/* ==========================================================================
   JTApplets - Modern Responsive Stylesheet
   Color Scheme: Professional Blues & Grays
   ========================================================================== */

/* CSS Custom Properties (Variables) */
:root {
    /* Primary Colors - Blues */
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #3b82f6;
    --color-primary-subtle: #eff6ff;

    /* Secondary Colors - Grays */
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;

    /* Accent Colors */
    --color-accent: #0891b2;
    --color-success: #059669;
    --color-warning: #d97706;
    --color-error: #dc2626;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', Menlo, Consolas, monospace;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;

    /* Container */
    --container-max: 1200px;
    --container-padding: 1rem;
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-gray-700);
    background-color: var(--color-gray-50);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-dark);
}

ul {
    list-style: none;
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.section {
    padding: var(--space-3xl) 0;
}

.section-alt {
    background-color: var(--color-gray-100);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--space-sm);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--color-gray-500);
}

.section-footer {
    text-align: center;
    margin-top: var(--space-2xl);
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 0.9375rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
    white-space: nowrap;
}

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

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

.btn-secondary {
    background-color: var(--color-gray-800);
    color: white;
    border-color: var(--color-gray-800);
}

.btn-secondary:hover {
    background-color: var(--color-gray-700);
    border-color: var(--color-gray-700);
    color: white;
}

.btn-outline {
    background-color: transparent;
    color: var(--color-primary);
    border-color: var(--color-primary);
}

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

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: white;
    box-shadow: var(--shadow-sm);
    border-bottom: 1px solid var(--color-gray-200);
}

.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--container-padding);
    max-width: var(--container-max);
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-gray-900);
}

.logo:hover {
    color: var(--color-primary);
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-menu {
    display: flex;
    gap: var(--space-lg);
}

.nav-link {
    color: var(--color-gray-600);
    font-weight: 500;
    padding: var(--space-sm) 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: width var(--transition-normal);
}

.nav-link:hover {
    color: var(--color-primary);
}

.nav-link:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-gray-700);
    transition: all var(--transition-fast);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
    padding: var(--space-3xl) 0;
    background: linear-gradient(135deg, var(--color-gray-900) 0%, var(--color-gray-800) 100%);
    color: white;
}

.hero-content {
    max-width: 700px;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--space-lg);
}

.hero p {
    font-size: 1.125rem;
    color: var(--color-gray-300);
    margin-bottom: var(--space-xl);
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

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

.hero .btn-primary:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary-light);
}

.hero .btn-secondary {
    background-color: transparent;
    border-color: white;
    color: white;
}

.hero .btn-secondary:hover {
    background-color: white;
    color: var(--color-gray-900);
}

/* ==========================================================================
   Cards
   ========================================================================== */

.card {
    background-color: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all var(--transition-normal);
    border: 1px solid var(--color-gray-200);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.card-body {
    padding: var(--space-lg);
}

.card-category {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    line-height: 1.3;
}

.card-title a {
    color: var(--color-gray-900);
}

.card-title a:hover {
    color: var(--color-primary);
}

.card-excerpt {
    color: var(--color-gray-600);
    margin-bottom: var(--space-md);
}

.card-meta {
    display: flex;
    gap: var(--space-md);
    font-size: 0.875rem;
    color: var(--color-gray-500);
}

/* ==========================================================================
   Blog Grid
   ========================================================================== */

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

/* ==========================================================================
   Tools Section
   ========================================================================== */

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
}

.tool-card {
    background-color: white;
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-gray-200);
    transition: all var(--transition-normal);
}

.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.tool-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.tool-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--space-sm);
}

.tool-description {
    color: var(--color-gray-600);
    margin-bottom: var(--space-lg);
    font-size: 0.9375rem;
}

/* ==========================================================================
   Archive Section
   ========================================================================== */

.archive-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-md);
}

.archive-card {
    background-color: white;
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    border: 1px solid var(--color-gray-200);
    transition: all var(--transition-fast);
}

.archive-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
}

.archive-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--space-sm);
}

.archive-description {
    color: var(--color-gray-600);
    font-size: 0.9375rem;
    margin-bottom: var(--space-md);
}

/* ==========================================================================
   About Section
   ========================================================================== */

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--space-lg);
}

.about-text p {
    color: var(--color-gray-600);
    margin-bottom: var(--space-lg);
    font-size: 1.0625rem;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-xl);
}

.about-features li {
    color: var(--color-gray-700);
    font-weight: 500;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
    background-color: var(--color-gray-900);
    color: var(--color-gray-300);
    padding: var(--space-3xl) 0 var(--space-xl);
    margin-top: auto;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-brand .logo-icon {
    font-size: 1.75rem;
}

.footer-brand .logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: white;
}

.footer-tagline {
    font-size: 0.9375rem;
    color: var(--color-gray-400);
}

.footer-links h4 {
    color: white;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-links a {
    color: var(--color-gray-400);
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid var(--color-gray-800);
    padding-top: var(--space-xl);
    text-align: center;
    font-size: 0.875rem;
    color: var(--color-gray-500);
}

.footer-note {
    margin-top: var(--space-xs);
    font-size: 0.8125rem;
}

/* ==========================================================================
   Mobile Navigation
   ========================================================================== */

.nav-menu.active {
    display: flex;
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: white;
        flex-direction: column;
        padding: var(--space-lg);
        gap: var(--space-md);
        border-bottom: 1px solid var(--color-gray-200);
        box-shadow: var(--shadow-lg);
        display: none;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-link {
        padding: var(--space-sm) 0;
        font-size: 1rem;
    }
}

/* ==========================================================================
   Responsive Typography & Layout
   ========================================================================== */

@media (max-width: 640px) {
    .hero {
        padding: var(--space-2xl) 0;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .section {
        padding: var(--space-2xl) 0;
    }

    .section-header h2 {
        font-size: 1.75rem;
    }

    .blog-grid,
    .tools-grid,
    .archive-grid {
        grid-template-columns: 1fr;
    }
}

@media (min-width: 768px) {
    :root {
        --container-padding: 2rem;
    }
}

@media (min-width: 1024px) {
    .hero h1 {
        font-size: 3rem;
    }

    .section-header h2 {
        font-size: 2.25rem;
    }
}

/* ==========================================================================
   Accessibility
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus States */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}