:root {
  
  --bg: #ffffff;
  --surface: #f7f8fa;
  --border: #e2e5ea;

  
  --primary: #4396F7;
  --primary-hover: #2b7de0;

  
  --green: #1a8c4e;
  --red: #d42b2b;
  --amber: #b8860b;

  
  --text: #111111;
  --text-secondary: #5a5f66;
}

[data-theme="dark"] {
  --bg: #111117;
  --surface: #1a1a24;
  --border: #2a2a38;
  --primary: #f0943a;
  --primary-hover: #e07e28;
  --green: #34d399;
  --red: #f87171;
  --amber: #fbbf24;
  --text: #e8e8ed;
  --text-secondary: #8b8b9a;
}

[data-theme="dark"] .mat-cell.wrong-cell { background: #2a1515; }
[data-theme="dark"] .input-grid input:focus,
[data-theme="dark"] .scalar-input input:focus,
[data-theme="dark"] .eq-inputs input:focus { background: #151c28; }
[data-theme="dark"] .input-grid input.correct { background: #0f2018; }
[data-theme="dark"] .input-grid input.wrong { background: #2a1515; }
[data-theme="dark"] .result-panel.correct { background: #0f2018; }
[data-theme="dark"] .result-panel.wrong { background: #2a1515; }

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

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; appearance: none; margin: 0; }
input[type="number"] { -moz-appearance: textfield; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  -webkit-font-smoothing: antialiased;
}

header {
  width: 100%;
  border-bottom: 1px solid var(--border);
}

.container {
  max-width: 720px;
  width: 100%;
  padding: 2rem 1.5rem;
  margin: 0 auto;
}

.nav-bar {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
}

.nav-bar h1 {
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--text);
  margin: 0;
}
.nav-bar h1 span { color: var(--primary); }

.nav-actions {
  display: flex;
  align-items: center;
  gap: .4rem;
}

.nav-user {
  font-size: .72rem;
  font-weight: 600;
  color: var(--text);
  font-family: 'JetBrains Mono', monospace;
  letter-spacing: .02em;
  height: 34px;
  line-height: 34px;
  padding: 0 .7rem;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--bg);
  transition: border-color .2s ease;
  max-width: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.nav-user:hover { border-color: var(--primary); color: var(--primary); }

.nav-btn {
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  border: 1px solid var(--border);
  cursor: pointer;
  color: var(--text-secondary);
  transition: border-color .2s ease, color .2s ease;
  padding: 0;
}
.nav-btn:hover { border-color: var(--primary); color: var(--primary); }
.nav-btn svg { width: 16px; height: 16px; }
.nav-lang-wrap { position: relative; }

.settings-panel {
  position: fixed;
  top: 0;
  right: -320px;
  z-index: 200;
  width: 300px;
  height: 100vh;
  background: var(--bg);
  border-left: 1px solid rgba(255,255,255,.3);
  padding: 2rem 1.5rem 3rem;
  overflow-y: auto;
  transition: right .3s cubic-bezier(.4,0,.2,1);
  box-shadow: -8px 0 32px rgba(0,0,0,.08);
}
.settings-panel.open { right: 0; }

[data-theme="dark"] .settings-panel {
  background: rgba(17,17,23,.78);
  border-left-color: rgba(255,255,255,.08);
  box-shadow: -8px 0 32px rgba(0,0,0,.4);
}

.settings-overlay {
  position: fixed;
  inset: 0;
  z-index: 199;
  background: rgba(0,0,0,.15);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s ease;
}
.settings-overlay.open { opacity: 1; pointer-events: auto; }

.settings-panel h3 {
  font-size: .85rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.settings-panel .sp-close {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-secondary);
  padding: .2rem;
  transition: color .2s ease;
}
.settings-panel .sp-close:hover { color: var(--text); }
.settings-panel .sp-close svg { width: 18px; height: 18px; }

.settings-panel .sp-section { margin-bottom: 1.5rem; }
.settings-panel .sp-label {
  font-size: .65rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: .6rem;
}

.sp-colors { display: flex; flex-wrap: wrap; gap: .4rem; }
.sp-colors button {
  width: 32px;
  height: 32px;
  border: 2px solid var(--border);
  cursor: pointer;
  transition: border-color .2s ease, transform .15s ease;
  padding: 0;
  background: none;
}
.sp-colors button:hover { transform: scale(1.1); }
.sp-colors button.active { border-color: var(--text); border-width: 3px; }

.sp-font-options { display: flex; flex-direction: column; gap: .4rem; }
.sp-font-options button {
  background: var(--bg);
  border: 1px solid var(--border);
  padding: .5rem .8rem;
  text-align: left;
  cursor: pointer;
  font-size: .8rem;
  font-weight: 500;
  color: var(--text);
  transition: border-color .2s ease;
  font-family: inherit;
}
.sp-font-options button:hover { border-color: var(--primary); }
.sp-font-options button.active { border-color: var(--text); font-weight: 600; }

.sp-slider { margin-bottom: .3rem; }
.sp-slider input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: var(--border);
  outline: none;
  margin: .6rem 0 .3rem;
}
.sp-slider input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  background: var(--primary);
  border: none;
  cursor: pointer;
}
.sp-slider input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background: var(--primary);
  border: none;
  cursor: pointer;
}
.sp-slider-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: .7rem;
  color: var(--text-secondary);
}
.sp-slider-info .sp-slider-val {
  font-weight: 700;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.search-overlay {
  position: fixed;
  inset: 0;
  z-index: 500;
  background: rgba(255,255,255,.95);
  display: none;
  flex-direction: column;
  align-items: center;
  padding-top: 12vh;
}
.search-overlay.open { display: flex; }
[data-theme="dark"] .search-overlay { background: rgba(17,17,23,.7); }

.search-modal {
  width: 90%;
  max-width: 520px;
  background: var(--bg);
  border: 1px solid var(--border);
  box-shadow: 0 4px 24px rgba(0,0,0,.08);
  animation: slideUp .25s cubic-bezier(.4,0,.2,1);
}
[data-theme="dark"] .search-modal { box-shadow: 0 4px 24px rgba(0,0,0,.3); }

.search-input {
  width: 100%;
  height: 52px;
  border: none;
  background: transparent;
  padding: 0 1.2rem;
  font-size: 1rem;
  font-weight: 500;
  color: var(--text);
  outline: none;
  font-family: inherit;
  border-bottom: 1px solid var(--border);
}
.search-input::placeholder { color: var(--text-secondary); }

.search-results { max-height: 50vh; overflow-y: auto; }

.search-item {
  display: flex;
  align-items: center;
  gap: .8rem;
  padding: .8rem 1.2rem;
  cursor: pointer;
  transition: background .15s ease;
  border-bottom: 1px solid rgba(0,0,0,.04);
}
.search-item:hover, .search-item.active { background: rgba(67,150,247,.08); }
[data-theme="dark"] .search-item:hover,
[data-theme="dark"] .search-item.active { background: rgba(90,168,255,.1); }

.search-item .si-icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border: 1px solid var(--border);
  flex-shrink: 0;
  font-size: .7rem;
  font-weight: 700;
  color: var(--primary);
}
.search-item .si-text { flex: 1; min-width: 0; }
.search-item .si-title { font-size: .85rem; font-weight: 600; color: var(--text); }
.search-item .si-sub { font-size: .68rem; color: var(--text-secondary); margin-top: .1rem; }
.search-item .si-match { color: var(--primary); font-weight: 700; }
.search-empty { padding: 2rem 1.2rem; text-align: center; font-size: .82rem; color: var(--text-secondary); }

.nav-lang-menu {
  display: none;
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: .3rem;
  background: var(--bg);
  border: 1px solid var(--border);
  z-index: 300;
  min-width: 120px;
  box-shadow: 0 4px 12px rgba(0,0,0,.08);
}
[data-theme="dark"] .nav-lang-menu { box-shadow: 0 4px 12px rgba(0,0,0,.3); }
.nav-lang-menu.open { display: block; }
.nav-lang-menu button {
  display: block;
  width: 100%;
  padding: .5rem .8rem;
  border: none;
  background: none;
  text-align: left;
  font-size: .75rem;
  font-weight: 500;
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  transition: background .15s ease;
}
.nav-lang-menu button:hover { background: var(--surface); }
.nav-lang-menu button.active { color: var(--primary); font-weight: 600; }

