/* Prevent FOUC */
      .initial-load .content-section {
        opacity: 0;
      }

      .js-loaded .content-section {
        opacity: 1;
        transition: opacity 0.2s ease-in;
      }

      /* Reset all mode toggles to default state first */
      .mode-toggle {
        opacity: 0.5;
        background: transparent;
        border: 1px solid var(--border-color);
        color: var(--text-color);
        box-shadow: none;
      }

      /* Then style only the active one */
      [data-mask-mode="asterisks"] .mode-toggle[data-mode="asterisks"],
      [data-mask-mode="field_numbers"] .mode-toggle[data-mode="field_numbers"] {
        opacity: 1;
        background: linear-gradient(45deg, #4776e6, #8e54e9);
        color: white;
        box-shadow: 0 0 20px rgba(71, 118, 230, 0.3);
        border: none;
      }

      /* Ensure other toggle remains in inactive state */
      [data-mask-mode="asterisks"] .mode-toggle[data-mode="field_numbers"],
      [data-mask-mode="field_numbers"] .mode-toggle[data-mode="asterisks"] {
        opacity: 0.5;
        background: transparent;
        border: 1px solid var(--border-color);
        color: var(--text-color);
        box-shadow: none;
      }

      :root {
        --primary-color: #c04e01;
        --bg-color: #f5f5f5;
        --text-color: #060b14;
        --border-color: #efd7ab;
        --button-hover: #07645d;
        --secondary-bg: #d8dadb;
        --accent-color: #efd7ab;
      }

      [data-theme="dark"] {
        --primary-color: #efd7ab;
        --bg-color: #060b14;
        --text-color: #f5f5f5;
        --border-color: #12403c;
        --button-hover: #c04e01;
        --secondary-bg: #12403c;
        --accent-color: #c04e01;
      }

      /* Hide content until initialization */
      .mode-toggle-container,
      .mask-words-section,
      #word-chips {
        visibility: hidden;
      }

      .js-loaded .mode-toggle-container,
      .js-loaded .mask-words-section,
      .js-loaded #word-chips {
        visibility: visible;
      }

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

      body {
        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
          Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
        line-height: 1.6;
        background-color: var(--bg-color);
        color: var(--text-color);
        min-height: 100vh;
        transition: background-color 0.3s, color 0.3s;
      }

      .container {
        max-width: 1200px;
        margin: 0 auto;
        padding: 2rem;
      }

      header {
        text-align: center;
        margin-bottom: 2rem;
        position: relative;
      }

      .settings-container {
        position: absolute;
        right: 0;
        top: 0;
        display: flex;
        gap: 0.5rem;
      }

      .settings-popup {
        display: none;
        position: absolute;
        right: 0;
        top: 100%;
        margin-top: 0.5rem;
        background: var(--bg-color);
        border: 1px solid var(--border-color);
        border-radius: 0.5rem;
        padding: 1rem;
        min-width: 200px;
        box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
          0 2px 4px -1px rgba(0, 0, 0, 0.06);
        z-index: 100;
      }

      .settings-popup.show {
        display: block;
      }

      .settings-popup h3 {
        font-size: 1rem;
        margin-bottom: 1rem;
        color: var(--text-color);
      }

      .settings-item {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 0.5rem 0;
        border-bottom: 1px solid var(--border-color);
      }

      .settings-item:last-child {
        border-bottom: none;
      }

      .settings-label {
        font-size: 0.875rem;
        color: var(--text-color);
      }

      .settings-info {
        font-size: 0.75rem;
        color: var(--text-color);
        opacity: 0.7;
        margin-top: 0.25rem;
      }

      .theme-toggle {
        position: absolute;
        right: 0;
        top: 0;
        background: none;
        border: 1px solid var(--border-color);
        color: var(--text-color);
        padding: 0.5rem;
        border-radius: 0.375rem;
        cursor: pointer;
        display: flex;
        align-items: center;
        gap: 0.5rem;
      }

      .theme-toggle:hover {
        background: var(--border-color);
      }

      h1,
      h2,
      h3,
      h4,
      h5,
      h6 {
        padding-left: 1rem; /* Adjust the padding value as needed */
      }

      h1 {
        color: var(--primary-color);
        font-size: 2.5rem;
        margin-bottom: 0.5rem;
      }

      .content {
        display: grid;
        grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
        gap: 2rem;
        width: 100%;
        position: relative;
      }

