frontend/src/index.css

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600;700&display=swap');

/* ── Reset & base ──────────────────────────────────────── */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --sidebar-width: 260px;
  --sidebar-collapsed-width: 64px;
  --header-height: 48px;
  
  /* HeatTransPlan Signature Brand Colors */
  --primary: #2B589C;
  --primary-hover: #1b3d73;
  --primary-light: #F4F6FB;
  --primary-gradient: linear-gradient(90deg, #2B589C 0%, #B4396E 50%, #E13945 100%);
  --brand-red: #E13945;
  --brand-magenta: #B4396E;
  
  --danger: #EF4444;
  --success: #10B981;
  --warning: #F59E0B;
  
  /* Core Surfaces - Azure Tinted */
  --bg: #F8FAFC; 
  --surface: #FFFFFF;
  --surface-hover: #F1F5F9;
  --surface-active: #E2E8F0;
  --surface-rgb: 255, 255, 255;
  
  /* Typography - Deep Slate instead of Gray */
  --text-main: #0F172A;
  --text-muted: #64748B;
  --text-on-primary: #FFFFFF;
  
  /* Borders - Softer blue-gray */
  --border: #E2E8F0;
  --border-strong: #CBD5E1;
  --radius-sm: 4px;
  --radius: 8px;
  --radius-lg: 12px;
  
  /* Modern Layered Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  
  font-size: 13px;
}

.dark {
  --primary: #60A5FA; /* Brighter blue for navy backgrounds */
  --primary-hover: #93C5FD;
  --primary-light: rgba(96, 165, 250, 0.1);
  --primary-gradient: linear-gradient(90deg, #60A5FA 0%, #B4396E 50%, #E13945 100%);
  
  --bg: #0F172A; /* Deep Navy Slate */
  --surface: #1E293B; /* Lighter Slate Blue */
  --surface-hover: #334155;
  --surface-active: #475569;
  --surface-rgb: 30, 41, 59;
  
  --text-main: #F8FAFC;
  --text-muted: #94A3B8;
  --text-on-primary: #FFFFFF;
  
  --border: #334155;
  --border-strong: #475569;
  
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.6);
}

body {
  font-family: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--text-main);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover {
  color: var(--primary-hover);
}

button {
  cursor: pointer;
  font-family: inherit;
}

/* ── Utility classes ──────────────────────────────────── */
.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-xs { gap: 2px; }
.gap-sm { gap: 4px; }
.gap-md { gap: 8px; }
.gap-lg { gap: 16px; }
.p-sm { padding: 4px; }
.p-md { padding: 8px; }
.p-lg { padding: 12px; }
.mt-sm { margin-top: 4px; }
.mt-md { margin-top: 8px; }
.mb-sm { margin-bottom: 4px; }
.mb-md { margin-bottom: 8px; }

/* ── Card ──────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 12px;
  transition: box-shadow 0.3s ease, transform 0.3s ease;
}
.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* ── Buttons ──────────────────────────────────────────── */
.body {
  margin: 0;
  display: flex;
  place-items: center;
  min-width: 320px;
  min-height: 100vh;
  top: 0 !important; /* Prevent Google Translate from pushing body down */
}

/* Hide Google Translate UI elements */
.skiptranslate iframe {
  display: none !important;
}
body {
  top: 0 !important;
}
.goog-te-combo {
  display: none !important;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-main);
  font-size: 13px;
  font-weight: 500;
  transition: all 0.1s ease-out;
}
.btn:hover {
  background: var(--surface-hover);
  border-color: var(--border-strong);
}
.btn:active {
  background: var(--border);
  transform: none;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #fff;
  border: none;
  box-shadow: 0 2px 4px rgba(43, 88, 156, 0.2);
}
.btn-primary:hover {
  background: linear-gradient(90deg, #1b3d73 0%, #902956 50%, #c42634 100%);
  color: #fff;
  box-shadow: 0 4px 8px rgba(43, 88, 156, 0.3);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
  border: none;
}
.btn-danger:hover {
  background: #DC2626;
  color: #fff;
}

.btn-sm {
  padding: 4px 10px;
  font-size: 12px;
  border-radius: var(--radius-sm);
}

/* ── Form controls ────────────────────────────────────── */
input[type='text'],
input[type='number'],
input[type='search'],
select,
textarea {
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 12px;
  font-family: inherit;
  background: var(--surface);
  color: var(--text-main);
  transition: border-color 0.15s;
}
input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px var(--primary-light);
}

label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

/* ── Tables ───────────────────────────────────────────── */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
th,
td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}
th {
  background: var(--bg);
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  color: var(--text-muted);
}
tr:hover td {
  background: var(--surface-hover);
}

/* ── Tabs ─────────────────────────────────────────────── */
.tabs {
  display: flex;
  border-bottom: 2px solid var(--border);
  gap: 0;
}
.tab {
  padding: 8px 16px;
  border: none;
  background: none;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: all 0.15s;
}
.tab:hover {
  color: var(--text);
}
.tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 600;
}

/* ── Collapsible sections ─────────────────────────────── */
.collapsible-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  cursor: pointer;
  user-select: none;
  border-radius: var(--radius);
  transition: background 0.15s;
}
.collapsible-header:hover {
  background: var(--surface-hover);
}
.collapsible-arrow {
  transition: transform 0.2s;
  font-size: 10px;
}
.collapsible-arrow.open {
  transform: rotate(90deg);
}

/* ── Scrollbar ────────────────────────────────────────── */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* ── Leaflet overrides ────────────────────────────────── */
.leaflet-container {
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

/* ── Plotly overrides ─────────────────────────────────── */
.js-plotly-plot .plotly .modebar {
  top: 4px !important;
  right: 4px !important;
}

/* ── Loading spinner ──────────────────────────────────── */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ── Toast / notification ─────────────────────────────── */
.toast {
  position: fixed;
  bottom: 20px;
  right: 20px;
  padding: 10px 18px;
  border-radius: var(--radius);
  color: #fff;
  font-size: 12px;
  z-index: 10000;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  animation: slide-up 0.3s ease;
}
.toast.success {
  background: var(--success);
}
.toast.error {
  background: var(--danger);
}
.toast.warning {
  background: var(--warning);
}
@keyframes slide-up {
  from {
    transform: translateY(20px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}