:root {
      --bg-start: #e8f0ff;
      --bg-end: #effff8;
      --bg-accent: #d9f7f0;
      --card-bg: #ffffff;
      --text: #1f2937;
      --muted: #6b7280;
      --accent: #0d9488;
      --accent-hover: #0f766e;
      --accent-soft: rgba(13, 148, 136, 0.16);
      --border: #d1d5db;
      --danger: #b91c1c;
      --success: #065f46;
      --shadow: 0 26px 60px rgba(16, 86, 111, 0.16);
      --radius: 18px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      min-height: 100vh;
      background: radial-gradient(1200px circle at 8% 10%, var(--bg-start), #f7fbff 56%, var(--bg-end));
      color: var(--text);
      font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
      position: relative;
      overflow-x: hidden;
    }

    body::before,
    body::after {
      content: "";
      position: fixed;
      border-radius: 50%;
      filter: blur(2px);
      z-index: -1;
      pointer-events: none;
    }

    body::before {
      width: 280px;
      height: 280px;
      right: -70px;
      top: 110px;
      background: radial-gradient(circle at 35% 35%, #b8efe3, #c9ddff);
      opacity: 0.55;
    }

    body::after {
      width: 240px;
      height: 240px;
      left: -80px;
      bottom: 120px;
      background: radial-gradient(circle at 30% 30%, #d7fcd7, #c6ecff);
      opacity: 0.5;
    }

    .page-shell {
      min-height: 100vh;
      display: flex;
      flex-direction: column;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 6;
      background: rgba(245, 250, 255, 0.86);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid #d8e4f0;
    }

    .header-inner {
      width: min(1200px, 100%);
      margin: 0 auto;
      padding: 10px 20px;
      display: grid;
      grid-template-columns: auto 1fr auto;
      align-items: center;
      gap: 12px;
    }

    .brand {
      text-decoration: none;
      color: #0e2a40;
      white-space: nowrap;
      letter-spacing: 0.3px;
      display: inline-flex;
      align-items: center;
      gap: 9px;
      font-weight: 800;
      padding: 8px 10px;
      border-radius: 12px;
      background: linear-gradient(180deg, #f5fbff, #eaf6ff);
      border: 1px solid #d2e5f5;
      box-shadow: 0 5px 16px rgba(17, 56, 84, 0.1);
    }

    .brand-mark {
      width: 16px;
      height: 16px;
      border-radius: 4px;
      background:
        linear-gradient(135deg, #0f766e 0 50%, transparent 50% 100%),
        linear-gradient(315deg, #33b4da 0 50%, #1d4f91 50% 100%);
      box-shadow: 0 0 0 1px rgba(18, 67, 101, 0.22) inset;
    }

    .brand-text {
      font-size: 1rem;
    }

    .brand-chip {
      font-size: 0.68rem;
      font-weight: 700;
      color: #0b4b69;
      background: #d9efff;
      border: 1px solid #b9dcf7;
      border-radius: 999px;
      padding: 2px 6px;
    }

    .top-nav {
      display: flex;
      flex-wrap: wrap;
      gap: 7px;
      justify-content: center;
    }

    .top-nav a {
      text-decoration: none;
      font-size: 0.83rem;
      font-weight: 700;
      color: #2c4154;
      padding: 8px 10px;
      border-radius: 10px;
      border: 1px solid #d6e3ef;
      background: linear-gradient(180deg, #fbfdff, #eff5fb);
      position: relative;
      overflow: hidden;
      transition: transform 0.2s ease, border-color 0.2s ease, color 0.2s ease;
    }

    .top-nav a span {
      position: relative;
      z-index: 1;
    }

    .top-nav a::before {
      content: "";
      position: absolute;
      inset: 0;
      transform: translateX(-101%);
      background: linear-gradient(90deg, transparent, rgba(34, 211, 238, 0.18), transparent);
      transition: transform 0.35s ease;
    }

    .top-nav a:hover {
      transform: translateY(-1px);
      color: #0b4b69;
      border-color: #9dc7e6;
    }

    .top-nav a:hover::before {
      transform: translateX(101%);
    }

    .nav-status {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      font-size: 0.75rem;
      font-weight: 700;
      color: #0b4b69;
      background: linear-gradient(180deg, #e7fff5, #ddf9f0);
      border: 1px solid #b8e6d9;
      border-radius: 999px;
      padding: 6px 10px;
      white-space: nowrap;
    }