.ad-rail {
  position: fixed;
  top: 60px;
  width: 160px;
  height: calc(100vh - 60px);
  display: flex;
  align-items: flex-start;
  padding-top: 1rem;
  z-index: 10;
}
.ad-rail-left { left: 0; }
.ad-rail-right { right: 0; }
.ad-rail ins { width: 160px; display: block; }

@media (max-width: 1100px) {
  .ad-rail { display: none; }
}

.auth-page {
  animation: slideUp .4s cubic-bezier(.4,0,.2,1);
  text-align: center;
  padding-top: 2rem;
}
.auth-page h2 { font-size: 1.1rem; font-weight: 700; margin-bottom: .5rem; }
.auth-page p { font-size: .8rem; color: var(--text-secondary); margin-bottom: 1.5rem; }

.auth-form {
  max-width: 320px;
  margin: 0 auto 1.5rem;
  display: flex;
  flex-direction: column;
  gap: .6rem;
}

.auth-form input, .auth-form select {
  width: 100%;
  height: 42px;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0 1rem;
  font-size: .85rem;
  font-weight: 500;
  outline: none;
  font-family: 'Inter', sans-serif;
  transition: border-color .2s ease;
}
.auth-form input:focus, .auth-form select:focus { border-color: var(--primary); }
.auth-form input::placeholder { color: var(--text-secondary); font-weight: 400; }
.auth-form select { color: var(--text-secondary); cursor: pointer; }

.auth-form .auth-btn {
  height: 42px;
  background: var(--primary);
  border: none;
  color: #fff;
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: background .2s ease;
  margin-top: .3rem;
}
.auth-form .auth-btn:hover { background: var(--primary-hover); }

.auth-form .auth-btn-secondary {
  height: 42px;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: .82rem;
  font-weight: 500;
  cursor: pointer;
  font-family: inherit;
  transition: border-color .2s ease;
}
.auth-form .auth-btn-secondary:hover { border-color: var(--primary); color: var(--primary); }

.auth-form .auth-error {
  font-size: .78rem;
  color: var(--red);
  font-weight: 500;
  text-align: left;
  display: none;
}

.pw-rules { text-align: left; margin: -.2rem 0 .4rem; }
.pw-rules .pw-rule {
  font-size: .72rem;
  font-weight: 500;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: .4rem;
  padding: .15rem 0;
  transition: color .2s ease;
}
.pw-rules .pw-rule.pass { color: var(--green); }
.pw-rules .pw-rule .pw-dot {
  width: 5px;
  height: 5px;
  border: 1px solid var(--text-secondary);
  flex-shrink: 0;
  transition: all .2s ease;
}
.pw-rules .pw-rule.pass .pw-dot {
  background: var(--green);
  border-color: var(--green);
}

.auth-tabs {
  display: flex;
  justify-content: center;
  gap: 0;
  margin-bottom: 2rem;
  max-width: 320px;
  margin-left: auto;
  margin-right: auto;
}
.auth-tabs button {
  flex: 1;
  height: 38px;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: .8rem;
  font-weight: 500;
  cursor: pointer;
  font-family: inherit;
  transition: all .2s ease;
}
.auth-tabs button.active {
  background: var(--surface);
  color: var(--text);
  font-weight: 600;
  border-color: var(--text);
}

.score-card {
  background: var(--primary);
  color: #fff;
  padding: 1.5rem;
  margin-bottom: .75rem;
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 1.5rem;
  align-items: center;
}
.score-card .sc-block { text-align: center; }
.score-card .sc-label {
  font-size: .6rem; font-weight: 500; letter-spacing: 0.1em;
  text-transform: uppercase; color: rgba(255,255,255,.6); margin-bottom: .2rem;
}
.score-card .sc-value {
  font-size: 1.8rem; font-weight: 700; font-variant-numeric: tabular-nums; line-height: 1.1;
}
.score-card .sc-detail { font-size: .68rem; color: rgba(255,255,255,.55); margin-top: .15rem; }
.score-card .sc-divider { width: 1px; height: 36px; background: rgba(255,255,255,.2); }
.score-card .sc-bar-wrap { grid-column: 1 / -1; height: 3px; background: rgba(255,255,255,.15); }
.score-card .sc-bar-fill { height: 100%; background: #fff; transition: width .5s cubic-bezier(.4,0,.2,1); }
.sc-block-rank { cursor: pointer; transition: opacity .2s ease; }
.sc-block-rank:hover { opacity: .8; }

.score-bar {
  display: flex; align-items: center; gap: 1.5rem;
  padding: 1rem 0; margin-bottom: 2rem; border-bottom: 1px solid var(--border);
}
.score-bar .label { font-size: .65rem; font-weight: 500; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-secondary); }
.score-bar .value { font-size: 1.4rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.progress-wrap { flex: 1; height: 3px; background: var(--border); }
.progress-fill { height: 100%; transition: width .5s cubic-bezier(.4,0,.2,1); }

.stopwatch {
  display: flex; align-items: center; justify-content: center; gap: 1rem;
  margin-bottom: 1.5rem; padding: .8rem 0;
  border: 1px solid var(--border); background: var(--surface);
}
.stopwatch .sw-time {
  font-family: 'JetBrains Mono', monospace; font-size: 1.6rem;
  font-weight: 600; font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em; color: var(--text); min-width: 120px; text-align: center;
}
.stopwatch .sw-label {
  font-size: .65rem; font-weight: 500; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--text-secondary);
}

.menu { display: grid; grid-template-columns: repeat(4, 1fr); gap: .75rem; margin-bottom: .75rem; }
.menu button {
  position: relative; overflow: hidden;
  background: var(--bg); border: 1px solid var(--border);
  padding: 4rem 1.2rem 2.5rem; text-align: left; cursor: pointer;
  transition: border-color .25s ease, box-shadow .25s ease;
  color: var(--text); font-family: inherit; min-height: 140px;
}
.menu button:hover { border-color: var(--primary); box-shadow: 0 0 0 1px var(--primary); }
.menu button .title {
  display: block; font-size: .95rem; font-weight: 600; letter-spacing: -0.01em;
  margin-bottom: .3rem; position: relative; z-index: 1;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.menu button .sub {
  font-size: .75rem; color: var(--text-secondary); font-weight: 400;
  position: relative; z-index: 1;
  overflow: hidden; text-overflow: ellipsis;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  line-clamp: 2;
  white-space: normal; line-height: 1.4;
}

.menu button .bg-icon {
  position: absolute; right: 10px; top: 50%; transform: translateY(-50%);
  font-family: 'Inter', sans-serif; font-weight: 800;
  font-size: 9rem; line-height: 1; letter-spacing: -0.04em;
  color: var(--border); opacity: .25;
  pointer-events: none; user-select: none;
  transition: opacity .25s ease, color .25s ease;
}
.menu button:hover .bg-icon { opacity: .3; color: var(--primary); }

.quick-start {
  position: relative; overflow: hidden;
  display: block; width: 100%; padding: 1.5rem; margin-bottom: .75rem;
  background: var(--bg); border: 1px solid var(--border); cursor: pointer;
  text-align: left; font-family: inherit;
  transition: border-color .25s ease, box-shadow .25s ease;
}
.quick-start:hover { border-color: var(--primary); box-shadow: 0 0 0 1px var(--primary); }
.quick-start .qs-label {
  display: block; font-size: 1.1rem; font-weight: 700;
  color: var(--text); letter-spacing: -0.01em; margin-bottom: .2rem;
  position: relative; z-index: 1;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.quick-start .qs-sub {
  display: block; font-size: .75rem; font-weight: 400;
  color: var(--text-secondary); position: relative; z-index: 1;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.quick-start .bg-icon {
  position: absolute; right: 16px; top: 50%; transform: translateY(-50%);
  font-family: 'Inter', sans-serif; font-weight: 800;
  font-size: 4rem; line-height: 1; letter-spacing: -0.04em;
  color: var(--border); opacity: .25;
  pointer-events: none; user-select: none;
  transition: opacity .25s ease, color .25s ease;
}
.quick-start:hover .bg-icon { opacity: .3; color: var(--primary); }

