/* ============================================
   Modern DevOps Portfolio - 2025 Design
   Dark theme with light mode fallback
   ============================================ */

/* Modern System Fonts Stack */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ============================================
   CSS Custom Properties - Light Mode (Default Fallback)
   ============================================ */
:root {
    /* Colors - Light Mode */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-elevated: #ffffff;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #64748b;
    --text-inverse: #ffffff;

    --accent-primary: #3b82f6;
    --accent-secondary: #06b6d4;
    --accent-tertiary: #8b5cf6;
    --accent-success: #10b981;
    --accent-warning: #f59e0b;

    --border-subtle: #e2e8f0;
    --border-medium: #cbd5e1;
    --border-strong: #94a3b8;

    /* 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);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Layout */
    --container-max: 1400px;
    --container-padding: 2rem;
    --nav-height: 4rem;
}

/* ============================================
   Dark Mode - System Preference
   ============================================ */
@media (prefers-color-scheme: dark) {
    :root {
        /* Colors - Dark Mode */
        --bg-primary: #0a0e1a;
        --bg-secondary: #0f172a;
        --bg-tertiary: #1e293b;
        --bg-elevated: #1e293b;

        --text-primary: #f1f5f9;
        --text-secondary: #cbd5e1;
        --text-tertiary: #94a3b8;
        --text-inverse: #0f172a;

        --accent-primary: #60a5fa;
        --accent-secondary: #22d3ee;
        --accent-tertiary: #a78bfa;
        --accent-success: #34d399;
        --accent-warning: #fbbf24;

        --border-subtle: #1e293b;
        --border-medium: #334155;
        --border-strong: #475569;

        /* Enhanced shadows for dark mode */
        --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.5);
        --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.5), 0 2px 4px -2px rgb(0 0 0 / 0.5);
        --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5), 0 4px 6px -4px rgb(0 0 0 / 0.5);
        --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.5), 0 8px 10px -6px rgb(0 0 0 / 0.5);
    }
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-height) + 2rem);
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-sans);
    font-weight: 600;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); font-weight: 700; }
h2 { font-size: clamp(2rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.5rem, 3vw, 1.875rem); }
h4 { font-size: clamp(1.25rem, 2.5vw, 1.5rem); }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
}

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

a:hover {
    color: var(--accent-secondary);
}

strong {
    font-weight: 600;
    color: var(--text-primary);
}

em {
    color: var(--text-tertiary);
    font-style: italic;
}

ul, ol {
    list-style: none;
}

code {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    padding: 0.125rem 0.375rem;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    color: var(--accent-secondary);
}

/* ============================================
   Layout Components
   ============================================ */

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

/* Main Content Wrapper */
.main-content {
    min-height: 100vh;
}

/* ============================================
   Navigation
   ============================================ */
.main-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--bg-primary);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    border-bottom: 1px solid var(--border-subtle);
    height: var(--nav-height);
    transition: all var(--transition-base);
}

.main-nav.scrolled {
    background-color: rgba(var(--bg-primary-rgb, 10, 14, 26), 0.8);
    box-shadow: var(--shadow-md);
}

.main-nav .container {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
}

.main-nav ul {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    width: 100%;
}

.main-nav a {
    position: relative;
    padding: var(--space-sm) var(--space-md);
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0.25rem;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    border-radius: var(--radius-full);
    transition: transform var(--transition-base);
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--text-primary);
    background-color: var(--bg-tertiary);
}

.main-nav a.active::after {
    transform: translateX(-50%) scaleX(1);
}

/* ============================================
   Hero Section
   ============================================ */
.header {
    padding: var(--space-3xl) 0;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    border-bottom: 1px solid var(--border-subtle);
}

.profile {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xl);
    text-align: center;
}

.profile-image {
    width: 140px;
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.profile-icon {
    font-size: 5rem;
    color: var(--text-inverse);
    opacity: 0.9;
}

.profile-content {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.profile-content h1 {
    margin-bottom: var(--space-sm);
    background: linear-gradient(135deg, var(--text-primary), var(--accent-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.profile-content h2 {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.profile-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    margin-top: var(--space-xl);
    justify-content: center;
}

