/* ===========================
   Tax Withholding Estimator — Premium Styles
   =========================== */
:root {
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-primary: #0F172A;
  --bg-secondary: #1E293B;
  --bg-tertiary: #334155;
  --bg-card: rgba(30, 41, 59, 0.7);
  --bg-hover: rgba(59, 130, 246, 0.08);
  --border: rgba(255,255,255,0.06);
  --border-active: rgba(59, 130, 246, 0.4);
  --text-primary: #F1F5F9;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --accent: #3B82F6;
  --accent-light: #60A5FA;
  --accent-pale: #93C5FD;
  --accent-glow: rgba(59, 130, 246, 0.15);
  --success: #34D399;
  --warning: #FBBF24;
  --error: #F87171;
  --glass: rgba(15, 23, 42, 0.6);
  --glass-border: rgba(255,255,255,0.08);
}

[data-theme="light"] {
  --bg-primary: #F8FAFC;
  --bg-secondary: #FFFFFF;
  --bg-tertiary: #F1F5F9;
  --bg-card: rgba(255, 255, 255, 0.8);
  --bg-hover: rgba(59, 130, 246, 0.06);
  --border: rgba(0,0,0,0.08);
  --border-active: rgba(59, 130, 246, 0.4);
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;
  --accent: #3B82F6;
  --accent-light: #60A5FA;
  --accent-pale: #93C5FD;
  --accent-glow: rgba(59, 130, 246, 0.1);
  --success: #059669;
  --warning: #D97706;
  --error: #DC2626;
  --glass: rgba(248, 250, 252, 0.7);
  --glass-border: rgba(0,0,0,0.06);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; }
body { font-family: var(--font); background: var(--bg-primary); color: var(--text-primary); min-height: 100vh; transition: background var(--transition), color var(--transition); line-height: 1.6; }

.header { position: sticky; top: 0; z-index: 100; background: var(--glass); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); border-bottom: 1px solid var(--glass-border); }
.header-content { max-width: 1200px; margin: 0 auto; padding: 0.75rem 1.5rem; display: flex; align-items: center; justify-content: space-between; }
.logo { display: flex; align-items: center; gap: 0.75rem; }
.logo-text { font-size: 1.125rem; font-weight: 700; letter-spacing: -0.02em; background: linear-gradient(135deg, var(--accent), var(--accent-pale)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.header-actions { display: flex; gap: 0.5rem; }

.icon-btn { width: 36px; height: 36px; border: 1px solid var(--border); border-radius: var(--radius-sm); background: var(--bg-card); color: var(--text-secondary); cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all var(--transition); font-size: 1.125rem; }
.icon-btn:hover { background: var(--bg-hover); color: var(--accent); border-color: var(--border-active); }
.icon-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.icon-btn-sm { width: 28px; height: 28px; font-size: 0.875rem; }

.btn { display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.5rem 1rem; border-radius: var(--radius-sm); font-family: var(--font); font-size: 0.8125rem; font-weight: 500; cursor: pointer; transition: all var(--transition); border: 1px solid var(--border); background: var(--bg-card); color: var(--text-secondary); }
.btn:hover { background: var(--bg-hover); color: var(--accent); border-color: var(--border-active); }
.btn-sm { padding: 0.3rem 0.625rem; font-size: 0.75rem; }
.btn-primary { background: var(--accent); color: white; border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-light); border-color: var(--accent-light); }
.btn-full { width: 100%; justify-content: center; }
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.hidden { display: none !important; }
[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

.main { max-width: 1200px; margin: 0 auto; padding: 1.5rem; }

/* Scenario Tabs */
.scenario-tabs { display: flex; align-items: center; gap: 0.5rem; margin-bottom: 1rem; overflow-x: auto; padding-bottom: 0.25rem; }
.tab-list { display: flex; gap: 0.375rem; }
.tab-btn { padding: 0.375rem 0.875rem; border: 1px solid var(--border); border-radius: 999px; background: var(--bg-card); color: var(--text-secondary); font-family: var(--font); font-size: 0.75rem; font-weight: 500; cursor: pointer; transition: all var(--transition); white-space: nowrap; display: flex; align-items: center; gap: 0.375rem; }
.tab-btn:hover { border-color: var(--border-active); color: var(--accent); }
.tab-btn.active { background: var(--accent); color: white; border-color: var(--accent); }
.tab-btn .tab-close { width: 14px; height: 14px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 10px; background: rgba(255,255,255,0.2); border: none; color: inherit; cursor: pointer; }

