/* ============================================================
   COAST FIRE CALCULATOR — style.css
   Theme: Dark-first, finance-premium, trust-building
   Fonts: Syne (headings) + DM Sans (body)
   Accent: Emerald Green #10B981 + Gold #F59E0B
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Syne:wght@400;500;600;700;800&family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;1,9..40,400&display=swap');

/* ---------- CSS Variables ---------- */
:root {
  --font-head: 'Syne', sans-serif;
  --font-body: 'DM Sans', sans-serif;

  /* Dark Mode (Default) */
  --bg:         #080f0c;
  --bg2:        #0d1612;
  --surface:    #111a15;
  --surface2:   #182219;
  --border:     rgba(16,185,129,0.12);
  --border2:    rgba(16,185,129,0.22);
  --text:       #e8f5ef;
  --text2:      #9ab8a8;
  --muted:      #5a7a68;
  --accent:     #10B981;
  --accent2:    #34D399;
  --accent3:    #F59E0B;
  --accent-rgb: 16,185,129;
  --gold:       #F59E0B;
  --gold2:      #FCD34D;
  --danger:     #ef4444;
  --card-bg:    rgba(17,26,21,0.9);
  --card-shadow: 0 4px 32px rgba(0,0,0,0.4);
  --glow:       0 0 40px rgba(16,185,129,0.15);
}

[data-theme="light"] {
  --bg:         #f0faf5;
  --bg2:        #e6f5ed;
  --surface:    #ffffff;
  --surface2:   #f4faf7;
  --border:     rgba(16,185,129,0.18);
  --border2:    rgba(16,185,129,0.3);
  --text:       #0a1a10;
  --text2:      #2d5a3d;
  --muted:      #6b9e80;
  --card-bg:    rgba(255,255,255,0.95);
  --card-shadow: 0 4px 24px rgba(16,185,129,0.1);
  --glow:       0 0 40px rgba(16,185,129,0.08);
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background 0.3s, color 0.3s;
}

/* Subtle grid bg texture */
body::before {
  content: '';
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(16,185,129,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16,185,129,0.025) 1px, transparent 1px);
  background-size: 48px 48px;
}

body > * { position: relative; z-index: 1; }

a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent2); }

img { max-width: 100%; display: block; }

h1, h2, h3, h4, h5 { font-family: var(--font-head); line-height: 1.2; }

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--accent); border-radius: 3px; }

/* ---------- Utility ---------- */
.container { max-width: 1200px; margin: 0 auto; padding: 0 clamp(16px,4vw,48px); }
.section { padding: 80px 0; }
.section-sm { padding: 48px 0; }

.text-accent { color: var(--accent); }
.text-gold   { color: var(--gold); }
.text-muted  { color: var(--muted); }

.badge {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 12px; border-radius: 99px;
  font-size: 0.75rem; font-weight: 600; letter-spacing: 0.06em;
  text-transform: uppercase;
  background: rgba(var(--accent-rgb),0.1);
  border: 1px solid rgba(var(--accent-rgb),0.25);
  color: var(--accent);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 28px;
  border-radius: 10px;
  font-family: var(--font-head); font-weight: 700; font-size: 0.95rem;
  cursor: pointer; border: none; transition: all 0.25s; text-decoration: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #050f09;
  box-shadow: 0 4px 20px rgba(var(--accent-rgb),0.35);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(var(--accent-rgb),0.5);
  color: #050f09;
}
.btn-secondary {
  background: var(--surface2);
  border: 1px solid var(--border2);
  color: var(--text);
}
.btn-secondary:hover {
  background: var(--surface);
  border-color: var(--accent);
  color: var(--accent);
}
.btn-gold {
  background: linear-gradient(135deg, var(--gold), var(--gold2));
  color: #1a0f00;
  box-shadow: 0 4px 20px rgba(245,158,11,0.35);
}
.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(245,158,11,0.5);
  color: #1a0f00;
}
.btn-lg { padding: 16px 36px; font-size: 1.05rem; border-radius: 12px; }
.btn-sm { padding: 8px 18px; font-size: 0.85rem; }

/* ---------- Cards ---------- */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  backdrop-filter: blur(12px);
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
}
.card:hover {
  border-color: var(--border2);
  box-shadow: var(--card-shadow), var(--glow);
}
.card-elevated {
  box-shadow: var(--card-shadow);
}

