/* ─────────────────────────────────────────────────────────────────────────
   Elliptic Curve Solver — main stylesheet
   ───────────────────────────────────────────────────────────────────────── */

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

:root {
  /* Dark theme (default) */
  --bg:          #0d1117;
  --surface:     #161b22;
  --surface2:    #21262d;
  --border:      #30363d;
  --accent:      #a371f7;
  --accent-glow: rgba(163,113,247,.25);
  --accent2:     #58a6ff;
  --green:       #3fb950;
  --red:         #f85149;
  --amber:       #d29922;
  --text:        #e6edf3;
  --text-dim:    #8b949e;
  --radius:      10px;
  --radius-sm:   6px;
  --shadow:      0 4px 24px rgba(0,0,0,.45);
  --font-mono:   "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

/* ── Light theme ─────────────────────────────────────────────────────────── */
html[data-theme="light"] {
  --bg:          #f6f8fa;
  --surface:     #ffffff;
  --surface2:    #eaeef2;
  --border:      #d0d7de;
  --accent:      #8250df;
  --accent-glow: rgba(130,80,223,.12);
  --accent2:     #0969da;
  --green:       #1a7f37;
  --red:         #cf222e;
  --amber:       #9a6700;
  --text:        #1f2328;
  --text-dim:    #656d76;
  --shadow:      0 4px 24px rgba(0,0,0,.08);
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 14px;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color .25s ease, color .25s ease;
}

/* ── Background wallpaper canvas ─────────────────────────────────────────── */
#bg-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 1;
}
/* Everything on top of the canvas */
body > *:not(#bg-canvas):not(#wp-picker-menu) { position: relative; z-index: 1; }

a { color: var(--accent2); text-decoration: none; }
a:hover { text-decoration: underline; }
code { font-family: var(--font-mono); font-size: .87em;
       background: var(--surface2); border-radius: 3px;
       padding: 1px 5px; }
.dim { color: var(--text-dim); }

/* ── Header ─────────────────────────────────────────────────────────────── */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(8px);
}
.header-inner {
  max-width: 1400px; margin: auto;
  padding: 12px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  flex-wrap: wrap;
}
.logo-group { display: flex; align-items: center; gap: 14px; }
.logo-icon {
  font-size: 2.4rem; line-height: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.site-title { font-size: 1.2rem; font-weight: 700; letter-spacing: -.3px; }
.site-sub    { font-size: .8rem; color: var(--text-dim); margin-top: 1px; }
.site-sub em { color: var(--accent); font-style: normal; }
.header-nav  { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.nav-link    { padding: 6px 12px; border-radius: var(--radius-sm);
               color: var(--text-dim); font-size: .85rem; transition: color .15s, background .15s; }
.nav-link:hover { color: var(--text); background: var(--surface2); text-decoration: none; }
.btn-outline {
  border: 1px solid var(--border) !important;
  color: var(--text) !important;
}
.btn-outline:hover { border-color: var(--accent) !important;
                     background: var(--accent-glow) !important; }

/* ── Theme toggle button ────────────────────────────────────────────────── */
.btn-theme-toggle {
  display: inline-flex; align-items: center; justify-content: center; gap: 5px;
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface2);
  color: var(--text);
  font-size: .82rem; font-weight: 600; line-height: 1;
  cursor: pointer;
  transition: color .15s, background .15s, border-color .15s;
  white-space: nowrap;
}
.btn-theme-toggle:hover {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--accent);
}
.theme-icon { font-size: 1rem; line-height: 1; }

/* ── Wallpaper picker ───────────────────────────────────────────────────── */
.wp-picker-wrap {
  position: relative;
}
.btn-wp-picker {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 30px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface2);
  cursor: pointer;
  font-size: 1rem; line-height: 1;
  transition: background .15s, border-color .15s;
}
.btn-wp-picker:hover,
.btn-wp-picker[aria-expanded="true"] {
  background: var(--accent-glow);
  border-color: var(--accent);
}
#wp-picker-menu {
  display: none;
  position: fixed;
  min-width: 180px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 28px rgba(0,0,0,.35);
  padding: 6px 5px;
  z-index: 9999;
}
#wp-picker-menu.open { display: block; }
.wp-picker-label {
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-dim);
  padding: 3px 9px 6px;
  margin: 0;
}
.wp-opt {
  display: block;
  width: 100%;
  text-align: left;
  padding: 6px 10px;
  border: none;
  background: none;
  color: var(--text);
  font-size: .84rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background .12s, color .12s;
}
.wp-opt:hover { background: var(--surface2); }
.wp-opt.active {
  background: var(--accent-glow);
  color: var(--accent);
  font-weight: 600;
}

/* ── Language selector ──────────────────────────────────────────────────── */
.lang-select {
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface2);
  color: var(--text);
  font-size: .82rem; font-weight: 600;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.lang-select:hover { border-color: var(--accent); background: var(--surface); }
.lang-select:focus { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ── Main grid ───────────────────────────────────────────────────────────── */
.main-grid {
  flex: 1;
  max-width: 1400px; width: 100%; margin: 24px auto; padding: 0 24px;
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 20px;
  align-items: start;
}

/* ── Panels ────────────────────────────────────────────────────────────── */
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}
.panel-title {
  font-size: 1rem; font-weight: 600;
  margin-bottom: 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 8px;
}
.panel-title::before {
  content: ""; display: inline-block;
  width: 3px; height: 1.1em;
  background: var(--accent); border-radius: 2px;
}

/* ── Input form ─────────────────────────────────────────────────────────── */
.param-section { margin-bottom: 18px; }
.param-label {
  display: block; font-size: .82rem; font-weight: 600;
  color: var(--text-dim); margin-bottom: 6px; text-transform: uppercase;
  letter-spacing: .5px;
}
.text-input {
  width: 100%; padding: 9px 12px;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-sm); color: var(--text);
  font-family: var(--font-mono); font-size: .9rem;
  outline: none; transition: border-color .15s, box-shadow .15s;
}
.text-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* ── LaTeX import panel ─────────────────────────────────────────────────── */
.latex-import {
  margin-top: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
}
.latex-import-toggle {
  padding: 7px 12px;
  font-size: .82rem;
  color: var(--text-dim);
  cursor: pointer;
  user-select: none;
  list-style: none;
}
.latex-import-toggle::-webkit-details-marker { display: none; }
.latex-import[open] .latex-import-toggle {
  border-bottom: 1px solid var(--border);
  color: var(--accent2);
}
.latex-import-body {
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.latex-textarea {
  width: 100%;
  padding: 8px 10px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: .82rem;
  resize: vertical;
  outline: none;
  transition: border-color .15s;
  box-sizing: border-box;
}
.latex-textarea:focus { border-color: var(--accent); }
.latex-import-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.latex-convert-status {
  font-size: .82rem;
  color: var(--text-dim);
}
.latex-convert-status.ok    { color: var(--green,  #3fb950); }
.latex-convert-status.error { color: var(--red,    #f85149); }
.num-input {
  width: 100%; padding: 7px 10px;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-sm); color: var(--text); font-size: .9rem;
  outline: none; transition: border-color .15s;
}
.num-input:focus { border-color: var(--accent); }