.op-select { display: grid; grid-template-columns: 1fr 1fr; gap: .6rem; margin-bottom: 2rem; }
.op-select button {
  position: relative; overflow: hidden;
  background: var(--bg); border: 1px solid var(--border);
  padding: 1.2rem 1rem; color: var(--text); font-size: .85rem;
  font-weight: 600; cursor: pointer; font-family: inherit;
  text-align: left; transition: border-color .25s ease, box-shadow .25s ease;
  min-height: 64px;
}
.op-select button:hover { border-color: var(--primary); box-shadow: 0 0 0 1px var(--primary); }
.op-select button .op-label {
  position: relative; z-index: 1;
  display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.op-select button .op-sub {
  display: block; font-size: .7rem; font-weight: 400; color: var(--text-secondary);
  margin-top: .2rem; position: relative; z-index: 1;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.op-select button .op-shape {
  position: absolute; right: 8px; top: 50%; transform: translateY(-50%);
  width: 56px; height: 56px; opacity: .18;
  pointer-events: none; transition: opacity .25s ease, color .25s ease;
  color: var(--border);
}
.op-select button:hover .op-shape { opacity: .25; color: var(--primary); }
.op-select button .op-shape svg { width: 100%; height: 100%; }

.op-select button.fill { background: var(--primary); border-color: var(--primary); color: #fff; }
.op-select button.fill:hover { background: var(--primary-hover); box-shadow: none; }
.op-select button.fill .op-sub { color: rgba(255,255,255,.7); }
.op-select button.fill .op-shape { opacity: .15; }
.op-select button.fill .op-shape svg path,
.op-select button.fill .op-shape svg rect,
.op-select button.fill .op-shape svg circle,
.op-select button.fill .op-shape svg polygon,
.op-select button.fill .op-shape svg line { stroke: #fff; fill: none; }

.question-area { animation: slideUp .4s cubic-bezier(.4,0,.2,1); }

.q-header {
  display: flex; justify-content: space-between; align-items: baseline;
  padding-bottom: 1rem; margin-bottom: 1.5rem; border-bottom: 2px solid var(--text);
}
.q-header .q-num { font-size: 1.1rem; font-weight: 700; letter-spacing: -0.02em; }
.q-header .q-type { font-size: 1rem; font-weight: 600; color: var(--primary); letter-spacing: 0.02em; }

.matrices { display: flex; align-items: center; justify-content: center; gap: 2rem; flex-wrap: wrap; margin-bottom: 2rem; }
.mat-block { text-align: center; }
.mat-block .mat-label { font-size: .7rem; font-weight: 600; color: var(--text-secondary); letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: .5rem; }

.mat-grid { display: inline-grid; gap: 1px; background: var(--border); border: 1px solid var(--border); padding: 1px; }
.mat-grid.n2 { grid-template-columns: repeat(2, 56px); }
.mat-grid.n3 { grid-template-columns: repeat(3, 52px); }
.mat-grid.n4 { grid-template-columns: repeat(4, 46px); }
.mat-grid.c1 { grid-template-columns: repeat(1, 56px); }
.mat-grid.c2 { grid-template-columns: repeat(2, 56px); }
.mat-grid.c3 { grid-template-columns: repeat(3, 52px); }
.mat-grid.c4 { grid-template-columns: repeat(4, 46px); }

.mat-cell {
  background: var(--bg); display: flex; align-items: center; justify-content: center;
  height: 44px; font-size: .95rem; font-weight: 600; color: var(--text); font-variant-numeric: tabular-nums;
}
.mat-cell.wrong-cell { color: var(--red); background: #fef2f2; }
.op-symbol { font-size: 1.4rem; color: var(--text-secondary); font-weight: 400; }

.input-section { text-align: center; margin-bottom: 2rem; }
.input-section h3 {
  margin-bottom: 1rem; font-size: .7rem; font-weight: 600;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-secondary);
}

.input-grid { display: inline-grid; gap: 1px; background: var(--primary); border: 2px solid var(--primary); padding: 1px; }
.input-grid.n2 { grid-template-columns: repeat(2, 68px); }
.input-grid.n3 { grid-template-columns: repeat(3, 62px); }
.input-grid.n4 { grid-template-columns: repeat(4, 54px); }
.input-grid.c1 { grid-template-columns: repeat(1, 68px); }
.input-grid.c2 { grid-template-columns: repeat(2, 68px); }
.input-grid.c3 { grid-template-columns: repeat(3, 62px); }
.input-grid.c4 { grid-template-columns: repeat(4, 54px); }

.input-grid input {
  width: 100%; height: 44px; background: var(--bg); border: none;
  color: var(--text); text-align: center; font-size: .95rem;
  font-weight: 600; outline: none; font-family: 'Inter', sans-serif;
  font-variant-numeric: tabular-nums; transition: background .2s ease;
}
.input-grid input:focus { background: #f0f7ff; }
.input-grid input.correct { background: #ecfdf5; }
.input-grid input.wrong { background: #fef2f2; color: var(--red); }

.eq-block { text-align: center; margin-bottom: 2rem; }
.eq-block .eq-line {
  font-family: 'JetBrains Mono', monospace; font-size: .95rem;
  font-weight: 600; line-height: 2; color: var(--text);
}
.eq-block .eq-label {
  font-size: .7rem; font-weight: 600; color: var(--text-secondary);
  letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: .5rem;
}

.eq-inputs {
  display: flex; align-items: center; justify-content: center; gap: .8rem;
  flex-wrap: wrap; margin-bottom: 2rem;
}
.eq-inputs label { font-size: .9rem; font-weight: 600; }
.eq-inputs input {
  width: 70px; height: 40px; background: var(--bg); border: 2px solid var(--primary);
  color: var(--text); text-align: center; font-size: .95rem; font-weight: 600;
  outline: none; font-family: 'Inter', sans-serif; transition: background .2s ease;
}
.eq-inputs input:focus { background: #f0f7ff; }

.scalar-input { display: flex; align-items: center; justify-content: center; gap: 1rem; margin-bottom: 2rem; }
.scalar-input label { font-size: .95rem; font-weight: 600; color: var(--text); }
.scalar-input input {
  width: 100px; height: 44px; background: var(--bg); border: 2px solid var(--primary);
  color: var(--text); text-align: center; font-size: 1rem; font-weight: 600;
  outline: none; font-family: 'Inter', sans-serif; transition: background .2s ease;
}
.scalar-input input:focus { background: #f0f7ff; }

.mc-options { display: flex; flex-direction: column; gap: .5rem; margin-bottom: 2rem; max-width: 480px; margin-left: auto; margin-right: auto; }
.mc-options button {
  background: var(--bg); border: 1px solid var(--border);
  padding: .8rem 1.2rem; text-align: left; cursor: pointer;
  font-family: inherit; font-size: .85rem; font-weight: 500;
  color: var(--text); transition: border-color .2s ease;
}
.mc-options button:hover { border-color: var(--primary); color: var(--primary); }
.mc-options button.selected { border-color: var(--primary); background: var(--surface); color: var(--primary); font-weight: 600; }
.mc-options button.mc-correct { border-color: var(--green); background: #f0fdf4; color: var(--green); font-weight: 600; }
.mc-options button.mc-wrong { border-color: var(--red); background: #fef2f2; color: var(--red); }
[data-theme="dark"] .mc-options button.mc-correct { background: #0f2018; }
[data-theme="dark"] .mc-options button.mc-wrong { background: #2a1515; }
.mc-options button .mc-label { font-size: .7rem; font-weight: 600; color: var(--text-secondary); margin-right: .5rem; }

.btn-submit {
  display: block; margin: 0 auto 1rem; background: var(--primary);
  border: none; padding: .75rem 2.5rem; color: #fff;
  font-size: .85rem; font-weight: 600; cursor: pointer;
  font-family: inherit; letter-spacing: 0.04em; transition: background .2s ease;
}
.btn-submit:hover { background: var(--primary-hover); }