.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }

.card { padding: 1.25rem; background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); backdrop-filter: blur(12px); margin-bottom: 1rem; }
.card-accent { border-color: var(--border-active); background: linear-gradient(135deg, rgba(59, 130, 246, 0.05), var(--bg-card)); }
.card-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 0.75rem; }
.card-title { display: flex; align-items: center; gap: 0.5rem; font-size: 0.8125rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 0.75rem; }
.card-header .card-title { margin-bottom: 0; }

/* Filing status radio */
.radio-group { display: grid; grid-template-columns: 1fr 1fr; gap: 0.5rem; }
.radio-card { display: flex; align-items: center; gap: 0.5rem; padding: 0.5rem 0.75rem; border: 1px solid var(--border); border-radius: var(--radius-xs); cursor: pointer; transition: all var(--transition); font-size: 0.8125rem; color: var(--text-secondary); }
.radio-card:hover { border-color: var(--border-active); background: var(--bg-hover); }
.radio-card:has(input:checked) { border-color: var(--accent); background: var(--accent-glow); color: var(--accent); }
.radio-card input { accent-color: var(--accent); }

/* Income sources */
.source-list { display: flex; flex-direction: column; gap: 0.5rem; margin-bottom: 0.75rem; }
.source-row { display: flex; gap: 0.5rem; align-items: center; }
.source-row input[type="text"] { flex: 1; padding: 0.5rem; background: var(--bg-secondary); border: 1px solid var(--border); border-radius: var(--radius-xs); font-family: var(--font); font-size: 0.8125rem; color: var(--text-primary); outline: none; transition: border-color var(--transition); }
.source-row input[type="text"]:focus { border-color: var(--accent); }
.currency-input { display: flex; align-items: center; background: var(--bg-secondary); border: 1px solid var(--border); border-radius: var(--radius-xs); overflow: hidden; transition: border-color var(--transition); min-width: 120px; }
.currency-input:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }
.currency-input span { padding: 0.5rem; color: var(--text-muted); font-size: 0.8125rem; }
.currency-input input { border: none; background: none; padding: 0.5rem 0.5rem 0.5rem 0; font-family: var(--font); font-size: 0.8125rem; color: var(--text-primary); width: 100%; outline: none; }
.currency-input input::-webkit-inner-spin-button { -webkit-appearance: none; }
.source-remove { width: 28px; height: 28px; border: 1px solid var(--border); border-radius: var(--radius-xs); background: none; color: var(--text-muted); cursor: pointer; display: flex; align-items: center; justify-content: center; font-size: 14px; transition: all var(--transition); }
.source-remove:hover { border-color: var(--error); color: var(--error); }

.total-row { display: flex; align-items: center; justify-content: space-between; padding: 0.625rem 0.75rem; background: var(--bg-tertiary); border-radius: var(--radius-xs); font-size: 0.8125rem; font-weight: 600; }
.total-value { color: var(--accent); font-variant-numeric: tabular-nums; }

/* Deductions */
.deduction-toggle { display: grid; grid-template-columns: 1fr 1fr; gap: 0.5rem; margin-bottom: 0.75rem; }
.deduction-info { display: flex; align-items: center; justify-content: space-between; padding: 0.5rem 0.75rem; background: var(--bg-tertiary); border-radius: var(--radius-xs); font-size: 0.8125rem; }
.input-row { display: flex; align-items: center; justify-content: space-between; gap: 0.75rem; margin-bottom: 0.5rem; }
.input-row label { font-size: 0.8125rem; color: var(--text-secondary); }
.checkbox-label { display: flex; align-items: center; gap: 0.5rem; font-size: 0.8125rem; color: var(--text-secondary); cursor: pointer; }
.checkbox-label input { accent-color: var(--accent); }

.select-field { width: 100%; padding: 0.5rem; background: var(--bg-secondary); border: 1px solid var(--border); border-radius: var(--radius-xs); font-family: var(--font); font-size: 0.8125rem; color: var(--text-primary); outline: none; cursor: pointer; }
.select-field:focus { border-color: var(--accent); }

