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

:root {
    --primary: #1a73e8;
    --primary-dark: #1557b0;
    --primary-light: #e8f0fe;
    --bg: #f8f9fa;
    --bg-card: #ffffff;
    --text: #1a1a2e;
    --text-secondary: #4a4a6a;
    --text-muted: #6c757d;
    --border: #e9ecef;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.15);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.3s ease;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

[data-theme="dark"] {
    --bg: #0d1117;
    --bg-card: #161b22;
    --text: #e6edf3;
    --text-secondary: #b0b8c4;
    --text-muted: #8b949e;
    --border: #30363d;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.6);
    --primary-light: #1c2d4a;
}

html { scroll-behavior: smooth; }
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}
header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 12px 0;
    transition: background 0.3s;
}
header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}
.logo {
    display: flex;
    align-items: center;
    gap: 8px;
}
.logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}
.logo .tagline {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: none;
}
@media (min-width: 600px) {
    .logo .tagline { display: inline; }
}
.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text);
    cursor: pointer;
    padding: 4px 8px;
}
#mainNav {
    display: flex;
    align-items: center;
    gap: 20px;
}
#mainNav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}
#mainNav ul li a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}
#mainNav ul li a:hover { color: var(--primary); }
.theme-toggle {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    padding: 4px 8px;
    color: var(--text);
}
@media (max-width: 768px) {
    .menu-toggle { display: block; }
    #mainNav {
        display: none;
        flex-direction: column;
        width: 100%;
        padding: 16px 0;
        gap: 12px;
        border-top: 1px solid var(--border);
        margin-top: 12px;
    }
    #mainNav.open { display: flex; }
    #mainNav ul {
        flex-direction: column;
        gap: 8px;
        width: 100%;
    }
    #mainNav ul li { width: 100%; }
    #mainNav ul li a { display: block; padding: 8px 0; }
    .theme-toggle { align-self: flex-start; }
}
.hero {
    padding: 60px 0;
    background: var(--primary-light);
    text-align: center;
}
.hero h1 {
    font-size: 2.5rem;
    color: var(--text);
    margin-bottom: 16px;
}
.hero p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 24px;
}
.search-container {
    display: flex;
    max-width: 500px;
    margin: 0 auto 24px;
    gap: 8px;
}
.search-container input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: var(--bg-card);
    color: var(--text);
    transition: border-color 0.2s;
}
.search-container input:focus {
    outline: none;
    border-color: var(--primary);
}
.search-container button {
    padding: 12px 24px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}
.search-container button:hover { background: var(--primary-dark); }
.hero-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    border: 2px solid transparent;
}
.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}
.btn-secondary {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}
.btn-secondary:hover {
    background: var(--primary-light);
    transform: translateY(-2px);
}
.categories { padding: 60px 0; }
.categories h2 {
    text-align: center;
    margin-bottom: 32px;
    font-size: 2rem;
}
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 16px;
}
.category-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px 16px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow);
}
.category-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary);
}
.category-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: 8px;
}
.category-card h3 {
    font-size: 1rem;
    color: var(--text);
}
.category-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 4px;
}
.popular-tools, .featured-tools {
    padding: 60px 0;
}
.popular-tools {
    background: var(--bg-card);
}
.popular-tools h2, .featured-tools h2 {
    text-align: center;
    margin-bottom: 32px;
    font-size: 2rem;
}
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 20px;
}
.tool-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    text-decoration: none;
    color: var(--text);
    transition: all 0.2s;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
}
.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary);
}
.tool-card .tool-icon {
    font-size: 1.8rem;
    margin-bottom: 8px;
}
.tool-card h3 {
    font-size: 1.05rem;
    margin-bottom: 4px;
    color: var(--text);
}
.tool-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    flex: 1;
}
.tool-card .tool-category {
    font-size: 0.75rem;
    color: var(--primary);
    font-weight: 600;
    margin-top: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 40px 0 20px;
    margin-top: 40px;
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 32px;
    margin-bottom: 24px;
}
.footer-brand h3 {
    color: var(--primary);
    font-size: 1.25rem;
}
.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 4px;
}
.footer-links h4 {
    color: var(--text);
    font-size: 1rem;
    margin-bottom: 8px;
}
.footer-links ul {
    list-style: none;
}
.footer-links ul li { margin-bottom: 4px; }
.footer-links ul li a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}
.footer-links ul li a:hover { color: var(--primary); }
.footer-bottom {
    text-align: center;
    padding-top: 16px;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.85rem;
}
.tool-page { padding: 40px 0; }
.tool-page h1 {
    font-size: 2rem;
    color: var(--text);
    margin-bottom: 8px;
}
.tool-page .tool-description {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 24px;
}
.tool-interface {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
}
.tool-interface label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text);
}
.tool-interface input,
.tool-interface select,
.tool-interface textarea {
    width: 100%;
    padding: 10px 12px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: var(--bg);
    color: var(--text);
    transition: border-color 0.2s;
    font-family: var(--font);
}
.tool-interface input:focus,
.tool-interface select:focus,
.tool-interface textarea:focus {
    outline: none;
    border-color: var(--primary);
}
.tool-interface textarea {
    min-height: 120px;
    resize: vertical;
}
.tool-interface .input-group { margin-bottom: 16px; }
.tool-interface .input-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}
.tool-interface button {
    padding: 10px 24px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    font-size: 1rem;
}
.tool-interface button:hover { background: var(--primary-dark); }
.tool-interface button.secondary {
    background: var(--border);
    color: var(--text);
}
.tool-interface button.secondary:hover {
    background: var(--text-muted);
    color: #fff;
}
.tool-result {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    margin-top: 16px;
    display: none;
}
.tool-result.visible { display: block; }
.tool-result h3 {
    margin-bottom: 12px;
    color: var(--text);
}
.tool-result .result-content {
    background: var(--bg);
    padding: 16px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    max-height: 400px;
    overflow: auto;
    white-space: pre-wrap;
    word-break: break-all;
    font-family: monospace;
    font-size: 0.9rem;
}
.tool-result .result-actions {
    display: flex;
    gap: 12px;
    margin-top: 12px;
    flex-wrap: wrap;
}
.tool-error {
    color: #dc3545;
    background: #f8d7da;
    padding: 12px;
    border-radius: var(--radius-sm);
    margin-bottom: 12px;
    display: none;
}
.tool-error.visible { display: block; }
.tool-info {
    color: var(--text-muted);
    font-size: 0.9rem;
    padding: 12px;
    background: var(--primary-light);
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
}
.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
    margin-top: 24px;
}
.blog-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
    transition: all 0.2s;
}
.blog-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}
.blog-card h2 {
    font-size: 1.2rem;
    margin-bottom: 8px;
}
.blog-card h2 a {
    color: var(--text);
    text-decoration: none;
}
.blog-card h2 a:hover { color: var(--primary); }
.blog-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 8px;
}
.blog-card small {
    color: var(--text-muted);
    font-size: 0.85rem;
}
.blog-card .blog-category {
    display: inline-block;
    background: var(--primary-light);
    color: var(--primary);
    padding: 2px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-top: 8px;
}
.blog-post {
    max-width: 800px;
    margin: 0 auto;
}
.blog-post h1 {
    font-size: 2.2rem;
    color: var(--text);
    margin-bottom: 8px;
}
.blog-post h2 {
    font-size: 1.5rem;
    color: var(--text);
    margin-top: 32px;
    margin-bottom: 12px;
}
.blog-post p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 16px;
}
.blog-post ul {
    margin: 16px 0 16px 24px;
    color: var(--text-secondary);
}
.blog-post ul li { margin-bottom: 8px; }
@media (max-width: 480px) {
    .hero h1 { font-size: 1.8rem; }
    .hero p { font-size: 1rem; }
    .tools-grid { grid-template-columns: 1fr 1fr; }
    .category-grid { grid-template-columns: 1fr 1fr; }
    .search-container { flex-direction: column; }
    .search-container button { width: 100%; }
    .hero-buttons { flex-direction: column; align-items: center; }
    .hero-buttons .btn { width: 100%; max-width: 280px; text-align: center; }
    .tool-interface .input-row { grid-template-columns: 1fr; }
    .blog-grid { grid-template-columns: 1fr; }
}
@media (min-width: 768px) {
    .tools-grid { grid-template-columns: repeat(3, 1fr); }
    .category-grid { grid-template-columns: repeat(4, 1fr); }
}
@media (min-width: 1024px) {
    .tools-grid { grid-template-columns: repeat(4, 1fr); }
}

