:root {
      --calc-primary:       #8B5CF6;
      --calc-primary-light: #EDE9FE;
      --calc-primary-dark:  #7C3AED;
      --ink:   #0F0A2C;
      --ink-2: #1B1640;
      --ink-3: #5B5572;
      --white: #FCFAF9;
      --off:   #F2EDEC;
      --line:  rgba(15,10,44,0.08);
      --ease:  cubic-bezier(0.4, 0, 0.2, 1);
      --pad:   2rem;
      --ff: 'Geist', system-ui, sans-serif;
      --shadow: 0 16px 40px -8px rgba(15,10,44,0.10);
    }
    * { box-sizing: border-box; }
    body {
      font-family: var(--ff);
      background: var(--off);
      color: var(--ink);
      margin: 0;
      -webkit-font-smoothing: antialiased;
    }
    @keyframes fade-up {
      from { opacity: 0; transform: translateY(16px); }
      to   { opacity: 1; transform: translateY(0); }
    }
    .perc-container {
      max-width: 1200px;
      margin: 6rem auto 4rem;
      padding: 0 var(--pad);
      animation: fade-up 0.5s var(--ease);
    }
    .calc-hero-header {
      text-align: center;
      margin-bottom: 3.5rem;
    }
    .cat-hero-label {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: var(--calc-primary-light);
      color: var(--calc-primary-dark);
      font-size: 0.75rem;
      font-weight: 700;
      letter-spacing: 0.07em;
      text-transform: uppercase;
      padding: 5px 14px;
      border-radius: 999px;
      margin-bottom: 1.25rem;
    }
    .calc-hero-header h1 {
      font-size: clamp(36px, 5vw, 60px);
      font-weight: 800;
      line-height: 1.1;
      letter-spacing: -0.025em;
      color: var(--ink);
      margin: 0 0 1rem;
    }
    .calc-hero-header h1 em {
      font-style: normal;
      color: var(--calc-primary);
    }
    .calc-hero-header p {
      font-size: 1.05rem;
      color: var(--ink-3);
      max-width: 560px;
      margin: 0 auto;
      line-height: 1.65;
    }
    .dashboard-grid {
      display: grid;
      grid-template-columns: 380px 1fr;
      gap: 2rem;
      align-items: start;
    }
    @media (max-width: 960px) {
      .dashboard-grid { grid-template-columns: 1fr; }
    }
    .left-panel {
      background: rgba(252,250,249,0.90);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border: 1px solid rgba(15,10,44,0.09);
      border-radius: 28px;
      box-shadow: var(--shadow);
      padding: 2rem;
    }
    .mode-tabs {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
      margin-bottom: 2rem;
    }
    .mode-tab {
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      gap: 4px;
      padding: 14px 16px;
      background: var(--off);
      border: 1.5px solid var(--line);
      border-radius: 16px;
      cursor: pointer;
      transition: all 0.18s var(--ease);
      text-align: left;
    }
    .mode-tab:hover {
      border-color: var(--calc-primary);
      background: var(--calc-primary-light);
    }
    .mode-tab.active {
      background: var(--calc-primary);
      border-color: var(--calc-primary);
    }
    .mode-tab-icon {
      width: 20px;
      height: 20px;
      color: var(--calc-primary);
      fill: none;
      stroke: currentColor;
      stroke-width: 2;
      stroke-linecap: round;
      stroke-linejoin: round;
    }
    .mode-tab.active .mode-tab-icon { color: rgba(255,255,255,0.9); }
    .mode-tab-label {
      font-size: 0.82rem;
      font-weight: 700;
      color: var(--ink-2);
      line-height: 1.2;
    }
    .mode-tab.active .mode-tab-label { color: #fff; }
    .mode-tab-desc {
      font-size: 0.72rem;
      color: var(--ink-3);
      line-height: 1.3;
    }
    .mode-tab.active .mode-tab-desc { color: rgba(255,255,255,0.75); }
    .mode-panel { display: none; }
    .mode-panel.active { display: block; animation: fade-up 0.22s var(--ease); }
    .input-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1rem;
      margin-bottom: 1.25rem;
    }
    .input-row.single { grid-template-columns: 1fr; }
    .input-row.triple { grid-template-columns: 1fr 1fr 1fr; }
    .input-field {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .input-field label {
      font-size: 0.78rem;
      font-weight: 700;
      color: var(--ink-3);
      text-transform: uppercase;
      letter-spacing: 0.06em;
    }
    .input-field input,
    .input-field select {
      background: #fff;