      #decode-section {
        display: none;
        margin-top: 2rem;
        background: var(--bg-color);
        border: 1px solid var(--accent-color);
        border-radius: 0.5rem;
        padding: 1.5rem;
      }

      .decode-title {
        margin-bottom: 1rem;
      }

      .decode-box {
        display: grid;
        grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
        gap: 2rem;
      }

      #decode-section .text-box {
        border-color: var(--border-color);
        box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
      }

      #decode-section .decode-input-box {
        border-color: #8e54e9;
        border-width: 2px;
      }

      #decode-section .decode-output-box {
        border-color: #4776e6;
        border-width: 2px;
      }

      .decode-section textarea {
        margin-bottom: 1rem;
      }

      .decode-output {
        white-space: pre-wrap;
        height: 200px;
        overflow-y: auto;
        background: var(--bg-color);
        padding: 1rem;
        border-radius: 0.375rem;
        border: 1px solid var(--border-color);
        position: relative;
        text-align: left;
      }

      .decode-output:empty::before {
        content: attr(data-placeholder);
        color: var(--text-color);
        opacity: 0.6;
        position: absolute;
        top: 1rem;
        left: 1rem;
        right: 1rem;
        pointer-events: none;
      }

      .text-box {
        background: var(--bg-color);
        border: 1px solid var(--border-color);
        border-radius: 0.5rem;
        padding: 1rem;
        box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
        width: 100%;
        box-sizing: border-box;
        position: relative;
        min-width: 0;
        overflow: hidden;
      }

      .text-box-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        margin-bottom: 1rem;
        min-height: 32px;
      }

      .text-box-header h2 {
        font-size: 1.25rem;
        color: var(--text-color);
        text-align: left;
        min-width: 150px;
      }

      .char-count {
        font-size: 0.875rem;
        color: var(--text-color);
        opacity: 0.8;
      }

      .button-group {
        display: flex;
        gap: 0.5rem;
        margin-top: 1rem;
      }

      .button {
        padding: 0.5rem 1rem;
        border-radius: 0.375rem;
        cursor: pointer;
        font-size: 0.875rem;
        display: flex;
        align-items: center;
        gap: 0.5rem;
        border: none;
      }

      .button-primary {
        background: var(--primary-color);
        color: white;
      }

      .button-primary.copy-btn {
        background: linear-gradient(45deg, #ff3366, #00ffff);
        border: none;
        position: relative;
        z-index: 1;
        overflow: hidden;
        transition: all 0.3s ease;
      }

      .button-primary.copy-btn:before {
        content: "";
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: linear-gradient(45deg, #ff3366, #00ffff);
        z-index: -1;
        transition: opacity 0.3s ease;
        opacity: 0.85;
      }

      .button-primary.copy-btn:hover:before {
        opacity: 1;
      }

      .button-primary.copy-btn:hover {
        transform: translateY(-2px);
        box-shadow: 0 0 15px rgba(255, 51, 102, 0.5);
      }

      .button-primary:hover {
        background: var(--button-hover);
        color: white;
      }

      .button-danger {
        background: transparent;
        color: #ef4444;
        border: 1px solid #ef4444;
      }

      .button-danger:hover {
        background: rgba(239, 68, 68, 0.1);
      }

      .button-secondary {
        background: transparent;
        border: 1px solid var(--border-color);
        color: var(--text-color);
      }

      .button-secondary:hover {
        background: var(--border-color);
      }

      textarea {
        width: 100%;
        height: 200px;
        padding: 1rem;
        border: 1px solid var(--border-color);
        border-radius: 0.375rem;
        font-size: 1rem;
        line-height: 1.5;
        resize: vertical;
        background: var(--bg-color);
        color: var(--text-color);
      }

      #output {
        white-space: pre-wrap;
        height: 200px;
        overflow-y: auto;
        background: var(--bg-color);
        padding: 1rem;
        border-radius: 0.375rem;
        border: 1px solid var(--border-color);
        position: relative;
        text-align: left;
        overflow-wrap: break-word;
        word-wrap: break-word;
        word-break: break-word;
        hyphens: auto;
      }

      #output:empty::before {
        content: attr(data-placeholder);
        color: var(--text-color);
        opacity: 0.6;
        position: absolute;
        top: 1rem;
        left: 1rem;
        right: 1rem;
        pointer-events: none;
      }

      @media (max-width: 768px) {
        .content {
          grid-template-columns: 1fr;
        }