    .status-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: #0d9488;
      box-shadow: 0 0 0 0 rgba(13, 148, 136, 0.7);
      animation: statusPing 1.8s infinite;
    }

    .content-wrap {
      flex: 1;
      padding: 20px;
    }

    .content-inner {
      width: min(1180px, 100%);
      margin: 0 auto;
      display: grid;
      gap: 20px;
      align-items: start;
    }

    .tool-hero {
      width: 100%;
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 22px;
      align-items: stretch;
    }

    .hero-panel {
      background: linear-gradient(135deg, #ecfffa, #f2f7ff 42%, #ffffff 100%);
      border: 1px solid #dce9f6;
      border-radius: 24px;
      padding: 26px;
      box-shadow: var(--shadow);
      animation: floatSoft 5.5s ease-in-out infinite;
    }

    .hero-title {
      margin: 0 0 12px;
      font-size: clamp(1.8rem, 2.8vw, 2.5rem);
      line-height: 1.15;
      letter-spacing: -0.5px;
      color: #18334a;
    }

    .hero-subtitle {
      margin: 0 0 18px;
      font-size: 1rem;
      line-height: 1.6;
      color: #405264;
      max-width: 60ch;
    }

    .hero-points {
      margin: 0;
      padding: 0;
      list-style: none;
      display: grid;
      gap: 10px;
    }

    .hero-points li {
      background: #ffffffcc;
      border: 1px solid #d8e5f2;
      border-radius: 12px;
      padding: 10px 12px;
      font-size: 0.94rem;
      color: #344556;
      transform: translateZ(0);
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }

    .hero-points li:hover {
      transform: translateY(-2px);
      box-shadow: 0 10px 18px rgba(26, 62, 92, 0.15);
    }

    .hero-points strong {
      color: #17364f;
    }

    .card {
      width: 100%;
      background: linear-gradient(180deg, #ffffff, #fcffff);
      border: 1px solid #dce8f2;
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      padding: 24px;
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }

    .card:hover {
      transform: translateY(-2px);
      box-shadow: 0 30px 52px rgba(19, 55, 84, 0.2);
    }

    .card h2 {
      margin: 0 0 6px;
      font-size: 1.45rem;
      text-align: center;
      color: #18334a;
    }

    .subtitle {
      margin: 0 0 18px;
      text-align: center;
      color: var(--muted);
      font-size: 0.95rem;
    }

    .helper {
      margin: -4px 0 6px;
      font-size: 0.83rem;
      color: #6b7280;
    }

    .trust-note {
      font-size: 0.78rem;
      color: #0b4b69;
      background: #e9f7ff;
      border: 1px solid #cce8fb;
      border-radius: 9px;
      padding: 6px 8px;
    }

    .field {
      display: grid;
      gap: 8px;
      margin-bottom: 14px;
    }

    .preset-wrap {
      display: flex;
      align-items: center;
      flex-wrap: wrap;
      gap: 7px;
      margin-top: 2px;
    }

    .preset-label {
      font-size: 0.78rem;
      color: #4b5563;
      font-weight: 700;
    }

    .preset-btn {
      width: auto;
      margin: 0;
      padding: 6px 9px;
      border-radius: 999px;
      font-size: 0.75rem;
      font-weight: 700;
      color: #0b4b69;
      border: 1px solid #bedbf0;
      background: linear-gradient(180deg, #f8fcff, #eaf4fb);
      box-shadow: none;
      animation: none;
      transition: transform 0.15s ease, border-color 0.15s ease;
    }

    .preset-btn:hover:enabled {
      transform: translateY(-1px);
      border-color: #8dbddd;
      box-shadow: none;
    }

    label {
      font-size: 0.92rem;
      font-weight: 600;
    }

    input {
      width: 100%;
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 11px 12px;
      font-size: 1rem;
      background: #fff;
    }

    input:focus {
      outline: 2px solid rgba(15, 118, 110, 0.25);
      border-color: var(--accent);
    }

    button {
      width: 100%;
      margin-top: 4px;
      border: 0;
      border-radius: 12px;
      padding: 13px;
      font-size: 1rem;
      font-weight: 700;
      color: #fff;
      background: linear-gradient(90deg, #0f766e, #0ea5a0, #1eaec0);
      background-size: 180% 180%;
      cursor: pointer;
      transition: transform 0.2s ease, box-shadow 0.2s ease;
      box-shadow: 0 0 0 rgba(14, 165, 160, 0.1);
      animation: glowPulse 1.8s ease-in-out infinite;
    }

    button:hover:enabled {
      transform: translateY(-1px);
      box-shadow: 0 0 0 6px var(--accent-soft), 0 10px 26px rgba(13, 148, 136, 0.35);
    }

    button:disabled {
      cursor: not-allowed;
      opacity: 0.7;
      animation: none;
      box-shadow: none;
    }

