/* ===== SOLVER PAGE STYLES ===== */
    .solver-page {
      background-color: #f8f9fa;
      min-height: 100vh;
    }

    /* Hero */
    .solver-hero {
      background: linear-gradient(135deg, var(--pink-bg) 0%, rgba(251,58,110,0.12) 100%);
      padding: 60px 20px 50px;
      text-align: center;
      border-bottom: 1px solid var(--border-color);
    }

    .solver-hero h1 {
      font-size: clamp(28px, 5vw, 48px);
      font-weight: 800;
      color: var(--text-color);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }

    .solver-hero h1 span {
      color: var(--pink-button);
    }

    .solver-hero p {
      font-size: clamp(15px, 2.5vw, 18px);
      color: #555;
      max-width: 600px;
      margin: 0 auto;
      line-height: 1.7;
    }

    /* Main Container */
    .solver-container {
      max-width: 860px;
      margin: 0 auto;
      padding: 40px 20px 60px;
    }

    /* Input Card */
    .solver-card {
      background: white;
      border-radius: 20px;
      padding: 36px;
      box-shadow: 0 4px 24px rgba(0,0,0,0.08);
      margin-bottom: 28px;
    }

    .solver-card-title {
      font-size: 18px;
      font-weight: 700;
      color: var(--text-color);
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .solver-card-subtitle {
      font-size: 14px;
      color: #888;
      margin-bottom: 28px;
    }

    /* Letter Box Visual */
    .letter-box-visual {
      display: grid;
      grid-template-areas:
        ". top ."
        "left . right"
        ". bottom .";
      grid-template-columns: 1fr 2fr 1fr;
      gap: 12px;
      margin-bottom: 28px;
      width: 100%;
      overflow: hidden;
    }

    .side-input-group {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
    }

    .side-input-group label {
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: #999;
    }

    .side-input {
      width: 100%;
      max-width: 110px;
      padding: 14px 10px;
      border: 2px solid var(--border-color);
      border-radius: 12px;
      font-size: 22px;
      font-weight: 700;
      text-align: center;
      letter-spacing: clamp(2px, 2vw, 8px);
      text-transform: uppercase;
      color: var(--text-color);
      background: #fafafa;
      transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
      outline: none;
      font-family: 'Courier New', monospace;
    }

    .side-input:focus {
      border-color: var(--pink-button);
      box-shadow: 0 0 0 4px rgba(251,58,110,0.1);
      background: white;
    }

    .side-input.error {
      border-color: #e53e3e;
      box-shadow: 0 0 0 4px rgba(229,62,62,0.1);
    }

    .side-input.valid {
      border-color: var(--green-score);
      box-shadow: 0 0 0 4px rgba(14,177,110,0.1);
    }

    .side-input-group.top    { grid-area: top; }
    .side-input-group.left   { grid-area: left; justify-content: center; }
    .side-input-group.right  { grid-area: right; justify-content: center; }
    .side-input-group.bottom { grid-area: bottom; }

    .side-input-group.left .side-input,
    .side-input-group.right .side-input {
      width: 100%;
       max-width: 90px;
      letter-spacing: 4px;
      font-size: 20px;
    }

    /* Box center decoration */
    .box-center {
      grid-area: left / top / right / right;
      display: flex;
      align-items: center;
      justify-content: center;
      grid-column: 2;
      grid-row: 2;
    }

    .box-center-inner {
      width: 90%;
      aspect-ratio: 1;
      border: 2.5px dashed #e0e0e0;
      border-radius: 16px;
      background: #fafbfc;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #ccc;
      font-size: 13px;
      font-weight: 500;
    }

    /* Actions */
    /* Auto Fill button */
    .autofill-row {
      margin-bottom: 14px;
    }

    .btn-autofill {
      background: linear-gradient(135deg, #fff8f9, #fff0f5);
      color: var(--pink-button);
      border: 2px solid rgba(251,58,110,0.3);
      padding: 13px 24px;
      border-radius: 10px;
      font-size: 15px;
      font-weight: 700;
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      width: 100%;
      justify-content: center;
      letter-spacing: 0.2px;
      font-family: inherit;
    }

