/* ============ SimLab — shared simulation-page styles ============ */

.sim-page { padding: 34px 0 60px; }

/* ---- header ---- */
.sim-head {
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 20px; flex-wrap: wrap;
  margin-bottom: 26px;
}
.sim-kicker {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--acc);
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}
.sim-head h1 {
  font-family: var(--font-head);
  font-size: clamp(1.9rem, 4vw, 2.7rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.05;
}
.sim-head h1 em {
  font-style: normal;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.sim-head-right { display: flex; align-items: center; gap: 12px; }

.mode-tabs {
  display: flex;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 4px;
  gap: 4px;
}
.mode-tab {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.86rem;
  color: var(--mut);
  background: transparent;
  border: none;
  border-radius: 9px;
  padding: 8px 20px;
  cursor: pointer;
  transition: color 0.25s, background 0.25s, box-shadow 0.3s, transform 0.15s;
}
.mode-tab:hover { color: var(--txt); background: rgba(255,255,255,0.04); }
.mode-tab:active { transform: scale(0.97); }
.mode-tab.active {
  color: #06121a;
  background: var(--grad);
  box-shadow: 0 4px 20px -4px rgba(110, 168, 254, 0.55), inset 0 1px 0 rgba(255,255,255,0.2);
}

.icon-btn {
  width: 38px; height: 38px;
  display: grid; place-items: center;
  border-radius: 11px;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--mut);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s, background 0.2s, transform 0.15s, box-shadow 0.2s;
}
.icon-btn:hover { color: var(--txt); border-color: var(--line-strong); background: var(--card-hover); box-shadow: 0 4px 12px -2px rgba(0,0,0,0.3); }
.icon-btn:active { transform: scale(0.93); }

/* ---- layout ---- */
.sim-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 350px;
  gap: 20px;
  align-items: start;
}
.card {
  background: linear-gradient(160deg, rgba(255,255,255,0.045), rgba(255,255,255,0.02));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 4px 24px -4px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.04);
}

/* ---- stage ---- */
.stage { padding: 16px 18px 18px; overflow: hidden; position: relative; }
.stage-top {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px; flex-wrap: wrap;
  margin-bottom: 6px;
}
.tip-chip {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.78rem;
  color: var(--mut);
  background: rgba(103, 232, 249, 0.06);
  border: 1px solid rgba(103, 232, 249, 0.18);
  border-radius: 999px;
  padding: 6px 14px;
}
.tip-chip svg { color: var(--acc); flex-shrink: 0; }
.stage-actions { display: flex; gap: 8px; }
.chip-btn {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-body);
  font-size: 0.76rem; font-weight: 600;
  color: var(--mut);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 13px;
  cursor: pointer;
  transition: all 0.2s;
}
.chip-btn:hover { color: var(--txt); border-color: var(--line-strong); }
.chip-btn.active {
  color: var(--acc);
  border-color: rgba(103, 232, 249, 0.45);
  background: rgba(103, 232, 249, 0.08);
}

.svg-wrap {
  margin: 4px -6px 0;
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  background: radial-gradient(ellipse 70% 60% at 50% 45%, rgba(103,232,249,0.03), transparent);
}
.svg-wrap::before {
  content: "";
  position: absolute; inset: 0;
  border: 1px solid rgba(255,255,255,0.04);
  border-radius: 12px;
  pointer-events: none;
  z-index: 1;
}
.svg-wrap svg { display: block; width: 100%; height: auto; position: relative; }

body[data-mode="explore"] .drag-hit { cursor: grab; }
body[data-mode="explore"] .drag-hit:active { cursor: grabbing; }

/* shared svg highlight */
line.hl { stroke: #e11d48 !important; stroke-width: 2.8 !important; }
.obj-label {
  font-family: var(--font-mono); font-size: 24px; font-weight: 700;
  fill: rgba(46, 22, 6, 0.55); text-anchor: middle;
}
.brand-engraving {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em;
  fill: #5b6982; text-anchor: middle;
}