.preview-box {
  margin-top: 8px; padding: 10px 14px;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-sm); min-height: 42px;
  font-size: 1.1em; text-align: center;
  color: var(--text-dim);
}
.preview-box.error { border-color: var(--red); color: var(--red); }

.hint { font-size: .78rem; color: var(--text-dim); margin-top: 6px; }

.range-group { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; }
.range-field  { display: flex; flex-direction: column; }

/* ── Tooltip ────────────────────────────────────────────────────────────── */
.tooltip-wrap { position: relative; display: inline-block; }
.tooltip-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--border); color: var(--text-dim);
  font-size: .7rem; cursor: default; margin-left: 4px;
}
.tooltip-text {
  display: none; position: absolute; left: 50%; transform: translateX(-50%);
  bottom: calc(100% + 6px); width: 200px;
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 8px 10px;
  font-size: .78rem; color: var(--text); font-weight: 400;
  text-transform: none; letter-spacing: 0; z-index: 50;
  pointer-events: none;
}
.tooltip-wrap:hover .tooltip-text { display: block; }

/* ── Buttons ────────────────────────────────────────────────────────────── */
.btn-row { display: flex; gap: 8px; margin-top: 4px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 9px 16px; border-radius: var(--radius-sm);
  font-size: .85rem; font-weight: 600; cursor: pointer;
  border: none; transition: opacity .15s, transform .1s, box-shadow .15s;
  white-space: nowrap;
}
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .4; cursor: not-allowed; pointer-events: none; }
.btn-primary {
  background: var(--accent); color: #fff;
  box-shadow: 0 2px 10px rgba(163,113,247,.4);
}
.btn-primary:hover { opacity: .88; box-shadow: 0 4px 16px rgba(163,113,247,.55); }
.btn-danger  { background: var(--red); color: #fff; }
.btn-danger:hover  { opacity: .88; }
.btn-ghost   {
  background: transparent; color: var(--text-dim);
  border: 1px solid var(--border);
}
.btn-ghost:hover  { background: var(--surface2); color: var(--text); }
.btn-sm { padding: 5px 10px; font-size: .78rem; }
.btn-icon { font-size: .75em; }

/* ── Progress ───────────────────────────────────────────────────────────── */
.progress-header { margin-bottom: 14px; }
.progress-bar-wrap {
  height: 6px; background: var(--surface2);
  border-radius: 3px; overflow: hidden; margin-bottom: 6px;
}
.progress-bar-fill {
  height: 100%; border-radius: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width .4s ease;
}
.progress-stats { font-size: .8rem; color: var(--text-dim); }

/* ── Status ─────────────────────────────────────────────────────────────── */
.status-idle    { color: var(--text-dim); padding: 8px 0; }
.status-running { color: var(--amber); padding: 8px 0; }
.status-done    { color: var(--green); padding: 8px 0; font-weight: 600; }
.status-error   { color: var(--red);   padding: 8px 0; }

/* ── Results table ───────────────────────────────────────────────────────── */
.table-header-row {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 12px; flex-wrap: wrap; gap: 8px;
}
.table-title { font-size: .95rem; font-weight: 600; }
.table-actions { display: flex; align-items: center; gap: 8px; }
.badge {
  background: var(--accent-glow); border: 1px solid var(--accent);
  color: var(--accent); border-radius: 20px;
  padding: 2px 10px; font-size: .78rem; font-weight: 600;
}
.table-scroll {
  overflow-x: auto; overflow-y: auto;
  max-height: 480px;
  border: 1px solid var(--border); border-radius: var(--radius-sm);
}
table {
  width: 100%; border-collapse: collapse;
  font-size: .85rem;
}
thead th {
  position: sticky; top: 0;
  background: var(--surface2); padding: 10px 14px;
  text-align: left; font-weight: 600; color: var(--text-dim);
  font-size: .78rem; text-transform: uppercase; letter-spacing: .5px;
  border-bottom: 1px solid var(--border);
}
tbody tr { border-bottom: 1px solid var(--border); }
tbody tr:last-child { border-bottom: none; }
tbody tr:hover { background: var(--surface2); }
tbody td { padding: 9px 14px; font-family: var(--font-mono); }
tbody td:first-child { color: var(--text-dim); font-size: .78rem; }
.cell-valid   { color: var(--green); font-size: .8rem; }
.cell-invalid { color: var(--red);   font-size: .8rem; }

/* ── Empty state ─────────────────────────────────────────────────────────── */
.empty-state {
  text-align: center; padding: 48px 24px; color: var(--text-dim);
}
.empty-icon { font-size: 2.5rem; display: block; margin-bottom: 12px; }

/* ── Info / How it works ─────────────────────────────────────────────────── */
.info-section {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 56px 24px;
}
.info-inner { max-width: 1000px; margin: auto; }
.info-inner h2 {
  font-size: 1.4rem; font-weight: 700; margin-bottom: 28px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px; margin-bottom: 36px;
}
.info-card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px;
  transition: border-color .2s, box-shadow .2s;
}
.info-card:hover { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent-glow); }
.info-icon {
  width: 32px; height: 32px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff; font-weight: 700; font-size: .85rem;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 12px;
}
.info-card h3 { font-size: .95rem; margin-bottom: 6px; }
.info-card p  { font-size: .83rem; color: var(--text-dim); }
.math-note {
  background: var(--bg); border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius); padding: 20px 24px;
}
.math-note h3 { font-size: .95rem; margin-bottom: 8px; }
.math-note p  { font-size: .85rem; color: var(--text-dim); line-height: 1.7; }
.math-note em { color: var(--accent); font-style: italic; }