/* ---------- Form Elements ---------- */
.form-group { margin-bottom: 20px; }
.form-label {
  display: block; margin-bottom: 8px;
  font-size: 0.88rem; font-weight: 600; color: var(--text2);
  letter-spacing: 0.02em;
}
.form-label span { color: var(--accent); font-size: 0.8rem; margin-left: 4px; }

.form-control {
  width: 100%; padding: 12px 16px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-family: var(--font-body); font-size: 1rem;
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
  -moz-appearance: textfield;
}
.form-control::-webkit-outer-spin-button,
.form-control::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.form-control:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(var(--accent-rgb),0.15);
}
.form-control::placeholder { color: var(--muted); }

/* Slider */
.range-wrapper { position: relative; }
.form-range {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 6px;
  background: var(--surface2); border-radius: 99px;
  outline: none; cursor: pointer;
  transition: background 0.2s;
}
.form-range::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 20px; height: 20px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(var(--accent-rgb),0.4);
  transition: transform 0.15s;
}
.form-range::-webkit-slider-thumb:hover { transform: scale(1.15); }
.form-range::-moz-range-thumb {
  width: 20px; height: 20px; border-radius: 50%; border: none;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(var(--accent-rgb),0.4);
}
.range-labels {
  display: flex; justify-content: space-between;
  margin-top: 6px; font-size: 0.75rem; color: var(--muted);
}
.range-value {
  display: inline-block;
  background: rgba(var(--accent-rgb),0.12);
  color: var(--accent); border-radius: 6px;
  padding: 2px 10px; font-weight: 700; font-size: 0.9rem;
  min-width: 52px; text-align: center;
}

/* ---------- Reveal Animation ---------- */
.reveal {
  opacity: 0; transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ---------- Page Hero ---------- */
.page-hero {
  padding: 80px 0 60px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute; top: -60px; left: 50%; transform: translateX(-50%);
  width: 600px; height: 400px;
  background: radial-gradient(ellipse at center, rgba(var(--accent-rgb),0.1) 0%, transparent 70%);
  pointer-events: none;
}
.page-hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800; margin-bottom: 20px;
}
.page-hero p {
  font-size: 1.1rem; color: var(--text2);
  max-width: 640px; margin: 0 auto 32px;
}

/* ---------- Section Headings ---------- */
.section-title {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 800; margin-bottom: 12px;
}
.section-subtitle {
  color: var(--text2); font-size: 1rem;
  max-width: 560px; margin: 0 auto 48px;
}

/* ---------- Result Display ---------- */
.result-number {
  font-family: var(--font-head); font-size: clamp(2rem,5vw,3.5rem);
  font-weight: 800; color: var(--accent);
  line-height: 1;
}
.result-label { font-size: 0.85rem; color: var(--muted); margin-top: 6px; }

/* ---------- Comparison Table ---------- */
.fire-table {
  width: 100%; border-collapse: collapse;
  font-size: 0.93rem;
}
.fire-table th {
  padding: 14px 18px; text-align: left;
  font-family: var(--font-head); font-weight: 700; font-size: 0.8rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  background: rgba(var(--accent-rgb),0.06);
  color: var(--accent); border-bottom: 2px solid var(--border2);
}
.fire-table td {
  padding: 14px 18px; border-bottom: 1px solid var(--border);
  color: var(--text2);
}
.fire-table tr:last-child td { border-bottom: none; }
.fire-table tr:hover td { background: rgba(var(--accent-rgb),0.03); }
.fire-table .highlight td { color: var(--text); font-weight: 600; }

/* ---------- FAQ Accordion ---------- */
.faq-item {
  border: 1px solid var(--border);
  border-radius: 12px; overflow: hidden;
  margin-bottom: 12px;
  transition: border-color 0.2s;
}
.faq-item.open { border-color: var(--border2); }
.faq-question {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 24px; cursor: pointer;
  font-family: var(--font-head); font-weight: 600; font-size: 1rem;
  color: var(--text); background: var(--surface);
  transition: background 0.2s, color 0.2s;
  gap: 12px;
  user-select: none;
}
.faq-item.open .faq-question { color: var(--accent); }
.faq-question:hover { background: var(--surface2); }
.faq-icon {
  width: 28px; height: 28px; flex-shrink: 0;
  border-radius: 50%; border: 1.5px solid var(--border2);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; font-weight: 700; color: var(--accent);
  transition: transform 0.3s, background 0.2s;
}
.faq-item.open .faq-icon { transform: rotate(45deg); background: rgba(var(--accent-rgb),0.1); }
.faq-answer {
  max-height: 0; overflow: hidden;
  transition: max-height 0.35s ease, padding 0.3s;
  padding: 0 24px; background: var(--surface);
}
.faq-item.open .faq-answer { max-height: 400px; padding: 0 24px 20px; }
.faq-answer p { color: var(--text2); font-size: 0.95rem; line-height: 1.75; }