/* ---- stage bottom: magnifier + controls ---- */
.stage-bottom {
  display: flex; gap: 16px; align-items: stretch;
  margin-top: 10px;
  flex-wrap: wrap;
}
.mag-box {
  position: relative;
  flex: 0 0 360px;
  border: 1px solid rgba(103, 232, 249, 0.25);
  border-radius: 14px;
  background: #e9edf4;
  overflow: hidden;
  box-shadow: inset 0 0 0 1px rgba(0,0,0,0.2), 0 10px 30px -12px rgba(0,0,0,0.5);
}
.mag-box.off { display: none; }
.mag-label {
  position: absolute; top: 8px; left: 10px;
  z-index: 2;
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.62rem; font-weight: 700; letter-spacing: 0.08em;
  color: #0e7490;
  background: rgba(255, 255, 255, 0.75);
  border-radius: 999px;
  padding: 3px 10px;
}
#magSvg { display: block; width: 100%; aspect-ratio: 190 / 104; }

.stage-controls { flex: 1; min-width: 260px; display: flex; flex-direction: column; justify-content: center; }
.ctrl-group { display: flex; flex-direction: column; gap: 10px; }
.ctrl-label {
  font-family: var(--font-mono);
  font-size: 0.68rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.12em;
  color: var(--mut);
}
.ctrl-label .mono { color: var(--acc); margin-left: 8px; text-transform: none; font-size: 0.78rem; }
.nudge-row { display: flex; gap: 8px; flex-wrap: wrap; }
.nudge { min-width: 42px; font-size: 1rem; font-family: var(--font-mono); }
.ze-label { margin-top: 6px; }

input[type="range"] {
  -webkit-appearance: none; appearance: none;
  width: 100%; max-width: 320px; height: 6px;
  border-radius: 6px;
  background: linear-gradient(90deg, rgba(251,113,133,0.5) 0%, rgba(42,52,80,0.6) 40%, rgba(103,232,249,0.5) 100%);
  outline: none;
  cursor: pointer;
  border: 1px solid rgba(255,255,255,0.06);
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 20px; height: 20px; border-radius: 50%;
  background: linear-gradient(135deg, #f0f4fc, #c8d0e0);
  border: 2px solid rgba(103,232,249,0.7);
  box-shadow: 0 2px 10px rgba(0,0,0,0.4), 0 0 12px rgba(103,232,249,0.2);
  transition: transform 0.15s, box-shadow 0.15s;
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.18); box-shadow: 0 2px 14px rgba(0,0,0,0.4), 0 0 18px rgba(103,232,249,0.35); }
input[type="range"]::-moz-range-thumb {
  width: 18px; height: 18px; border-radius: 50%;
  background: linear-gradient(135deg, #f0f4fc, #c8d0e0);
  border: 2px solid rgba(103,232,249,0.7);
  box-shadow: 0 2px 10px rgba(0,0,0,0.4);
}

.phase-tabs { display: flex; gap: 8px; flex-wrap: wrap; }
.phase-tab {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-body);
  font-size: 0.84rem; font-weight: 600;
  color: var(--mut);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 11px;
  padding: 10px 18px;
  cursor: pointer;
  transition: all 0.2s;
}
.phase-tab:hover { color: var(--txt); border-color: var(--line-strong); }
.phase-tab.active {
  color: var(--acc);
  border-color: rgba(103, 232, 249, 0.45);
  background: rgba(103, 232, 249, 0.08);
}
.phase-note { font-size: 0.76rem; color: var(--mut); }

/* ---- mode visibility ---- */
body[data-mode="explore"] .only-practice { display: none !important; }
body[data-mode="practice"] .only-explore { display: none !important; }

/* ---- side panels ---- */
.side { display: flex; flex-direction: column; gap: 18px; }
.panel { padding: 20px 22px; }
.panel-title {
  font-family: var(--font-head);
  font-size: 1.02rem; font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  display: flex; align-items: baseline; justify-content: space-between;
}
.q-num { font-size: 0.72rem; color: var(--mut); font-weight: 500; }
.mono { font-family: var(--font-mono); }

