/* Root Variables */
:root {
    --primary: #667eea;
    --primary-dark: #5568d3;
    --secondary: #764ba2;
    --success: #48bb78;
    --warning: #f6ad55;
    --error: #f56565;
    --bg-light: #f7fafc;
    --bg-white: #ffffff;
    --text-dark: #2d3748;
    --text-light: #718096;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.15);
}

/* Dark Mode */
[data-theme="dark"] {
    --bg-light: #1a202c;
    --bg-white: #2d3748;
    --text-dark: #f7fafc;
    --text-light: #cbd5e0;
    --border-color: #4a5568;
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Container */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 40px 0;
    box-shadow: var(--shadow);
    position: relative;
}

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

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.tagline {
    font-size: 1rem;
    opacity: 0.95;
    margin-top: 5px;
    flex-basis: 100%;
}

/* Theme Toggle */
.theme-toggle {
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid rgba(255, 255, 255, 0.3);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.05);
}

.theme-toggle:focus {
    outline: 3px solid rgba(255, 255, 255, 0.5);
    outline-offset: 2px;
}

/* Main Content */
main {
    padding: 40px 0;
}

/* Sections */
.input-section,
.algorithm-section,
.output-section,
.history-section {
    background: var(--bg-white);
    border-radius: 8px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-color);
}

/* Tabs */
.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 25px;
    border-bottom: 2px solid var(--border-color);
    flex-wrap: wrap;
}

.tab-btn {
    background: none;
    border: none;
    padding: 12px 20px;
    font-size: 1rem;
    color: var(--text-light);
    cursor: pointer;
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
    font-weight: 500;
}

.tab-btn:hover {
    color: var(--text-dark);
}

.tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.tab-btn:focus {
    outline: 2px solid var(--primary);
    outline-offset: -2px;
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Form Groups */
.form-group {
    margin-bottom: 20px;
}

.form-group:last-child {
    margin-bottom: 0;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-dark);
    font-size: 0.95rem;
}

legend {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 15px;
    font-size: 0.95rem;
}

/* Input Fields */
.input-field,
.file-input {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.95rem;
    background-color: var(--bg-light);
    color: var(--text-dark);
    transition: all 0.3s ease;
    resize: vertical;
}

.input-field:hover,
.file-input:hover {
    border-color: var(--primary);
}

.input-field:focus,
.file-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    background-color: var(--bg-white);
}

textarea.input-field {
    min-height: 120px;
    resize: vertical;
    max-height: 300px;
}

/* File Input */
.file-input {
    display: none;
}

.file-label {
    display: inline-block;
    padding: 10px 20px;
    background: var(--primary);
    color: white;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.3s ease;
    font-weight: 600;
}

.file-label:hover {
    background: var(--primary-dark);
}

.file-label:focus-within {
    outline: 3px solid var(--primary);
    outline-offset: 2px;
}

.file-drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 15px;
    background-color: var(--bg-light);
}

.file-drop-zone:hover {
    border-color: var(--primary);
    background-color: rgba(102, 126, 234, 0.05);
}

.file-drop-zone.drag-over {
    border-color: var(--primary);
    background-color: rgba(102, 126, 234, 0.1);
}

.file-drop-zone p {
    color: var(--text-light);
    margin: 0;
}

/* Input Meta */
.input-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
    font-size: 0.85rem;
    color: var(--text-light);
}

.char-count,
.file-info {
    display: block;
}

.clear-btn {
    background: none;
    border: none;
    color: var(--primary);
    cursor: pointer;
    text-decoration: underline;
    font-size: 0.85rem;
    padding: 0;
    transition: color 0.3s ease;
}

.clear-btn:hover {
    color: var(--primary-dark);
}

.clear-btn:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Checkboxes */
.checkbox-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 15px;
    margin-top: 15px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    user-select: none;
    font-weight: 500;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary);
}

.checkbox-label input[type="checkbox"]:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Toggle */
.toggle-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    user-select: none;
    font-weight: 500;
}