/* ---------- Toast / Alert ---------- */
.toast {
  position: fixed; bottom: 24px; right: 24px; z-index: 9999;
  background: var(--surface); border: 1px solid var(--border2);
  border-radius: 12px; padding: 14px 20px;
  display: flex; align-items: center; gap: 10px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.3);
  transform: translateY(80px); opacity: 0;
  transition: all 0.35s cubic-bezier(.34,1.56,.64,1);
  pointer-events: none;
}
.toast.show { transform: translateY(0); opacity: 1; pointer-events: all; }
.toast-icon { font-size: 1.2rem; }
.toast-text { font-size: 0.9rem; color: var(--text); }

/* ---------- Tabs ---------- */
.tabs { display: flex; gap: 4px; background: var(--surface); border-radius: 12px; padding: 4px; margin-bottom: 28px; }
.tab-btn {
  flex: 1; padding: 10px 16px; border: none; cursor: pointer;
  background: transparent; color: var(--text2);
  font-family: var(--font-head); font-size: 0.88rem; font-weight: 600;
  border-radius: 9px; transition: all 0.2s;
}
.tab-btn.active { background: var(--accent); color: #050f09; }
.tab-btn:hover:not(.active) { background: var(--surface2); color: var(--text); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ---------- Progress / Steps ---------- */
.step-indicator {
  display: flex; align-items: center; gap: 0; margin-bottom: 32px;
}
.step { display: flex; align-items: center; gap: 8px; flex: 1; }
.step:last-child { flex: 0; }
.step-num {
  width: 32px; height: 32px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 0.85rem;
  background: var(--surface2); border: 2px solid var(--border);
  color: var(--muted); transition: all 0.3s;
}
.step.active .step-num { background: var(--accent); border-color: var(--accent); color: #050f09; }
.step.done .step-num { background: rgba(var(--accent-rgb),0.15); border-color: var(--accent); color: var(--accent); }
.step-line { flex: 1; height: 2px; background: var(--border); }
.step.done + .step .step-line { background: var(--accent); }

/* ---------- Responsive Utilities ---------- */
@media (max-width: 768px) {
  .section { padding: 56px 0; }
  .hide-mobile { display: none !important; }
}
@media (min-width: 769px) {
  .hide-desktop { display: none !important; }
}

/* ---------- Print ---------- */
@media print {
  header, footer, .no-print { display: none !important; }
  body { background: white; color: black; }
  .card { border: 1px solid #ccc; }
}

/* ============================================================
   HOW TO USE SECTION
   ============================================================ */

.howto-section {
  padding: 80px 0;
  background: var(--bg);
}

/* Header */
.section-header { text-align: center; margin-bottom: 56px; }
.section-header .section-subtitle {
  color: var(--text2); font-size: 1rem;
  max-width: 560px; margin: 12px auto 0;
}

/* Step Cards Grid */
.howto-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 64px;
}

.howto-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  position: relative;
  transition: border-color 0.25s, transform 0.25s, box-shadow 0.25s;
}
.howto-card:hover {
  border-color: var(--border2);
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(16,185,129,0.1);
}

.howto-step-num {
  position: absolute;
  top: -14px; left: 24px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #050f09;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  padding: 4px 12px;
  border-radius: 99px;
}

.howto-icon {
  font-size: 2rem;
  margin-bottom: 12px;
  display: block;
}

.howto-card h3 {
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
}

.howto-card > p {
  color: var(--text2);
  font-size: 0.9rem;
  line-height: 1.7;
  margin-bottom: 14px;
}

/* Tip Box */
.howto-tip {
  background: rgba(16,185,129,0.06);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 12px 14px;
  margin-bottom: 12px;
}
.tip-label {
  display: block;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 5px;
}
.howto-tip p, .howto-tip {
  color: var(--text2);
  font-size: 0.85rem;
  line-height: 1.65;
}