/* ── Examples section ───────────────────────────────────────────────────── */
.examples-section {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 56px 24px;
}
.example-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 14px; margin-top: 4px;
}
.example-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 18px;
  cursor: pointer; transition: border-color .2s, transform .15s, box-shadow .2s;
  display: flex; flex-direction: column; gap: 6px;
  overflow: hidden; position: relative;
}
.example-card:hover {
  border-color: var(--accent); transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(163,113,247,.15);
}
.example-name  { font-weight: 700; font-size: .88rem; }
.example-expr  { font-family: var(--font-mono); font-size: .8rem; color: var(--text-dim); }
.example-math  { font-size: .95em; min-height: 26px; }
.example-desc  { font-size: .78rem; color: var(--text-dim); margin-top: 4px; }
.example-load  {
  font-size: .75rem; color: var(--accent); margin-top: 6px; font-weight: 600;
  display: flex; align-items: center; gap: 4px;
}

/* ── Footer ─────────────────────────────────────────────────────────────── */
.site-footer {
  background: var(--surface); border-top: 1px solid var(--border);
  text-align: center; padding: 20px;
  font-size: .8rem; color: var(--text-dim);
}
.site-footer a { color: var(--accent2); }

/* ── Checkbox filter row ─────────────────────────────────────────────────── */
.checkbox-row {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  margin-top: 4px;
}
.chk-label {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: .85rem;
  color: var(--text-dim);
  cursor: pointer;
  user-select: none;
}
.chk-label input[type="checkbox"] {
  width: 15px;
  height: 15px;
  accent-color: var(--accent);
  cursor: pointer;
}

/* ── Warning banner ─────────────────────────────────────────────────────── */
.warning-banner {
  background: rgba(210,153,34,.12);
  border: 1px solid var(--amber);
  border-left: 3px solid var(--amber);
  color: var(--amber);
  border-radius: var(--radius-sm);
  padding: 9px 14px;
  font-size: .82rem;
  margin-bottom: 12px;
}

/* ── N Summary ───────────────────────────────────────────────────────────── */
#n-summary-section {
  margin: 14px 0;
  padding: 14px 16px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--green);
  border-radius: var(--radius-sm);
}
.n-summary-title {
  font-size: .82rem; font-weight: 600;
  color: var(--text-dim); text-transform: uppercase;
  letter-spacing: .5px; margin-bottom: 8px;
}
.n-summary-title em { color: var(--accent); font-style: normal; }
.n-summary-header { font-size: .83rem; color: var(--text-dim); margin-bottom: 8px; }
.n-summary-count { font-weight: 700; color: var(--green); font-size: .95rem; }
.n-chips-row { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 4px; }
.n-chip {
  background: rgba(63,185,80,.12);
  border: 1px solid rgba(63,185,80,.5);
  color: var(--green); border-radius: 20px;
  padding: 2px 10px;
  font-family: var(--font-mono); font-size: .82rem; font-weight: 600;
}

/* ── Table n-group row ──────────────────────────────────────────────────── */
.n-group-row td {
  background: var(--surface2);
  color: var(--accent); font-weight: 700;
  font-family: var(--font-mono); font-size: .78rem;
  padding: 5px 14px; letter-spacing: .3px;
  border-bottom: 1px solid var(--border);
}

/* ── Auto-scale toggle ───────────────────────────────────────────────────── */
.autoscale-row { margin-bottom: 4px; }
.toggle-label {
  display: inline-flex; align-items: center; gap: 8px;
  cursor: pointer; user-select: none;
}
.toggle-label input[type="checkbox"] { display: none; }
.toggle-track {
  position: relative; display: inline-block;
  width: 34px; height: 18px;
  background: var(--border); border-radius: 9px;
  transition: background .2s; flex-shrink: 0;
}
.toggle-label input:checked + .toggle-track { background: var(--accent); }
.toggle-thumb {
  position: absolute; top: 2px; left: 2px;
  width: 14px; height: 14px; border-radius: 50%;
  background: #fff; transition: left .2s;
}
.toggle-label input:checked + .toggle-track .toggle-thumb { left: 18px; }
.toggle-text { color: var(--text); font-size: .85rem; font-weight: 500; }
#x-scale-wrap {
  margin-top: 10px; padding: 10px 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
}

/* ── Responsive ─────────────────────────────────────────────────────────── */
@media (max-width: 900px) {
  .main-grid { grid-template-columns: 1fr; }
  .range-group { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px) {
  .header-inner { flex-direction: column; align-items: flex-start; }
  .range-group  { grid-template-columns: 1fr; }
  .info-grid    { grid-template-columns: 1fr; }
}

/* ── Hero section ───────────────────────────────────────────────────────── */
.hero {
  position: relative;
  overflow: hidden;
  padding: 96px 24px 80px;
  background: radial-gradient(ellipse 80% 60% at 50% -10%,
    rgba(163,113,247,.18) 0%,
    rgba(88,166,255,.08) 50%,
    transparent 80%),
    var(--bg);
  border-bottom: 1px solid var(--border);
  text-align: center;
}
.hero-bg {
  position: absolute; inset: 0; pointer-events: none; overflow: hidden;
}
.hero-symbol {
  position: absolute;
  font-size: 5rem;
  opacity: .04;
  color: var(--accent);
  user-select: none;
  animation: heroFloat 8s ease-in-out infinite;
}
.hero-symbol.s1 { top: 10%;  left:  5%;  animation-delay: 0s;   font-size: 6rem; }
.hero-symbol.s2 { top: 20%;  left: 85%;  animation-delay: 1.2s; font-size: 4rem; color: var(--accent2); }
.hero-symbol.s3 { top: 60%;  left: 90%;  animation-delay: 2.5s; font-size: 5rem; }
.hero-symbol.s4 { top: 70%;  left:  3%;  animation-delay: 0.8s; font-size: 4.5rem; color: var(--accent2); }
.hero-symbol.s5 { top: 45%;  left: 50%;  animation-delay: 1.8s; font-size: 3.5rem; }
.hero-symbol.s6 { top:  5%;  left: 45%;  animation-delay: 3s;   font-size: 4rem; color: var(--green); }
@keyframes heroFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50%       { transform: translateY(-14px) rotate(4deg); }
}

