/* date-difference-calculator.css */

:root {
    --primary-blue: #0052cc;
    --hero-gradient: linear-gradient(135deg, #0061ff 0%, #0033aa 100%);
    --bg-light: #f8fafc;
    --white: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --transition: all 0.3s ease;
    --success-bg: #ecfdf5;
    --success-text: #047857;
    --warning-bg: #fff7ed;
    --warning-text: #c2410c;
    --danger-bg: #fef2f2;
    --danger-text: #b91c1c;
  }
  
  *,
  *::before,
  *::after {
    box-sizing: border-box;
  }
  
  html {
    scroll-behavior: smooth;
  }
  
  body {
    margin: 0;
    font-family: "Inter", sans-serif;
    color: var(--text-main);
    background: var(--white);
    line-height: 1.7;
  }
  
  a {
    color: var(--primary-blue);
    text-decoration: none;
    transition: var(--transition);
  }
  
  a:hover {
    text-decoration: underline;
  }
  
  .container {
    width: 100%;
    max-width: 1200px;
    padding: 0 16px;
    margin: 0 auto;
  }
  
  .hidden {
    display: none !important;
  }
  
  .sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
  }
  
  .dd-hero {
    background: var(--hero-gradient);
    color: var(--white);
    padding: 34px 0 38px;
  }
  
  .breadcrumb {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
    font-size: 0.92rem;
  }
  
  .breadcrumb a,
  .breadcrumb span {
    color: rgba(255, 255, 255, 0.92);
  }
  
  .dd-hero h1 {
    margin: 0;
    color: var(--white);
    font-size: clamp(2.2rem, 5vw, 3.55rem);
    line-height: 1.08;
    letter-spacing: -0.04em;
  }
  
  .main-area {
    padding: 42px 0 58px;
    background: var(--bg-light);
  }
  
  .calculator-shell {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 24px;
    align-items: start;
  }
  
  .calculator-card {
    min-width: 0;
    padding: 28px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow-sm);
  }
  
  .result-card {
    position: sticky;
    top: 18px;
  }
  
  .card-heading {
    display: flex;
    gap: 16px;
    margin-bottom: 22px;
  }
  
  .card-heading h2 {
    margin: 0 0 6px;
    font-size: clamp(1.35rem, 2.5vw, 1.8rem);
    letter-spacing: -0.02em;
  }
  
  .card-heading p {
    margin: 0;
    color: var(--text-muted);
  }
  
  .card-icon {
    width: 56px;
    height: 56px;
    min-width: 56px;
    border-radius: 18px;
    background: rgba(0, 82, 204, 0.08);
    color: var(--primary-blue);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
  }
  
  .mode-selector {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 10px;
    margin: 0 0 22px;
    padding: 0;
    border: 0;
  }
  
  .mode-selector label {
    cursor: pointer;
  }
  
  .mode-selector input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
  }
  
  .mode-selector span {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 50px;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 999px;
    background: var(--white);
    color: var(--text-main);
    font-size: 0.88rem;
    font-weight: 800;
    text-align: center;
    transition: var(--transition);
  }
  
  .mode-selector input:checked + span {
    color: var(--white);
    background: var(--primary-blue);
    border-color: var(--primary-blue);
  }
  
  .mode-selector input:focus + span,
  .form-group input:focus,
  .form-group textarea:focus,
  .btn:focus,
  details summary:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(0, 82, 204, 0.16);
  }
  
  .form-grid {
    display: grid;
    gap: 18px;
  }
  
  .form-grid.two-col {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  
  .form-group {
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
  }
  
  .form-group label {
    font-weight: 700;
  }
  
  .form-group input,
  .form-group textarea {
    width: 100%;
    min-height: 48px;
    padding: 12px 14px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: var(--white);
    color: var(--text-main);
    font: inherit;
  }
  
  .form-group textarea {
    resize: vertical;
    line-height: 1.5;
  }
  
  .form-group input:focus,
  .form-group textarea:focus {
    border-color: var(--primary-blue);
  }
  
  .form-group small {
    color: var(--text-muted);
    line-height: 1.5;
  }
  
  .option-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    margin-top: 18px;
  }
  
  .check-option {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    padding: 14px 15px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-light);
    cursor: pointer;
    transition: var(--transition);
  }
  
