/* RC Drift Calculators — shared styles */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:           #0d0d0d;
  --surface:      #1a1a1a;
  --border:       #2e2e2e;
  --accent:       #3a7bd5;
  --accent-h:     #5292e8;
  --amber:        #f8b500;
  --input-bg:     #252525;
  --result-bg:    #0d1a0d;
  --result-border:#1f4a1f;
  --result-text:  #7ec850;
  --text:         #e0e0e0;
  --text-dim:     #777;
  --text-label:   #aaa;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Exo 2', 'Segoe UI', system-ui, sans-serif;
  font-size: 14px;
  min-height: 100vh;
}

/* ── NAV ─────────────────────────────────────── */
nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  height: 48px;
  gap: 10px;
}

.nav-logo {
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 1px;
  color: var(--text);
  white-space: nowrap;
  text-decoration: none;
  cursor: pointer;
}
.nav-logo:hover { color: var(--text); opacity: .8; }
.nav-logo span { color: var(--accent); }

.nav-calcs { display: flex; gap: 5px; }

.nav-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-family: inherit;
  font-size: 12px;
  font-weight: 600;
  padding: 5px 13px;
  border-radius: 5px;
  cursor: pointer;
  letter-spacing: 0.4px;
  transition: border-color .15s, color .15s;
  white-space: nowrap;
}
.nav-btn:hover { border-color: var(--accent); color: var(--text); }
.nav-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  cursor: default;
  font-size: 13px;
}

.nav-lang { display: flex; gap: 5px; }

.lang-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-family: inherit;
  font-size: 11px;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 4px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  transition: border-color .15s, color .15s;
}
.lang-btn svg { width: 18px; height: 12px; border-radius: 2px; display: block; }
.lang-btn:hover { border-color: var(--amber); color: var(--text); }
.lang-btn.active { border-color: var(--amber); color: var(--amber); cursor: default; }

/* ── MAIN ────────────────────────────────────── */
main {
  max-width: 700px;
  margin: 20px auto;
  padding: 0 14px 40px;
}

/* ── CARD ────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 16px;
  margin-bottom: 12px;
}

.card-title {
  font-size: 10px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
  font-weight: 600;
}
.card-title.green { color: #5cac30; }

/* ── INPUT GRID ──────────────────────────────── */
.input-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px 14px;
}

.field-group { display: flex; flex-direction: column; gap: 5px; }

.field-label {
  font-size: 10px;
  color: var(--text-dim);
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.field-row {
  display: flex;
  align-items: center;
  gap: 5px;
}

.sub-label {
  font-size: 10px;
  color: var(--text-dim);
  width: 30px;
  text-align: right;
  flex-shrink: 0;
}

.unit { font-size: 11px; color: var(--text-dim); }

/* ── INPUTS ──────────────────────────────────── */
input[type=number], input[type=text] {
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  padding: 6px 8px;
  width: 64px;
  text-align: center;
  transition: border-color .15s;
  -moz-appearance: textfield;
}
input[type=number]::-webkit-outer-spin-button,
input[type=number]::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
input:focus { outline: none; border-color: var(--accent); }

input.wide { width: 110px; }

/* ── DIVIDER ─────────────────────────────────── */
.divider { height: 1px; background: var(--border); margin: 14px 0; }

/* ── MOTOR ROW ───────────────────────────────── */
.motor-row {
  display: flex;
  align-items: flex-end;
  gap: 16px;
  flex-wrap: wrap;
}

.radio-group { display: flex; gap: 12px; }

.radio-opt {
  display: flex;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  font-size: 12px;
  color: var(--text-label);
}
.radio-opt input[type=radio] { accent-color: var(--accent); width: 14px; height: 14px; }

/* ── BUTTONS ─────────────────────────────────── */
.btn-row { display: flex; gap: 7px; flex-wrap: wrap; }

.btn {
  font-family: inherit;
  font-size: 12px;
  font-weight: 600;
  padding: 7px 18px;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  letter-spacing: 0.4px;
  transition: background .15s, border-color .15s;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-h); }
.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
}
.btn-secondary:hover { border-color: var(--text-dim); color: var(--text); }

/* ── RESULTS CARD ────────────────────────────── */
.results-card {
  background: #111a11;
  border: 1px solid var(--result-border);
  border-radius: 10px;
  padding: 18px 16px;
  margin-bottom: 12px;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px 14px;
}

.result-item { display: flex; flex-direction: column; gap: 4px; }

.result-label {
  font-size: 10px;
  color: #4a7a4a;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* result inputs styled as outputs but still editable */
.results-card input[type=number],
.results-card input[type=text] {
  background: var(--result-bg);
  border: 1px solid var(--result-border);
  color: var(--result-text);
  width: 100%;
  font-size: 14px;
}
.results-card input:focus {
  border-color: var(--accent);
  color: var(--text);
}

.result-amber input[type=number],
.result-amber input[type=text] { color: var(--amber); }

/* speed section — spans full results-grid width, 2-column inside */
.results-speed-section {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px 14px;
}

