:root {
  --bg: #0a0e1a;
  --bg-elev: #11172a;
  --bg-card: rgba(20, 26, 48, 0.7);
  --border: rgba(120, 140, 200, 0.15);
  --border-strong: rgba(120, 140, 200, 0.35);
  --text: #e6ecff;
  --text-dim: #94a0c4;
  --text-muted: #6a7398;
  --accent: #6c8eff;
  --accent-hover: #8aa4ff;
  --green: #4ade80;
  --orange: #fb923c;
  --purple: #c084fc;
  --red: #f87171;
  --warning: #fbbf24;
  --shadow-glow: 0 0 60px rgba(108, 142, 255, 0.15);
}

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

html, body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "ss01", "cv02", "cv11";
  position: relative;
  overflow-x: hidden;
}

.bg-gradient {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(ellipse 80% 60% at 20% 0%, rgba(108, 142, 255, 0.18), transparent 60%),
    radial-gradient(ellipse 70% 60% at 80% 100%, rgba(192, 132, 252, 0.12), transparent 60%),
    radial-gradient(ellipse 60% 40% at 50% 50%, rgba(74, 222, 128, 0.05), transparent 70%),
    var(--bg);
}

.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(120, 140, 200, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120, 140, 200, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse 100% 80% at 50% 30%, black 30%, transparent 90%);
  -webkit-mask-image: radial-gradient(ellipse 100% 80% at 50% 30%, black 30%, transparent 90%);
}

header {
  max-width: 1280px;
  margin: 0 auto;
  padding: 28px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.logo-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--purple));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 8px 24px rgba(108, 142, 255, 0.35);
}

.logo-icon svg {
  width: 26px;
  height: 26px;
}

h1 {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
  background: linear-gradient(90deg, #fff, #b8c5e8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  font-size: 13px;
  color: var(--text-dim);
  margin-top: 2px;
}

.theme-badge {
  font-size: 12px;
  color: var(--green);
  background: rgba(74, 222, 128, 0.1);
  border: 1px solid rgba(74, 222, 128, 0.25);
  padding: 6px 12px;
  border-radius: 20px;
  font-weight: 500;
  letter-spacing: 0.02em;
}

main {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 32px 64px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 28px;
  box-shadow: var(--shadow-glow);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
}

.inputs { grid-column: 1; }
.results { grid-column: 2; }
.chart-card { grid-column: 1 / -1; }
.table-card { grid-column: 1 / -1; }
.formulas-card { grid-column: 1 / -1; }

.section-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 22px;
  flex-wrap: wrap;
}

.section-title h2 {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent);
}
.dot-green { background: var(--green); box-shadow: 0 0 12px var(--green); }
.dot-blue { background: #60a5fa; box-shadow: 0 0 12px #60a5fa; }
.dot-purple { background: var(--purple); box-shadow: 0 0 12px var(--purple); }
.dot-orange { background: var(--orange); box-shadow: 0 0 12px var(--orange); }

.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 14px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all 0.2s;
}

.input-group:hover {
  border-color: var(--border-strong);
  background: rgba(255, 255, 255, 0.03);
}

.input-group.highlight {
  background: linear-gradient(135deg, rgba(108, 142, 255, 0.08), rgba(192, 132, 252, 0.04));
  border-color: rgba(108, 142, 255, 0.3);
}

.input-group label {
  display: flex;
  flex-direction: column;
  font-size: 13px;
  cursor: pointer;
}

.label-text {
  color: var(--text);
  font-weight: 500;
}

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

.input-wrap {
  display: flex;
  align-items: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0 12px;
  transition: all 0.2s;
}

.input-wrap:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(108, 142, 255, 0.15);
}

.input-wrap input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text);
  font-family: 'JetBrains Mono', monospace;
  font-size: 16px;
  font-weight: 500;
  padding: 10px 0;
  width: 100%;
}

.input-wrap input::-webkit-outer-spin-button,
.input-wrap input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.input-wrap input[type=number] {
  -moz-appearance: textfield;
}

.unit {
  color: var(--text-muted);
  font-size: 13px;
  font-family: 'JetBrains Mono', monospace;
  padding-left: 8px;
  border-left: 1px solid var(--border);
  margin-left: 4px;
}

input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent);
  border-radius: 50%;
  border: 2px solid white;
  box-shadow: 0 2px 8px rgba(108, 142, 255, 0.4);
  cursor: pointer;
  transition: all 0.15s;
}

input[type=range]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  background: var(--accent-hover);
}

input[type=range]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background: var(--accent);
  border-radius: 50%;
  border: 2px solid white;
  cursor: pointer;
}

.presets {
  margin-top: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.presets-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-right: 4px;
}

.preset-btn {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 7px 13px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  font-family: inherit;
}

.preset-btn:hover {
  background: rgba(108, 142, 255, 0.15);
  border-color: var(--accent);
  transform: translateY(-1px);
}

.preset-btn:active {
  transform: translateY(0);
}

/* Results */
.result-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.result-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  position: relative;
  overflow: hidden;
}