.q-actions { display: flex; justify-content: center; gap: .5rem; margin-bottom: 2rem; }

.btn-give-up, .btn-exit {
  background: var(--bg); border: 1px solid var(--border);
  padding: .55rem 1.5rem; color: var(--text-secondary); font-size: .78rem;
  font-weight: 500; cursor: pointer; font-family: inherit;
  transition: border-color .2s ease, color .2s ease;
}
.btn-give-up:hover { border-color: var(--red); color: var(--red); }
.btn-exit:hover { border-color: var(--text); color: var(--text); }

.btn-next {
  display: block; margin: 0 auto 2rem; background: var(--bg);
  border: 1px solid var(--border); padding: .7rem 2rem;
  color: var(--text); font-size: .82rem; font-weight: 500;
  cursor: pointer; font-family: inherit; letter-spacing: 0.02em;
  transition: border-color .2s ease, color .2s ease;
}
.btn-next:hover { border-color: var(--primary); color: var(--primary); }

.btn-danger {
  color: var(--text); border-color: var(--red);
  transition: background .2s ease, color .2s ease, border-color .2s ease;
}
.btn-danger:hover { background: var(--red); color: #fff; border-color: var(--red); }

.result-panel { padding: 1.2rem 1.5rem; margin-bottom: 1.5rem; animation: slideUp .35s cubic-bezier(.4,0,.2,1); }
.result-panel.correct { border-left: 3px solid var(--green); background: #f0fdf4; }
.result-panel.wrong { border-left: 3px solid var(--red); background: #fef2f2; }
.result-panel h3 { font-size: .95rem; font-weight: 600; margin-bottom: .4rem; }
.result-panel.correct h3 { color: var(--green); }
.result-panel.wrong h3 { color: var(--red); }

.explain-panel {
  background: var(--surface); border-left: 3px solid var(--amber);
  padding: 1.2rem 1.5rem; margin-bottom: 2rem;
  animation: slideUp .4s cubic-bezier(.4,0,.2,1) .1s both;
}
.explain-panel h4 { font-size: .7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--amber); margin-bottom: .8rem; }
.explain-panel .step { margin: .3rem 0; font-family: 'JetBrains Mono', monospace; font-size: .82rem; color: var(--text-secondary); line-height: 1.6; }
.explain-panel .step .val { color: var(--primary); font-weight: 600; }

.wrong-detail { margin-top: .8rem; }
.wrong-detail .item { font-size: .82rem; color: var(--text); margin: .25rem 0; font-variant-numeric: tabular-nums; }
.wrong-detail .item .got { color: var(--red); font-weight: 600; }
.wrong-detail .item .exp { color: var(--green); font-weight: 600; }
.answer-matrices { display: flex; align-items: flex-start; justify-content: center; gap: 2rem; flex-wrap: wrap; margin: 1rem 0; }

.time-result { display: flex; align-items: center; gap: .8rem; font-size: .82rem; color: var(--text-secondary); margin-top: .4rem; }
.time-result .tr-time { font-family: 'JetBrains Mono', monospace; font-weight: 600; color: var(--text); }
.time-result .tr-score { font-weight: 600; }

.composite-score {
  background: var(--surface); border: 1px solid var(--border);
  padding: 1.5rem; margin-bottom: 2rem;
  animation: slideUp .4s cubic-bezier(.4,0,.2,1);
}
.composite-score h4 { font-size: .7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-secondary); margin-bottom: 1rem; }

.score-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin-bottom: 1rem; }
.score-item { text-align: center; }
.score-item .s-label { font-size: .65rem; font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase; color: var(--text-secondary); margin-bottom: .3rem; }
.score-item .s-value { font-size: 1.8rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.score-item .s-detail { font-size: .72rem; color: var(--text-secondary); margin-top: .2rem; }

.total-score { text-align: center; padding-top: 1rem; border-top: 1px solid var(--border); }
.total-score .s-label { font-size: .7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-secondary); margin-bottom: .3rem; }
.total-score .s-value { font-size: 2.4rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.total-score .s-detail { font-size: .75rem; color: var(--text-secondary); margin-top: .2rem; }

.grade-bar { height: 4px; background: var(--border); margin-top: .8rem; }
.grade-fill { height: 100%; transition: width .6s cubic-bezier(.4,0,.2,1); }

.section-label { font-size: .7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-secondary); margin-bottom: 1rem; }

.stats-page { animation: slideUp .4s cubic-bezier(.4,0,.2,1); }
.stats-empty { text-align: center; padding: 3rem 0; color: var(--text-secondary); font-size: .9rem; }

.chart-container { position: relative; margin-bottom: 2rem; }
.chart-header { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 1rem; }
.chart-header h3 { font-size: .7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-secondary); }

.chart-tabs { display: flex; gap: .3rem; }
.chart-tabs button {
  background: var(--bg); border: 1px solid var(--border); padding: .3rem .7rem;
  font-size: .7rem; font-weight: 500; cursor: pointer; font-family: inherit;
  color: var(--text-secondary); transition: all .2s ease;
}
.chart-tabs button.active { background: var(--primary); border-color: var(--primary); color: #fff; }
.chart-tabs button:hover:not(.active) { border-color: var(--primary); color: var(--primary); }

canvas { width: 100% !important; height: 220px !important; display: block; }

.chart-tooltip {
  position: absolute; background: var(--text); color: #fff; padding: .4rem .7rem;
  font-size: .75rem; font-weight: 500; pointer-events: none;
  opacity: 0; transition: opacity .15s ease; white-space: nowrap;
  font-family: 'JetBrains Mono', monospace;
}

.stats-table { width: 100%; border-collapse: collapse; margin-bottom: 2rem; }
.stats-table th {
  font-size: .65rem; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--text-secondary);
  text-align: left; padding: .6rem .5rem; border-bottom: 2px solid var(--text);
}
.stats-table td {
  font-size: .82rem; padding: .5rem; border-bottom: 1px solid var(--border);
  font-variant-numeric: tabular-nums;
}
.stats-table .correct-mark { color: var(--green); font-weight: 600; }
.stats-table .wrong-mark { color: var(--red); font-weight: 600; }

.exam-progress { display: flex; align-items: center; gap: .8rem; margin-bottom: 1.5rem; padding: .6rem 0; }
.exam-progress .ep-label { font-size: .65rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--text-secondary); white-space: nowrap; }
.exam-progress .ep-bar { flex: 1; height: 3px; background: var(--border); }
.exam-progress .ep-fill { height: 100%; background: var(--primary); transition: width .4s cubic-bezier(.4,0,.2,1); }
.exam-progress .ep-count { font-size: .82rem; font-weight: 700; font-variant-numeric: tabular-nums; color: var(--text); white-space: nowrap; }

.rank-card {
  --rc-c1: #7eb8e0; --rc-c2: #9ba4d4; --rc-c3: #c49ab8; --rc-c4: #c4b07a; --rc-c5: #7ac4a0;
  position: relative; overflow: hidden;
  padding: 2rem 1.5rem; margin-bottom: 2rem; text-align: center;
  border: none; color: #fff;
}
.rank-card::before {
  content: ''; position: absolute; inset: 0; z-index: 0;
  background: linear-gradient(135deg, var(--rc-c1), var(--rc-c2), var(--rc-c3), var(--rc-c4), var(--rc-c5), var(--rc-c1));
  background-size: 400% 400%; background-position: 0% 50%;
}
.rank-card::after { display: none; }
.rank-card { animation: slideUp .4s cubic-bezier(.4,0,.2,1); }