.toggle-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary);
}

/* Buttons */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn:focus {
    outline: 3px solid var(--primary);
    outline-offset: 2px;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background: var(--bg-light);
    color: var(--text-dark);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--border-color);
    border-color: var(--primary);
    color: var(--primary);
}

.btn-tertiary {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
}

.btn-tertiary:hover:not(:disabled) {
    background: rgba(102, 126, 234, 0.1);
    border-color: var(--primary-dark);
}

.btn-copy {
    padding: 6px 12px;
    font-size: 0.85rem;
}

/* Controls Section */
.controls {
    margin-bottom: 20px;
}

.output-controls {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    align-items: center;
    margin-top: 20px;
}

/* Output Section */
.hash-output {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.hash-item {
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 15px;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 15px;
    transition: all 0.3s ease;
}

.hash-item:hover {
    border-color: var(--primary);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.1);
}

.hash-item-content {
    flex: 1;
    min-width: 0;
}

.hash-algorithm {
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 6px;
    font-size: 0.9rem;
}

.hash-value {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    word-break: break-all;
    color: var(--text-dark);
    font-size: 0.85rem;
    line-height: 1.4;
    background: var(--bg-white);
    padding: 10px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

.hash-actions {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.btn-copy {
    background: var(--primary);
    color: white;
    white-space: nowrap;
}

.btn-copy:hover:not(:disabled) {
    background: var(--primary-dark);
}

.btn-copy.copied {
    background: var(--success);
}

.empty-state {
    text-align: center;
    color: var(--text-light);
    padding: 40px 20px;
    font-style: italic;
}

/* Verify Result */
.verify-result {
    margin-top: 20px;
    padding: 15px;
    border-radius: 6px;
    display: none;
}

.verify-result.show {
    display: block;
}

.verify-result.match {
    background: rgba(72, 187, 120, 0.1);
    border: 1px solid var(--success);
    color: var(--success);
}

.verify-result.mismatch {
    background: rgba(245, 101, 101, 0.1);
    border: 1px solid var(--error);
    color: var(--error);
}

/* History Section */
.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    gap: 10px;
}

.history-header h2 {
    margin: 0;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.history-item {
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.history-item:hover {
    background: rgba(102, 126, 234, 0.05);
    border-color: var(--primary);
}

.history-item-text {
    flex: 1;
    min-width: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Footer */
.footer {
    background: var(--bg-white);
    border-top: 1px solid var(--border-color);
    padding: 30px 0;
    margin-top: 60px;
    text-align: center;
    color: var(--text-light);
    font-size: 0.9rem;
}

.footer p {
    margin: 5px 0;
}

.footer a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 3px;
}

.footer a:hover,
.footer a:focus {
    color: var(--primary-dark);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.disclaimer {
    font-style: italic;
    margin-top: 10px;
}

/* Responsive */
@media (max-width: 768px) {
    .header h1 {
        font-size: 1.8rem;
    }

    .header-content {
        flex-direction: column;
        align-items: flex-start;
    }

    .theme-toggle {
        align-self: flex-end;
    }

    .tagline {
        flex-basis: auto;
        margin-top: 0;
    }

    .input-section,
    .algorithm-section,
    .output-section,
    .history-section {
        padding: 20px;
    }

    .checkbox-grid {
        grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    }

    .hash-item {
        flex-direction: column;
    }

    .hash-actions {
        width: 100%;
    }

    .btn-copy {
        flex: 1;
    }

    .output-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .btn-secondary {
        width: 100%;
    }

    .history-item {
        flex-direction: column;
        align-items: flex-start;
    }

    main {
        padding: 20px 0;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 25px 0;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .tabs {
        gap: 5px;
    }

    .tab-btn {
        padding: 10px 12px;
        font-size: 0.85rem;
    }

    .checkbox-grid {
        grid-template-columns: 1fr;
    }

    .input-field,
    .file-input {
        font-size: 16px; /* Prevents zoom on iOS */
    }

    .container {
        padding: 0 15px;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
    }
}

