/* CSS Custom Properties for theming and accessibility */
:root {
    --color-primary: #1C1E21;
    --color-secondary: #050505;
    --color-accent: #0051D5;
    --color-accent-hover: #0041AA;
    --color-text: #050505;
    --color-text-light: #65676B;
    --color-link: #0051D5;
    --color-link-hover: #0041AA;
    --color-bg: #FFFFFF;
    --color-bg-alt: #F0F2F5;
    --color-bg-card: #FFFFFF;
    --color-border: rgba(0, 0, 0, 0.08);
    --font-main: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    --max-width: 1200px;
    --spacing-unit: 1rem;
    --border-radius: 12px;
    --border-radius-lg: 24px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 24px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --color-primary: #E4E6EB;
        --color-secondary: #F0F2F5;
        --color-accent: #4493F8;
        --color-accent-hover: #5BA0FF;
        --color-text: #E4E6EB;
        --color-text-light: #B0B3B8;
        --color-link: #4493F8;
        --color-link-hover: #5BA0FF;
        --color-bg: #18191A;
        --color-bg-alt: #242526;
        --color-bg-card: #242526;
        --color-border: rgba(255, 255, 255, 0.1);
        --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
        --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.3);
        --shadow-lg: 0 12px 24px rgba(0, 0, 0, 0.4);
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

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

html {
    font-size: 100%;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    font-size: 1rem;
    line-height: 1.75;
    color: var(--color-text);
    background-color: var(--color-bg);
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Global link styles */
a {
    color: var(--color-link);
    font-weight: 600;
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
    transition: var(--transition);
}

a:hover {
    color: var(--color-link-hover);
    text-decoration-thickness: 2px;
}

a:focus {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
    border-radius: 2px;
}

/* Skip navigation link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-accent);
    color: white !important;
    padding: 12px 24px;
    text-decoration: none;
    z-index: 100;
    border-radius: 0 0 var(--border-radius) 0;
    font-weight: 600;
}

.skip-link:hover {
    color: white !important;
    text-decoration: none;
    background: var(--color-accent-hover);
}

.skip-link:focus {
    top: 0;
    color: white !important;
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 2);
}

/* Header */
header {
    background: var(--color-bg);
    padding: calc(var(--spacing-unit) * 3) 0;
    text-align: center;
    position: relative;
}

header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-border), transparent);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: calc(var(--spacing-unit) * 1);
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.tagline {
    font-size: clamp(1.125rem, 2.5vw, 1.5rem);
    font-weight: 400;
    color: var(--color-text-light);
    margin-bottom: calc(var(--spacing-unit) * 2);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

/* Buttons */
.button-group {
    display: flex;
    gap: calc(var(--spacing-unit) * 1.5);
    justify-content: center;
    flex-wrap: wrap;
    margin-top: calc(var(--spacing-unit) * 2);
}

.button {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--border-radius-lg);
    transition: var(--transition);
    border: none;
    position: relative;
    overflow: hidden;
    min-height: 48px;
}

.button-primary {
    background: var(--color-accent);
    color: white !important;
    box-shadow: var(--shadow-md);
    text-decoration: none;
    font-weight: 600;
}

.button-primary:hover {
    background: var(--color-accent-hover);
    color: white !important;
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
    text-decoration: none;
}

.button-secondary {
    background: var(--color-bg-alt);
    color: var(--color-accent);
    box-shadow: var(--shadow-sm);
    border: 2px solid var(--color-accent);
    text-decoration: none;
    font-weight: 600;
}

.button-secondary:hover {
    background: var(--color-accent);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    text-decoration: none;
}

.button:focus {
    outline: 2px solid var(--color-accent);
    outline-offset: 3px;
}

.button:active {
    transform: translateY(0);
}

/* Main content sections */
main {
    padding: calc(var(--spacing-unit) * 3) 0;
    background: var(--color-bg);
}

section {
    margin-bottom: calc(var(--spacing-unit) * 4);
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: calc(var(--spacing-unit) * 2);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.about-content {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
    width: 100%;
}

.about-content p {
    margin-bottom: calc(var(--spacing-unit) * 2);
}

/* Featured case study box */
.featured-box {
    background: var(--color-bg-card);
    padding: calc(var(--spacing-unit) * 2);
    border-radius: var(--border-radius);
    margin-top: calc(var(--spacing-unit) * 2);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--color-border);
}

.featured-box:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.featured-box h3 {
    margin-top: 0;
    margin-bottom: calc(var(--spacing-unit) * 1);
    color: var(--color-primary);
    font-size: 1.5rem;
    font-weight: 600;
}

.featured-box p {
    margin-bottom: calc(var(--spacing-unit) * 2);
    color: var(--color-text-light);
    line-height: 1.7;
}

/* Achievement Cards */
.achievements {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: calc(var(--spacing-unit) * 2);
    list-style: none;
    padding: 0;
}

