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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-page);
  color: var(--text-primary);
  min-height: 100vh;
  transition: background 0.3s, color 0.3s;
}

/* ── Theme Variables ── */
:root {
  --bg-page:        #f2f2f7;
  --bg-card:        #ffffff;
  --bg-input:       #ffffff;
  --bg-hover:       #f9f9f9;
  --text-primary:   #1c1c1e;
  --text-secondary: #3a3a3c;
  --text-muted:     #8e8e93;
  --border:         #d1d1d6;
  --separator:      #f2f2f7;
  --accent:         #007aff;
  --accent-hover:   #0066d6;
  --danger:         #ff3b30;
  --danger-hover:   #d63029;
  --shadow:         rgba(0,0,0,0.08);
  --over-limit-bg:  #fff1f0;
  --over-limit-border: #ffb3b0;
  --over-limit-text:   #c0392b;
}

body.dark {
  --bg-page:        #1c1c1e;
  --bg-card:        #2c2c2e;
  --bg-input:       #3a3a3c;
  --bg-hover:       #3a3a3c;
  --text-primary:   #f2f2f7;
  --text-secondary: #d1d1d6;
  --text-muted:     #8e8e93;
  --border:         #48484a;
  --separator:      #3a3a3c;
  --accent:         #0a84ff;
  --accent-hover:   #409cff;
  --danger:         #ff453a;
  --danger-hover:   #ff6961;
  --shadow:         rgba(0,0,0,0.3);
  --over-limit-bg:  #3b1a18;
  --over-limit-border: #7a2e28;
  --over-limit-text:   #ff6b6b;
}

/* ── App Layout ── */
.app-wrapper {
  max-width: 560px;
  margin: 0 auto;
  padding: 20px 16px 40px;
}

/* ── Header ── */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.app-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
}

.theme-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  width: 52px;
  height: 28px;
  cursor: pointer;
  position: relative;
  transition: background 0.3s;
  flex-shrink: 0;
}

.theme-toggle::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--accent);
  transition: transform 0.3s, background 0.3s;
}

body.dark .theme-toggle::after {
  transform: translateX(24px);
}

.toggle-icon {
  position: absolute;
  font-size: 12px;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
}
.toggle-sun { left: 6px; }
.toggle-moon { right: 5px; }

/* ── Cards ── */
.card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 16px;
  box-shadow: 0 1px 4px var(--shadow);
  transition: background 0.3s, box-shadow 0.3s;
}

/* ── Balance ── */
.balance-card {
  text-align: center;
  padding: 24px 20px;
}

.balance-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.balance-amount {
  font-size: 36px;
  font-weight: 600;
  color: var(--accent);
}

/* ── Section Title ── */
.section-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

/* ── Form ── */
.form-group {
  margin-bottom: 14px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
  color: var(--text-primary);
  background: var(--bg-input);
  outline: none;
  transition: border-color 0.2s, background 0.3s;
  appearance: auto;
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--accent);
}

.form-group input::placeholder {
  color: var(--text-muted);
}

.btn-add {
  width: 100%;
  padding: 13px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  margin-top: 4px;
  transition: background 0.2s, transform 0.1s;
}

.btn-add:hover { background: var(--accent-hover); }
.btn-add:active { transform: scale(0.98); }

/* ── Spending Limit ── */
.limit-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.limit-row input {
  flex: 1;
}

.limit-status {
  font-size: 12px;
  font-weight: 600;
  white-space: nowrap;
  padding: 4px 10px;
  border-radius: 20px;
  transition: all 0.3s;
}

.limit-status.ok {
  background: #e3faf0;
  color: #1a7f52;
}

.limit-status.over {
  background: var(--over-limit-bg);
  color: var(--over-limit-text);
}

body.dark .limit-status.ok {
  background: #1a3d2e;
  color: #4cd964;
}

/* ── Bottom Grid ── */
.bottom-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

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

/* ── Transactions ── */
.transactions-card { min-height: 200px; }

.transaction-item {
  padding: 10px 0;
  border-bottom: 1px solid var(--separator);
  transition: background 0.2s;
}

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

.transaction-item.over-limit {
  background: var(--over-limit-bg);
  border-left: 3px solid var(--over-limit-text);
  padding-left: 10px;
  border-radius: 4px;
  margin: 0 -4px;
}

.transaction-name {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.transaction-amount {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 2px;
}

.transaction-item.over-limit .transaction-amount {
  color: var(--over-limit-text);
}

.over-limit-badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  background: var(--over-limit-text);
  color: #fff;
  border-radius: 4px;
  padding: 1px 6px;
  margin-left: 6px;
  letter-spacing: 0.04em;
}

.transaction-category {
  font-size: 11px;
  color: var(--text-muted);
}

.transaction-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.btn-delete {
  background: var(--danger);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  flex-shrink: 0;
  transition: background 0.2s;
}

.btn-delete:hover { background: var(--danger-hover); }

.empty-state {
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
  padding: 24px 0;
}

/* ── Chart ── */
.chart-card {
  display: flex;
  flex-direction: column;
}

.chart-wrapper {
  position: relative;
  width: 100%;
  height: 180px;
  margin-bottom: 12px;
}

.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 11px;
  color: var(--text-secondary);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 4px;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  flex-shrink: 0;
}

/* ── Tab Nav ── */
.tab-nav {
  display: flex;
  gap: 0;
  margin-bottom: 16px;
  background: var(--bg-card);
  border-radius: 10px;
  padding: 4px;
  box-shadow: 0 1px 4px var(--shadow);
}

.tab-btn {
  flex: 1;
  padding: 8px 0;
  background: none;
  border: none;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.tab-btn.active {
  background: var(--accent);
  color: #fff;
}

/* ── Monthly Summary ── */
.month-selector {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.month-nav-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 12px;
  font-size: 18px;
  cursor: pointer;
  color: var(--text-primary);
  line-height: 1;
  transition: background 0.2s;
}

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

.month-label {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
}

.summary-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 16px;
}

.stat-box {
  background: var(--bg-page);
  border-radius: 10px;
  padding: 12px;
  text-align: center;
  transition: background 0.3s;
}

.stat-label {
  font-size: 11px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.stat-value {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
}

.stat-value.accent { color: var(--accent); }
.stat-value.danger { color: var(--danger); }

.month-breakdown {
  border-top: 1px solid var(--separator);
  padding-top: 12px;
}

.breakdown-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.breakdown-cat {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  min-width: 70px;
}

.breakdown-bar-wrap {
  flex: 1;
  background: var(--separator);
  border-radius: 4px;
  height: 8px;
  overflow: hidden;
}

.breakdown-bar {
  height: 100%;
  border-radius: 4px;
  transition: width 0.5s ease;
}

.breakdown-val {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  min-width: 56px;
  text-align: right;
}

.no-data {
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
  padding: 32px 0;
}