:root {
  --bg: #f7f8fa;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-600: #1d4ed8;
  --success: #16a34a;
  --danger: #ef4444;
  --warning: #f59e0b;
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
  --nav-height: 64px;
}

html[data-theme="dark"] {
  --bg: #0b1220;
  --card: #0f172a;
  --text: #e5e7eb;
  --muted: #94a3b8;
  --border: #1f2937;
  --primary: #60a5fa;
  --primary-600: #3b82f6;
  --success: #22c55e;
  --danger: #f87171;
  --warning: #f59e0b;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: radial-gradient(1200px 600px at 80% -10%, rgba(37,99,235,0.08), transparent 60%),
              radial-gradient(1000px 500px at -10% 20%, rgba(16,185,129,0.06), transparent 55%),
              var(--bg);
  color: var(--text);
  line-height: 1.5;
}
html[data-theme="dark"] body {
  background: radial-gradient(1200px 600px at 80% -10%, rgba(96,165,250,0.15), transparent 60%),
              radial-gradient(1000px 500px at -10% 20%, rgba(34,197,94,0.12), transparent 55%),
              var(--bg);
}

.nav {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav__container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
}

.nav__brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.nav__links {
  display: flex;
  gap: 24px;
}

.nav__link {
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
  padding: 8px 12px;
  border-radius: 8px;
  transition: all 0.2s ease;
}

.nav__link:hover {
  color: var(--text);
  background: var(--bg);
}

.nav__link--active {
  color: var(--primary);
  background: rgba(37, 99, 235, 0.1);
}

.app {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 16px 48px;
}

.app__title {
  margin: 8px 0 20px;
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.composer {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  box-shadow: var(--shadow);
}
.composer__form { display: flex; gap: 12px; }
.composer__input {
  flex: 1 1 auto;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
  font-size: 16px;
}
.composer__input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12);
}
.composer__input::placeholder { color: #9ca3af; }

.hint { margin-top: 8px; font-size: 12px; color: var(--muted); }
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}

.btn {
  appearance: none;
  border: 0;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, transform 0.08s ease, box-shadow 0.2s ease;
}
.btn:active { transform: translateY(1px); }
.btn--primary { background: linear-gradient(180deg, var(--primary), var(--primary-600)); color: #fff; box-shadow: 0 8px 20px rgba(37,99,235,0.25); }
.btn--primary:hover { background: var(--primary-600); }
.btn:focus-visible { outline: 3px solid rgba(37,99,235,.35); outline-offset: 2px; }
.btn--ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}
.btn--ghost:hover { color: #111827; border-color: #d1d5db; }
html[data-theme="dark"] .btn--ghost:hover { color: #e5e7eb; border-color: #334155; }

.list { margin-top: 18px; }
.list__summary { color: var(--muted); font-size: 13px; margin: 6px 2px 10px; }
.empty {
  display: none;
  background: var(--card);
  border: 1px dashed var(--border);
  color: var(--muted);
  border-radius: 12px;
  padding: 16px;
  text-align: center;
}

.list__items {
  list-style: none;
  margin: 10px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.task {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 12px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  box-shadow: var(--shadow);
  animation: fadeInUp 260ms ease both;
}
.task__checkbox {
  width: 20px; height: 20px;
  accent-color: var(--success);
}
.task__title {
  margin: 0;
  font-size: 15px;
  word-wrap: break-word;
}
.task--done .task__title { color: var(--muted); text-decoration: line-through; }
.task__delete {
  background: transparent;
  color: var(--danger);
  border: 1px solid var(--border);
}
.task__delete:hover { border-color: #fca5a5; background: #fff1f2; }
li.task:focus-within { box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12); }