.profile-links a {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.profile-links a:hover {
    background-color: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--text-inverse);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.profile-links a i {
    font-size: 1.125rem;
}

/* ============================================
   Sections
   ============================================ */
.section {
    padding: var(--space-3xl) 0;
    border-bottom: 1px solid var(--border-subtle);
}

.section:last-of-type {
    border-bottom: none;
}

.section-title {
    position: relative;
    font-size: clamp(1.875rem, 4vw, 2.25rem);
    margin-bottom: var(--space-2xl);
    padding-bottom: var(--space-md);
}

.section-title::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    border-radius: var(--radius-full);
}

.section-content {
    font-size: 1.0625rem;
    line-height: 1.75;
    color: var(--text-secondary);
}

/* ============================================
   Experience Section
   ============================================ */
#experience .section-content > hr {
    margin: var(--space-2xl) 0;
    border: none;
    border-top: 1px solid var(--border-subtle);
}

#experience .section-content h2 {
    font-size: clamp(1.375rem, 3vw, 1.625rem);
    color: var(--text-primary);
    margin-bottom: var(--space-xs);
}

#experience .section-content h2 + p {
    font-size: 0.9375rem;
    color: var(--text-tertiary);
    margin-bottom: var(--space-lg);
}

#experience .section-content strong {
    color: var(--accent-primary);
    font-weight: 600;
}

#experience .section-content ul {
    margin: var(--space-lg) 0;
    padding-left: var(--space-xl);
}

#experience .section-content ul li {
    position: relative;
    margin-bottom: var(--space-md);
    padding-left: var(--space-lg);
    line-height: 1.7;
}

#experience .section-content ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.6em;
    width: 6px;
    height: 6px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: var(--radius-full);
}

#experience .section-content p:has(strong) {
    background-color: var(--bg-tertiary);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--accent-primary);
    margin: var(--space-lg) 0;
}

/* ============================================
   Skills Section
   ============================================ */
#skills .section-content h2 {
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
    color: var(--text-primary);
    margin-top: var(--space-2xl);
    margin-bottom: var(--space-lg);
}

#skills .section-content h2:first-of-type {
    margin-top: 0;
}

#skills .section-content h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--accent-primary);
    margin: var(--space-xl) 0 var(--space-md);
}

#skills .section-content ul {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
}

#skills .section-content ul li {
    position: relative;
    padding: var(--space-md) var(--space-lg);
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    color: var(--text-secondary);
    transition: all var(--transition-base);
    overflow: hidden;
}

#skills .section-content ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--accent-primary), var(--accent-secondary));
    opacity: 0;
    transition: opacity var(--transition-base);
}

#skills .section-content ul li:hover {
    background-color: var(--bg-elevated);
    border-color: var(--accent-primary);
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
}

#skills .section-content ul li:hover::before {
    opacity: 1;
}

#skills .section-content ul li strong {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-xs);
}

/* ============================================
   Education Section
   ============================================ */
#education .section-content h2 {
    font-size: clamp(1.375rem, 3vw, 1.625rem);
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

#education .section-content p {
    font-size: 0.9375rem;
}

#education .section-content strong {
    color: var(--accent-primary);
}

/* ============================================
   Languages Section
   ============================================ */
#languages .section-content ul {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
}

#languages .section-content ul li {
    padding: var(--space-sm) var(--space-lg);
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-full);
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

#languages .section-content ul li:hover {
    background-color: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--text-inverse);
    transform: translateY(-2px);
}

/* ============================================
   Courses Section
   ============================================ */
#courses .section-content ul {
    display: grid;
    gap: var(--space-md);
}

#courses .section-content ul li {
    position: relative;
    padding: var(--space-md) var(--space-md) var(--space-md) 3rem;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    line-height: 1.6;
    transition: all var(--transition-base);
}

#courses .section-content ul li::before {
    content: '\f19d';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    position: absolute;
    left: var(--space-md);
    top: var(--space-md);
    color: var(--accent-primary);
    font-size: 1rem;
    width: 1.25rem;
    text-align: center;
}