.achievements li {
    background: var(--color-bg-card);
    padding: calc(var(--spacing-unit) * 1.5);
    padding-left: calc(var(--spacing-unit) * 4);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    font-size: 1rem;
    line-height: 1.7;
    border: 1px solid var(--color-border);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: flex-start;
    gap: calc(var(--spacing-unit) * 1);
}

.achievements li::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--color-accent);
    transform: scaleY(0);
    transition: transform 0.3s ease;
}

.achievements li:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.achievements li:hover::before {
    transform: scaleY(1);
}

/* Achievement icons */
.achievement-icon {
    position: absolute;
    left: calc(var(--spacing-unit) * 1.5);
    top: calc(var(--spacing-unit) * 1.5);
    color: var(--color-accent);
    flex-shrink: 0;
    width: 24px;
    height: 24px;
}

/* Contact section */
.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: calc(var(--spacing-unit) * 2);
    font-size: 1.125rem;
    margin-top: calc(var(--spacing-unit) * 2);
}

.contact-info p {
    background: var(--color-bg-card);
    padding: calc(var(--spacing-unit) * 2);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
    transition: var(--transition);
}

.contact-info p:hover {
    box-shadow: var(--shadow-sm);
    transform: translateY(-1px);
}

.contact-info a {
    color: var(--color-link);
    text-decoration: underline;
    font-weight: 600;
    transition: var(--transition);
}

.contact-info a:hover {
    color: var(--color-link-hover);
    text-decoration-thickness: 2px;
}

.contact-info a:focus {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
    border-radius: 4px;
}

/* Certifications */
.certifications {
    background: var(--color-bg-card);
    padding: calc(var(--spacing-unit) * 2);
    border-radius: var(--border-radius);
    margin-top: calc(var(--spacing-unit) * 2);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
}

.cert-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: calc(var(--spacing-unit) * 1.5);
}

.cert-list li {
    padding: calc(var(--spacing-unit) * 1.5);
    background: var(--color-bg-alt);
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
}

.cert-list li:hover {
    background: var(--color-bg);
    box-shadow: var(--shadow-sm);
}

/* Footer */
footer {
    background: var(--color-bg-alt);
    padding: calc(var(--spacing-unit) * 3) 0;
    text-align: center;
    margin-top: calc(var(--spacing-unit) * 3);
}

.accessibility-note {
    font-size: 0.95rem;
    color: var(--color-text-light);
    margin-top: calc(var(--spacing-unit) * 1.5);
    line-height: 1.8;
}

.accessibility-note a {
    color: var(--color-link);
    text-decoration: underline;
    font-weight: 600;
    transition: var(--transition);
}

.accessibility-note a:hover {
    color: var(--color-link-hover);
    text-decoration-thickness: 2px;
}

/* Icons */
.icon {
    width: 20px;
    height: 20px;
    display: inline-block;
    vertical-align: middle;
    transition: var(--transition);
}

.button:hover .icon {
    transform: scale(1.1);
}

/* Print styles */
@media print {
    body {
        color: black;
        background: white;
    }
    
    .button-group,
    .skip-link {
        display: none;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
    
    .achievements li,
    .featured-box,
    .certifications {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}

/* Test results styling */
.test-success {
    background: linear-gradient(135deg, #E8F5E9, #F1F8F4);
    color: #1B5E20;
    padding: calc(var(--spacing-unit) * 2);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    margin-top: var(--spacing-unit);
    border: 1px solid rgba(76, 175, 80, 0.2);
    animation: slideIn 0.5s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@media (prefers-color-scheme: dark) {
    .test-success {
        background: linear-gradient(135deg, #1B3A1F, #224026);
        color: #66BB6A;
        border-color: rgba(102, 187, 106, 0.2);
    }
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .container {
        padding: 0 calc(var(--spacing-unit) * 1.5);
    }
    
    header {
        padding: calc(var(--spacing-unit) * 4) 0;
    }
    
    main {
        padding: calc(var(--spacing-unit) * 4) 0;
    }
    
    section {
        margin-bottom: calc(var(--spacing-unit) * 4);
    }
    
    .button-group {
        flex-direction: column;
        align-items: stretch;
    }
    
    .button {
        text-align: center;
        justify-content: center;
    }
    
    .achievements {
        grid-template-columns: 1fr;
    }
    
    .contact-info {
        grid-template-columns: 1fr;
    }
    
    .cert-list {
        grid-template-columns: 1fr;
    }
}

/* Loading animation for sections */
section:nth-child(1) { animation-delay: 0.1s; }
section:nth-child(2) { animation-delay: 0.2s; }
section:nth-child(3) { animation-delay: 0.3s; }
section:nth-child(4) { animation-delay: 0.4s; }
section:nth-child(5) { animation-delay: 0.5s; }