/* ====================================
   CSS Variables
   ==================================== */
:root {
    /* Colors */
    --color-primary: #F7931A;        /* Brand accent color */
    --color-primary-dark: #D97F0F;
    --color-primary-light: #FFA940;
    --color-text: #1a1a1a;
    --color-text-light: #4a4a4a;
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-border: #e0e0e0;
    --color-shadow: rgba(0, 0, 0, 0.1);

    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;

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

    /* Layout */
    --container-max-width: 1200px;
    --border-radius: 8px;
    --navbar-height: 70px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: var(--line-height-base);
    overflow-x: hidden;
}

/* ====================================
   Typography
   ==================================== */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
    font-weight: 600;
    color: var(--color-text);
}

h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

h2 {
    font-size: 2rem;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

h3 {
    font-size: 1.5rem;
    margin-top: var(--spacing-md);
}

h4 {
    font-size: 1.25rem;
}

p {
    margin-bottom: var(--spacing-sm);
}

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

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

strong {
    font-weight: 600;
}

ul, ol {
    margin-left: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

li {
    margin-bottom: var(--spacing-xs);
}

hr {
    border: none;
    border-top: 2px solid var(--color-border);
    margin: var(--spacing-lg) 0;
}

/* ====================================
   Layout
   ==================================== */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

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

.content-wrapper {
    max-width: 900px;
    margin: 0 auto;
}

/* ====================================
   Navigation
   ==================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--color-bg);
    box-shadow: 0 2px 10px var(--color-shadow);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.navbar.scrolled {
    box-shadow: 0 2px 20px var(--color-shadow);
}

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

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    margin: 0;
}

.nav-link {
    color: var(--color-text);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: all var(--transition-fast);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background-color: var(--color-primary);
    transition: transform var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: translateX(-50%) scaleX(1);
}

/* Mobile Navigation Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.nav-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--color-text);
    transition: all var(--transition-normal);
    border-radius: 3px;
}

/* ====================================
   Hero Section
   ==================================== */
.hero-section {
    background: linear-gradient(160deg, var(--color-bg) 0%, #f0f4f8 40%, #e8edf2 100%);
    text-align: center;
    padding-top: calc(var(--navbar-height) + var(--spacing-xl));
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.8s ease;
}

.hero-content h2 {
    font-size: 1.75rem;
    color: var(--color-primary);
    font-weight: 500;
    margin-top: 0;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-content p {
    font-size: 1.125rem;
    color: var(--color-text-light);
    max-width: 700px;
    margin: var(--spacing-md) auto;
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-content strong {
    font-weight: 600;
    color: var(--color-text);
}

.hero-cta {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: transparent;
    color: var(--color-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--color-primary);
    border-radius: var(--border-radius);
    font-weight: 600;
    font-family: var(--font-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    margin-top: var(--spacing-md);
    animation: fadeInUp 0.8s ease 0.6s both;
}

.hero-cta:hover {
    background-color: var(--color-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(247, 147, 26, 0.3);
}

.hero-cta svg {
    width: 20px;
    height: 20px;
    transition: transform var(--transition-normal);
}

.hero-cta:hover svg {
    transform: translateY(3px);
}

/* ====================================
   Experience Section with Photo
   ==================================== */
.experience-layout {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.experience-photo {
    position: sticky;
    top: calc(var(--navbar-height) + var(--spacing-md));
}

.experience-photo img {
    width: 100%;
    border-radius: var(--border-radius);
    box-shadow: 0 10px 30px var(--color-shadow);
    transition: transform var(--transition-normal);
}

.experience-photo img:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px var(--color-shadow);
}

.experience-content h1 {
    margin-top: 0;
}

/* ====================================
   Contact Section
   ==================================== */
.section-contact {
    background: linear-gradient(135deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
    text-align: center;
}

.contact-wrapper h1 {
    margin-bottom: var(--spacing-sm);
}

.contact-intro {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: all var(--transition-normal);
    box-shadow: 0 4px 15px rgba(247, 147, 26, 0.3);
}

.btn-primary:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(247, 147, 26, 0.4);
    color: white;
}

.btn-primary svg {
    width: 24px;
    height: 24px;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background-color: white;
    color: var(--color-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--color-primary);
    border-radius: var(--border-radius);
    font-weight: 600;
    font-family: var(--font-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: 0 4px 15px rgba(247, 147, 26, 0.2);
}

.btn-secondary:hover {
    background-color: var(--color-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(247, 147, 26, 0.4);
}

.btn-secondary svg {
    width: 24px;
    height: 24px;
}

/* ====================================
   PDF Button in Navigation
   ==================================== */
.btn-pdf {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background-color: var(--color-primary);
    color: white;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    font-family: var(--font-primary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: 0 2px 10px rgba(247, 147, 26, 0.3);
}

.btn-pdf:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(247, 147, 26, 0.4);
}

.btn-pdf svg {
    width: 16px;
    height: 16px;
}

.btn-pdf-text {
    font-weight: 600;
}

/* ====================================
   Footer
   ==================================== */
.footer {
    background-color: var(--color-text);
    color: var(--color-bg);
    text-align: center;
    padding: var(--spacing-md) 0;
}

.footer p {
    margin: 0;
    opacity: 0.8;
}

/* ====================================
   Scroll to Top Button
   ==================================== */
.scroll-top-btn {
    position: fixed;
    bottom: var(--spacing-md);
    right: var(--spacing-md);
    background-color: var(--color-primary);
    color: white;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(247, 147, 26, 0.3);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 999;
}