.hero-inner {
  position: relative; z-index: 1;
  max-width: 780px; margin: 0 auto;
  display: flex; flex-direction: column; align-items: center; gap: 20px;
}
.hero-badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 20px;
  border: 1px solid var(--accent);
  background: var(--accent-glow);
  color: var(--accent);
  font-size: .75rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 1px;
}
.hero-title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.5px;
  color: var(--text);
}
.hero-eq {
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-sub {
  font-size: clamp(.9rem, 2vw, 1.05rem);
  color: var(--text-dim);
  max-width: 600px;
  line-height: 1.75;
}
.hero-actions {
  display: flex; gap: 12px; flex-wrap: wrap; justify-content: center;
  margin-top: 4px;
}
.btn-hero {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff; font-size: .95rem; padding: 12px 28px;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 20px rgba(163,113,247,.4);
  font-weight: 700; letter-spacing: .2px;
  transition: opacity .15s, transform .1s, box-shadow .15s;
  text-decoration: none;
}
.btn-hero:hover {
  opacity: .9; text-decoration: none;
  box-shadow: 0 6px 28px rgba(163,113,247,.6);
  transform: translateY(-1px);
}
.hero-ghost {
  font-size: .95rem; padding: 12px 24px;
  border-radius: var(--radius-sm);
}
.hero-stats {
  display: flex; align-items: center; gap: 0;
  flex-wrap: wrap; justify-content: center;
  margin-top: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 28px;
  gap: 0;
}
.hero-stat {
  display: flex; flex-direction: column; align-items: center;
  padding: 0 24px;
}
.hero-stat strong {
  font-size: 1.2rem; font-weight: 800;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-stat span {
  font-size: .72rem; color: var(--text-dim); text-transform: uppercase;
  letter-spacing: .5px; margin-top: 2px;
}
.hero-stat-sep {
  width: 1px; height: 36px; background: var(--border);
  flex-shrink: 0;
}

/* ── Footer (new) ───────────────────────────────────────────────────────── */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 36px 24px 28px;
}
.footer-inner {
  max-width: 1000px; margin: auto;
  display: flex; flex-direction: column; align-items: center; gap: 16px;
}
.footer-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: .95rem;
}
.footer-brand .logo-icon {
  font-size: 1.6rem;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.footer-links {
  display: flex; gap: 20px; flex-wrap: wrap; justify-content: center;
}
.footer-links a {
  color: var(--text-dim); font-size: .83rem;
  transition: color .15s;
}
.footer-links a:hover { color: var(--text); text-decoration: none; }
.footer-copy {
  font-size: .78rem; color: var(--text-dim); text-align: center;
}
.footer-copy a { color: var(--accent2); }

/* ── Curve info cards ─────────────────────────────────────────────────────── */
.curve-info-row td {
  padding: 0 14px 10px;
  background: transparent;
  border-bottom: none !important;
}
.curve-info-card {
  background: rgba(88, 166, 255, 0.04);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent2);
  border-radius: 7px;
  font-size: .82rem;
  overflow: hidden;
}
.curve-info-card summary.ci-summary {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  cursor: pointer;
  user-select: none;
}
.curve-info-card summary.ci-summary::-webkit-details-marker { display: none; }
.ci-chevron {
  font-size: .68rem;
  color: var(--accent2);
  transition: transform .15s;
  flex-shrink: 0;
}
.curve-info-card[open] .ci-chevron { transform: rotate(90deg); }
.ci-label  { font-weight: 600; color: var(--text); font-size: .82rem; }
.ci-badge  {
  background: rgba(88, 166, 255, .12);
  border: 1px solid rgba(88, 166, 255, .35);
  color: var(--accent2);
  padding: 2px 9px;
  border-radius: 10px;
  font-size: .72rem;
  font-weight: 500;
  margin-left: auto;
  white-space: nowrap;
}
.ci-body {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 0 20px;
  padding: 2px 14px 12px;
  border-top: 1px solid var(--border);
}
.ci-error {
  grid-column: 1 / -1;
  color: #f85149;
  padding: 6px 0 2px;
  font-size: .8rem;
}
.ci-section { padding-top: 10px; }
.ci-sh {
  font-size: .68rem;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--text-dim);
  font-weight: 700;
  margin-bottom: 5px;
}
.ci-kv {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 3px 0;
  border-bottom: 1px solid rgba(48, 54, 61, .5);
}
.ci-kv:last-child { border-bottom: none; }
.ci-key {
  color: var(--text-dim);
  font-size: .78rem;
  flex-shrink: 0;
}
.ci-val {
  color: var(--text);
  font-family: var(--font-mono);
  font-size: .78rem;
  text-align: right;
  word-break: break-all;
}
.ci-val.ci-na {
  color: var(--text-dim);
  font-family: inherit;
  font-size: .75rem;
  font-style: normal;
}
.ci-actions {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  margin-top: 6px;
}
.ci-lmfdb-label { color: var(--text-dim); font-size: .78rem; }
.ci-lmfdb-ainv  {
  background: var(--surface2);
  color: var(--text);
  font-size: .78rem;
  padding: 2px 8px;
  border-radius: 4px;
  border: 1px solid var(--border);
}
.ci-lmfdb-btn {
  display: inline-block;
  padding: 4px 12px;
  border: 1px solid var(--accent2);
  color: var(--accent2);
  border-radius: 4px;
  font-size: .78rem;
  text-decoration: none;
  transition: background .15s, color .15s;
}
.ci-lmfdb-btn:hover { background: var(--accent2); color: var(--bg); }

/* ── Solver mode tabs ─────────────────────────────────────────────────────── */
.solver-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 18px;
  border: 1px solid var(--border);
  border-radius: 7px;
  overflow: hidden;
}
.solver-tab {
  flex: 1;
  padding: 9px 12px;
  background: var(--surface2);
  color: var(--text-dim);
  border: none;
  cursor: pointer;
  font-size: .82rem;
  font-weight: 600;
  font-family: inherit;
  transition: background .15s, color .15s;
}
.solver-tab:not(:last-child) { border-right: 1px solid var(--border); }
.solver-tab:hover { background: var(--surface); color: var(--text); }
.solver-tab.active {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
}