        .container {
          padding: 1rem;
        }

        .settings-container {
          position: static;
          justify-content: center;
          margin: 1rem 0;
        }

        .settings-popup {
          position: fixed;
          top: 50%;
          left: 50%;
          transform: translate(-50%, -50%);
          margin: 0;
          width: 90%;
          max-width: 300px;
        }

        /* Adjust toggle buttons on mobile for proper sizing */
        .mode-toggle-container {
          gap: 0.75rem;
          padding: 0.25rem;
        }

        .mode-toggle {
          /* Allow buttons to flex and remove fixed min width */
          min-width: auto;
          flex: 1;
          padding: 0.75rem 1rem;
          font-size: 1rem;
          height: auto;
        }
        .decode-box {
          grid-template-columns: 1fr;
        }

        /* Mobile: keep header title and clear-button separate in two columns */
        .mask-words-header,
        .text-box-header {
          display: grid;
          grid-template-columns: 1fr auto; /* title on left, button on right */
          column-gap: 0.5rem;
          align-items: start; /* button stays top-aligned */
        }

        .mask-words-header h2,
        .text-box-header h2 {
          margin: 0; /* remove any extra margins */
          min-width: 0; /* allow wrapping within column */
        }

        .mask-words-header button,
        .text-box-header button {
          margin: 0; /* ensure button sits inside its grid cell */
        }
      }

      .mask-words-section {
        margin-top: 1rem;
        margin-bottom: 2rem;
        background: var(--bg-color);
        border: 1px solid var(--border-color);
        border-radius: 0.5rem;
        padding: 1.5rem;
        width: 100%;
        box-sizing: border-box;
      }

      .mask-words-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        margin-bottom: 1rem;
        min-height: 32px;
      }

      .mask-words-controls {
        display: flex;
        justify-content: space-between;
        align-items: center;
        margin-top: 1rem;
      }

      .mask-words-input {
        width: 100%;
        padding: 0.75rem;
        border: 1px solid var(--border-color);
        border-radius: 0.375rem;
        font-size: 1rem;
        background: var(--bg-color);
        color: var(--text-color);
      }

      .mask-words-input::placeholder {
        color: var(--text-color);
        opacity: 0.6;
      }

      .mask-words-help {
        font-size: 0.875rem;
        color: var(--text-color);
        opacity: 0.8;
        margin-top: 0.5rem;
      }

      .word-chips-container {
        display: flex;
        flex-wrap: wrap;
        gap: 0.5rem;
        margin-top: 1rem;
        min-height: 2rem;
      }

      .word-chip {
        background: var(--accent-color);
        color: var(--text-color);
        padding: 0.25rem 0.75rem;
        border-radius: 1rem;
        font-size: 0.875rem;
        display: flex;
        align-items: center;
        gap: 0.5rem;
      }

      .word-chip button {
        background: none;
        border: none;
        color: var(--text-color);
        cursor: pointer;
        padding: 0;
        font-size: 1rem;
        line-height: 1;
        display: flex;
        align-items: center;
      }

      .mode-toggle-container {
        display: flex;
        justify-content: center;
        gap: 1.5rem;
        margin-top: 1rem;
        padding: 0.5rem;
        border-radius: 1rem;
        width: 100%;
        box-sizing: border-box;
      }

      .mode-toggle {
        padding: 1rem 1.5rem;
        transition: all 0.3s ease;
        background: transparent;
        border: none;
        color: var(--text-color);
        position: relative;
        overflow: hidden;
        min-width: 200px;
        width: 200px;
        opacity: 0.5;
        border-radius: 2rem;
        border: 1px solid var(--border-color);
        display: flex;
        justify-content: center;
        align-items: center;
        font-size: 1.1rem;
        font-weight: 500;
        height: 50px;
        flex: 0 0 auto;
      }

      .mode-toggle:before {
        content: "";
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: linear-gradient(45deg, #4776e6, #8e54e9);
        opacity: 0;
        transition: opacity 0.3s ease;
        z-index: -1;
      }

      .mode-toggle:hover {
        opacity: 0.8;
        color: white;
      }

      .mode-toggle.active {
        opacity: 1;
        background: linear-gradient(45deg, #4776e6, #8e54e9);
        color: white;
        box-shadow: 0 0 20px rgba(71, 118, 230, 0.3);
        border: none;
      }