    .btn-autofill:hover:not(:disabled) {
      background: linear-gradient(135deg, var(--pink-button), #ff6b9d);
      color: white;
      border-color: var(--pink-button);
      transform: translateY(-1px);
      box-shadow: 0 6px 18px rgba(251,58,110,0.25);
    }

    .btn-autofill:active:not(:disabled) {
      transform: translateY(0);
    }

    .btn-autofill:disabled {
      opacity: 0.65;
      cursor: not-allowed;
    }

    .btn-autofill.autofill-done {
      background: linear-gradient(135deg, var(--green-score), #0dcf7f);
      color: white;
      border-color: var(--green-score);
    }

    .autofill-spinner {
      display: inline-block;
      width: 14px;
      height: 14px;
      border: 2px solid rgba(251,58,110,0.3);
      border-top-color: var(--pink-button);
      border-radius: 50%;
      animation: spin 0.7s linear infinite;
      flex-shrink: 0;
    }

    /* Filter chips */
    .filter-card {
      background: white;
      border-radius: 14px;
      padding: 18px 24px;
      box-shadow: 0 2px 12px rgba(0,0,0,0.06);
      margin-bottom: 20px;
      display: flex;
      align-items: center;
      gap: 16px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .filter-label {
      font-size: 13px;
      font-weight: 600;
      color: #888;
      text-transform: uppercase;
      letter-spacing: 0.8px;
      white-space: nowrap;
    }

    .filter-chips {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
    }

    .filter-radio {
      background: #f4f4f5;
      color: #666;
      border: 1.5px solid transparent;
      padding: 8px 18px;
      border-radius: 999px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
      transition: all 0.18s ease;
      font-family: inherit;
      white-space: nowrap;
    }

    .filter-radio:hover {
      background: #ffe8ee;
      color: var(--pink-button);
      border-color: rgba(251,58,110,0.25);
    }

    .filter-radio.active {
      background: var(--pink-button);
      color: white;
      border-color: var(--pink-button);
      box-shadow: 0 3px 10px rgba(251,58,110,0.3);
    }

    .filter-radio.active:hover {
      background: var(--pink-button-hover);
      border-color: var(--pink-button-hover);
    }

    .solver-actions {
      display: flex;
      gap: 12px;
      flex-wrap: wrap;
      align-items: center;
      justify-content: center;
    }

    .btn-solve {
      background: var(--pink-button);
      color: white;
      border: none;
      padding: 14px 36px;
      border-radius: 10px;
      font-size: 16px;
      font-weight: 700;
      cursor: pointer;
      transition: background 0.2s ease, transform 0.15s ease, box-shadow 0.2s ease;
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: 0.3px;
    }

    .btn-solve:hover:not(:disabled) {
      background: var(--pink-button-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 18px rgba(251,58,110,0.35);
    }

    .btn-solve:active:not(:disabled) {
      transform: translateY(0);
    }

    .btn-solve:disabled {
      opacity: 0.65;
      cursor: not-allowed;
    }

    .btn-clear {
      background: white;
      color: var(--text-color);
      border: 2px solid var(--border-color);
      padding: 13px 24px;
      border-radius: 10px;
      font-size: 15px;
      font-weight: 600;
      cursor: pointer;
      transition: background 0.2s ease, border-color 0.2s ease;
    }

    .btn-clear:hover {
      background: #f5f5f5;
      border-color: #ccc;
    }

    /* Error message */
    .validation-error {
      margin-top: 14px;
      padding: 12px 16px;
      background: #fff5f5;
      border: 1px solid #fed7d7;
      border-radius: 8px;
      color: #c53030;
      font-size: 14px;
      display: none;
    }

    .validation-error.show {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    /* Loading Spinner */
    .solver-loading {
      display: none;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 48px 20px;
      gap: 16px;
    }