/* ── Variable count sub-tabs ─────────────────────────────────────────────── */
.var-tabs {
  display: flex;
  margin-bottom: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.var-tab {
  flex: 1;
  padding: 7px 10px;
  background: var(--bg);
  color: var(--text-dim);
  border: none;
  cursor: pointer;
  font-size: .75rem;
  font-weight: 500;
  font-family: inherit;
  transition: background .15s, color .15s;
  text-align: center;
  line-height: 1.35;
}
.var-tab:not(:last-child) { border-right: 1px solid var(--border); }
.var-tab:hover { background: var(--surface2); color: var(--text); }
.var-tab.active {
  background: var(--surface2);
  color: var(--accent);
  font-weight: 600;
  border-bottom: 2px solid var(--accent);
}
.var-tab strong { display: block; font-size: .78rem; margin-bottom: 1px; }

/* ── General Diophantine example badge ────────────────────────────────────── */
.example-mode-badge {
  display: inline-block;
  margin-left: 8px;
  padding: 1px 7px;
  background: rgba(88,166,255,.12);
  border: 1px solid rgba(88,166,255,.35);
  color: var(--accent2);
  border-radius: 10px;
  font-size: .68rem;
  font-weight: 600;
  vertical-align: middle;
}

/* ── Hero responsive ────────────────────────────────────────────────────── */
@media (max-width: 600px) {
  .hero { padding: 64px 20px 56px; }
  .hero-stats { padding: 14px 16px; gap: 4px; }
  .hero-stat  { padding: 0 14px; }
  .hero-stat-sep { display: none; }
}

/* ── Export button group ─────────────────────────────────────────────────── */
.export-group {
  display: flex;
  gap: 6px;
}

/* ── Curve Visualization plot ────────────────────────────────────────────── */
#plot-section {
  margin: 16px 0 4px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.plot-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
}
.plot-title { margin: 0; font-size: .87rem; font-weight: 600; }
.plot-n-label {
  font-size: .8rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}
.plot-header .btn { margin-left: auto; }
.plot-toolbar {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 5px 14px;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
}
.plot-toolbar-sep { flex: 1; }
.btn.btn-xs {
  padding: 2px 8px;
  font-size: .75rem;
  line-height: 1.5;
}
.plot-container {
  padding: 12px 14px 10px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}
#curve-canvas {
  display: block;
  max-width: 100%;
  border: 1px solid var(--border);
  border-radius: 4px;
}
.plot-legend {
  display: flex;
  gap: 18px;
  margin-top: 7px;
  font-size: .78rem;
}
.plot-legend-curve  { color: #2563eb; font-weight: 600; }
html[data-theme="dark"] .plot-legend-curve { color: #60a5fa; }
.plot-legend-points { color: #ef4444; font-weight: 600; }
.plot-caption {
  font-size: .73rem;
  color: var(--text-dim);
  margin: 5px 0 0;
}

/* ── Print / PDF styles ──────────────────────────────────────────────────── */
@media print {
  /* Hide everything except the results panel */
  body > *:not(main)                  { display: none !important; }
  main > *:not(.panel-results)        { display: none !important; }
  .panel-results > *:not(#print-header):not(#table-wrap) { display: none !important; }
  #table-wrap   { display: block !important; box-shadow: none; border: none; }
  .table-actions { display: none !important; }

  /* Print header injected by JS */
  #print-header {
    display: block !important;
    margin-bottom: 14px;
  }
  #print-header h2       { font-size: 1.05rem; margin: 0 0 4px; font-family: serif; }
  #print-header .ph-generated { font-size: .78rem; color: #444; margin: 0 0 8px; }
  #print-header .ph-meta      { font-size: .78rem; color: #222; margin-top: 6px;
                                  border-top: 1px solid #bbb; padding-top: 6px; }
  #print-header .ph-meta strong { display: block; margin-bottom: 4px; font-size: .8rem; }
  #print-header .ph-meta ul  { margin: 0 0 0 16px; padding: 0; }
  #print-header .ph-meta li  { margin: 2px 0; line-height: 1.4; }
  #print-header .ph-plot      { margin-top: 10px; border-top: 1px solid #bbb; padding-top: 8px; }
  #print-header .ph-plot strong { display: block; font-size: .8rem; margin-bottom: 4px; }
  #print-header .ph-plot-img  { max-width: 100%; height: auto; page-break-inside: avoid; }

  /* Clean table */
  #results-table { width: 100%; border-collapse: collapse; font-size: .82rem; }
  #results-table th,
  #results-table td { border: 1px solid #bbb; padding: 3px 7px; text-align: left; }
  #results-table thead tr { background: #eee !important; -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  .n-group-row td { background: #f5f5f5 !important; font-weight: 600; -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  .curve-info-row { display: none !important; }

  /* Avoid splitting rows across pages */
  #results-table tr { page-break-inside: avoid; }
  @page { margin: 15mm; size: A4 portrait; }
}

/* ═══════════════════════════════════════════════════════════════════════════
   SEARCH HISTORY DRAWER
   ═══════════════════════════════════════════════════════════════════════════ */

.btn-history {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  background: var(--surface2);
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font: inherit;
  font-size: .85rem;
  cursor: pointer;
  transition: background .15s, color .15s;
  white-space: nowrap;
}
.btn-history:hover { background: var(--surface); color: var(--text); }

.btn-history .history-count-badge {
  background: var(--accent);
  color: #fff;
  border-radius: 10px;
  padding: 1px 6px;
  font-size: .72rem;
  font-weight: 700;
  min-width: 18px;
  text-align: center;
  display: none;
}
.btn-history .history-count-badge.visible { display: inline-block; }

/* Backdrop */
.history-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.45);
  z-index: 400;
  opacity: 0;
  pointer-events: none;
  transition: opacity .22s;
}
.history-backdrop.open { opacity: 1; pointer-events: all; }

/* Drawer */
.history-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: min(400px, 100vw);
  height: 100dvh;
  background: var(--surface);
  border-left: 1px solid var(--border);
  box-shadow: -4px 0 24px rgba(0,0,0,.35);
  z-index: 401;
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform .25s cubic-bezier(.4,0,.2,1);
}
.history-drawer.open { transform: translateX(0); }