.actions { margin-top: 16px; display: flex; justify-content: flex-end; }

/* Weather Card */
.weather-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  box-shadow: var(--shadow);
  margin-bottom: 16px;
  animation: fadeInUp 260ms ease both;
}
.weather-card__row { display:flex; align-items:center; justify-content: space-between; gap: 12px; }
.weather-card__main { display:flex; align-items:center; gap: 12px; }
.weather-card__icon { font-size: 32px; line-height: 1; }
.weather-card__temp { font-size: 24px; font-weight: 700; }
.weather-card__desc { font-size: 13px; color: var(--muted); }
.weather-card__city { font-weight: 600; }
.weather-card__wind { font-size: 13px; color: var(--muted); }

/* Currency Converter Styles */
.converter {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 16px;
  align-items: end;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow);
}

.converter__group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.converter__label {
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
}

.converter__input {
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 16px;
  background: #fff;
}

.converter__input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12);
}

.converter__select {
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 16px;
  background: #fff;
  cursor: pointer;
}

.converter__swap {
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.converter__swap:hover {
  background: var(--primary-600);
  transform: scale(1.05);
}

.rates {
  margin-top: 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  box-shadow: var(--shadow);
}

.rates__title {
  margin: 0 0 12px;
  font-size: 16px;
  font-weight: 600;
}

.rates__list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px;
}

.rate {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 12px;
  background: var(--bg);
  border-radius: 8px;
  font-size: 14px;
}

.rate__currency {
  font-weight: 500;
}

.rate__value {
  color: var(--muted);
}

/* Expense Tracker Styles */
.expense-form {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
  animation: fadeInUp 260ms ease both;
}

.expense-form__grid {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 16px;
  align-items: end;
}

.expense-form__group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.expense-form__label {
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
}

.expense-form__input {
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 16px;
  background: #fff;
}

.expense-form__input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12);
}

.expense-form__select {
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 16px;
  background: #fff;
  cursor: pointer;
}

.expense-form__date {
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 16px;
  background: #fff;
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow);
  text-align: center;
}

.stat-card__value {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary);
  margin: 0 0 4px;
}

.stat-card__label {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

.progress { height: 10px; background: #e5e7eb; border-radius: 999px; overflow: hidden; }
html[data-theme="dark"] .progress { background: #1f2937; }
.progress__bar { height: 100%; background: linear-gradient(90deg, var(--primary), var(--primary-600)); width: 0; transition: width .3s ease; }

.expense-list {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow);
  animation: fadeInUp 260ms ease both;
}

.expense-list__header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.expense-list__title {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
}

.expense-list__filter {
  display: flex;
  gap: 8px;
}

.filter-btn {
  padding: 6px 12px;
  border: 1px solid var(--border);
  background: transparent;
  border-radius: 6px;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-btn:hover {
  background: var(--bg);
}

.filter-btn--active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.budget-warning { color: #b91c1c; font-weight: 600; }
.budget-ok { color: #16a34a; font-weight: 600; }

.expense-item {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  gap: 16px;
  align-items: center;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}

.expense-item:last-child {
  border-bottom: none;
}

.expense-item__category {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--primary);
}

.expense-item__details {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.expense-item__title {
  margin: 0;
  font-size: 14px;
  font-weight: 500;
}

.expense-item__date {
  margin: 0;
  font-size: 12px;
  color: var(--muted);
}

.expense-item__amount {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

.expense-item__delete {
  background: transparent;
  color: var(--danger);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 8px;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.expense-item__delete:hover {
  background: #fff1f2;
  border-color: #fca5a5;
}

.chart-container {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow);
  margin-top: 24px;
  animation: fadeInUp 260ms ease both;
}

.chart-container__title {
  margin: 0 0 16px;
  font-size: 16px;
  font-weight: 600;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--card);
  cursor: pointer;
  font-size: 13px;
}
.chip:hover { background: var(--bg); }

.quick-templates { margin-top: 10px; display: flex; flex-wrap: wrap; gap: 8px; }

.tag-chip {
  display: inline-block;
  padding: 2px 8px;
  background: rgba(37,99,235,0.15);
  color: var(--primary-600);
  border-radius: 999px;
  font-size: 11px;
}

.heatmap { display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px; }
.heatmap div { height: 20px; border-radius: 4px; background: #e5e7eb; }
html[data-theme="dark"] .heatmap div { background: #1f2937; }