@media (prefers-contrast: more) {
    :root {
        --primary: #3d3be8;
        --text-dark: #000;
        --border-color: #000;
    }

    [data-theme="dark"] {
        --text-dark: #fff;
        --border-color: #fff;
    }
}

/* Print Styles */
@media print {
    .header,
    .input-section,
    .algorithm-section,
    .output-controls,
    .footer,
    .history-section {
        display: none;
    }

    .hash-output {
        break-inside: avoid;
    }
}

/* Focus Visible */
:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 2px;
}

/* New Section Styles */

/* Section Blurbs */
.section-blurb {
    font-size: 1.05rem;
    color: var(--text-light);
    margin: 12px 0 24px 0;
    line-height: 1.7;
    font-weight: 300;
}

/* Intro Section */
.intro-section,
.author-section {
    margin-bottom: 40px;
    padding: 30px;
    background: var(--bg-white);
    border-radius: 12px;
    border-left: 4px solid var(--primary);
}

.intro-section h2,
.author-section h2 {
    margin-bottom: 16px;
    color: var(--text-dark);
}

/* Tab Descriptions */
.tab-description {
    font-size: 0.95rem;
    color: var(--text-light);
    margin: 12px 0 20px 0;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

/* Algorithm Note */
.algo-note {
    font-size: 0.85rem;
    color: var(--text-light);
    font-weight: 400;
}

/* Algorithm List */
.algorithm-list {
    margin: 20px 0 0 20px;
    list-style: disc;
}

.algorithm-list li {
    margin: 12px 0;
    line-height: 1.6;
}

.algorithm-list strong {
    color: var(--primary);
}

/* FAQ Section */
.faq-section {
    margin-top: 50px;
    padding: 30px;
    background: var(--bg-white);
    border-radius: 12px;
}

.faq-section h2 {
    margin-bottom: 12px;
    color: var(--text-dark);
}

.faq-container {
    margin-top: 30px;
}

.faq-item {
    margin-bottom: 28px;
    padding: 20px;
    background: var(--bg-light);
    border-radius: 8px;
    border-left: 3px solid var(--primary);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.faq-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.1);
}

.faq-question {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 12px;
    cursor: pointer;
}

.faq-answer {
    color: var(--text-light);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* Use Cases Section */
.use-cases-section {
    margin-top: 50px;
    padding: 30px;
    background: var(--bg-white);
    border-radius: 12px;
}

.use-cases-section h2 {
    margin-bottom: 12px;
    color: var(--text-dark);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 30px;
}

.use-case-card {
    padding: 24px;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.05) 0%, rgba(118, 75, 162, 0.05) 100%);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    transition: all 0.3s ease;
}

.use-case-card:hover {
    border-color: var(--primary);
    box-shadow: 0 6px 16px rgba(102, 126, 234, 0.15);
    transform: translateY(-4px);
}

.use-case-card h3 {
    font-size: 1.1rem;
    color: var(--primary);
    margin-bottom: 12px;
    font-weight: 600;
}

.use-case-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Footer Date */
.footer-date {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-top: 8px;
}

/* Legal Pages */
.legal-section {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    margin-bottom: 30px;
    padding: 30px;
}

.legal-section h2 {
    color: var(--text-dark);
    font-size: 1.5rem;
    margin-bottom: 14px;
}

.legal-section p,
.legal-section li {
    color: var(--text-light);
    margin-bottom: 12px;
}

.legal-section ul {
    padding-left: 22px;
}

.legal-section a {
    color: var(--primary);
    font-weight: 600;
}

.legal-section a:hover,
.legal-section a:focus {
    color: var(--primary-dark);
}

/* Responsive Adjustments for New Sections */
@media (max-width: 768px) {
    .intro-section,
    .faq-section,
    .use-cases-section,
    .legal-section {
        padding: 20px;
    }
    
    .use-cases-grid {
        grid-template-columns: 1fr;
    }
    
    .faq-item {
        padding: 16px;
    }
    
    .section-blurb {
        font-size: 1rem;
    }
}