    #downloadBtn {
      margin-top: 10px;
      background: linear-gradient(90deg, #1d4ed8, #2563eb, #3b82f6);
      animation: glowPulseBlue 1.8s ease-in-out infinite;
    }

    .status {
      min-height: 22px;
      margin-top: 14px;
      font-size: 0.92rem;
      color: var(--muted);
      text-align: center;
    }

    .progress-wrap {
      display: none;
      margin-top: 12px;
    }

    .progress-wrap.active {
      display: block;
    }

    .progress-track {
      width: 100%;
      height: 8px;
      border-radius: 999px;
      background: #e7edf4;
      overflow: hidden;
      position: relative;
    }

    .progress-bar {
      position: absolute;
      left: 0;
      width: 0%;
      height: 100%;
      background: linear-gradient(90deg, #0f766e, #14b8a6);
      border-radius: 999px;
      transition: width 0.12s linear;
    }

    .progress-note {
      margin: 7px 0 0;
      text-align: center;
      font-size: 0.82rem;
      color: #667085;
      letter-spacing: 0.2px;
    }

    .status.error {
      color: var(--danger);
    }

    .status.success {
      color: var(--success);
    }

    .result-stats {
      margin-top: 10px;
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 8px;
    }

    .stat-box {
      border: 1px solid #d9e6f2;
      border-radius: 10px;
      background: #f8fbff;
      padding: 8px;
      text-align: center;
    }

    .stat-label {
      display: block;
      font-size: 0.72rem;
      color: #5b6b7c;
      margin-bottom: 2px;
    }

    .stat-value {
      display: block;
      font-size: 0.9rem;
      font-weight: 800;
      color: #17364f;
    }

    .info-block {
      width: 100%;
      background: #ffffffd9;
      border: 1px solid #dde5ef;
      border-radius: 14px;
      padding: 18px 20px;
      box-shadow: 0 10px 28px rgba(22, 41, 61, 0.07);
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }

    .info-block:hover {
      transform: translateY(-2px);
      box-shadow: 0 16px 30px rgba(22, 41, 61, 0.12);
    }

    .info-block h2 {
      margin: 0 0 8px;
      font-size: 1.05rem;
    }

    .info-block p {
      margin: 0 0 10px;
      line-height: 1.55;
      color: #4b5563;
      font-size: 0.93rem;
    }

    .info-block ul {
      margin: 0;
      padding-left: 18px;
      color: #4b5563;
      font-size: 0.93rem;
      line-height: 1.55;
    }

    .info-block li {
      margin-bottom: 8px;
    }

    .site-footer {
      border-top: 1px solid #dbe3ee;
      background: #f7fafc;
    }

    .footer-inner {
      width: min(1100px, 100%);
      margin: 0 auto;
      padding: 20px;
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 16px;
    }

    .foot-title {
      margin: 0 0 8px;
      font-size: 0.95rem;
      color: #111827;
    }

    .foot-links {
      margin: 0;
      padding: 0;
      list-style: none;
      display: grid;
      gap: 6px;
    }

    .foot-links a {
      text-decoration: none;
      color: #4b5563;
      font-size: 0.88rem;
    }

    .foot-links a:hover {
      color: #0f766e;
    }

    .copyright {
      border-top: 1px solid #e4eaf1;
      padding: 12px 20px 18px;
      text-align: center;
      font-size: 0.84rem;
      color: #6b7280;
    }

    .reveal {
      opacity: 0;
      transform: translateY(22px);
      transition: opacity 0.65s ease, transform 0.65s ease;
    }

    .reveal.is-visible {
      opacity: 1;
      transform: translateY(0);
    }

    @media (max-width: 1024px) {
      .header-inner {
        grid-template-columns: auto 1fr;
        row-gap: 10px;
      }