/* Drawer header */
.history-drawer-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.history-drawer-title {
  flex: 1;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
}
.history-clear-btn {
  font: inherit;
  font-size: .78rem;
  padding: 4px 10px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-muted);
  cursor: pointer;
  transition: background .15s, color .15s;
}
.history-clear-btn:hover { background: rgba(220,53,53,.12); color: #e06c6c; border-color: #e06c6c; }
.history-close-btn {
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--text-muted);
  cursor: pointer;
  padding: 2px 7px;
  border-radius: 4px;
  transition: background .15s, color .15s;
  line-height: 1;
}
.history-close-btn:hover { background: var(--surface2); color: var(--text); }

/* List container */
.history-list {
  flex: 1;
  overflow-y: auto;
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* Empty state */
.history-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-muted);
  font-size: .9rem;
  text-align: center;
  gap: 10px;
  padding: 30px;
}
.history-empty-icon { font-size: 2.5rem; opacity: .5; }

/* Entry card */
.history-entry {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color .15s;
}
.history-entry:hover { border-color: var(--accent); }
.history-entry-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
}
.history-entry-time { font-size: .72rem; color: var(--text-muted); }
.history-entry-sols {
  font-size: .72rem;
  font-weight: 700;
  background: var(--surface2);
  padding: 2px 8px;
  border-radius: 10px;
  color: var(--accent);
}
.history-entry-expr {
  font-family: monospace;
  font-size: .83rem;
  color: var(--text);
  word-break: break-all;
  white-space: pre-wrap;
}
.history-entry-detail { font-size: .75rem; color: var(--text-muted); }
.history-entry-actions { display: flex; gap: 6px; margin-top: 4px; }
.history-restore-btn {
  flex: 1;
  font: inherit;
  font-size: .78rem;
  padding: 5px 0;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  opacity: .9;
  transition: opacity .15s;
}
.history-restore-btn:hover { opacity: 1; }
.history-delete-btn {
  font: inherit;
  font-size: .78rem;
  padding: 5px 12px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-muted);
  cursor: pointer;
  transition: background .15s, color .15s;
}
.history-delete-btn:hover { background: rgba(220,53,53,.12); color: #e06c6c; border-color: #e06c6c; }

/* ═══════════════════════════════════════════════════════════════════════════
   PREMIUM MICRO-INTERACTIONS
   ═══════════════════════════════════════════════════════════════════════════ */

/* ── Button ripple ──────────────────────────────────────────────────────── */
button { position: relative; overflow: hidden; }
.ripple {
  position: absolute;
  border-radius: 50%;
  transform: scale(0);
  animation: ripple-anim .55s linear;
  background: rgba(255,255,255,0.22);
  pointer-events: none;
}
@keyframes ripple-anim {
  to { transform: scale(4); opacity: 0; }
}

/* ── Table row entrance ─────────────────────────────────────────────────── */
@keyframes rowSlideIn {
  from { opacity: 0; transform: translateX(-10px); }
  to   { opacity: 1; transform: translateX(0); }
}
#results-tbody tr.new-row {
  animation: rowSlideIn .22s ease both;
}

/* ── Solution count badge pop ───────────────────────────────────────────── */
@keyframes badgePop {
  0%   { transform: scale(1); }
  40%  { transform: scale(1.22); }
  70%  { transform: scale(0.95); }
  100% { transform: scale(1); }
}
.badge.pop { animation: badgePop .35s ease both; }

/* ═══════════════════════════════════════════════════════════════════════════
   COPY-TO-CLIPBOARD TOAST
   ═══════════════════════════════════════════════════════════════════════════ */
.copy-toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%) translateY(12px);
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  padding: 10px 22px;
  font-size: .88rem;
  font-weight: 600;
  box-shadow: 0 4px 22px rgba(0,0,0,.35);
  z-index: 600;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s, transform .2s;
  white-space: nowrap;
}
.copy-toast.visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ═══════════════════════════════════════════════════════════════════════════
   HEIGHT BADGE (results table)
   ═══════════════════════════════════════════════════════════════════════════ */
.cell-height {
  color: var(--text-dim);
  font-size: .75rem;
  font-family: var(--font-mono);
}
#th-height {
  font-size: .72rem;
  color: var(--accent2);
  cursor: help;
}

/* ═══════════════════════════════════════════════════════════════════════════
   TORSION & FROBENIUS INLINE PANELS (inside curve-info card)
   ═══════════════════════════════════════════════════════════════════════════ */
.ci-tools-row {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  margin-top: 6px;
}
.ci-tool-btn {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 12px;
  border: 1px solid var(--accent);
  background: var(--accent-glow);
  color: var(--accent);
  border-radius: 4px;
  font-size: .78rem; font-weight: 600;
  cursor: pointer;
  transition: background .15s, color .15s;
}
.ci-tool-btn:hover { background: var(--accent); color: #fff; }
.ci-tool-btn:disabled { opacity: .4; cursor: not-allowed; }

.ci-inline-result {
  grid-column: 1 / -1;
  margin-top: 8px;
  padding: 10px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent2);
  border-radius: 6px;
  font-size: .82rem;
}
.ci-inline-result .ci-inline-title {
  font-weight: 700;
  color: var(--accent2);
  margin-bottom: 6px;
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .4px;
}
.ci-torsion-group {
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 4px;
}
.ci-torsion-points {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 6px;
}
.ci-torsion-pt {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: .78rem;
}
.ci-torsion-pt .torsion-order {
  color: var(--accent2);
  font-size: .7rem;
  margin-left: 4px;
}

/* Frobenius trace table */
.frobenius-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .78rem;
  margin-top: 6px;
}
.frobenius-table th {
  background: var(--surface2);
  padding: 4px 10px;
  text-align: left;
  color: var(--text-dim);
  font-size: .7rem;
  text-transform: uppercase;
  letter-spacing: .4px;
  border-bottom: 1px solid var(--border);
}
.frobenius-table td {
  padding: 4px 10px;
  font-family: var(--font-mono);
  border-bottom: 1px solid rgba(48,54,61,.4);
}
.frobenius-table tr:last-child td { border-bottom: none; }
.frobenius-ap-pos { color: var(--green); }
.frobenius-ap-neg { color: var(--red); }
.frobenius-ap-zero { color: var(--amber); font-weight: 700; }
.frobenius-bad { color: var(--text-dim); font-style: italic; }
.bsd-heuristic {
  margin-top: 8px;
  font-size: .78rem;
  color: var(--text-dim);
}
.bsd-heuristic strong { color: var(--accent2); }