  .check-option:hover {
    border-color: rgba(0, 82, 204, 0.35);
    background: rgba(0, 82, 204, 0.04);
  }
  
  .check-option input {
    width: 18px;
    height: 18px;
    margin-top: 4px;
    accent-color: var(--primary-blue);
  }
  
  .check-option span {
    font-weight: 700;
    line-height: 1.45;
  }
  
  .note-box {
    margin-top: 20px;
    padding: 15px 17px;
    border-radius: 12px;
    border: 1px solid rgba(194, 65, 12, 0.16);
    background: var(--warning-bg);
    color: var(--warning-text);
  }
  
  .form-message {
    display: none;
    margin-top: 18px;
    padding: 14px 16px;
    border-radius: 10px;
    font-weight: 700;
  }
  
  .form-message.error {
    display: block;
    color: var(--danger-text);
    background: var(--danger-bg);
  }
  
  .button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 22px;
  }
  
  .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 18px;
    border: 1px solid transparent;
    border-radius: var(--radius);
    font: inherit;
    font-weight: 800;
    cursor: pointer;
    transition: var(--transition);
  }
  
  .btn-primary {
    color: var(--white);
    background: var(--primary-blue);
    box-shadow: var(--shadow-sm);
  }
  
  .btn-primary:hover {
    background: #003f9e;
    transform: translateY(-1px);
  }
  
  .btn-secondary {
    color: var(--text-main);
    background: var(--white);
    border-color: var(--border-color);
  }
  
  .btn-secondary:hover {
    background: var(--bg-light);
  }
  
  .results-placeholder {
    text-align: center;
    padding: 42px 18px;
  }
  
  .placeholder-icon {
    width: 92px;
    height: 92px;
    margin: 0 auto 18px;
    border-radius: 999px;
    background: rgba(0, 82, 204, 0.08);
    color: var(--primary-blue);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
  }
  
  .results-placeholder h3 {
    margin: 0 0 10px;
    font-size: 1.35rem;
  }
  
  .results-placeholder p,
  .summary-message {
    color: var(--text-muted);
  }
  
  .mini-label {
    display: inline-block;
    margin-bottom: 10px;
    color: var(--primary-blue);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
  }
  
  .main-result-card {
    padding: 22px;
    border-radius: 16px;
    background: linear-gradient(180deg, rgba(0, 82, 204, 0.08), rgba(0, 82, 204, 0.03));
    border: 1px solid rgba(0, 82, 204, 0.16);
  }
  
  .main-result-card p {
    margin: 0 0 8px;
    color: var(--text-muted);
    font-weight: 700;
  }
  
  .main-result-card h2 {
    margin: 0 0 14px;
    color: var(--primary-blue);
    font-size: clamp(1.9rem, 4.5vw, 2.75rem);
    line-height: 1.08;
    overflow-wrap: anywhere;
  }
  
  .date-badge {
    display: inline-flex;
    align-items: center;
    padding: 7px 11px;
    border-radius: 999px;
    background: var(--success-bg);
    color: var(--success-text);
    font-size: 0.9rem;
    font-weight: 800;
  }
  
  .date-badge.warning {
    background: var(--warning-bg);
    color: var(--warning-text);
  }
  
  .date-badge.danger {
    background: var(--danger-bg);
    color: var(--danger-text);
  }
  
  .result-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
    margin: 20px 0;
  }
  
  .result-tile {
    min-width: 0;
    padding: 16px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--white);
  }
  
  .result-tile span {
    display: block;
    margin-bottom: 8px;
    color: var(--text-muted);
    font-size: 0.92rem;
  }
  
  .result-tile strong {
    display: block;
    font-size: 1.04rem;
    overflow-wrap: anywhere;
  }
  
  .insight-card {
    margin: 18px 0;
    padding: 17px 18px;
    border-radius: 12px;
    border: 1px solid rgba(4, 120, 87, 0.16);
    background: var(--success-bg);
    color: var(--success-text);
  }
  
  .insight-card.warning {
    border-color: rgba(194, 65, 12, 0.16);
    background: var(--warning-bg);
    color: var(--warning-text);
  }
  
  .insight-card.danger {
    border-color: rgba(185, 28, 28, 0.16);
    background: var(--danger-bg);
    color: var(--danger-text);
  }
  