    .solver-loading.show {
      display: flex;
    }

    .spinner {
      width: 44px;
      height: 44px;
      border: 4px solid #f0f0f0;
      border-top-color: var(--pink-button);
      border-radius: 50%;
      animation: spin 0.7s linear infinite;
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }

    .solver-loading p {
      color: #888;
      font-size: 15px;
      font-weight: 500;
    }

    /* Results */
    .results-section {
      display: none;
    }

    .results-section.show {
      display: block;
      animation: fadeInUp 0.4s ease;
    }

    @keyframes fadeInUp {
      from { opacity: 0; transform: translateY(16px); }
      to   { opacity: 1; transform: translateY(0); }
    }

    .results-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 12px;
      margin-bottom: 20px;
    }

    .results-count {
      font-size: 15px;
      color: #666;
      font-weight: 500;
    }

    .results-count strong {
      color: var(--pink-button);
    }

    /* Best Solution */
    .best-solution-card {
      background: linear-gradient(135deg, #fff8f9, #fff);
      border: 2px solid rgba(251,58,110,0.2);
      border-radius: 16px;
      padding: 28px;
      margin-bottom: 20px;
      position: relative;
      overflow: hidden;
    }

    .best-solution-card::before {
      content: '';
      position: absolute;
      top: 0; left: 0; right: 0;
      height: 3px;
      background: linear-gradient(90deg, var(--pink-button), #ff6b9d);
    }

    .best-label {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: var(--pink-button);
      color: white;
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      padding: 4px 10px;
      border-radius: 20px;
      margin-bottom: 14px;
    }

    .solution-chain {
      display: flex;
      align-items: center;
      flex-wrap: wrap;
      gap: 8px;
      font-size: 20px;
      font-weight: 700;
      color: var(--text-color);
    }

    .solution-word {
      background: #f8f9fa;
      border: 1.5px solid #e8e8e8;
      padding: 6px 14px;
      border-radius: 8px;
      font-size: 18px;
      font-weight: 700;
      letter-spacing: 0.5px;
      transition: background 0.15s;
      cursor: default;
    }

    .best-solution-card .solution-word {
      background: white;
      border-color: rgba(251,58,110,0.2);
    }

    .solution-word:hover {
      background: #fff0f3;
    }

    .solution-arrow {
      color: var(--pink-button);
      font-size: 16px;
      font-weight: 700;
    }

    .copy-btn {
      background: white;
      border: 1.5px solid var(--border-color);
      color: var(--text-color);
      padding: 8px 18px;
      border-radius: 8px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: all 0.2s ease;
      margin-top: 16px;
    }

    .copy-btn:hover {
      background: var(--pink-button);
      color: white;
      border-color: var(--pink-button);
    }

    .copy-btn.copied {
      background: var(--green-score);
      color: white;
      border-color: var(--green-score);
    }

    /* All Solutions */
    .all-solutions-card {
      background: white;
      border-radius: 16px;
      padding: 28px;
      box-shadow: 0 2px 16px rgba(0,0,0,0.06);
    }

    .all-solutions-title {
      font-size: 16px;
      font-weight: 700;
      color: var(--text-color);
      margin-bottom: 18px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .solutions-list {
      display: flex;
      flex-direction: column;
      gap: 10px;
      max-height: 420px;
      overflow-y: auto;
      padding-right: 4px;
    }

    .solutions-list::-webkit-scrollbar {
      width: 5px;
    }

    .solutions-list::-webkit-scrollbar-track {
      background: #f0f0f0;
      border-radius: 4px;
    }

    .solutions-list::-webkit-scrollbar-thumb {
      background: #ccc;
      border-radius: 4px;
    }

    .solution-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 12px 16px;
      background: #fafafa;
      border: 1px solid #f0f0f0;
      border-radius: 10px;
      transition: background 0.15s, border-color 0.15s;
      gap: 12px;
    }

    .solution-item:hover {
      background: #fff8f9;
      border-color: rgba(251,58,110,0.2);
    }