.rank-card .rank-bg {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  font-family: 'Inter', sans-serif; font-weight: 800;
  font-size: 7rem; line-height: 1; letter-spacing: -0.04em;
  opacity: .1; pointer-events: none; user-select: none; color: #fff; z-index: 1;
}
.rank-card .rank-tier {
  font-size: .65rem; font-weight: 600; letter-spacing: 0.12em;
  text-transform: uppercase; color: rgba(255,255,255,.7); margin-bottom: .3rem;
  position: relative; z-index: 1;
}
.rank-card .rank-name {
  font-size: 1.6rem; font-weight: 800; letter-spacing: -0.02em;
  position: relative; margin-bottom: .2rem; color: #fff; z-index: 1;
}
.rank-card .rank-sub { font-size: .75rem; color: rgba(255,255,255,.7); position: relative; margin-bottom: 1rem; z-index: 1; }
.rank-card .rank-progress { display: flex; align-items: center; gap: .8rem; justify-content: center; position: relative; z-index: 1; }
.rank-card .rank-progress .rp-bar { width: 160px; height: 4px; background: rgba(255,255,255,.2); border-radius: 2px; }
.rank-card .rank-progress .rp-fill { height: 100%; border-radius: 2px; background: #fff; transition: width .6s cubic-bezier(.4,0,.2,1); }
.rank-card .rank-progress .rp-label { font-size: .7rem; font-weight: 600; font-variant-numeric: tabular-nums; color: rgba(255,255,255,.7); }
.rank-card .rank-next { font-size: .7rem; color: rgba(255,255,255,.6); margin-top: .6rem; position: relative; z-index: 1; }

.ai-summary {
  background: var(--surface); border: 1px solid var(--border);
  padding: 1.5rem; margin-bottom: 2rem;
  animation: slideUp .4s cubic-bezier(.4,0,.2,1) .15s both;
}
.ai-summary h4 { font-size: .7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-secondary); margin-bottom: .8rem; }
.ai-summary p { font-size: .85rem; line-height: 1.7; color: var(--text); margin-bottom: .5rem; }
.ai-summary p:last-child { margin-bottom: 0; }
.ai-summary .ai-tag {
  display: inline-block; font-size: .68rem; font-weight: 600;
  padding: .15rem .5rem; margin-right: .3rem; margin-top: .4rem;
  border: 1px solid var(--border); color: var(--text-secondary);
}

.print-config { animation: slideUp .4s cubic-bezier(.4,0,.2,1); }
.print-config .pc-row { display: flex; gap: .8rem; margin-bottom: .8rem; flex-wrap: wrap; align-items: center; }
.print-config .pc-row label { font-size: .75rem; font-weight: 600; color: var(--text-secondary); min-width: 80px; letter-spacing: 0.04em; }
.print-config .pc-row select, .print-config .pc-row input {
  height: 42px; background: var(--bg); border: 1px solid var(--border);
  color: var(--text); padding: 0 .8rem; font-size: .82rem; font-family: inherit;
  outline: none; flex: 1; min-width: 80px;
}
.print-config .pc-row select:focus, .print-config .pc-row input:focus { border-color: var(--primary); }
.pc-actions { display: flex; gap: .5rem; margin-top: 1.5rem; flex-wrap: wrap; }
.pc-actions .btn-submit, .pc-actions .btn-next { flex: 1; min-width: 100px; height: 42px; display: flex; align-items: center; justify-content: center; margin: 0; }

.pc-toggles { display: grid; grid-template-columns: 1fr 1fr; gap: .4rem; margin-bottom: 1rem; }
.pc-toggle {
  display: flex; align-items: center; gap: .6rem;
  padding: .6rem .8rem; border: 1px solid var(--border);
  cursor: pointer; transition: border-color .2s ease; user-select: none;
}
.pc-toggle:hover { border-color: var(--primary); }
.pc-toggle.active { border-color: var(--primary); background: var(--surface); }
.pc-toggle .tog-switch {
  width: 28px; height: 16px; background: var(--border); position: relative;
  flex-shrink: 0; transition: background .2s ease;
}
.pc-toggle.active .tog-switch { background: var(--primary); }
.pc-toggle .tog-switch::after {
  content: ''; position: absolute; top: 2px; left: 2px;
  width: 12px; height: 12px; background: #fff; transition: left .2s ease;
}
.pc-toggle.active .tog-switch::after { left: 14px; }
.pc-toggle .tog-label { font-size: .75rem; font-weight: 500; color: var(--text); }
.pc-toggle .tog-sub { font-size: .6rem; color: var(--text-secondary); display: block; }

.pp-pages { margin: 1.5rem 0; }
.pp-page {
  background: var(--bg); border: 1px solid var(--border);
  padding: 1.5rem; margin-bottom: 1rem; min-height: 600px;
  display: flex; flex-direction: column;
}
.pp-page-header { text-align: center; margin-bottom: 1rem; padding-bottom: .8rem; border-bottom: 1px solid var(--border); position: relative; }
.pp-page-header h2 { font-size: 1rem; font-weight: 700; margin-bottom: .2rem; }
.pp-page-header .pp-info { font-size: .65rem; color: var(--text-secondary); }
.pp-page-header .pp-name { text-align: right; font-size: .7rem; color: var(--text-secondary); margin-top: .3rem; }
.pp-page-header .pp-qr { position: absolute; top: 0; right: 0; }
.pp-page-header .pp-qr canvas { display: block; width: 32px !important; height: 32px !important; image-rendering: pixelated; }
.pp-page-header .pp-qr-label { font-size: .38rem; color: var(--text-secondary); text-align: center; }

.pp-grid { display: grid; grid-template-columns: 1fr 1fr; gap: .8rem; flex: 1; }
.pp-q { border: 1px solid var(--border); padding: .6rem; display: flex; flex-direction: column; overflow: hidden; }
.pp-q-header { font-size: .72rem; font-weight: 600; margin-bottom: .4rem; color: var(--text); }
.pp-q-body { font-size: .7rem; flex: 1; overflow: hidden; }

.pp-mat { display: inline-grid; gap: 1px; background: var(--border); border: 1px solid var(--border); padding: 1px; vertical-align: middle; margin: .1rem; }
.pp-mat.c1 { grid-template-columns: repeat(1, 28px); }
.pp-mat.c2 { grid-template-columns: repeat(2, 28px); }
.pp-mat.c3 { grid-template-columns: repeat(3, 24px); }
.pp-mat.c4 { grid-template-columns: repeat(4, 20px); }
.pp-cell { background: var(--bg); display: flex; align-items: center; justify-content: center; height: 22px; font-size: .65rem; font-weight: 600; font-variant-numeric: tabular-nums; }

.pp-blank-grid { display: inline-grid; gap: 1px; background: var(--border); border: 1px solid var(--border); padding: 1px; margin-top: .3rem; }
.pp-blank-grid.c1 { grid-template-columns: repeat(1, 28px); }
.pp-blank-grid.c2 { grid-template-columns: repeat(2, 28px); }
.pp-blank-grid.c3 { grid-template-columns: repeat(3, 24px); }
.pp-blank-grid.c4 { grid-template-columns: repeat(4, 20px); }
.pp-blank { background: var(--surface); height: 22px; }

.pp-page-footer { display: none; }
.pp-page-num { font-size: .6rem; color: var(--text-secondary); text-align: center; margin-top: .3rem; }

.pp-answer-page { background: var(--bg); border: 1px solid var(--border); padding: 1.5rem; margin-bottom: 1rem; }
.pp-answer-page h3 { font-size: .85rem; font-weight: 700; margin-bottom: 1rem; text-align: center; }
.pp-answer-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: .3rem; }
.pp-answer-item { font-size: .72rem; padding: .3rem .5rem; border-bottom: 1px solid var(--border); font-family: 'JetBrains Mono', monospace; }
.pp-answer-item strong { font-size: .68rem; color: var(--text-secondary); margin-right: .3rem; }

.pp-loading { text-align: center; padding: 3rem 0; animation: slideUp .3s ease; }
.pp-loading .pp-load-text { font-size: .85rem; font-weight: 600; color: var(--text); margin-bottom: 1rem; }
.pp-loading .pp-load-bar { width: 200px; height: 4px; background: var(--border); margin: 0 auto; }
.pp-loading .pp-load-fill { height: 100%; background: var(--primary); transition: width .15s ease; width: 0; }

@media print {
  body > *:not(.print-window) { display: none !important; }
  .print-window { position: static; width: 100%; padding: 1cm; }
  .print-window .pp-q { page-break-inside: avoid; }
}

