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

:root {
  --bg: #F3F4F6;
  --surface: #FFFFFF;
  --surface2: #F9FAFB;
  --border: #E5E7EB;
  --border2: #D1D5DB;
  --text: #111827;
  --text2: #6B7280;
  --text3: #9CA3AF;
  --blue: #2563EB;
  --green: #059669;
  --red: #EF4444;
  --amber: #D97706;
  --purple: #7C3AED;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.05);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111827;
    --surface: #1F2937;
    --surface2: #374151;
    --border: #374151;
    --border2: #4B5563;
    --text: #F9FAFB;
    --text2: #9CA3AF;
    --text3: #6B7280;
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.3);
  }
}

html { scroll-behavior: smooth; min-height: 100vh; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.6;
}

/* ─── Header ─── */
.header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.logo-mark {
  width: 34px; height: 34px;
  background: var(--blue);
  border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
}
.logo-mark svg { width: 18px; height: 18px; }
.logo-text {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}
.header-sub {
  font-size: 13px;
  color: var(--text2);
  margin-left: 4px;
}
.header-sep { flex: 1; }
.header-badge {
  font-size: 11px;
  background: #EFF6FF;
  color: var(--blue);
  padding: 4px 10px;
  border-radius: 20px;
  font-weight: 500;
}
@media (prefers-color-scheme: dark) {
  .header-badge { background: #1E3A5F; color: #93C5FD; }
}

/* ─── Layout ─── */
.main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px;
  padding-bottom: 0;
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 20px;
  align-items: start;
}
@media (max-width: 900px) {
  .main { 
    grid-template-columns: 1fr; 
    padding: 16px; 
  }
}

/* ─── Inputs Panel ─── */
.inputs-panel {
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: sticky;
  top: 87px;
  height: calc(100vh - 100px);
  overflow-y: auto;
  padding-right: 4px;
  padding-bottom: 24px;
}
.inputs-panel > * { flex-shrink: 0; }
.inputs-panel::-webkit-scrollbar { width: 4px; }
.inputs-panel::-webkit-scrollbar-track { background: transparent; }
.inputs-panel::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 4px; }
@media (max-width: 900px) {
  .inputs-panel { position: static; height: auto; overflow: visible; padding-bottom: 0; }
}

/* ─── Card ─── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.card-header {
  padding: 14px 16px 10px;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid var(--border);
}
.card-icon {
  width: 28px; height: 28px;
  border-radius: 7px;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px;
  flex-shrink: 0;
}
.card-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}
.card-body { padding: 14px 16px; }

/* ─── Scenario tabs ─── */
.sc-tabs {
  display: flex;
  border-bottom: 1px solid var(--border);
}
.sc-tab {
  flex: 1;
  padding: 10px 8px;
  font-size: 12px;
  font-weight: 500;
  text-align: center;
  cursor: pointer;
  border: none;
  background: none;
  color: var(--text2);
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
.sc-tab.active { color: var(--text); border-bottom-color: currentColor; }
.sc-tab:hover { color: var(--text); background: var(--surface2); }

.sc-panel { display: none; padding: 14px 16px; }
.sc-panel.active { display: block; }

/* ─── Fields ─── */
.field-group { display: flex; flex-direction: column; gap: 10px; }
.field { display: flex; flex-direction: column; gap: 4px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
label {
  font-size: 11px;
  font-weight: 500;
  color: var(--text2);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
input[type="text"],
input[type="number"] {
  height: 36px;
  padding: 0 10px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: inherit;
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
  width: 100%;
}
input[type="text"]:focus,
input[type="number"]:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
}
input[type="text"]::placeholder { color: var(--text3); }

.field-hint {
  font-size: 11px;
  color: var(--text3);
  margin-top: 2px;
}

.info-btn {
  display: inline-block;
  cursor: help;
  opacity: 0.5;
  font-size: 11px;
  margin-left: 4px;
  position: relative;
}
.info-btn:hover { opacity: 1; }
.info-btn::after {
  content: attr(data-tip);
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(6px);
  background: var(--surface2);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 11px;
  font-family: 'Inter', sans-serif;
  width: max-content;
  max-width: 220px;
  text-align: center;
  pointer-events: none;
  z-index: 100;
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
  border: 1px solid var(--border2);
  opacity: 0;
  visibility: hidden;
  transition: all 0.2s;
}
.info-btn:hover::after {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(2px);
}

.reset-btn {
  margin-top: 8px;
  padding: 10px;
  background: transparent;
  border: 1px dashed var(--border2);
  border-radius: var(--radius-sm);
  color: var(--text2);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
}
.reset-btn:hover {
  background: var(--surface2);
  color: var(--text);
  border-style: solid;
}