.result-card.primary {
  background: linear-gradient(135deg, rgba(108, 142, 255, 0.15), rgba(108, 142, 255, 0.05));
  border-color: rgba(108, 142, 255, 0.4);
}

.result-card.warning {
  background: linear-gradient(135deg, rgba(251, 191, 36, 0.12), rgba(251, 146, 60, 0.05));
  border-color: rgba(251, 191, 36, 0.35);
}

.result-card.accent {
  background: linear-gradient(135deg, rgba(74, 222, 128, 0.12), rgba(74, 222, 128, 0.04));
  border-color: rgba(74, 222, 128, 0.3);
}

.result-label {
  font-size: 12px;
  color: var(--text-dim);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}

.result-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 30px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  line-height: 1;
  margin-bottom: 6px;
}

.result-card.warning .result-value { color: var(--warning); }
.result-card.accent .result-value { color: var(--green); }
.result-card.primary .result-value { color: var(--accent-hover); }

.result-unit {
  font-size: 12px;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
}

.formula {
  margin-left: 8px;
  color: var(--text-dim);
}

.small-hint {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
}

.speed-check {
  margin-top: 18px;
  padding: 14px 16px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 12px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.speed-check label {
  font-size: 13px;
  color: var(--text-dim);
  white-space: nowrap;
}

.speed-check input[type=range] {
  flex: 1;
}

.speed-value {
  font-family: 'JetBrains Mono', monospace;
  font-weight: 600;
  color: var(--accent-hover);
  min-width: 80px;
  text-align: right;
  font-size: 14px;
}

/* Chart */
.chart-controls {
  margin-left: auto;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.chk {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-dim);
  cursor: pointer;
  user-select: none;
}

.chk input[type=checkbox] {
  accent-color: var(--accent);
  cursor: pointer;
}

.export-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: linear-gradient(135deg, var(--accent), var(--purple));
  border: 1px solid rgba(255, 255, 255, 0.18);
  color: #fff;
  padding: 7px 14px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: transform 0.12s, box-shadow 0.15s, filter 0.15s;
  box-shadow: 0 4px 14px rgba(108, 142, 255, 0.35);
  letter-spacing: 0.01em;
}

.export-btn:hover {
  transform: translateY(-1px);
  filter: brightness(1.1);
  box-shadow: 0 6px 18px rgba(108, 142, 255, 0.5);
}

.export-btn:active {
  transform: translateY(0);
}

.export-btn:disabled {
  opacity: 0.6;
  cursor: progress;
}

.chart-wrap {
  position: relative;
  height: 420px;
  width: 100%;
}

/* Table */
.table-wrap {
  overflow-x: auto;
  border-radius: 12px;
  border: 1px solid var(--border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

thead {
  background: rgba(255, 255, 255, 0.03);
}

th {
  text-align: left;
  padding: 12px 16px;
  font-weight: 600;
  color: var(--text-dim);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

td {
  padding: 11px 16px;
  border-bottom: 1px solid var(--border);
  font-family: 'JetBrains Mono', monospace;
  color: var(--text);
}

tbody tr:hover {
  background: rgba(108, 142, 255, 0.05);
}

tbody tr:last-child td {
  border-bottom: none;
}

.badge-ok {
  background: rgba(74, 222, 128, 0.15);
  color: var(--green);
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
  font-family: 'Inter', sans-serif;
  display: inline-block;
}

.badge-warn {
  background: rgba(251, 191, 36, 0.15);
  color: var(--warning);
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
  font-family: 'Inter', sans-serif;
  display: inline-block;
}

.badge-bad {
  background: rgba(248, 113, 113, 0.15);
  color: var(--red);
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
  font-family: 'Inter', sans-serif;
  display: inline-block;
}

/* Formulas */
.formulas {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.formula-block {
  padding: 18px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 12px;
}

.formula-name {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
  margin-bottom: 8px;
}

.formula-math {
  font-family: 'JetBrains Mono', monospace;
  font-size: 18px;
  font-weight: 600;
  color: var(--accent-hover);
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.formula-desc {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.5;
}

footer {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px 32px 40px;
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}

.footer-hint {
  color: var(--text-dim);
}

/* Responsive */
@media (max-width: 980px) {
  main {
    grid-template-columns: 1fr;
    padding: 0 20px 48px;
  }
  .inputs, .results { grid-column: 1; }
  header { padding: 20px; }
  .input-grid { grid-template-columns: 1fr; }
  .result-grid { grid-template-columns: 1fr; }
  .chart-wrap { height: 320px; }
  .chart-controls { width: 100%; }
  footer {
    flex-direction: column;
    gap: 8px;
    text-align: center;
    justify-content: center;
  }
}

@media (max-width: 540px) {
  .card { padding: 20px; border-radius: 16px; }
  h1 { font-size: 17px; }
  .result-value { font-size: 24px; }
  .speed-check { flex-wrap: wrap; }
}