab-btn:not(.active) .tab-count { background: var(--border); color: var(--text-muted); }

/* ============================================================
   Sentence Cards
   ============================================================ */
.tab-panel { display: none; animation: fadeUp 0.3s ease; }
.tab-panel.active { display: block; }

.sentences-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(310px, 1fr)); gap: 14px; }

.sentence-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  padding: 18px 20px;
  transition: box-shadow 0.2s, transform 0.2s, border-color 0.2s;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}
.sentence-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 4px; height: 100%;
  border-radius: 4px 0 0 4px;
}
.sentence-card.blue::before   { background: linear-gradient(to bottom, #3b82f6, #1d4ed8); }
.sentence-card.purple::before { background: linear-gradient(to bottom, #8b5cf6, #6d28d9); }
.sentence-card.green::before  { background: linear-gradient(to bottom, #10b981, #059669); }

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

.sc-header { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-bottom: 10px; }

.sc-label {
  font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: .6px;
  padding: 3px 10px;
  border-radius: 100px;
}
.blue .sc-label   { background: var(--blue-light);   color: var(--blue);   border: 1px solid var(--blue-border); }
.purple .sc-label { background: var(--purple-light); color: var(--purple); border: 1px solid var(--purple-border); }
.green .sc-label  { background: var(--green-light);  color: var(--green);  border: 1px solid var(--green-border); }

.sc-copy {
  background: none; border: none; cursor: pointer;
  font-size: 15px; padding: 4px 6px; border-radius: 6px;
  opacity: 0; transition: opacity 0.2s, background 0.15s;
  color: var(--text-muted);
}
.sentence-card:hover .sc-copy { opacity: 1; }
.sc-copy:hover { background: var(--bg); }

.sc-sentence {
  font-size: 17px; font-weight: 600; color: var(--text-primary);
  margin-bottom: 6px; line-height: 1.5;
}
.sc-sentence .verb-highlight { color: var(--brand-from); font-family: var(--font-code); }
[data-theme="dark"] .sc-sentence .verb-highlight { color: #a5b4fc; }

.sc-description { font-size: 12px; color: var(--text-muted); line-height: 1.5; }

/* Translation slot */
.sc-translation {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--border);
  display: flex;
  align-items: flex-start;
  gap: 8px;
  animation: fadeIn 0.35s ease;
}
.sc-trans-flag { font-size: 18px; flex-shrink: 0; line-height: 1.4; }
.sc-trans-text {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-secondary);
  line-height: 1.5;
  flex: 1;
}
.sc-trans-text[dir="rtl"] { text-align: right; }

/* Shimmer skeleton for loading translations */
.sc-translation-loading {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--border);
}
.sc-trans-skeleton {
  height: 18px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--border) 25%, var(--bg-card-hover) 50%, var(--border) 75%);
  background-size: 300% 100%;
  animation: shimmer 1.6s infinite;
}
.sc-trans-skeleton + .sc-trans-skeleton { margin-top: 6px; width: 60%; }

@keyframes shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   Toast
   ============================================================ */
.toast {
  position: fixed;
  bottom: 32px; right: 32px;
  background: #1e293b;
  color: white;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 600;
  box-shadow: var(--shadow-lg);
  opacity: 0; transform: translateY(10px);
  pointer-events: none;
  transition: all 0.3s ease;
  z-index: 999;
}
.toast.show { opacity: 1; transform: translateY(0); }

/* ============================================================
   Footer
   ============================================================ */
.footer {
  text-align: center;
  padding: 22px;
  color: var(--text-muted);
  font-size: 13px;
  border-top: 1px solid var(--border);
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 720px) {
  .search-inputs { grid-template-columns: 1fr; }
  .vf-grid { grid-template-columns: repeat(2, 1fr); }
  .sentences-grid { grid-template-columns: 1fr; }
  .tabs-nav { flex-direction: column; }
  .tab-btn { justify-content: flex-start; }
  .vf-header { flex-direction: column; }
  .sc-copy { opacity: 1; }
  .hero-title { font-size: 26px; }
  .translation-banner { flex-wrap: wrap; }
  .tb-change { margin-left: 0; }
}

@media (max-width: 480px) {
  .hero { padding: 36px 14px 56px; }
  .search-card { padding: 18px 14px; }
  .results { padding: 20px 14px 56px; }
  .verb-forms-card { padding: 18px 14px; }
  .vf-grid { grid-template-columns: 1fr 1fr; }
  .toast { bottom: 12px; right: 12px; left: 12px; }
}