/* ================================================================
   BTC Difficulty Forecast — Dark Tech Theme
   Consistent with btcmine.info
   ================================================================ */

:root {
  --bg-primary: #080808;
  --bg-secondary: #0f0f0f;
  --bg-card: #111111;
  --bg-card-hover: #171717;
  --bg-elevated: #1a1a1a;
  --bg-input: #141414;

  --border-subtle: #1e1e1e;
  --border-default: #242424;
  --border-strong: #333333;

  --text-primary: #f0f0f0;
  --text-secondary: #a0a0a0;
  --text-muted: #606060;
  --text-disabled: #3a3a3a;

  --accent-blue: #3b82f6;
  --accent-blue-dim: rgba(59, 130, 246, 0.12);
  --accent-cyan: #06b6d4;

  --green: #10b981;
  --green-dim: rgba(16, 185, 129, 0.12);
  --red: #ef4444;
  --red-dim: rgba(239, 68, 68, 0.12);
  --orange: #f59e0b;
  --orange-dim: rgba(245, 158, 11, 0.12);
  --purple: #8b5cf6;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.5);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
}

/* ── LIGHT THEME ───────────────────────────────────────── */
[data-theme="light"] {
  --bg-primary: #f5f5f7;
  --bg-secondary: #eeeef0;
  --bg-card: #ffffff;
  --bg-card-hover: #f9f9fb;
  --bg-elevated: #f0f0f2;
  --bg-input: #f5f5f7;
  --border-subtle: #e2e2e5;
  --border-default: #d4d4d8;
  --border-strong: #b0b0b8;
  --text-primary: #18181b;
  --text-secondary: #52525b;
  --text-muted: #93939e;
  --text-disabled: #c8c8ce;
  --accent-blue: #2563eb;
  --accent-blue-dim: rgba(37, 99, 235, 0.10);
  --accent-cyan: #0891b2;
  --green: #059669;
  --green-dim: rgba(5, 150, 105, 0.10);
  --red: #dc2626;
  --red-dim: rgba(220, 38, 38, 0.10);
  --orange: #d97706;
  --orange-dim: rgba(217, 119, 6, 0.10);
  --purple: #7c3aed;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.10);
}
[data-theme="light"] #header { background: rgba(245,245,247,0.92); }
[data-theme="light"] .stat-card { border-color: var(--border-default); }
[data-theme="light"] ::-webkit-scrollbar-track { background: var(--bg-secondary); }
[data-theme="light"] ::-webkit-scrollbar-thumb { background: var(--border-strong); }

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 13px;
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #555; }

/* ── HEADER ────────────────────────────────────────────── */
#header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(8,8,8,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 24px;
  height: 56px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}
.logo-text {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.3px;
}
.logo-badge {
  font-size: 9px;
  font-weight: 600;
  color: var(--orange);
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.header-nav {
  display: flex;
  gap: 4px;
  flex: 1;
  overflow-x: auto;
}
.nav-tab {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s;
}
.nav-tab:hover { color: var(--text-secondary); background: var(--bg-elevated); }
.nav-tab.active {
  color: var(--text-primary);
  background: var(--bg-card);
  border: 1px solid var(--border-default);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.btc-ticker {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
}
.btc-price { color: var(--text-primary); }
.btc-change-pos { color: var(--green); font-size: 11px; }
.btc-change-neg { color: var(--red); font-size: 11px; }

.toggle-group { display: flex; gap: 4px; }
.toggle-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  font-size: 11px;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s;
}
.toggle-btn:hover { background: var(--bg-card-hover); color: var(--text-primary); }

.data-badge {
  font-size: 9px;
  font-weight: 700;
  color: var(--green);
  background: var(--green-dim);
  padding: 2px 8px;
  border-radius: 10px;
  letter-spacing: 0.5px;
}

/* ── MAIN LAYOUT ──────────────────────────────────────── */
#app {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px 24px 60px;
}

.page { display: none; }
.page.active { display: block; }

/* ── SECTION ──────────────────────────────────────────── */
.section-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.section-title .icon { font-size: 16px; }
.section-subtitle {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 20px;
}

/* ── STAT CARDS ───────────────────────────────────────── */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 16px;
  transition: all 0.2s;
}
.stat-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-default);
}
.stat-label {
  font-size: 11px;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}
.stat-value {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}
.stat-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 4px;
}
.stat-change {
  font-family: var(--font-mono);
  font-size: 11px;
  margin-top: 4px;
}
.stat-change.up { color: var(--green); }
.stat-change.down { color: var(--red); }

/* ── CHART CONTAINER ──────────────────────────────────── */
.chart-container {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 24px;
}
.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}
.chart-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}
.chart-legend {
  display: flex;
  gap: 16px;
}
.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  color: var(--text-secondary);
}
.legend-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}
.chart-wrap {
  position: relative;
  height: 350px;
}
.chart-wrap canvas {
  width: 100% !important;
  height: 100% !important;
}