      .mode-toggle.active:before {
        opacity: 1;
      }

      .mode-toggle.active:hover {
        color: white;
      }

      [data-theme="dark"] .mode-toggle {
        color: rgba(255, 255, 255, 0.9);
      }

      [data-theme="dark"] .mode-toggle:not(.active) {
        opacity: 0.5;
      }

      [data-theme="dark"] .mode-toggle:hover:not(.active) {
        opacity: 0.8;
      }

      /* Toast Notification */
      .toast-notification {
        position: fixed;
        bottom: 20px;
        right: 20px;
        max-width: 350px;
        background-color: var(--secondary-bg);
        color: var(--text-color);
        border-left: 4px solid var(--primary-color);
        padding: 16px;
        border-radius: 4px;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
        display: flex;
        flex-direction: column;
        z-index: 1000;
        transform: translateY(150%);
        transition: transform 0.3s ease-out;
      }

      .toast-notification.show {
        transform: translateY(0);
      }

      .toast-content {
        display: flex;
        align-items: center;
        margin-bottom: 12px;
      }

      .toast-icon {
        margin-right: 12px;
        font-size: 24px;
      }

      .toast-message {
        flex: 1;
      }

      .toast-title {
        font-weight: bold;
        margin-bottom: 4px;
      }

      .toast-actions {
        display: flex;
        justify-content: flex-end;
        gap: 8px;
      }

      .toast-button {
        padding: 6px 12px;
        border-radius: 4px;
        border: none;
        cursor: pointer;
        font-size: 14px;
        transition: background-color 0.2s;
      }

      .toast-primary {
        background-color: var(--primary-color);
        color: white;
      }

      .toast-primary:hover {
        background-color: var(--button-hover);
      }

      .toast-secondary {
        background-color: transparent;
        color: var(--text-color);
        border: 1px solid var(--border-color);
      }

      .toast-secondary:hover {
        background-color: var(--border-color);
      }

      .primary-link {
        color: var(--primary-color);
        text-decoration: none;
      }

      .footer-note {
        text-align: center;
        margin-top: 2rem;
        padding-bottom: 1rem;
        color: var(--text-color);
        opacity: 0.7;
        font-size: 0.9rem;
      }

      /* Mobile toggle overrides placed after default styles for higher specificity */
      @media (max-width: 768px) {
        .mode-toggle-container {
          gap: 0.75rem;
          padding: 0.25rem;
        }
        .mode-toggle {
          min-width: 0 !important;
          width: auto !important;
          flex: 1 1 0;
          padding: 0.75rem 1rem;
          font-size: 1rem;
          height: auto;
        }
      }

      #words-heading {
        min-width: 200px;
      }

      .content-section {
        width: 100%;
        transition: opacity 0.2s ease-in;
      }

      html {
        overflow-y: scroll; /* Always show vertical scrollbar */
      }

      .loading .content-section {
        display: none; /* Hide content sections initially */
      }

      .init-warning {
        display: none;
        margin: 1rem auto 0;
        max-width: 1200px;
        padding: 0.75rem 1rem;
        border: 1px solid #ef4444;
        border-radius: 0.5rem;
        background: rgba(239, 68, 68, 0.1);
        color: var(--text-color);
        font-size: 0.9rem;
      }

      .init-warning.show {
        display: block;
      }

      .mask-words-header h2 {
        text-align: left; /* Ensure the title is left-aligned */
      }

      /* Fix clear buttons so they stay inside their section on mobile */
      @media (max-width: 768px) {
        .mask-words-header {
          display: flex;
          justify-content: space-between;
          align-items: center;
          flex-wrap: wrap;
          gap: 0.5rem;
        }
        #words-heading {
          min-width: 0; /* override the desktop-only min-width */
          flex: 1; /* take up remaining space */
        }
        #clear-words-btn {
          flex-shrink: 0; /* stay visible, don't shrink below content */
        }

        .text-box-header {
          display: flex;
          justify-content: space-between;
          align-items: center;
          flex-wrap: wrap;
          gap: 0.5rem;
        }
        .text-box-header h2 {
          min-width: 0; /* allow the heading to shrink on mobile */
          flex: 1;
        }
        .text-box-header button {
          flex-shrink: 0;
        }
      }

      /* only vertically stack Input/Output headers on *very* narrow viewports */
      @media (max-width: 360px) {
        .text-box-header {
          display: flex;
          flex-direction: column;
          align-items: flex-start;
          gap: 0.5rem;
        }
      }