/* Example Box */
.howto-example {
  background: var(--surface2);
  border-radius: 8px;
  padding: 10px 14px;
  margin-top: 10px;
}
.ex-label {
  display: block;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--gold);
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}
.howto-example, .howto-example * {
  color: var(--text2);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* Rate Guide */
.howto-rate-guide {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 12px 0;
}
.rate-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  color: var(--text2);
}
.rate-badge {
  flex-shrink: 0;
  padding: 3px 10px;
  border-radius: 99px;
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font-head);
}
.rate-badge.conservative { background: rgba(16,185,129,0.12); color: var(--accent2); }
.rate-badge.moderate     { background: rgba(245,158,11,0.12); color: var(--gold); }
.rate-badge.aggressive   { background: rgba(239,68,68,0.12);  color: #f87171; }

/* ---- Results Explained ---- */
.howto-results-section {
  margin-bottom: 56px;
}
.howto-results-section h3 {
  font-family: var(--font-head);
  font-size: 1.4rem;
  margin-bottom: 6px;
}
.howto-results-sub {
  color: var(--text2); font-size: 0.9rem; margin-bottom: 28px;
}

.results-explain-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.result-explain-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px 20px;
  transition: border-color 0.2s;
}
.result-explain-card:hover { border-color: var(--border2); }

.re-icon { font-size: 1.8rem; margin-bottom: 10px; }
.result-explain-card h4 {
  font-family: var(--font-head);
  font-size: 0.95rem; font-weight: 700;
  color: var(--accent); margin-bottom: 8px;
}
.result-explain-card p {
  color: var(--text2); font-size: 0.85rem; line-height: 1.65;
  margin-bottom: 12px;
}
.re-formula {
  background: var(--surface2);
  border-radius: 6px;
  padding: 8px 12px;
  font-family: monospace;
  font-size: 0.78rem;
  color: var(--accent2);
}

/* ---- Mini Tools Explained ---- */
.howto-mini-section {
  margin-bottom: 56px;
}
.howto-mini-section h3 {
  font-family: var(--font-head);
  font-size: 1.4rem;
  margin-bottom: 24px;
}

.mini-explain-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.mini-explain-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px 24px;
  position: relative;
}
.mei-num {
  position: absolute;
  top: -12px; right: 20px;
  width: 28px; height: 28px;
  border-radius: 50%;
  background: var(--accent);
  color: #050f09;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 0.8rem;
  display: flex; align-items: center; justify-content: center;
}
.mini-explain-card h4 {
  font-family: var(--font-head);
  font-size: 1rem; color: var(--text);
  margin-bottom: 10px;
}
.mini-explain-card p {
  color: var(--text2); font-size: 0.88rem;
  line-height: 1.7; margin-bottom: 10px;
}

/* ---- Chart Explained ---- */
.howto-chart-section { margin-bottom: 16px; }
.chart-explain-box {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 36px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: start;
}
.ce-left h3 {
  font-family: var(--font-head);
  font-size: 1.3rem;
  margin: 12px 0 20px;
}
.chart-legend-list { list-style: none; }
.chart-legend-list li {
  display: flex; align-items: center; gap: 10px;
  color: var(--text2); font-size: 0.9rem;
  padding: 8px 0; border-bottom: 1px solid var(--border);
}
.chart-legend-list li:last-child { border-bottom: none; }
.legend-dot {
  width: 14px; height: 14px;
  border-radius: 50%; flex-shrink: 0;
}
.legend-dot.green       { background: #10B981; }
.legend-dot.green-dash  { background: transparent; border: 2px dashed #34D399; border-radius: 0; width: 20px; height: 0; }
.legend-dot.gold-dash   { background: transparent; border: 2px dashed #F59E0B; border-radius: 0; width: 20px; height: 0; }
.legend-dot.gold-dot    { background: #F59E0B; }

.ce-stat-box {
  background: var(--surface2);
  border-radius: 12px;
  padding: 20px;
  display: flex; flex-direction: column; gap: 14px;
}
.ce-stat { display: flex; flex-direction: column; gap: 3px; }
.ce-val {
  font-family: var(--font-head);
  font-weight: 700; font-size: 1rem;
  color: var(--accent);
}
.ce-lbl { font-size: 0.82rem; color: var(--text2); }

/* ---- Responsive ---- */
@media (max-width: 1024px) {
  .howto-grid { grid-template-columns: repeat(2, 1fr); }
  .results-explain-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .howto-grid { grid-template-columns: 1fr; }
  .results-explain-grid { grid-template-columns: 1fr 1fr; }
  .mini-explain-grid { grid-template-columns: 1fr; }
  .chart-explain-box { grid-template-columns: 1fr; gap: 24px; }
}
@media (max-width: 520px) {
  .results-explain-grid { grid-template-columns: 1fr; }
}