:root {
  --bg: #f4f0ff;
  --bg-gradient: linear-gradient(135deg, #f6d365 0%, #fda085 25%, #a18cd1 60%, #6ee7de 100%);
  --card-bg: rgba(255, 255, 255, 0.9);
  --text: #2b2540;
  --text-muted: #6b6483;
  --border: rgba(43, 37, 64, 0.08);
  --shadow: 0 8px 30px rgba(90, 60, 150, 0.12);

  --purple: #8b5cf6;
  --pink: #ec4899;
  --orange: #f97316;
  --yellow: #eab308;
  --green: #22c55e;
  --teal: #14b8a6;
  --blue: #3b82f6;
  --red: #ef4444;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #181425;
    --bg-gradient: linear-gradient(135deg, #1e1b3a 0%, #2d1b4e 40%, #401b52 70%, #1b2e4e 100%);
    --card-bg: rgba(35, 30, 55, 0.85);
    --text: #f1edff;
    --text-muted: #b3a9d1;
    --border: rgba(255, 255, 255, 0.08);
    --shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  }
}

:root[data-theme="dark"] {
  --bg: #181425;
  --bg-gradient: linear-gradient(135deg, #1e1b3a 0%, #2d1b4e 40%, #401b52 70%, #1b2e4e 100%);
  --card-bg: rgba(35, 30, 55, 0.85);
  --text: #f1edff;
  --text-muted: #b3a9d1;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}

:root[data-theme="light"] {
  --bg: #f4f0ff;
  --bg-gradient: linear-gradient(135deg, #f6d365 0%, #fda085 25%, #a18cd1 60%, #6ee7de 100%);
  --card-bg: rgba(255, 255, 255, 0.9);
  --text: #2b2540;
  --text-muted: #6b6483;
  --border: rgba(43, 37, 64, 0.08);
  --shadow: 0 8px 30px rgba(90, 60, 150, 0.12);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg-gradient);
  min-height: 100vh;
  color: var(--text);
}

.hidden { display: none !important; }

/* ===== LOGIN SCREEN ===== */
.login-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.login-card {
  background: var(--card-bg);
  border-radius: 24px;
  padding: 48px 40px;
  text-align: center;
  box-shadow: var(--shadow);
  max-width: 380px;
  width: 100%;
  backdrop-filter: blur(10px);
}

.login-logo { font-size: 56px; }

.login-card h1 {
  margin: 8px 0 4px;
  font-size: 32px;
  background: linear-gradient(90deg, var(--purple), var(--pink), var(--orange));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-weight: 800;
}

.login-sub {
  color: var(--text-muted);
  margin: 0 0 32px;
}

.btn-google {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  width: 100%;
  padding: 14px 20px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: #fff;
  color: #3c4043;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn-google:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.15);
}

.login-footer {
  margin-top: 24px;
  font-size: 12px;
  color: var(--text-muted);
}

/* ===== APP SHELL ===== */
.app-shell {
  min-height: 100vh;
  padding-bottom: 40px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 28px;
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
}

.brand-logo { font-size: 26px; }

.brand-name {
  background: linear-gradient(90deg, var(--purple), var(--pink));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.user-box {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-photo {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2px solid var(--purple);
  object-fit: cover;
}

.user-name {
  font-weight: 600;
  font-size: 14px;
  color: var(--text);
}

.btn-logout {
  padding: 8px 16px;
  border-radius: 10px;
  border: none;
  background: linear-gradient(90deg, var(--red), var(--orange));
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  font-size: 13px;
  transition: transform 0.15s ease;
}

.btn-logout:hover { transform: translateY(-1px); }

/* ===== MAIN GRID ===== */
.main-grid {
  max-width: 1100px;
  margin: 24px auto;
  padding: 0 20px;
  display: grid;
  gap: 20px;
  grid-template-columns: 1fr 1fr;
}