.onboarding-overlay {
  position: fixed; inset: 0; z-index: 900;
  background: rgba(255,255,255,.45);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  display: none; flex-direction: column; align-items: center;
  overflow-y: auto; -webkit-overflow-scrolling: touch;
}
.onboarding-overlay.open { display: flex; }
[data-theme="dark"] .onboarding-overlay { background: rgba(17,17,23,.45); }

.ob-content { max-width: 480px; width: 90%; padding: 3rem 0 4rem; animation: slideUp .5s cubic-bezier(.4,0,.2,1); text-align: center; }
.ob-hero { margin-bottom: 2.5rem; padding-top: 2rem; }
.ob-hero h1 { font-size: 2.8rem; font-weight: 800; letter-spacing: -0.04em; color: var(--text); margin-bottom: 0; }
.ob-hero h1 span { color: var(--primary); }

.ob-steps { display: flex; flex-direction: column; gap: 1.5rem; margin-bottom: 2.5rem; text-align: left; }
.ob-step { display: flex; gap: 1rem; align-items: flex-start; }
.ob-num {
  width: 36px; height: 36px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 1rem; font-weight: 800; color: #fff;
  background: var(--primary); font-family: 'JetBrains Mono', monospace;
}
.ob-text { flex: 1; }
.ob-text h3 { font-size: .9rem; font-weight: 700; color: var(--text); margin-bottom: .2rem; letter-spacing: -0.01em; }
.ob-text p { font-size: .78rem; color: var(--text-secondary); line-height: 1.6; font-weight: 400; }

.ob-start {
  display: block; width: 100%; height: 46px;
  background: var(--primary); border: none; color: #fff;
  font-size: .9rem; font-weight: 700; cursor: pointer;
  font-family: inherit; letter-spacing: .02em; transition: background .2s ease;
}
.ob-start:hover { background: var(--primary-hover); }

.nav-hamburger {
  display: none; width: 34px; height: 34px;
  background: var(--bg); border: 1px solid var(--border);
  cursor: pointer; color: var(--text-secondary); padding: 0;
  align-items: center; justify-content: center;
  transition: border-color .2s ease, color .2s ease;
}
.nav-hamburger:hover { border-color: var(--primary); color: var(--primary); }
.nav-hamburger svg { width: 18px; height: 18px; }

.mobile-sidebar-overlay {
  position: fixed; inset: 0; z-index: 599;
  background: rgba(0,0,0,.3);
  opacity: 0; pointer-events: none; transition: opacity .3s ease;
}
.mobile-sidebar-overlay.open { opacity: 1; pointer-events: auto; }

.mobile-sidebar {
  position: fixed; top: 0; right: -280px; z-index: 600;
  width: 260px; height: 100vh;
  background: var(--bg); border-left: 1px solid var(--border);
  padding: 0; overflow-y: auto;
  transition: right .3s cubic-bezier(.4,0,.2,1);
  box-shadow: -4px 0 24px rgba(0,0,0,.08);
  display: none;
}
.mobile-sidebar.open { right: 0; }
[data-theme="dark"] .mobile-sidebar { box-shadow: -4px 0 24px rgba(0,0,0,.4); }

.msb-header { display: flex; align-items: center; justify-content: space-between; padding: 1rem 1.2rem; border-bottom: 1px solid var(--border); }
.msb-header h2 { font-size: 1.1rem; font-weight: 800; letter-spacing: -0.04em; color: var(--text); }
.msb-header h2 span { color: var(--primary); }
.msb-close { width: 28px; height: 28px; background: none; border: none; cursor: pointer; color: var(--text-secondary); padding: 0; display: flex; align-items: center; justify-content: center; }
.msb-close:hover { color: var(--text); }
.msb-close svg { width: 18px; height: 18px; }

.msb-user { padding: .8rem 1.2rem; font-size: .78rem; font-weight: 600; color: var(--primary); font-family: 'JetBrains Mono', monospace; border-bottom: 1px solid var(--border); letter-spacing: .02em; }

.msb-items { padding: .5rem 0; }
.msb-items button {
  display: flex; align-items: center; gap: .8rem;
  width: 100%; padding: .75rem 1.2rem; border: none; background: none;
  text-align: left; font-size: .82rem; font-weight: 500;
  color: var(--text); cursor: pointer; font-family: inherit;
  transition: background .15s ease;
}
.msb-items button:hover { background: var(--surface); }
.msb-items button svg { width: 18px; height: 18px; color: var(--text-secondary); flex-shrink: 0; }
.msb-items button:hover svg { color: var(--primary); }
.msb-logout { border-top: 1px solid var(--border); margin-top: .5rem; padding-top: .75rem; }
.msb-logout:hover { color: var(--red); }
.msb-logout:hover svg { color: var(--red) !important; }

.challenge-page { animation: slideUp .4s cubic-bezier(.4,0,.2,1); }

.ch-tabs { display: flex; gap: 0; margin-bottom: 1.5rem; }
.ch-tabs button {
  flex: 1; height: 40px; background: var(--bg); border: 1px solid var(--border);
  color: var(--text-secondary); font-size: .78rem; font-weight: 500;
  cursor: pointer; font-family: inherit; transition: all .2s ease;
}
.ch-tabs button.active { background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 600; }
.ch-tabs button:hover:not(.active) { border-color: var(--primary); color: var(--primary); }

.ch-daily { text-align: center; padding: 1.5rem 0; }
.ch-daily-header { margin-bottom: 1.5rem; }
.ch-date { font-family: 'JetBrains Mono', monospace; font-size: 1.1rem; font-weight: 700; color: var(--primary); margin-bottom: .4rem; }
.ch-desc { font-size: .82rem; color: var(--text-secondary); }

.ch-info { display: flex; justify-content: center; gap: 2rem; margin-bottom: 1rem; }
.ch-info-item { text-align: center; }
.ch-info-val { display: block; font-size: 1.8rem; font-weight: 700; font-variant-numeric: tabular-nums; color: var(--text); }
.ch-info-label { font-size: .65rem; font-weight: 500; letter-spacing: .08em; text-transform: uppercase; color: var(--text-secondary); }

.ch-loading, .ch-empty, .ch-error { text-align: center; padding: 2rem 0; font-size: .85rem; color: var(--text-secondary); }
.ch-error { color: var(--red); }
.challenge-login-msg { text-align: center; padding: 2rem 0; }
.challenge-login-msg p { font-size: .9rem; color: var(--text-secondary); margin-bottom: 1.5rem; }

.ch-date-label { font-family: 'JetBrains Mono', monospace; font-size: .82rem; font-weight: 600; color: var(--primary); margin-bottom: 1rem; text-align: center; }

.lb-table { width: 100%; border-collapse: collapse; margin-bottom: 1.5rem; }
.lb-table th {
  font-size: .65rem; font-weight: 600; letter-spacing: .08em;
  text-transform: uppercase; color: var(--text-secondary);
  text-align: left; padding: .6rem .5rem; border-bottom: 2px solid var(--text);
}
.lb-table td { font-size: .82rem; padding: .55rem .5rem; border-bottom: 1px solid var(--border); font-variant-numeric: tabular-nums; color: var(--text); }
.lb-table tr:hover td { background: var(--surface); }
.lb-rank { font-weight: 700; color: var(--primary); font-family: 'JetBrains Mono', monospace; }
.lb-score { font-weight: 700; }

.ch-complete { text-align: center; padding: 2rem 0; animation: slideUp .4s cubic-bezier(.4,0,.2,1); }
.ch-complete h3 { font-size: 1.1rem; font-weight: 700; color: var(--primary); margin-bottom: 1.5rem; }
.ch-final-score { margin-bottom: 1rem; }
.ch-fs-val { font-size: 3rem; font-weight: 800; font-variant-numeric: tabular-nums; color: var(--text); line-height: 1.1; }
.ch-fs-label { font-size: .7rem; font-weight: 500; letter-spacing: .08em; text-transform: uppercase; color: var(--text-secondary); margin-top: .3rem; }
.ch-final-stats { display: flex; justify-content: center; gap: 1.5rem; font-size: .82rem; color: var(--text-secondary); margin-bottom: 1rem; }
.ch-submit-status { font-size: .85rem; color: var(--text); font-weight: 600; }
.ch-submit-status strong { color: var(--primary); }

