/* ===== Svarog Thermal Battery - Custom Styles ===== */

/* CSS Custom Properties */
:root {
  --bg-dark: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --accent-warm: #f59e0b;
  --accent-orange: #ea580c;
  --accent-teal: #14b8a6;
  --accent-teal-dark: #0d9488;
  --border-color: #334155;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.4), 0 4px 6px -4px rgb(0 0 0 / 0.4);
  --radius: 0.75rem;
  --radius-lg: 1rem;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-dark);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-warm);
}

/* ===== Navigation ===== */
.nav-blur {
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(15, 23, 42, 0.85);
  border-bottom: 1px solid var(--border-color);
}

.nav-link {
  position: relative;
  padding: 0.5rem 0;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-warm);
  transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent-warm);
}

.nav-link.active::after,
.nav-link:hover::after {
  width: 100%;
}

/* Mobile Nav */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 64px;
    right: -100%;
    width: 80%;
    max-width: 300px;
    height: calc(100vh - 64px);
    background: var(--bg-card);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    transition: right 0.3s ease;
    z-index: 40;
    border-left: 1px solid var(--border-color);
  }

  .nav-links.open {
    right: 0;
  }

  .hamburger {
    display: flex;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    padding: 4px;
  }

  .hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
  }

  .hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(4px, 4px);
  }

  .hamburger.active span:nth-child(2) {
    opacity: 0;
  }

  .hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(4px, -4px);
  }
}

/* ===== Hero Section ===== */
.hero-gradient {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #451a03 100%);
  position: relative;
  overflow: hidden;
}

.hero-gradient::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(245, 158, 11, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero-gradient::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(20, 184, 166, 0.1) 0%, transparent 70%);
  pointer-events: none;
}

/* ===== Cards ===== */
.card-base {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: var(--transition);
}

.card-base:hover {
  transform: translateY(-4px);
  border-color: var(--accent-warm);
  box-shadow: var(--shadow-lg);
}

.card-highlight {
  border-color: var(--accent-warm);
  background: linear-gradient(135deg, var(--bg-card), rgba(245, 158, 11, 0.05));
}

/* ===== Tables ===== */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.data-table thead th {
  background: rgba(30, 41, 59, 0.8);
  color: var(--accent-warm);
  font-weight: 600;
  text-align: left;
  padding: 0.875rem 1rem;
  border-bottom: 2px solid var(--accent-warm);
  white-space: nowrap;
  position: sticky;
  top: 0;
  z-index: 10;
}

.data-table tbody tr {
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.data-table tbody tr:hover {
  background: rgba(245, 158, 11, 0.05);
}

.data-table tbody td {
  padding: 0.75rem 1rem;
  color: var(--text-secondary);
  vertical-align: top;
}

.data-table tbody td:first-child {
  color: var(--text-primary);
  font-weight: 500;
}

.table-scroll {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
}

/* ===== Badges ===== */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
}

.badge-warm {
  background: rgba(245, 158, 11, 0.15);
  color: var(--accent-warm);
}

.badge-teal {
  background: rgba(20, 184, 166, 0.15);
  color: var(--accent-teal);
}

.badge-orange {
  background: rgba(234, 88, 12, 0.15);
  color: var(--accent-orange);
}

.badge-green {
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
}

.badge-blue {
  background: rgba(59, 130, 246, 0.15);
  color: #60a5fa;
}

/* ===== Priority Indicators ===== */
.priority-high {
  color: #ef4444;
  font-weight: 700;
}

.priority-medium {
  color: var(--accent-warm);
  font-weight: 700;
}

.priority-low {
  color: var(--accent-teal);
  font-weight: 700;
}

/* ===== Formula Callouts ===== */
.formula-box {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.1), rgba(20, 184, 166, 0.05));
  border: 1px solid rgba(245, 158, 11, 0.3);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin: 1rem 0;
}

.formula-box code {
  color: var(--accent-warm);
  font-family: 'Fira Code', 'Cascadia Code', monospace;
  font-size: 0.95rem;
  display: block;
  padding: 0.5rem 0;
}

.formula-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-warm);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

/* ===== Tabs ===== */
.tab-container {
  border-bottom: 2px solid var(--border-color);
  display: flex;
  gap: 0.25rem;
  margin-bottom: 1.5rem;
}

.tab-btn {
  padding: 0.75rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn.active {
  color: var(--accent-warm);
  border-bottom-color: var(--accent-warm);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

/* ===== Animations ===== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.6;
  }
}

@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

.animate-fade-in {
  animation: fadeInUp 0.6s ease forwards;
}

.scroll-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.scroll-reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.stagger-children > * {
  opacity: 0;
  transform: translateY(20px);
}