      border: 1.5px solid rgba(15,10,44,0.12);
      border-radius: 12px;
      padding: 11px 14px;
      font-family: var(--ff);
      font-size: 1rem;
      font-weight: 700;
      color: var(--ink);
      outline: none;
      transition: border-color 0.18s, box-shadow 0.18s;
      width: 100%;
    }
    .input-field input:focus,
    .input-field select:focus {
      border-color: var(--calc-primary);
      box-shadow: 0 0 0 4px var(--calc-primary-light);
    }
    .formula-hint {
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 10px 14px;
      background: var(--calc-primary-light);
      border-radius: 10px;
      font-size: 0.8rem;
      color: var(--calc-primary-dark);
      font-weight: 600;
      margin-top: 0.5rem;
    }
    .formula-hint svg {
      width: 14px;
      height: 14px;
      flex-shrink: 0;
      fill: none;
      stroke: currentColor;
      stroke-width: 2.5;
    }
    .right-panel {
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }
    .result-hero {
      background: linear-gradient(135deg, var(--calc-primary) 0%, var(--calc-primary-dark) 100%);
      border-radius: 28px;
      padding: 3rem 2.5rem;
      text-align: center;
      position: relative;
      overflow: hidden;
      min-height: 200px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
    }
    .result-hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(ellipse at 70% 20%, rgba(255,255,255,0.12) 0%, transparent 65%);
    }
    .result-hero-label {
      font-size: 0.75rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: rgba(255,255,255,0.65);
      position: relative;
    }
    .result-hero-value {
      font-size: clamp(3rem, 7vw, 5rem);
      font-weight: 800;
      color: #fff;
      line-height: 1;
      letter-spacing: -0.03em;
      position: relative;
    }
    .result-hero-sub {
      font-size: 0.9rem;
      color: rgba(255,255,255,0.65);
      position: relative;
    }
    .chart-area {
      background: #fff;
      border: 1px solid var(--line);
      border-radius: 22px;
      padding: 1.25rem;
      position: relative;
      height: 240px;
      overflow: hidden;
    }
    .chart-canvas {
      position: absolute;
      top: 1.25rem;
      left: 1.25rem;
      right: 1.25rem;
      bottom: 1.25rem;
      width: calc(100% - 2.5rem) !important;
      height: calc(100% - 2.5rem) !important;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.2s ease;
    }
    .chart-canvas.active {
      opacity: 1;
      pointer-events: auto;
    }
    .seo-content {
      margin-top: 7rem;
      padding-top: 4rem;
      border-top: 1px solid var(--line);
      display: grid;
      grid-template-columns: 1fr 360px;
      gap: 5rem;
    }
    @media (max-width: 960px) {
      .seo-content { grid-template-columns: 1fr; }
    }
    .article-text h2 {
      font-size: 2.25rem;
      font-weight: 800;
      letter-spacing: -0.02em;
      margin-bottom: 1.5rem;
      color: var(--ink);
    }
    .article-text h3 {
      font-size: 1.3rem;
      font-weight: 700;
      margin: 2.5rem 0 1rem;
      color: var(--ink);
    }
    .article-text p {
      font-size: 1.05rem;
      line-height: 1.8;
      color: var(--ink-2);
      margin-bottom: 1.25rem;
    }
    .article-text ul { margin-bottom: 1.5rem; }
    .article-text li {
      font-size: 1rem;
      color: var(--ink-2);
      margin-bottom: 0.85rem;
      display: flex;
      gap: 10px;
    }
    .article-text li::before {
      content: "→";
      color: var(--calc-primary);
      font-weight: 700;
      flex-shrink: 0;
    }
    .sidebar-guide {
      background: var(--off);
      border: 1px solid var(--line);
      border-radius: 28px;
      padding: 2rem;
      height: fit-content;
      position: sticky;
      top: 100px;
    }
    .sidebar-guide h4 {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 1.25rem;
      color: var(--ink);
    }
    .guide-item { margin-bottom: 1.75rem; }
    .guide-item strong {
      display: block;
      font-size: 0.95rem;
      margin-bottom: 0.4rem;
      color: var(--calc-primary);
    }
    .guide-item p {
      font-size: 0.88rem;
      color: var(--ink-3);
      line-height: 1.6;
      margin: 0;
    }
    .hidden { display: none !important; }