/* ═══════════════════════════════════════════════════════════════════════════
   GROUP LAW CALCULATOR PANEL
   ═══════════════════════════════════════════════════════════════════════════ */
.group-law-section {
  margin: 16px 0 4px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.group-law-header {
  padding: 10px 16px 8px;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
}
.group-law-title {
  margin: 0 0 4px;
  font-size: .9rem;
  font-weight: 700;
  color: var(--accent);
}
.group-law-hint {
  margin: 0;
  font-size: .78rem;
  color: var(--text-dim);
}
.group-law-inputs {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  padding: 12px 16px;
  flex-wrap: wrap;
}
.gl-point-box {
  display: flex;
  flex-direction: column;
  gap: 5px;
  flex: 1;
  min-width: 140px;
}
.gl-op-badge {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent);
  padding-bottom: 4px;
  align-self: flex-end;
  flex-shrink: 0;
}
.gl-result {
  margin: 0 16px 14px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--green);
  border-radius: 5px;
  background: var(--bg);
  font-size: .85rem;
}
.gl-result .gl-result-title {
  font-weight: 700;
  color: var(--green);
  margin-bottom: 4px;
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .4px;
}
.gl-result-point {
  font-family: var(--font-mono);
  font-size: .9rem;
  color: var(--text);
}
.gl-result-infinity {
  font-style: italic;
  color: var(--text-dim);
}
.gl-result-rational {
  font-size: .75rem;
  color: var(--amber);
  margin-top: 4px;
}
.gl-result-integer {
  font-size: .75rem;
  color: var(--green);
  margin-top: 4px;
}
.mode-select {
  width: 100%;
  padding: 7px 10px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: .85rem;
  outline: none;
  cursor: pointer;
  transition: border-color .15s;
}
.mode-select:focus { border-color: var(--accent); }

/* ── Point-type filter toggle (All / ℤ Integer / ℚ Rational) ─────────────── */
.pt-filter-group {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  flex-shrink: 0;
}
.pt-filter-btn {
  background: var(--surface2);
  border: none;
  border-right: 1px solid var(--border);
  color: var(--text-dim);
  cursor: pointer;
  font-size: .78rem;
  font-weight: 500;
  line-height: 1;
  padding: 5px 10px;
  transition: background .15s, color .15s;
  white-space: nowrap;
}
.pt-filter-btn:last-child { border-right: none; }
.pt-filter-btn:hover:not(.active) { background: var(--border); color: var(--text); }
.pt-filter-btn.active { background: var(--accent); color: #fff; }
.pt-filter-compact .pt-filter-btn { font-size: .72rem; padding: 3px 7px; }

/* ── Share & Save buttons ────────────────────────────────────────────────── */
.btn-share { color: var(--accent) !important; }
.btn-save  { color: #3fb950 !important; }



/* ── Gallery section enhancements ───────────────────────────────────────── */
.gallery-section { padding: 48px 0 64px; }
.gallery-categories { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 28px; }
.gallery-cat-btn {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 20px;
  color: var(--text-dim);
  cursor: pointer;
  font-size: .8rem;
  font-weight: 600;
  padding: 5px 14px;
  transition: all .15s;
}
.gallery-cat-btn.active,
.gallery-cat-btn:hover { background: var(--accent); border-color: var(--accent); color: #fff; }

.example-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  overflow: hidden;
  padding: 20px;
  position: relative;
  transition: border-color .2s, transform .15s, box-shadow .2s;
}
.example-card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 20px rgba(163,113,247,.15);
  transform: translateY(-2px);
}
.example-card-header { align-items: flex-start; display: flex; gap: 12px; margin-bottom: 10px; }
.example-card-icon { font-size: 1.6rem; flex-shrink: 0; line-height: 1; margin-top: 2px; }
.example-card-name { font-size: .95rem; font-weight: 700; line-height: 1.3; margin: 0 0 3px; }
.example-card-eq   { color: var(--accent); font-family: monospace; font-size: .78rem; opacity: .9; }
.example-card-desc { color: var(--text-dim); font-size: .8rem; line-height: 1.5; margin: 0 0 12px; }
.example-card-tags { display: flex; flex-wrap: wrap; gap: 5px; }
.example-tag {
  background: var(--surface2);
  border-radius: 10px;
  color: var(--text-dim);
  font-size: .7rem;
  font-weight: 600;
  padding: 2px 8px;
}
.example-card-action {
  background: var(--accent);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  cursor: pointer;
  font-size: .78rem;
  font-weight: 600;
  margin-top: 14px;
  padding: 6px 14px;
  transition: opacity .15s;
}
.example-card-action:hover { opacity: .85; }

/* ═══════════════════════════════════════════════════════════════════════════
   HERO TYPEWRITER
   ═══════════════════════════════════════════════════════════════════════════ */
.hero-eq-cursor {
  display: inline-block;
  margin-left: 2px;
  font-weight: 300;
  color: var(--accent);
  animation: heroBlink 1s steps(2, start) infinite;
}
@keyframes heroBlink { to { visibility: hidden; } }

/* ═══════════════════════════════════════════════════════════════════════════
   RANDOM CURVE BUTTON  (🎲)
   ═══════════════════════════════════════════════════════════════════════════ */
.btn-random {
  font-size: 1.25em;
  padding: 8px 12px;
  transition: transform .25s cubic-bezier(.68,-.55,.27,1.55);
}
.btn-random:hover  { transform: rotate(-15deg) scale(1.15); }
.btn-random:active { transform: rotate(180deg) scale(.95); }

/* ═══════════════════════════════════════════════════════════════════════════
   MATH FACT CARD
   ═══════════════════════════════════════════════════════════════════════════ */
.math-fact-card {
  margin: 22px auto 0;
  max-width: 520px;
  padding: 14px 18px;
  border: 1px solid rgba(120, 180, 255, .25);
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(120,180,255,.06), rgba(180,120,255,.05));
  text-align: left;
  animation: factPulse 3.5s ease-in-out infinite;
}
@keyframes factPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(120, 180, 255, .15); }
  50%      { box-shadow: 0 0 0 8px rgba(120, 180, 255, 0); }
}
.math-fact-label {
  font-size: .78em;
  font-weight: 600;
  letter-spacing: .04em;
  opacity: .75;
  margin-bottom: 6px;
}
.math-fact-text {
  font-size: .95em;
  line-height: 1.55;
  transition: opacity .35s;
}
.math-fact-text.fade { opacity: 0; }