@keyframes slideUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: none; }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  25% { background-position: 100% 0%; }
  50% { background-position: 100% 100%; }
  75% { background-position: 0% 100%; }
  100% { background-position: 0% 50%; }
}
@keyframes glowPulse {
  0%, 100% { box-shadow: 0 4px 30px var(--rc-c1); }
  33% { box-shadow: 0 4px 30px var(--rc-c3); }
  66% { box-shadow: 0 4px 30px var(--rc-c5); }
}

@media (max-width: 768px) {
  
  .nav-actions { display: none; }
  .nav-hamburger { display: flex; }
  .mobile-sidebar { display: block; }

  header { padding: 0; }
  .nav-bar { padding: .8rem 1rem; }
  .nav-bar h1 { font-size: 1.2rem; }
  .container { padding: 1.5rem 1rem; }

  
  .score-bar { gap: 1rem; flex-wrap: wrap; }
  .score-bar .value { font-size: 1.2rem; }

  
  .ob-content { padding: 2rem 0 3rem; }
  .ob-hero h1 { font-size: 2.2rem; }
  .ob-hero { margin-bottom: 2rem; padding-top: 1.5rem; }
  .ob-steps { gap: 1.2rem; margin-bottom: 2rem; }

  
  .menu { grid-template-columns: 1fr 1fr; gap: .6rem; }
  .menu button { padding: 1.2rem 1rem; min-height: 100px; }
  .menu button .bg-icon { font-size: 5rem; }
  .menu button .title { font-size: .85rem; }
  .menu button .sub { font-size: .7rem; }

  
  .quick-start { padding: 1rem 1.2rem; margin-bottom: .6rem; min-height: 60px; }
  .quick-start .qs-label { font-size: .9rem; }
  .quick-start .qs-sub { font-size: .68rem; }
  .quick-start .bg-icon { font-size: 2.8rem; }

  
  .score-card { grid-template-columns: 1fr auto 1fr; gap: 1rem; padding: 1.2rem; }
  .score-card .sc-divider-rank { display: none; }
  .score-card .sc-block-rank { display: none; }
  .score-card .sc-value { font-size: 1.5rem; }

  .score-grid { grid-template-columns: repeat(3, 1fr); gap: .6rem; }
  .score-item .s-value { font-size: 1.4rem; }
  .total-score .s-value { font-size: 2rem; }
  .chart-header { flex-direction: column; gap: .5rem; }
  .stats-table { font-size: .75rem; }
  .stats-table th, .stats-table td { padding: .4rem .3rem; }

  
  .rank-card { padding: 1.5rem 1.2rem; }
  .rank-card .rank-bg { font-size: 5rem; }
  .rank-card .rank-name { font-size: 1.3rem; }
  .ai-summary { padding: 1.2rem; }
  .ai-summary p { font-size: .82rem; }

  .op-select { grid-template-columns: 1fr 1fr; }
  .op-select button .op-shape { width: 44px; height: 44px; }
  .settings-panel { width: 280px; }
  .auth-form { max-width: 280px; }
  .auth-tabs { max-width: 280px; }
  .mc-options { max-width: 100%; }

  
  .ch-tabs button { font-size: .72rem; height: 36px; }
  .lb-table th { font-size: .6rem; }
  .lb-table td { font-size: .75rem; padding: .45rem .4rem; }
  .eq-block .eq-line { font-size: .88rem; }
  .eq-inputs { gap: .6rem; }
  .pw-rules .pw-rule { font-size: .68rem; }
}

@media (max-width: 480px) {
  .container { padding: 1rem .75rem; }

  
  .score-bar { gap: .6rem; padding: .8rem 0; margin-bottom: 1.2rem; }
  .score-bar .value { font-size: 1rem; }
  .score-bar .label { font-size: .6rem; }

  
  .ob-content { padding: 1.5rem 0 2.5rem; }
  .ob-hero h1 { font-size: 2rem; }
  .ob-hero p { font-size: .78rem; }
  .ob-hero { margin-bottom: 2rem; padding-top: 1rem; }
  .ob-steps { gap: 1.2rem; margin-bottom: 2rem; }
  .ob-num { width: 30px; height: 30px; font-size: .85rem; }
  .ob-text h3 { font-size: .82rem; }
  .ob-text p { font-size: .72rem; }
  .ob-start { height: 42px; font-size: .82rem; }

  
  .menu { grid-template-columns: 1fr 1fr; gap: .5rem; }
  .menu button { padding: 1rem .8rem; min-height: 90px; }
  .menu button .bg-icon { font-size: 4rem; }
  .menu button .title { font-size: .8rem; }
  .menu button .sub { font-size: .65rem; }

  
  .quick-start { padding: .8rem 1rem; margin-bottom: .5rem; min-height: 52px; }
  .quick-start .qs-label { font-size: .82rem; }
  .quick-start .qs-sub { font-size: .62rem; }
  .quick-start .bg-icon { font-size: 2.2rem; right: 10px; }

  
  .score-card { grid-template-columns: 1fr auto 1fr; gap: .8rem; padding: 1rem; }
  .score-card .sc-divider-rank { display: none; }
  .score-card .sc-block-rank { display: none; }
  .score-card .sc-value { font-size: 1.3rem; }
  .score-card .sc-label { font-size: .55rem; }
  .score-card .sc-detail { font-size: .6rem; }
  .score-card .sc-divider { height: 28px; }

  
  .op-select { grid-template-columns: 1fr; gap: .4rem; }
  .op-select button { padding: .9rem .75rem; font-size: .78rem; }
  .op-select button .op-shape { width: 38px; height: 38px; right: 6px; }
  .op-select button .op-sub { font-size: .65rem; }

  
  .pc-toggles { grid-template-columns: 1fr; }
  .pc-toggle { padding: .5rem .6rem; }
  .pc-toggle .tog-label { font-size: .7rem; }
  .pc-toggle .tog-sub { font-size: .55rem; }

  
  .matrices { gap: .8rem; margin-bottom: 1.5rem; }
  .mat-grid.n2, .mat-grid.c2 { grid-template-columns: repeat(2, 50px); }
  .mat-grid.n3, .mat-grid.c3 { grid-template-columns: repeat(3, 44px); }
  .mat-grid.n4, .mat-grid.c4 { grid-template-columns: repeat(4, 36px); }
  .mat-grid.c1 { grid-template-columns: repeat(1, 50px); }
  .mat-cell { height: 38px; font-size: .85rem; }

  .input-grid.n2, .input-grid.c2 { grid-template-columns: repeat(2, 60px); }
  .input-grid.n3, .input-grid.c3 { grid-template-columns: repeat(3, 52px); }
  .input-grid.n4, .input-grid.c4 { grid-template-columns: repeat(4, 42px); }
  .input-grid.c1 { grid-template-columns: repeat(1, 60px); }
  .input-grid input { height: 38px; font-size: .85rem; }

  .scalar-input input { width: 90px; height: 38px; font-size: .9rem; }
  .scalar-input label { font-size: .85rem; }

  
  .eq-block .eq-line { font-size: .78rem; }
  .eq-block .eq-label { font-size: .65rem; }
  .eq-inputs { gap: .5rem; }
  .eq-inputs input { width: 55px; height: 36px; font-size: .82rem; }
  .eq-inputs label { font-size: .82rem; }

  
  .stopwatch { padding: .6rem 0; gap: .6rem; }
  .stopwatch .sw-time { font-size: 1.3rem; min-width: 100px; }
  .stopwatch .sw-label { font-size: .6rem; }

  
  .q-header .q-num { font-size: .95rem; }
  .q-header .q-type { font-size: .82rem; }

  
  .btn-submit { padding: .7rem 2rem; font-size: .82rem; }
  .btn-give-up, .btn-exit { padding: .5rem 1rem; font-size: .72rem; }
  .btn-next { padding: .6rem 1.5rem; font-size: .78rem; }