  .insight-card p {
    margin: 6px 0 0;
  }
  
  .result-note {
    margin-top: 18px;
    padding: 14px 16px;
    border-radius: 12px;
    background: var(--warning-bg);
    color: var(--warning-text);
    font-size: 0.95rem;
  }
  
  .date-list-block {
    margin-top: 18px;
  }
  
  .date-list-block h3 {
    margin: 0 0 10px;
    font-size: 1rem;
  }
  
  .pill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }
  
  .pill-list span {
    display: inline-flex;
    padding: 7px 10px;
    border-radius: 999px;
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    font-size: 0.88rem;
    font-weight: 700;
  }
  
  .related-tools-section {
    margin-top: 30px;
    padding: 28px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow-sm);
  }
  
  .related-tools-section h2 {
    margin: 0 0 18px;
    font-size: clamp(1.45rem, 3vw, 2rem);
    line-height: 1.25;
    letter-spacing: -0.02em;
  }
  
  .related-tools-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
  }
  
  .related-tools-grid a {
    display: flex;
    align-items: center;
    min-height: 48px;
    padding: 13px 15px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: var(--bg-light);
    color: var(--primary-blue);
    font-weight: 800;
    font-size: 0.92rem;
    line-height: 1.35;
    text-decoration: none;
    transition: var(--transition);
  }
  
  .related-tools-grid a:hover {
    background: rgba(0, 82, 204, 0.06);
    border-color: rgba(0, 82, 204, 0.28);
    transform: translateY(-1px);
  }
  
  .split-section {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px;
  }
  
  .example-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
    margin-top: 18px;
  }
  
  .example-grid > div {
    padding: 18px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-light);
  }
  
  .faq-section details {
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--white);
    overflow: hidden;
  }
  
  .faq-section details + details {
    margin-top: 12px;
  }
  
  .faq-section summary {
    padding: 18px 20px;
    cursor: pointer;
    font-weight: 800;
    list-style: none;
  }
  
  .faq-section summary::-webkit-details-marker {
    display: none;
  }
  
  .faq-section details p {
    padding: 0 20px 20px;
    color: var(--text-muted);
  }
  
  .final-cta {
    margin-top: 30px;
    padding: 30px;
    border-radius: var(--radius);
    background: linear-gradient(180deg, rgba(0, 82, 204, 0.08), rgba(0, 82, 204, 0.03));
    border: 1px solid rgba(0, 82, 204, 0.14);
  }
  
  .final-cta h2 {
    margin: 0 0 12px;
    font-size: clamp(1.55rem, 3vw, 2.1rem);
  }
  
  .final-cta p {
    margin: 0;
  }
  
  @media (max-width: 980px) {
    .calculator-shell,
    .split-section {
      grid-template-columns: 1fr;
    }
  
    .result-card {
      position: static;
    }
  
    .example-grid {
      grid-template-columns: repeat(2, minmax(0, 1fr));
    }
  }

  @media (max-width: 860px) {
    .related-tools-grid {
      grid-template-columns: repeat(2, minmax(0, 1fr));
    }
  }
  
  @media (max-width: 760px) {
    .main-area {
      padding: 28px 0 42px;
    }
  
    .calculator-card,
    .final-cta {
      padding: 22px;
    }
  
    .card-heading {
      flex-direction: column;
    }
  
    .mode-selector {
      grid-template-columns: repeat(2, minmax(0, 1fr));
    }
  
    .form-grid.two-col,
    .option-grid,
    .result-grid,
    .example-grid {
      grid-template-columns: 1fr;
    }
  
    .button-row {
      flex-direction: column;
    }
  
    .btn {
      width: 100%;
    }
  }

  @media (max-width: 560px) {
    .related-tools-grid {
      grid-template-columns: 1fr;
    }
  }
  
  @media (max-width: 480px) {
    .container {
      padding: 0 14px;
    }
  
    .dd-hero {
      padding: 28px 0 32px;
    }
  
    .calculator-card,
    .final-cta {
      padding: 18px;
    }
  
    .mode-selector {
      grid-template-columns: 1fr;
    }
  
    .main-result-card h2 {
      font-size: 1.85rem;
    }
  }