/* ═══════════════════════════════════════════════════════════════════════════
   ACHIEVEMENTS
   ═══════════════════════════════════════════════════════════════════════════ */
.btn-achievements {
  position: relative;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 7px 11px;
  font-size: 1.1em;
  cursor: pointer;
  transition: transform .2s, border-color .2s, background .2s;
  color: var(--text);
}
.btn-achievements:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
  background: rgba(120, 180, 255, .08);
}
.ach-count-badge {
  position: absolute;
  top: -6px;
  right: -6px;
  min-width: 18px;
  height: 18px;
  padding: 0 5px;
  border-radius: 9px;
  background: linear-gradient(135deg, #ffb84d, #ff8c00);
  color: #fff;
  font-size: .7em;
  font-weight: 700;
  line-height: 18px;
  text-align: center;
  display: none;
  box-shadow: 0 2px 6px rgba(255,140,0,.4);
}
.ach-count-badge.visible { display: inline-block; }

.ach-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .55);
  backdrop-filter: blur(3px);
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s;
}
.ach-backdrop.open { opacity: 1; pointer-events: auto; }

.ach-modal {
  position: fixed;
  top: 50%;
  left: 50%;
  width: min(640px, 92vw);
  max-height: 80vh;
  transform: translate(-50%, -50%) scale(.92);
  background: var(--panel-bg, #1a1f2e);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 20px 60px rgba(0,0,0,.5);
  z-index: 1000;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s, transform .25s;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.ach-modal.open {
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, -50%) scale(1);
}
.ach-modal-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(135deg, rgba(255,184,77,.08), rgba(255,140,0,.04));
}
.ach-modal-title {
  font-size: 1.15em;
  font-weight: 700;
  flex: 1;
}
.ach-modal-progress {
  font-size: .85em;
  opacity: .75;
  font-variant-numeric: tabular-nums;
}
.ach-close-btn {
  background: transparent;
  border: 0;
  color: var(--text);
  font-size: 1.2em;
  cursor: pointer;
  opacity: .7;
  padding: 4px 8px;
  border-radius: 6px;
}
.ach-close-btn:hover { opacity: 1; background: rgba(255,255,255,.05); }
.ach-modal-body {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
  padding: 18px;
  overflow-y: auto;
}
.ach-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  text-align: center;
  background: rgba(255,255,255,.02);
  transition: transform .2s, border-color .2s, background .2s;
  position: relative;
}
.ach-card.unlocked {
  border-color: rgba(255,184,77,.5);
  background: linear-gradient(135deg, rgba(255,184,77,.08), rgba(255,140,0,.04));
}
.ach-card.unlocked:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(255,140,0,.18);
}
.ach-card.locked .ach-card-icon { filter: grayscale(1); opacity: .35; }
.ach-card.locked .ach-card-name { opacity: .55; }
.ach-card-icon {
  font-size: 2em;
  display: block;
  margin-bottom: 6px;
}
.ach-card-name {
  font-weight: 600;
  font-size: .92em;
  margin-bottom: 4px;
}
.ach-card-desc {
  font-size: .78em;
  opacity: .7;
  line-height: 1.4;
}
.ach-card.just-unlocked {
  animation: achPop .8s cubic-bezier(.34,1.56,.64,1);
}
@keyframes achPop {
  0%   { transform: scale(.5); opacity: 0; }
  60%  { transform: scale(1.08); opacity: 1; }
  100% { transform: scale(1); }
}

/* Toast variant for achievement unlocks */
.copy-toast.ach-toast {
  background: linear-gradient(135deg, #ffb84d, #ff8c00);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 8px 24px rgba(255,140,0,.4);
}


/* ═══════════════════════════════════════════════════════════════════════════
   BUY ME A COFFEE  — floating bottom-right donation button
   ═══════════════════════════════════════════════════════════════════════════ */
.bmc-float {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 950;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 18px 11px 14px;
  background: linear-gradient(135deg, #ffdd00 0%, #ffb84d 100%);
  color: #1a1a1a;
  text-decoration: none;
  font-weight: 700;
  font-size: .95em;
  border-radius: 999px;
  box-shadow: 0 6px 20px rgba(255, 184, 77, .35),
              0 2px 6px rgba(0, 0, 0, .15);
  transition: transform .25s cubic-bezier(.34,1.56,.64,1),
              box-shadow .25s, opacity .3s;
  animation: bmcEntry .6s cubic-bezier(.34,1.56,.64,1) .8s both,
             bmcWiggle 5s ease-in-out 4s infinite;
  cursor: pointer;
}
.bmc-float:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow: 0 10px 28px rgba(255, 184, 77, .55),
              0 3px 10px rgba(0, 0, 0, .2);
  animation-play-state: paused;
}
.bmc-float:active { transform: translateY(-1px) scale(1.0); }

.bmc-icon {
  font-size: 1.25em;
  display: inline-block;
  animation: bmcSteam 2.5s ease-in-out infinite;
}

.bmc-close {
  background: rgba(0, 0, 0, .08);
  border: 0;
  color: #1a1a1a;
  font-size: .75em;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  margin-left: 4px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: .55;
  transition: opacity .2s, background .2s;
  padding: 0;
  line-height: 1;
}
.bmc-close:hover { opacity: 1; background: rgba(0,0,0,.18); }

@keyframes bmcEntry {
  from { opacity: 0; transform: translateY(40px) scale(.7); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes bmcWiggle {
  0%, 92%, 100% { transform: translateY(0) rotate(0); }
  94%           { transform: translateY(-3px) rotate(-4deg); }
  96%           { transform: translateY(-3px) rotate(4deg); }
  98%           { transform: translateY(-3px) rotate(-2deg); }
}
@keyframes bmcSteam {
  0%, 100% { transform: translateY(0) rotate(-3deg); }
  50%      { transform: translateY(-2px) rotate(3deg); }
}

/* Hidden state (when user dismisses) */
.bmc-float.bmc-hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(20px) scale(.85);
}

/* Compact (icon-only) variant on small screens */
@media (max-width: 600px) {
  .bmc-float {
    right: 14px;
    bottom: 14px;
    padding: 11px 14px;
  }
  .bmc-label { display: none; }
}