.stagger-children.visible > *:nth-child(1) { transition: opacity 0.5s 0.05s, transform 0.5s 0.05s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(2) { transition: opacity 0.5s 0.1s, transform 0.5s 0.1s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(3) { transition: opacity 0.5s 0.15s, transform 0.5s 0.15s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(4) { transition: opacity 0.5s 0.2s, transform 0.5s 0.2s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(5) { transition: opacity 0.5s 0.25s, transform 0.5s 0.25s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(6) { transition: opacity 0.5s 0.3s, transform 0.5s 0.3s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(7) { transition: opacity 0.5s 0.35s, transform 0.5s 0.35s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(8) { transition: opacity 0.5s 0.4s, transform 0.5s 0.4s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(9) { transition: opacity 0.5s 0.45s, transform 0.5s 0.45s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(10) { transition: opacity 0.5s 0.5s, transform 0.5s 0.5s; opacity: 1; transform: translateY(0); }

/* ===== Section Headers ===== */
.section-header {
  margin-bottom: 3rem;
  text-align: center;
}

.section-header h2 {
  font-size: 2.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-warm), var(--accent-orange));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.75rem;
}

.section-header p {
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== Icon Wrapper ===== */
.icon-wrap {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  background: rgba(245, 158, 11, 0.15);
  color: var(--accent-warm);
  font-size: 1.25rem;
  flex-shrink: 0;
}

.icon-wrap.teal {
  background: rgba(20, 184, 166, 0.15);
  color: var(--accent-teal);
}

/* ===== Stats/Metric Cards ===== */
.metric-card {
  text-align: center;
  padding: 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
}

.metric-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-warm);
  display: block;
}

.metric-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

/* ===== Tier Cards ===== */
.tier-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.tier-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent-warm);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.tier-card:hover::before {
  transform: scaleX(1);
}

.tier-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-warm);
  box-shadow: var(--shadow-lg);
}

/* ===== Pros/Cons ===== */
.pros-cons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.pros-cons .pros,
.pros-cons .cons {
  padding: 1.25rem;
  border-radius: var(--radius);
}

.pros-cons .pros {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.pros-cons .cons {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.pros-cons h5 {
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.pros-cons .pros h5 {
  color: #10b981;
}

.pros-cons .cons h5 {
  color: #ef4444;
}

.pros-cons ul {
  list-style: none;
}

.pros-cons li {
  font-size: 0.875rem;
  color: var(--text-secondary);
  padding: 0.25rem 0;
  padding-left: 1.25rem;
  position: relative;
}

.pros-cons .pros li::before {
  content: '\2713';
  position: absolute;
  left: 0;
  color: #10b981;
  font-weight: 700;
}

.pros-cons .cons li::before {
  content: '\2717';
  position: absolute;
  left: 0;
  color: #ef4444;
  font-weight: 700;
}

@media (max-width: 640px) {
  .pros-cons {
    grid-template-columns: 1fr;
  }
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border-color);
  background: var(--bg-dark);
}

/* ===== Utility ===== */
.gradient-text {
  background: linear-gradient(135deg, var(--accent-warm), var(--accent-orange));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.glow-warm {
  box-shadow: 0 0 20px rgba(245, 158, 11, 0.15);
}

/* ===== Savings & Sizing Calculator ===== */
.calc-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: start;
}

.calc-inputs {
  position: sticky;
  top: 88px;
}

.calc-field {
  margin-bottom: 1.1rem;
}

.calc-field label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

.calc-field .calc-val {
  color: var(--accent-warm);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.calc-field input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 999px;
  background: var(--border-color);
  outline: none;
  cursor: pointer;
}

.calc-field input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-warm);
  border: 2px solid var(--bg-dark);
  box-shadow: 0 0 0 1px var(--accent-warm);
  transition: transform 0.15s ease;
}

.calc-field input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.calc-field input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-warm);
  border: 2px solid var(--bg-dark);
  box-shadow: 0 0 0 1px var(--accent-warm);
  cursor: pointer;
}

.calc-headline {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}

.calc-headline-item {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.12), rgba(20, 184, 166, 0.06));
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
}

.calc-headline-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #10b981;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.calc-headline-value {
  font-size: 1.9rem;
  font-weight: 800;
  color: #10b981;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.calc-metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.calc-metric {
  background: rgba(30, 41, 59, 0.5);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
}

.calc-metric-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-secondary);
  margin-bottom: 0.2rem;
}

.calc-metric-value {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.calc-warning {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.35);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  margin-bottom: 1rem;
  font-size: 0.85rem;
  color: #fca5a5;
}

.calc-warning i {
  margin-top: 0.15rem;
}

@media (max-width: 860px) {
  .calc-wrap {
    grid-template-columns: 1fr;
  }

  .calc-inputs {
    position: static;
  }
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .section-header h2 {
    font-size: 1.75rem;
  }

  .section-header p {
    font-size: 1rem;
  }

  .card-base,
  .tier-card {
    padding: 1.25rem;
  }

  .data-table {
    font-size: 0.8rem;
  }

  .data-table thead th,
  .data-table tbody td {
    padding: 0.625rem 0.75rem;
  }
}

/* Print styles */
@media print {
  .nav-blur,
  .hamburger {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }

  .card-base,
  .tier-card {
    break-inside: avoid;
    border: 1px solid #ccc;
  }
}