/* readout rows */
.ro-row {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 12px;
  padding: 9px 2px;
  border-bottom: 1px dashed var(--line);
  font-size: 0.84rem;
  color: var(--mut);
}
.ro-row b { color: var(--txt); font-weight: 700; font-size: 0.95rem; }
.ro-total { border-bottom: none; padding-top: 12px; }
.ro-total span { color: var(--txt); font-weight: 600; }
.ro-total b {
  font-size: 1.35rem;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.ro-corr { border-bottom: none; padding-top: 0; }
.ro-corr b { color: var(--ok); font-size: 1.05rem; }
.formula {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--mut);
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 8px 12px;
  text-align: center;
}
.ze-note { margin-top: 10px; font-size: 0.74rem; color: var(--warn); }

/* practice stats */
.stats-row {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-bottom: 18px;
}
.stat {
  display: flex; flex-direction: column; align-items: center;
  background: linear-gradient(160deg, rgba(255,255,255,0.05), rgba(255,255,255,0.015));
  border: 1px solid var(--line);
  border-radius: 11px;
  padding: 10px 4px 8px;
  transition: border-color 0.2s, transform 0.15s;
}
.stat:hover { border-color: var(--line-strong); transform: translateY(-1px); }
.stat b { font-size: 1.1rem; color: var(--txt); }
.stat span {
  font-size: 0.58rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.1em;
  color: var(--mut);
  margin-top: 1px;
}
.stat b.fire { color: #fbbf24; text-shadow: 0 0 12px rgba(251,191,36,0.5); }

.q-text { font-size: 0.86rem; color: var(--mut); margin-bottom: 16px; }

.ans-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.66rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.12em;
  color: var(--mut);
  margin-bottom: 7px;
}
.ans-row { display: flex; gap: 10px; }
.ans-field {
  position: relative; flex: 1;
}
.ans-field input {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 1.15rem; font-weight: 700;
  color: var(--txt);
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  padding: 11px 52px 11px 16px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  box-sizing: border-box;
}
.ans-field input:focus {
  border-color: rgba(103, 232, 249, 0.55);
  box-shadow: 0 0 0 3px rgba(103, 232, 249, 0.12);
}
.ans-field input::-webkit-outer-spin-button,
.ans-field input::-webkit-inner-spin-button { -webkit-appearance: none; }
.ans-field input[type="number"] { -moz-appearance: textfield; appearance: textfield; }
.ans-field input:disabled { opacity: 0.55; }
.ans-unit {
  position: absolute; right: 14px; top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 0.8rem; color: var(--mut);
  pointer-events: none;
}
.ans-field.shake { animation: shake 0.4s; }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

.feedback {
  margin-top: 12px;
  font-size: 0.84rem; font-weight: 600;
  border-radius: 11px;
  padding: 11px 14px;
  animation: pop 0.3s cubic-bezier(.22,.68,0,1.2);
}
@keyframes pop { from { opacity: 0; transform: scale(0.92) translateY(4px); } }
.feedback.ok   { color: var(--ok);   background: rgba(52, 211, 153, 0.1);  border: 1px solid rgba(52, 211, 153, 0.3); box-shadow: 0 4px 16px -4px rgba(52,211,153,0.15); }
.feedback.err  { color: var(--err);  background: rgba(251, 113, 133, 0.08); border: 1px solid rgba(251, 113, 133, 0.28); box-shadow: 0 4px 16px -4px rgba(251,113,133,0.1); }
.feedback.warn { color: var(--warn); background: rgba(251, 191, 36, 0.08);  border: 1px solid rgba(251, 191, 36, 0.28); box-shadow: 0 4px 16px -4px rgba(251,191,36,0.1); }