    .solution-item-chain {
      display: flex;
      align-items: center;
      flex-wrap: wrap;
      gap: 6px;
      font-size: 15px;
      font-weight: 600;
    }

    .solution-item-copy {
      background: transparent;
      border: 1px solid #e0e0e0;
      color: #aaa;
      width: 32px;
      height: 32px;
      border-radius: 6px;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
      transition: all 0.2s;
      font-size: 14px;
    }

    .solution-item-copy:hover {
      background: var(--pink-button);
      color: white;
      border-color: var(--pink-button);
    }

    .solution-item-copy.copied {
      background: var(--green-score);
      color: white;
      border-color: var(--green-score);
    }

    /* No result */
    .no-result-card {
      background: white;
      border-radius: 16px;
      padding: 48px 28px;
      box-shadow: 0 2px 16px rgba(0,0,0,0.06);
      text-align: center;
    }

    .no-result-icon {
      font-size: 52px;
      margin-bottom: 16px;
    }

    .no-result-card h3 {
      font-size: 20px;
      font-weight: 700;
      color: var(--text-color);
      margin-bottom: 10px;
    }

    .no-result-card p {
      color: #888;
      font-size: 15px;
      line-height: 1.6;
    }

    /* How it works section */
    .solver-info-section {
      background: white;
      padding: 60px 20px;
      border-top: 1px solid var(--border-color);
    }

    .solver-info-inner {
      max-width: 860px;
      margin: 0 auto;
    }

    .info-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
      gap: 24px;
      margin-top: 36px;
    }

    .info-card {
      background: #f8f9fa;
      border-radius: 14px;
      padding: 28px 24px;
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }

    .info-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    }

    .info-card-icon {
      font-size: 36px;
      margin-bottom: 14px;
    }

    .info-card h3 {
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-color);
    }

    .info-card p {
      font-size: 14px;
      color: #666;
      line-height: 1.6;
    }

    /* FAQ */
    .solver-faq {
      background: #f8f9fa;
      padding: 60px 20px;
      border-top: 1px solid var(--border-color);
    }

    .solver-faq-inner {
      max-width: 760px;
      margin: 0 auto;
    }

    .faq-list {
      margin-top: 36px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: white;
      border: 1px solid var(--border-color);
      border-radius: 12px;
      overflow: hidden;
    }

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 18px 20px;
      text-align: left;
      font-size: 15px;
      font-weight: 600;
      color: var(--text-color);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 12px;
      font-family: inherit;
      transition: background 0.15s;
    }

    .faq-question:hover {
      background: #fafafa;
    }

    .faq-question .faq-icon {
      color: var(--pink-button);
      font-size: 18px;
      font-weight: 700;
      transition: transform 0.25s;
      flex-shrink: 0;
    }

    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
    }

    .faq-item.open .faq-answer {
      max-height: 300px;
    }

    .faq-answer p {
      padding: 0 20px 18px;
      font-size: 14px;
      color: #666;
      line-height: 1.7;
    }

    /* Highlight letters */
    .letter-chip {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background: rgba(251,58,110,0.1);
      color: var(--pink-button);
      font-weight: 700;
      border-radius: 4px;
      padding: 1px 5px;
      font-size: 0.9em;
    }

    /* Mobile responsive */
    @media (max-width: 600px) {
      .solver-card {
        padding: 22px 16px;
      }

      .letter-box-visual {
        grid-template-columns: 1fr 1.4fr 1fr;
        gap: 8px;
      }

      .side-input {
        width: 88px;
        font-size: 18px;
        letter-spacing: 5px;
        padding: 12px 6px;
      }

      .side-input-group.left .side-input,
      .side-input-group.right .side-input {
        width: 72px;
        font-size: 16px;
        letter-spacing: 3px;
      }

      .solver-actions {
        flex-direction: column;
        align-items: stretch;
      }

      .btn-solve, .btn-clear {
        width: 100%;
        justify-content: center;
      }

      .solution-chain {
        font-size: 16px;
      }

      .solution-word {
        font-size: 15px;
      }
    }