/* ============================================================
   MOBILE & ACCESSIBILITY IMPROVEMENTS (Additive)
   ============================================================ */

/* Better color contrast (WCAG 2.1 AA) */
:root {
    --text-secondary: #3d3d5c;
    --text-muted: #5a5a72;
}
[data-theme="dark"] {
    --text-secondary: #c5cdd8;
    --text-muted: #a4abb5;
}

/* Minimum tap target size on mobile (48px) */
@media (max-width: 768px) {
    button,
    .btn,
    .theme-toggle,
    .menu-toggle,
    a.btn,
    .tool-interface button,
    .search-container button {
        min-height: 48px;
        min-width: 48px;
        font-size: 1rem;
        padding: 12px 20px;
    }

    input,
    select,
    textarea {
        min-height: 48px;
        font-size: 16px; /* Prevents iOS zoom on focus */
    }

    h1 { font-size: 1.75rem; }
    h2 { font-size: 1.35rem; }

    .container { padding: 0 16px; }
    .hero { padding: 40px 0; }
    .hero h1 { font-size: 1.75rem; line-height: 1.3; }
    .hero p { font-size: 1rem; }

    .tools-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
    .tool-card { padding: 14px; }
    .tool-card h3 { font-size: 0.95rem; }
    .tool-card p { font-size: 0.8rem; }

    .category-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
    .category-card { padding: 16px 10px; }
}

/* Prevent horizontal scroll on all devices */
html, body { overflow-x: hidden; max-width: 100%; }

/* Better focus states for keyboard users */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 2px;
}

/* Smooth image rendering on retina */
img { max-width: 100%; height: auto; }