.chart-placeholder {
  height: 200px;
  background: var(--bg);
  border: 2px dashed var(--border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  font-size: 14px;
}

/* Calculator */
.calc { position: fixed; inset: 0; z-index: 200; }
.calc__overlay { position: absolute; inset: 0; background: rgba(0,0,0,0.4); backdrop-filter: blur(2px); }
.calc__panel {
  position: relative;
  max-width: 380px;
  margin: 6vh auto;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
  animation: fadeInUp 220ms ease both;
}
.calc__header { display: flex; align-items: center; justify-content: space-between; padding: 12px 16px; border-bottom: 1px solid var(--border); }
.calc__title { margin: 0; font-size: 16px; }
.calc__display { font-variant-numeric: tabular-nums; font-size: 32px; padding: 16px; text-align: right; border-bottom: 1px solid var(--border); }
.calc__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  padding: 12px;
  background: linear-gradient(180deg, rgba(0,0,0,0.02), transparent);
}
.calc__btn {
  height: 52px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.06s ease, background 0.2s ease, border-color 0.2s ease;
}
.calc__btn:active { transform: translateY(1px); }
.calc__btn--op { background: var(--primary); color: #fff; border-color: var(--primary); }
.calc__btn--fn { background: #e5e7eb; color: #111827; }
html[data-theme="dark"] .calc__btn--fn { background: #1f2937; color: #e5e7eb; }
.calc__btn--zero { grid-column: span 2; }
.calc__actions { padding: 12px; border-top: 1px solid var(--border); display: flex; justify-content: flex-end; }

.error-message {
  background: #fef2f2;
  border: 1px solid #fecaca;
  color: #dc2626;
  padding: 12px 16px;
  border-radius: 8px;
  margin-top: 16px;
  font-size: 14px;
}

.expense-items {
  max-height: 400px;
  overflow-y: auto;
}

.expense-items::-webkit-scrollbar {
  width: 6px;
}

.expense-items::-webkit-scrollbar-track {
  background: var(--bg);
}

.expense-items::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

.expense-items::-webkit-scrollbar-thumb:hover {
  background: var(--muted);
}

@media (max-width: 768px) {
  .nav__links {
    gap: 12px;
  }
  
  .nav__link {
    padding: 6px 8px;
    font-size: 14px;
  }
  
  .converter {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  
  .converter__swap {
    order: 3;
    align-self: center;
  }
  
  .expense-form__grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  
  .expense-item {
    grid-template-columns: auto 1fr auto;
    gap: 12px;
  }
  
  .expense-item__details {
    min-width: 0;
  }
  
  .expense-item__title {
    font-size: 13px;
  }
  
  .expense-item__amount {
    font-size: 14px;
  }
  
  .stats {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .stat-card {
    padding: 16px;
  }
  
  .stat-card__value {
    font-size: 20px;
  }
}

@media (max-width: 480px) {
  .app { padding: 20px 12px 40px; }
  .composer__form { gap: 8px; }
  .btn { padding: 10px 12px; font-size: 13px; }
  .task { grid-template-columns: auto 1fr auto; padding: 10px; }
  .task__title { font-size: 14px; }
  .app__title { font-size: 24px; }
  
  .nav__container {
    padding: 0 12px;
  }
  
  .nav__links {
    gap: 8px;
  }
  
  .nav__link {
    padding: 4px 6px;
    font-size: 13px;
  }
  
  .converter {
    padding: 16px;
  }
  
  .expense-form {
    padding: 16px;
  }
  
  .expense-item {
    padding: 12px 16px;
  }
  
  .stats {
    grid-template-columns: 1fr;
  }
}

.footer {
  margin-top: 40px;
  padding: 24px 16px;
  color: var(--muted);
  border-top: 1px solid var(--border);
  text-align: center;
}
.footer a { color: var(--primary); text-decoration: none; }
.footer a:hover { text-decoration: underline; }

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
}
.theme-toggle__icon { font-size: 16px; }

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}