/* speed pair */
.speed-pair { display: flex; flex-direction: column; gap: 4px; }
.speed-row { display: flex; align-items: center; gap: 5px; }
.speed-tag {
  font-size: 9px;
  text-transform: uppercase;
  color: #4a7a4a;
  width: 24px;
  flex-shrink: 0;
  letter-spacing: 0.5px;
}

/* ── RESULTS SEPARATOR ───────────────────────── */
.results-sep {
  grid-column: span 3;
  height: 1px;
  background: #1a3a1a;
}

/* ── FOOTER ──────────────────────────────────── */
.calc-footer {
  margin-top: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}
.calc-footer a { color: var(--accent); font-size: 12px; text-decoration: none; cursor: pointer; }
.calc-footer a:hover { text-decoration: underline; }
.calc-footer .copy { font-size: 11px; color: var(--text-dim); }

/* ── INPUT ERROR HIGHLIGHT ───────────────────── */
.input-error {
  border-color: #f8b500 !important;
  animation: input-pulse .35s ease 3;
}
@keyframes input-pulse {
  0%, 100% { box-shadow: none; }
  50%       { box-shadow: 0 0 7px rgba(248,181,0,.55); }
}
#calc-msg {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: #1a1300;
  border: 1px solid #f8b500;
  color: #f8b500;
  padding: 8px 18px;
  border-radius: 7px;
  font-size: 13px;
  white-space: nowrap;
  z-index: 9999;
  pointer-events: none;
  opacity: 0;
  transition: opacity .2s;
}
#calc-msg.visible { opacity: 1; }

/* ── START VALIDATION ────────────────────────── */
.section-error .tile-row {
  animation: pulse-border .4s ease 2;
}
@keyframes pulse-border {
  0%, 100% { outline: 2px solid transparent; border-radius: 9px; }
  50%       { outline: 2px solid #f8b500;    border-radius: 9px; }
}
#start-msg {
  font-size: 12px;
  color: #f8b500;
  min-height: 18px;
  text-align: center;
}

/* ── START PAGE ──────────────────────────────── */
.start-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: 28px;
  padding: 32px 16px;
}

.start-logo { text-align: center; }
.start-logo .logo-icon { font-size: 36px; line-height: 1; margin-bottom: 8px; }
.start-logo h1 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--text);
}
.start-logo h1 span { color: var(--accent); }
.start-logo .by { font-size: 11px; color: var(--text-dim); letter-spacing: 3px; margin-top: 4px; }

.start-section { width: 100%; max-width: 400px; }
.start-section h3 {
  font-size: 10px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 8px;
  text-align: center;
}

.tile-row { display: flex; gap: 8px; }

.tile {
  flex: 1;
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: 9px;
  padding: 14px 10px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
  user-select: none;
}
.tile:hover { border-color: var(--amber); }
.tile.sel-lang { border-color: var(--amber); background: #1a1700; }
.tile.sel-calc { border-color: var(--accent); background: #0d1425; }

.tile-flag { font-size: 26px; line-height: 1; margin-bottom: 5px; }
.tile-name { font-size: 13px; font-weight: 700; color: var(--text); }
.tile-desc { font-size: 10px; color: var(--text-dim); margin-top: 3px; line-height: 1.4; }

.start-run {
  width: 100%;
  max-width: 400px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 1px;
  padding: 13px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 9px;
  cursor: pointer;
  transition: background .15s;
}
.start-run:hover { background: var(--accent-h); }

/* ── RWD NOTE ────────────────────────────────── */
.rwd-note {
  font-size: 11px;
  color: var(--text-dim);
  text-align: center;
  margin-bottom: 12px;
  line-height: 1.5;
}
.rwd-note a { color: var(--accent); text-decoration: none; cursor: pointer; }
.rwd-note a:hover { text-decoration: underline; }

/* ── LIGHTBOX ────────────────────────────────── */
.lightbox {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.82);
  z-index: 1000;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.lightbox.open { display: flex; }
.lightbox-inner {
  position: relative;
  max-width: 100%;
  max-height: 100%;
}
.lightbox-inner img {
  display: block;
  max-width: min(860px, 90vw);
  max-height: 80vh;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 8px 40px rgba(0,0,0,.7);
}
.lightbox-close {
  position: absolute;
  top: -14px;
  right: -14px;
  width: 28px;
  height: 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 50%;
  color: var(--text-dim);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color .15s, color .15s;
}
.lightbox-close:hover { border-color: var(--text-dim); color: var(--text); }

/* iframe variant */
.lightbox-frame-inner {
  width: min(720px, 92vw);
  height: min(380px, 80vh);
  position: relative;
}
.lightbox-iframe {
  width: 100%;
  height: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  display: block;
}

/* ── RESPONSIVE — mobile ─────────────────────── */
@media (max-width: 600px) {
  .calc-wrap   { padding: 8px; }
  .card        { padding: 14px 10px; }
  .input-grid  { grid-template-columns: repeat(2, 1fr); }
  .results-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-logo    { font-size: 13px; }
  .nav-links   { gap: 4px; }
  .nav-btn     { font-size: 11px; padding: 4px 8px; }
  .lang-btn    { font-size: 11px; padding: 3px 6px; }
  .calc-footer { flex-direction: column; gap: 6px; text-align: center; }
}