.scroll-top-btn.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top-btn:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(247, 147, 26, 0.4);
}

/* ====================================
   Animations
   ==================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* CSS-only animations for above-the-fold sections */
/* Hero section - dramatic entrance */
#hero .hero-content {
    animation: fadeInUp 0.8s ease 0.1s both;
}

/* About section - content with CSS animation (often visible on load) */
#about .experience-content {
    animation: fadeInUp 0.6s ease 0.3s both;
}

/* Scroll-triggered animations via Intersection Observer */
/* Photo and below-the-fold sections start hidden */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Below-the-fold sections: animated on scroll via JS */
.scroll-reveal {
    opacity: 0;
    transform: translateY(25px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.scroll-reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ====================================
   Markdown Content Styling
   ==================================== */
.content-wrapper h1:first-child,
.experience-content h1:first-child,
.contact-wrapper h1:first-child,
.hero-content h1:first-child {
    color: var(--color-text);
    border-bottom: 3px solid var(--color-primary);
    padding-bottom: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.content-wrapper h2,
.experience-content h2 {
    color: var(--color-primary);
    font-size: 1.75rem;
}

.content-wrapper h3,
.experience-content h3 {
    color: var(--color-text);
    font-size: 1.25rem;
    margin-top: var(--spacing-md);
}

.content-wrapper ul,
.experience-content ul {
    list-style: none;
    margin-left: 0;
}

.content-wrapper ul li,
.experience-content ul li {
    padding-left: var(--spacing-md);
    position: relative;
}

.content-wrapper ul li::before,
.experience-content ul li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

/* Nested lists */
.content-wrapper ul ul,
.experience-content ul ul {
    margin-left: var(--spacing-md);
    margin-top: var(--spacing-xs);
}

/* ====================================
   Skeleton Loaders
   ==================================== */
.skeleton-loader {
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 0.5;
    }
    50% {
        opacity: 0.7;
    }
}

.skeleton-title,
.skeleton-subtitle,
.skeleton-text {
    background: linear-gradient(90deg, #e0e0e0 25%, #f0f0f0 50%, #e0e0e0 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: 4px;
    margin-bottom: var(--spacing-sm);
}

@keyframes shimmer {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

.skeleton-title {
    height: 2.5rem;
    width: 60%;
    margin-bottom: var(--spacing-md);
}

.skeleton-subtitle {
    height: 2rem;
    width: 50%;
    margin-bottom: var(--spacing-md);
}

.skeleton-text {
    height: 1rem;
    width: 100%;
}

.skeleton-text:nth-child(even) {
    width: 85%;
}

/* Hide skeleton when content is loaded */
[data-markdown].loaded .skeleton-loader {
    display: none;
}

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

/* Tablets and below (768px) */
@media (max-width: 768px) {
    :root {
        --navbar-height: 60px;
        --spacing-xl: 3rem;
        --spacing-lg: 2rem;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .hero-content h1 {
        font-size: 2.25rem;
    }

    .hero-content h2 {
        font-size: 1.25rem;
    }

    /* Mobile Navigation */
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: var(--navbar-height);
        left: -100%;
        width: 100%;
        height: calc(100vh - var(--navbar-height));
        background-color: var(--color-bg);
        flex-direction: column;
        padding: var(--spacing-md);
        box-shadow: 0 10px 30px var(--color-shadow);
        transition: left var(--transition-normal);
        gap: 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-link {
        display: block;
        padding: var(--spacing-sm) 0;
        border-bottom: 1px solid var(--color-border);
    }

    .nav-link::after {
        display: none;
    }

    /* Toggle animation when active */
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }

    /* Experience layout */
    .experience-layout {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .experience-photo {
        position: relative;
        top: 0;
        max-width: 300px;
        margin: 0 auto;
    }

    /* Sections */
    .section {
        min-height: auto;
        padding: var(--spacing-lg) 0;
    }

    .hero-section {
        padding-top: calc(var(--navbar-height) + var(--spacing-lg));
    }

    /* Contact links */
    .contact-links {
        flex-direction: column;
        align-items: center;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }

    /* PDF button in mobile menu */
    .btn-pdf {
        width: 100%;
        justify-content: center;
        padding: 0.75rem 1rem;
        margin-top: var(--spacing-xs);
    }
}

/* Mobile phones (480px) */
@media (max-width: 480px) {
    :root {
        --spacing-md: 1.5rem;
        --spacing-sm: 0.75rem;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    h1 {
        font-size: 1.75rem;
    }

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

    .nav-brand {
        font-size: 1.125rem;
    }

    .experience-photo {
        max-width: 250px;
    }
}

/* Large screens (1400px+) */
@media (min-width: 1400px) {
    :root {
        --container-max-width: 1400px;
    }

    .experience-layout {
        grid-template-columns: 350px 1fr;
        gap: var(--spacing-xl);
    }
}

/* ====================================
   Print Styles
   ==================================== */
@media print {
    .navbar,
    .scroll-top-btn,
    .nav-toggle {
        display: none;
    }

    .section {
        min-height: auto;
        page-break-inside: avoid;
    }

    body {
        color: black;
        background: white;
    }

    a {
        text-decoration: underline;
    }
}