.panel-actions { display: flex; gap: 10px; margin-top: 14px; }

.solution {
  margin-top: 16px;
  font-size: 0.82rem;
  color: var(--mut);
  background: linear-gradient(135deg, rgba(167,139,250,0.06), rgba(255,255,255,0.02));
  border: 1px solid rgba(167,139,250,0.15);
  border-left: 3px solid var(--acc-2);
  border-radius: 11px;
  padding: 14px 16px;
  animation: pop 0.3s cubic-bezier(.22,.68,0,1.2);
  box-shadow: 0 4px 16px -4px rgba(167,139,250,0.08);
}
.solution ol { padding-left: 18px; display: flex; flex-direction: column; gap: 7px; }
.solution b { color: var(--txt); font-family: var(--font-mono); font-weight: 700; }
.solution .sol-final { color: var(--ok); }

/* zero-error toggle */
.ze-toggle {
  display: flex; align-items: center; gap: 11px;
  margin-top: 18px; padding-top: 16px;
  border-top: 1px dashed var(--line);
  cursor: pointer;
  user-select: none;
}
.ze-toggle input { display: none; }
.switch {
  width: 38px; height: 21px;
  border-radius: 999px;
  background: #232c40;
  border: 1px solid var(--line-strong);
  position: relative;
  transition: background 0.25s;
  flex-shrink: 0;
}
.switch::after {
  content: "";
  position: absolute; top: 2px; left: 2px;
  width: 15px; height: 15px;
  border-radius: 50%;
  background: #8b95ab;
  transition: transform 0.25s, background 0.25s;
}
.ze-toggle input:checked + .switch { background: rgba(103, 232, 249, 0.25); border-color: rgba(103,232,249,0.4); }
.ze-toggle input:checked + .switch::after { transform: translateX(17px); background: var(--acc); }
.ze-toggle-txt { font-size: 0.8rem; color: var(--mut); font-weight: 500; }

/* quick reference */
.ref-panel { background: linear-gradient(160deg, rgba(103,232,249,0.03), rgba(255,255,255,0.02)); }
.ref-list { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.ref-list li {
  font-size: 0.78rem; color: var(--mut);
  padding-left: 18px; position: relative;
  line-height: 1.5;
}
.ref-list li::before {
  content: "▸"; position: absolute; left: 0;
  color: var(--acc); font-size: 0.7rem;
}
.ref-list b { color: var(--txt); font-weight: 600; }

/* ---- help dialog ---- */
.help-dlg {
  width: min(620px, calc(100vw - 40px));
  background: linear-gradient(160deg, #111827, #0d1322);
  color: var(--txt);
  border: 1px solid var(--line-strong);
  border-radius: 22px;
  padding: 28px 30px;
  box-shadow: 0 24px 80px -16px rgba(0,0,0,0.7), 0 0 60px -20px rgba(103,232,249,0.1);
  animation: dlg-in 0.3s cubic-bezier(.22,.68,0,1.2);
}
@keyframes dlg-in { from { opacity: 0; transform: scale(0.95) translateY(8px); } }
.help-dlg::backdrop { background: rgba(4, 7, 14, 0.75); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); }
.help-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
.help-head h2 { font-family: var(--font-head); font-size: 1.25rem; font-weight: 600; letter-spacing: -0.01em; }
.help-steps { padding-left: 20px; display: flex; flex-direction: column; gap: 12px; font-size: 0.88rem; color: var(--mut); }
.help-steps b { color: var(--txt); }
.help-tip {
  margin-top: 20px;
  font-size: 0.82rem;
  background: rgba(103, 232, 249, 0.07);
  border: 1px solid rgba(103, 232, 249, 0.2);
  border-radius: 11px;
  padding: 12px 15px;
  color: var(--mut);
}

/* ---- responsive ---- */
@media (max-width: 1020px) {
  .sim-layout { grid-template-columns: 1fr; }
  .mag-box { flex: 1 1 300px; }
}
@media (max-width: 560px) {
  .stage-bottom { flex-direction: column; }
  .mag-box { flex: none; }
  .stats-row { grid-template-columns: repeat(4, 1fr); gap: 6px; }
  .sim-page { padding-top: 22px; }
}