/* Summary */
.summary-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.5rem; }
.summary-item { padding: 0.75rem; background: var(--bg-secondary); border-radius: var(--radius-xs); border: 1px solid var(--border); }
.summary-item.highlight { grid-column: 1/-1; background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), var(--bg-secondary)); border-color: var(--accent); }
.summary-label { display: block; font-size: 0.6875rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); margin-bottom: 0.25rem; }
.summary-value { display: block; font-size: 1rem; font-weight: 700; color: var(--text-primary); font-variant-numeric: tabular-nums; }
.summary-value.large { font-size: 1.5rem; color: var(--accent); }

/* Quarterly */
.quarterly-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0.5rem; }
.quarter-card { padding: 0.75rem; background: var(--bg-secondary); border: 1px solid var(--border); border-radius: var(--radius-xs); text-align: center; }
.quarter-label { display: block; font-size: 0.6875rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); margin-bottom: 0.25rem; }
.quarter-amount { display: block; font-size: 1rem; font-weight: 700; color: var(--text-primary); font-variant-numeric: tabular-nums; }
.quarter-due { display: block; font-size: 0.625rem; color: var(--text-muted); margin-top: 0.25rem; }

/* Brackets */
.bracket-list { display: flex; flex-direction: column; gap: 0.375rem; }
.bracket-row { display: flex; align-items: center; gap: 0.75rem; padding: 0.5rem 0.75rem; border-radius: var(--radius-xs); transition: background var(--transition); }
.bracket-row:hover { background: var(--bg-hover); }
.bracket-rate { font-size: 0.8125rem; font-weight: 700; color: var(--accent); min-width: 40px; }
.bracket-range { font-size: 0.75rem; color: var(--text-muted); flex: 1; }
.bracket-amount { font-size: 0.8125rem; font-weight: 600; color: var(--text-primary); font-variant-numeric: tabular-nums; }
.bracket-bar { height: 6px; background: var(--bg-tertiary); border-radius: 3px; flex: 0 0 80px; overflow: hidden; }
.bracket-bar-fill { height: 100%; border-radius: 3px; background: linear-gradient(90deg, var(--accent), var(--accent-light)); transition: width 0.5s ease; }

/* Bar Chart */
.bar-chart { display: flex; flex-direction: column; gap: 0.75rem; }
.bar-item { display: flex; align-items: center; gap: 0.75rem; }
.bar-label { font-size: 0.75rem; color: var(--text-secondary); min-width: 80px; }
.bar-track { flex: 1; height: 24px; background: var(--bg-tertiary); border-radius: 12px; overflow: hidden; position: relative; }
.bar-fill { height: 100%; border-radius: 12px; transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1); display: flex; align-items: center; justify-content: flex-end; padding-right: 0.5rem; font-size: 0.625rem; font-weight: 600; color: white; min-width: 24px; }
.bar-fill.income { background: linear-gradient(90deg, var(--accent), var(--accent-light)); }
.bar-fill.tax { background: linear-gradient(90deg, var(--error), #FCA5A5); }
.bar-fill.takehome { background: linear-gradient(90deg, var(--success), #6EE7B7); }

/* Toast */
.toast-container { position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 2000; display: flex; flex-direction: column; gap: 0.5rem; }
.toast { padding: 0.75rem 1rem; border-radius: var(--radius-sm); background: var(--bg-secondary); border: 1px solid var(--border); box-shadow: 0 8px 32px rgba(0,0,0,0.18); font-size: 0.8125rem; max-width: 320px; animation: toastIn 0.3s ease, toastOut 0.3s ease 2.7s forwards; }
.toast.success { border-left: 3px solid var(--success); }
.toast.info { border-left: 3px solid var(--accent); }

@keyframes toastIn { from { opacity: 0; transform: translateX(20px); } to { opacity: 1; transform: translateX(0); } }
@keyframes toastOut { from { opacity: 1; } to { opacity: 0; transform: translateX(20px); } }

@media (max-width: 768px) {
  .grid { grid-template-columns: 1fr; }
  .radio-group { grid-template-columns: 1fr; }
  .summary-grid { grid-template-columns: 1fr; }
  .quarterly-grid { grid-template-columns: 1fr 1fr; }
  .main { padding: 1rem; }
}

@media (max-width: 480px) {
  .header-content { padding: 0.75rem 1rem; }
  .quarterly-grid { grid-template-columns: 1fr; }
  .source-row { flex-wrap: wrap; }
}

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--text-muted); border-radius: 3px; }