  
  .result-panel { padding: 1rem; }
  .result-panel h3 { font-size: .88rem; }
  .explain-panel { padding: 1rem; }
  .explain-panel .step { font-size: .72rem; }
  .explain-panel h4 { font-size: .65rem; }

  
  .score-grid { grid-template-columns: 1fr; gap: .5rem; }
  .score-item .s-value { font-size: 1.5rem; }
  .total-score .s-value { font-size: 1.8rem; }
  .composite-score { padding: 1rem; }
  .composite-score h4 { font-size: .65rem; }

  
  canvas { height: 180px !important; }
  .chart-header { flex-direction: column; gap: .4rem; }
  .chart-tabs button { padding: .25rem .5rem; font-size: .62rem; }
  .answer-matrices { gap: .8rem; }
  .time-result { flex-wrap: wrap; gap: .4rem; font-size: .75rem; }
  .wrong-detail .item { font-size: .75rem; }
  .exam-progress .ep-label { font-size: .6rem; }
  .exam-progress .ep-count { font-size: .75rem; }

  
  .rank-card { padding: 1.2rem 1rem; margin-bottom: 1.5rem; }
  .rank-card .rank-bg { font-size: 4rem; }
  .rank-card .rank-name { font-size: 1.2rem; }
  .rank-card .rank-sub { font-size: .68rem; }
  .rank-card .rank-tier { font-size: .6rem; }
  .rank-card .rank-next { font-size: .65rem; }
  .rank-card .rank-progress .rp-bar { width: 120px; }
  .rank-card .rank-progress .rp-label { font-size: .65rem; }

  
  .ai-summary { padding: 1rem; margin-bottom: 1.5rem; }
  .ai-summary h4 { font-size: .65rem; }
  .ai-summary p { font-size: .78rem; line-height: 1.6; }
  .ai-summary .ai-tag { font-size: .62rem; padding: .1rem .4rem; }

  
  .mc-options { gap: .4rem; }
  .mc-options button { padding: .7rem 1rem; font-size: .78rem; }
  .mc-options button .mc-label { font-size: .65rem; }

  
  .nav-bar { padding: .6rem .75rem; }
  .nav-bar h1 { font-size: 1.05rem; }
  .nav-hamburger { width: 30px; height: 30px; }
  .nav-hamburger svg { width: 16px; height: 16px; }
  .mobile-sidebar { width: 240px; right: -260px; }
  .settings-panel { width: 260px; padding: 1.5rem 1rem; }

  
  .auth-form { max-width: 100%; }
  .auth-form input, .auth-form select { height: 38px; font-size: .82rem; }
  .auth-form .auth-btn, .auth-form .auth-btn-secondary { height: 38px; font-size: .78rem; }
  .auth-tabs { max-width: 100%; }
  .auth-tabs button { height: 34px; font-size: .75rem; }
  .pw-rules .pw-rule { font-size: .65rem; }
  .section-label { font-size: .65rem; }

  
  .ch-tabs button { font-size: .68rem; height: 34px; }
  .ch-info { gap: 1.2rem; }
  .ch-info-val { font-size: 1.4rem; }
  .ch-fs-val { font-size: 2.2rem; }
  .ch-final-stats { flex-direction: column; gap: .4rem; }
  .lb-table th { font-size: .58rem; padding: .4rem .3rem; }
  .lb-table td { font-size: .72rem; padding: .4rem .3rem; }
}

/* ─── Footer ─── */
.site-footer {
  width: 100%;
  text-align: center;
  padding: .6rem 1rem .8rem;
  margin-top: auto;
}

.footer-text {
  font-size: .65rem;
  color: var(--text-secondary);
  letter-spacing: .04em;
}

/* ─── Home Button (below menu grid) ─── */
.home-btn-wrap {
  text-align: center;
  margin: 1.5rem 0 0;
}
.home-btn {
  height: 32px;
  padding: 0 1.2rem;
  font-size: .72rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  background: none;
  border: none;
  color: var(--text-secondary);
  transition: color .25s ease;
}
.home-btn:hover {
  color: var(--primary);
}

/* ─── Profile Page (type bars + recent dots) ─── */
.rank-glow {
  position: relative;
  overflow: hidden;
  border-color: var(--rank-color) !important;
  box-shadow: 0 0 20px color-mix(in srgb, var(--rank-color) 25%, transparent),
              inset 0 0 30px color-mix(in srgb, var(--rank-color) 8%, transparent);
}
.rank-glow::before {
  content: '';
  position: absolute;
  inset: -2px;
  border-radius: inherit;
  background: radial-gradient(ellipse at 50% 0%, color-mix(in srgb, var(--rank-color) 15%, transparent) 0%, transparent 70%);
  pointer-events: none;
}
@keyframes rankPulse {
  0%, 100% { opacity: .6; }
  50% { opacity: 1; }
}
.rank-glow::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 50% 50%, color-mix(in srgb, var(--rank-color) 6%, transparent) 0%, transparent 50%);
  animation: rankPulse 3s ease-in-out infinite;
  pointer-events: none;
}
.pf-recent {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}
.pf-dot {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  transition: transform .15s;
}
.pf-dot:hover { transform: scale(1.4); }
.pf-dot.correct { background: var(--green); }
.pf-dot.wrong { background: var(--red); opacity: .7; }
.pf-types {
  display: flex;
  flex-direction: column;
  gap: .6rem;
}
.pf-type-row {
  display: flex;
  align-items: center;
  gap: .5rem;
}
.pf-type-label {
  font-size: .72rem;
  font-weight: 600;
  color: var(--text);
  min-width: 70px;
  white-space: nowrap;
}
.pf-type-bar-wrap {
  flex: 1;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}
.pf-type-bar {
  height: 100%;
  border-radius: 3px;
  transition: width .6s cubic-bezier(.4,0,.2,1);
}
.pf-type-pct {
  font-size: .7rem;
  font-weight: 600;
  color: var(--text);
  min-width: 32px;
  text-align: right;
  font-family: 'JetBrains Mono', monospace;
}
.pf-type-count {
  font-size: .65rem;
  color: var(--text-secondary);
  min-width: 40px;
}
@media (max-width: 480px) {
  .pf-type-label { min-width: 50px; font-size: .68rem; }
}

/* ─── Visual Elements (Geo/Stat/Prob SVGs) ─── */
.visual-box {
  width: 100%;
  max-width: 280px;
  height: 180px;
  margin: .8rem auto;
  border: 1px solid var(--border);
  border-radius: 0;
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: .5rem;
  flex-shrink: 0;
}
.visual-box svg {
  width: 100%;
  height: 100%;
  display: block;
}
.geo-problem, .prob-problem {
  display: flex;
  flex-direction: column;
}
.geo-desc, .prob-desc {
  font-size: .92rem;
  font-weight: 600;
  color: var(--text);
  margin: .6rem 0 .3rem;
  line-height: 1.6;
}
.geo-formula {
  font-size: .82rem;
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  margin-bottom: .3rem;
}
.geo-values {
  font-size: .82rem;
  color: var(--text-secondary);
  display: flex;
  gap: .8rem;
  flex-wrap: wrap;
}
@media (max-width: 480px) {
  .visual-box { max-width: 100%; height: 150px; }
  .geo-desc, .prob-desc { font-size: .84rem; }
}

/* ─── Problem Description (global) ─── */
.formula-block {
  text-align: center;
  margin: 1rem 0;
}
.formula-label {
  font-size: .82rem;
  color: var(--text-secondary);
  margin-bottom: .4rem;
}
.formula-display {
  font-size: 1.1rem;
  font-weight: 600;
  font-family: 'JetBrains Mono', monospace;
  color: var(--text);
  line-height: 1.8;
}
.dataset-block {
  margin: .6rem 0;
}
.ds-label {
  font-size: .78rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: .06em;
  margin-bottom: .3rem;
}
.ds-values {
  font-size: .92rem;
  font-family: 'JetBrains Mono', monospace;
  color: var(--text);
  line-height: 1.6;
}
.scalar-input label {
  font-size: .82rem;
  font-weight: 600;
  color: var(--text);
}