      .top-nav {
        grid-column: 1 / -1;
        justify-content: flex-start;
        flex-wrap: nowrap;
        overflow-x: auto;
        padding-bottom: 4px;
        scrollbar-width: thin;
      }

      .top-nav a {
        flex: 0 0 auto;
      }

      .nav-status {
        justify-self: end;
      }

      .content-wrap {
        padding: 16px;
      }

      .content-inner {
        gap: 16px;
      }

      .tool-hero {
        gap: 16px;
      }

      .hero-panel,
      .card {
        padding: 20px;
      }
    }

    @media (max-width: 760px) {
      .header-inner {
        grid-template-columns: 1fr;
        align-items: flex-start;
        padding: 10px 14px;
        gap: 8px;
      }

      .top-nav {
        width: 100%;
        justify-content: flex-start;
        padding-bottom: 6px;
      }

      .nav-status {
        margin-top: 0;
        font-size: 0.71rem;
        padding: 5px 9px;
      }

      .content-wrap {
        padding: 12px;
      }

      .hero-panel {
        padding: 18px;
        border-radius: 18px;
      }

      .hero-title {
        font-size: 1.72rem;
      }

      .hero-subtitle {
        font-size: 0.95rem;
      }

      .hero-points {
        display: none;
      }

      .card {
        padding: 18px;
      }

      .card h2 {
        font-size: 1.25rem;
      }

      .field {
        margin-bottom: 12px;
      }

      .preset-btn {
        min-height: 34px;
      }

      input,
      button {
        min-height: 46px;
      }

      .info-block {
        padding: 15px;
      }

      .info-block h2 {
        font-size: 1rem;
      }

      .info-block p,
      .info-block ul {
        font-size: 0.9rem;
      }

      .result-stats {
        grid-template-columns: 1fr;
      }

      .content-inner > .info-block {
        display: none;
      }

      .footer-inner {
        padding: 16px;
        gap: 14px;
      }

      .copyright {
        padding: 10px 14px 14px;
      }

      .footer-inner {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 960px) {
      .tool-hero {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 480px) {
      body::before {
        width: 190px;
        height: 190px;
        right: -60px;
      }

      body::after {
        width: 170px;
        height: 170px;
        left: -60px;
      }

      .brand-chip {
        display: none;
      }

      .nav-status {
        display: none;
      }

      .site-footer {
        display: none;
      }

      .top-nav a {
        font-size: 0.8rem;
        padding: 7px 9px;
      }
    }

    @media (max-width: 420px) {
      .hero-title {
        font-size: 1.56rem;
      }

      .hero-points li {
        padding: 9px 10px;
        font-size: 0.9rem;
      }
    }

    @keyframes glowPulse {
      0% {
        box-shadow: 0 0 0 0 rgba(14, 165, 160, 0.35), 0 0 0 rgba(14, 165, 160, 0);
        background-position: 0% 50%;
      }
      50% {
        box-shadow: 0 0 0 8px rgba(14, 165, 160, 0.12), 0 14px 30px rgba(13, 148, 136, 0.28);
        background-position: 100% 50%;
      }
      100% {
        box-shadow: 0 0 0 0 rgba(14, 165, 160, 0.35), 0 0 0 rgba(14, 165, 160, 0);
        background-position: 0% 50%;
      }
    }

    @keyframes glowPulseBlue {
      0% {
        box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.35), 0 0 0 rgba(37, 99, 235, 0);
        background-position: 0% 50%;
      }
      50% {
        box-shadow: 0 0 0 8px rgba(37, 99, 235, 0.12), 0 14px 30px rgba(29, 78, 216, 0.26);
        background-position: 100% 50%;
      }
      100% {
        box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.35), 0 0 0 rgba(37, 99, 235, 0);
        background-position: 0% 50%;
      }
    }

    @keyframes statusPing {
      0% {
        box-shadow: 0 0 0 0 rgba(13, 148, 136, 0.65);
      }
      100% {
        box-shadow: 0 0 0 10px rgba(13, 148, 136, 0);
      }
    }

    @keyframes floatSoft {
      0% {
        transform: translateY(0px);
      }
      50% {
        transform: translateY(-3px);
      }
      100% {
        transform: translateY(0px);
      }
    }

    @media (prefers-reduced-motion: reduce) {
      .hero-panel,
      .status-dot,
      button,
      #downloadBtn,
      .reveal {
        animation: none !important;
        transition: none !important;
      }
    }