/* ─── Results Panel ─── */
.results-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-right: 4px;
  padding-bottom: 24px;
}
.results-panel > * { flex-shrink: 0; }
@media (max-width: 900px) {
  .results-panel { padding-bottom: 0; }
}

/* ─── Metric cards ─── */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
@media (max-width: 700px) {
  .metrics-grid { grid-template-columns: 1fr; }
}
.metric-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 14px 16px;
  box-shadow: var(--shadow);
}
.mc-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 12px;
}
.mc-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}
.mc-emi {
  font-size: 11px;
  color: var(--text2);
  background: var(--surface2);
  padding: 2px 7px;
  border-radius: 20px;
  border: 1px solid var(--border);
}
.mc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.mc-item { display: flex; flex-direction: column; gap: 2px; }
.mc-key { font-size: 10px; text-transform: uppercase; letter-spacing: 0.04em; color: var(--text3); font-weight: 500; }
.mc-val { font-size: 14px; font-weight: 600; color: var(--text); }
.mc-val.neg { color: var(--red); }

/* ─── Chart cards ─── */
.chart-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow);
}
.chart-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}
.chart-sub {
  font-size: 11px;
  color: var(--text2);
  margin-bottom: 14px;
}
.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 14px;
}
.leg {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  color: var(--text2);
}
.leg-line {
  width: 20px; height: 2.5px;
  border-radius: 2px;
}
.leg-line.thin { height: 1.5px; }

.chart-wrap { position: relative; width: 100%; }
.chart-wrap canvas { display: block; }

/* ─── Flow scenario selector ─── */
.flow-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
  flex-wrap: wrap;
  gap: 8px;
}
.flow-btns { display: flex; gap: 6px; }
.flow-btn {
  padding: 4px 12px;
  font-size: 11px;
  font-weight: 500;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: none;
  color: var(--text2);
  cursor: pointer;
  transition: all 0.15s;
}
.flow-btn:hover { border-color: var(--border2); color: var(--text); }
.flow-btn.active { font-weight: 600; }

/* ─── Section divider ─── */
.section-divider {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 16px 10px;
}
.divider-label {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text3);
  white-space: nowrap;
}
.divider-line { flex: 1; height: 1px; background: var(--border); }

/* ─── Footer ─── */
.footer {
  text-align: center;
  padding: 24px;
  font-size: 12px;
  color: var(--text3);
}
.footer a:hover { color: var(--text); }

/* ─── Remove number input spinners (all breakpoints) ─── */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
input[type="number"] { -moz-appearance: textfield; appearance: textfield; }

/* ─── Mobile Optimizations ─── */
@media (max-width: 768px) {
  .header {
    position: static;
  }
  .header-inner {
    flex-direction: column;
    padding: 16px 16px 12px;
    gap: 10px;
    align-items: center;
  }
  .header-sub, .header-sep { display: none; }
  .header nav {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
  }
  .header a {
    font-size: 13px !important;
    margin-right: 0 !important;
  }
  /* Prevent iOS Safari from zooming in on input focus by setting font-size to 16px */
  input[type="text"],
  input[type="number"] {
    font-size: 16px;
    height: 44px; /* Larger tap targets */
  }
  .chart-card {
    padding: 14px 12px;
  }
  .card-body {
    padding: 16px;
  }
  #onboardingBanner {
    flex-direction: column;
    align-items: flex-start !important;
    gap: 12px !important;
  }
  #onboardingBanner > div:first-child {
    display: none; /* Hide wave emoji to save vertical space */
  }
  
  .hover-panel {
    display: none;
    grid-template-columns: 1fr 1fr;
    gap: 8px 12px;
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px 14px;
    margin-bottom: 16px;
    font-size: 13px;
    animation: fadeUp 0.2s ease-out;
  }
  .hover-panel-title {
    grid-column: 1 / -1;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--text);
  }
  .hover-panel-item {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text2);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .hover-panel-color {
    width: 10px;
    height: 10px;
    border-radius: 3px;
    flex-shrink: 0;
  }
}

.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 9999;
  pointer-events: none;
}
.toast-msg {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 14px 20px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 500;
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
  display: flex;
  align-items: center;
  gap: 10px;
  transform: translateY(20px);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.toast-msg.show {
  transform: translateY(0);
  opacity: 1;
}

@media (max-width: 768px) {
  .toast-container {
    bottom: 24px;
    left: 24px;
    right: 24px;
    align-items: center;
  }
}