#courses .section-content ul li:hover {
    background-color: var(--bg-elevated);
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-md);
}

#courses .section-content ul li strong {
    display: block;
    color: var(--text-primary);
    margin-bottom: var(--space-xs);
}

/* ============================================
   Footer
   ============================================ */
.footer {
    padding: var(--space-2xl) 0;
    text-align: center;
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-subtle);
}

.footer p {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

/* ============================================
   Back to Top Button
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    width: 3rem;
    height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: var(--text-inverse);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(1rem);
    transition: all var(--transition-base);
    z-index: 999;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(1rem);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* Subtle entrance animations */
.section {
    animation: fadeIn 0.6s ease-out;
}

.section-content > * {
    animation: fadeIn 0.5s ease-out;
    animation-fill-mode: both;
}

/* ============================================
   Responsive Design
   ============================================ */

/* Tablet and below */
@media (max-width: 1024px) {
    :root {
        --container-padding: 1.5rem;
        --space-3xl: 3rem;
    }

    #skills .section-content ul {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }
}

/* Mobile */
@media (max-width: 768px) {
    :root {
        --container-padding: 1rem;
        --space-2xl: 2rem;
        --space-3xl: 2.5rem;
    }

    .main-nav {
        position: sticky;
        height: auto;
        padding: 0.5rem 0;
    }

    .main-nav .container {
        padding: 0;
    }

    .main-nav ul {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0.5rem;
        padding: 0 1rem;
    }

    .main-nav li {
        flex: 0 0 calc(50% - 0.25rem);
    }

    .main-nav a {
        display: block;
        width: 100%;
        text-align: center;
        padding: 0.75rem 0.5rem;
        font-size: 0.875rem;
        background-color: var(--bg-tertiary);
        border: 1px solid var(--border-medium);
        border-radius: var(--radius-md);
    }

    .main-nav a:hover,
    .main-nav a.active {
        background-color: var(--accent-primary);
        border-color: var(--accent-primary);
        color: var(--text-inverse);
    }

    .main-nav a::after {
        display: none;
    }

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

    .profile-image {
        width: 100px;
        height: 100px;
    }

    .profile-icon {
        font-size: 3.5rem;
    }

    .profile-links {
        flex-direction: column;
        width: 100%;
    }

    .profile-links a {
        width: 100%;
        justify-content: center;
    }

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

    .section-title {
        margin-bottom: var(--space-xl);
    }

    #skills .section-content ul {
        grid-template-columns: 1fr;
    }

    .back-to-top {
        bottom: var(--space-md);
        right: var(--space-md);
        width: 2.75rem;
        height: 2.75rem;
    }
}

/* Small mobile */
@media (max-width: 480px) {
    :root {
        --container-padding: 0.75rem;
    }

    .main-nav ul {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
    }

    .main-nav ul::-webkit-scrollbar {
        display: none;
    }

    .section-title::after {
        width: 40px;
        height: 3px;
    }
}

/* ============================================
   Print Styles
   ============================================ */
@media print {
    :root {
        --bg-primary: #ffffff;
        --bg-secondary: #ffffff;
        --bg-tertiary: #f8f9fa;
        --text-primary: #000000;
        --text-secondary: #333333;
        --border-subtle: #e0e0e0;
    }

    body {
        background: white;
        color: black;
    }

    .main-nav,
    .profile-links,
    .back-to-top,
    .footer {
        display: none !important;
    }

    .header {
        border-bottom: 2px solid #000;
        padding: 1rem 0;
    }

    .section {
        page-break-inside: avoid;
        border-bottom: 1px solid #ddd;
        padding: 1.5rem 0;
    }

    a {
        color: #000;
        text-decoration: underline;
    }

    .profile {
        flex-direction: row;
        justify-content: flex-start;
        text-align: left;
        gap: 1rem;
    }

    .profile-content {
        align-items: flex-start;
        text-align: left;
    }

    .profile-links {
        justify-content: flex-start;
    }

    .profile-image {
        width: 80px;
        height: 80px;
        box-shadow: none;
    }

    * {
        animation: none !important;
        transition: none !important;
    }
}