.card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 24px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.card h2 {
  margin: 0 0 16px;
  font-size: 17px;
  font-weight: 700;
}

.add-expense-card {
  grid-column: 1 / -1;
}

.expense-form {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  align-items: end;
}

.field { display: flex; flex-direction: column; gap: 6px; }
.field-wide { grid-column: span 2; }

.field label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
}

.field input,
.field select,
#filterCategory {
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(128,128,128,0.06);
  color: var(--text);
  font-size: 14px;
  outline: none;
  transition: border-color 0.15s ease;
}

.field input:focus,
.field select:focus {
  border-color: var(--purple);
}

.btn-add {
  grid-column: span 4;
  padding: 13px;
  border-radius: 12px;
  border: none;
  background: linear-gradient(90deg, var(--purple), var(--pink), var(--orange));
  background-size: 200% auto;
  color: #fff;
  font-weight: 700;
  font-size: 15px;
  cursor: pointer;
  transition: background-position 0.4s ease, transform 0.15s ease;
}

.btn-add:hover {
  background-position: right center;
  transform: translateY(-1px);
}

/* ===== STATS ===== */
.stats-row {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.stat-card {
  border-radius: 18px;
  padding: 18px 20px;
  color: #fff;
  box-shadow: var(--shadow);
}

.stat-today { background: linear-gradient(135deg, var(--purple), #6d28d9); }
.stat-week  { background: linear-gradient(135deg, var(--pink), #db2777); }
.stat-month { background: linear-gradient(135deg, var(--orange), #ea580c); }
.stat-total { background: linear-gradient(135deg, var(--teal), #0d9488); }

.stat-label {
  font-size: 12px;
  opacity: 0.85;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.stat-value {
  font-size: 26px;
  font-weight: 800;
  margin-top: 4px;
}

/* ===== CHARTS ===== */
.chart-card { min-height: 280px; }

.chart-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

.chart-toggle {
  display: flex;
  gap: 6px;
  background: rgba(128,128,128,0.08);
  padding: 4px;
  border-radius: 10px;
}

.toggle-btn {
  border: none;
  background: transparent;
  padding: 6px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s ease;
}

.toggle-btn.active {
  background: linear-gradient(90deg, var(--purple), var(--pink));
  color: #fff;
}

/* ===== LIST ===== */
.list-card { grid-column: 1 / -1; }

.list-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

#filterCategory { width: auto; }

.expense-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-height: 420px;
  overflow-y: auto;
}

.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 30px 0;
}

.expense-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 14px;
  border-radius: 14px;
  background: rgba(128,128,128,0.06);
  border: 1px solid var(--border);
  transition: transform 0.15s ease;
}

.expense-item:hover { transform: translateX(2px); }

.expense-icon {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
  color: #fff;
}

.expense-info { flex: 1; min-width: 0; }

.expense-category {
  font-weight: 700;
  font-size: 14px;
}

.expense-note {
  font-size: 12px;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

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

.expense-amount {
  font-weight: 800;
  font-size: 15px;
  white-space: nowrap;
}

.expense-delete {
  border: none;
  background: transparent;
  color: var(--red);
  cursor: pointer;
  font-size: 16px;
  padding: 6px;
  border-radius: 8px;
  opacity: 0.6;
  transition: opacity 0.15s ease, background 0.15s ease;
}

.expense-delete:hover {
  opacity: 1;
  background: rgba(239, 68, 68, 0.12);
}

/* ===== TOAST ===== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text);
  color: var(--bg);
  padding: 12px 22px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600;
  box-shadow: var(--shadow);
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 100;
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 720px) {
  .main-grid { grid-template-columns: 1fr; }
  .expense-form { grid-template-columns: 1fr 1fr; }
  .field-wide { grid-column: span 2; }
  .btn-add { grid-column: span 2; }
  .stats-row { grid-template-columns: 1fr 1fr; }
  .topbar { padding: 14px 16px; }
  .user-name { display: none; }
}