/* ── CONTROLS / PARAMETER PANEL ───────────────────────── */
.controls-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 24px;
}
.controls-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}
.controls-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}
.control-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.control-label {
  font-size: 11px;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.3px;
}
.control-input {
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--bg-input);
  border: 1px solid var(--border-default);
  color: var(--text-primary);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.15s;
}
.control-input:focus {
  border-color: var(--accent-blue);
}
.control-input::placeholder { color: var(--text-disabled); }

select.control-input {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%23a0a0a0'%3E%3Cpath d='M2 4l4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 30px;
}

.control-range {
  -webkit-appearance: none;
  width: 100%;
  height: 4px;
  border-radius: 2px;
  background: var(--border-default);
  outline: none;
}
.control-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent-blue);
  cursor: pointer;
}

.btn-run {
  background: var(--accent-blue);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  border: none;
  padding: 10px 24px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s;
  margin-top: 8px;
}
.btn-run:hover { background: #2563eb; }

/* ── TABLE ────────────────────────────────────────────── */
.table-container {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 24px;
}
.table-header {
  padding: 16px 20px 12px;
  border-bottom: 1px solid var(--border-subtle);
}
.table-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}
.table-scroll {
  overflow-x: auto;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
}
th {
  text-align: left;
  padding: 10px 16px;
  font-size: 10px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 1px solid var(--border-subtle);
  white-space: nowrap;
  position: sticky;
  top: 0;
  background: var(--bg-card);
}
td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 12px;
  white-space: nowrap;
}
tr:hover td { background: var(--bg-card-hover); }
.td-green { color: var(--green); }
.td-red { color: var(--red); }

/* ── METHODOLOGY SECTION ──────────────────────────────── */
.method-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 24px;
}
.method-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
}
.method-text {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 8px;
}
.method-formula {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent-cyan);
  background: var(--bg-secondary);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  margin: 10px 0;
  overflow-x: auto;
}
.method-tag {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 10px;
  margin-right: 6px;
  margin-bottom: 4px;
}
.tag-input { background: var(--accent-blue-dim); color: var(--accent-blue); }
.tag-output { background: var(--green-dim); color: var(--green); }
.tag-param { background: var(--orange-dim); color: var(--orange); }

/* ── SCENARIO TABS ────────────────────────────────────── */
.scenario-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
}
.scenario-tab {
  font-size: 12px;
  font-weight: 500;
  padding: 6px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-default);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
}
.scenario-tab:hover { background: var(--bg-elevated); color: var(--text-primary); }
.scenario-tab.active { background: var(--bg-card); color: var(--text-primary); border-color: var(--accent-blue); }
.scenario-tab.bull.active { border-color: var(--green); color: var(--green); }
.scenario-tab.base.active { border-color: var(--accent-blue); color: var(--accent-blue); }
.scenario-tab.bear.active { border-color: var(--red); color: var(--red); }

/* ── FOOTER ───────────────────────────────────────────── */
.footer {
  text-align: center;
  padding: 32px 0 16px;
  font-size: 11px;
  color: var(--text-muted);
  border-top: 1px solid var(--border-subtle);
  margin-top: 40px;
}
.footer a {
  color: var(--accent-blue);
  text-decoration: none;
}
.footer a:hover { text-decoration: underline; }

/* ── LOADING ──────────────────────────────────────────── */
.loading-overlay {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 0;
  color: var(--text-muted);
  font-size: 13px;
  gap: 10px;
}
.spinner {
  width: 18px;
  height: 18px;
  border: 2px solid var(--border-default);
  border-top-color: var(--accent-blue);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── INTRO ────────────────────────────────────────────── */
.site-intro {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 24px;
}
.site-intro-title {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 8px;
}
.site-intro-text {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ── RESPONSIVE ───────────────────────────────────────── */
@media (max-width: 900px) {
  #header { padding: 0 12px; gap: 12px; }
  .header-nav { display: none; }
  #app { padding: 12px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .controls-grid { grid-template-columns: 1fr; }
  .chart-wrap { height: 250px; }
}
@media (max-width: 600px) {
  .stats-grid { grid-template-columns: 1fr; }
  .stat-value { font-size: 18px; }
  .btc-ticker { display: none; }
}

/* ── HALVING MARKER ───────────────────────────────────── */
.halving-badge {
  display: inline-block;
  font-size: 9px;
  font-weight: 700;
  color: var(--orange);
  background: var(--orange-dim);
  padding: 1px 6px;
  border-radius: 8px;
  letter-spacing: 0.3px;
}

/* ── SUMMARY CARDS (3-scenario) ───────────────────────── */
.scenario-summary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 24px;
}
.scenario-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  border-top: 3px solid var(--border-default);
}
.scenario-card.bull { border-top-color: var(--green); }
.scenario-card.base { border-top-color: var(--accent-blue); }
.scenario-card.bear { border-top-color: var(--red); }
.scenario-card-title {
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 12px;
}
.scenario-card.bull .scenario-card-title { color: var(--green); }
.scenario-card.base .scenario-card-title { color: var(--accent-blue); }
.scenario-card.bear .scenario-card-title { color: var(--red); }
.scenario-metric {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 4px 0;
}
.scenario-metric-label {
  font-size: 11px;
  color: var(--text-muted);
}
.scenario-metric-value {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-primary);
}

@media (max-width: 900px) {
  .scenario-summary { grid-template-columns: 1fr; }
}