/* ===== RESET & BASE STYLES ===== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* Apple-inspired Color Palette */
    --color-primary: #007AFF;
    --color-primary-dark: #0051D5;
    --color-secondary: #5856D6;
    --color-success: #34C759;
    --color-warning: #FF9500;
    --color-error: #FF3B30;
    
    /* Neutral Colors */
    --color-black: #000000;
    --color-white: #FFFFFF;
    --color-gray-50: #F9F9F9;
    --color-gray-100: #F5F5F7;
    --color-gray-200: #E5E5EA;
    --color-gray-300: #D1D1D6;
    --color-gray-400: #A1A1AA;
    --color-gray-500: #6E6E73;
    --color-gray-600: #515154;
    --color-gray-700: #3A3A3C;
    --color-gray-800: #2C2C2E;
    --color-gray-900: #1C1C1E;
    
    /* Typography */
    --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-weight-light: 200;
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-black: 900;
    
    /* Font Sizes */
    --font-size-xs: 0.75rem;    /* 12px */
    --font-size-sm: 0.875rem;   /* 14px */
    --font-size-base: 1rem;     /* 16px */
    --font-size-lg: 1.125rem;   /* 18px */
    --font-size-xl: 1.25rem;    /* 20px */
    --font-size-2xl: 1.5rem;    /* 24px */
    --font-size-3xl: 1.875rem;  /* 30px */
    --font-size-4xl: 2.25rem;   /* 36px */
    --font-size-5xl: 3rem;      /* 48px */
    --font-size-6xl: 3.75rem;   /* 60px */
    --font-size-7xl: 4.5rem;    /* 72px */
    
    /* Spacing */
    --spacing-xs: 0.25rem;  /* 4px */
    --spacing-sm: 0.5rem;   /* 8px */
    --spacing-md: 1rem;     /* 16px */
    --spacing-lg: 1.5rem;   /* 24px */
    --spacing-xl: 2rem;     /* 32px */
    --spacing-2xl: 3rem;    /* 48px */
    --spacing-3xl: 4rem;    /* 64px */
    --spacing-4xl: 6rem;    /* 96px */
    --spacing-5xl: 8rem;    /* 128px */
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.25);
    
    /* Border Radius */
    --radius-sm: 0.375rem;   /* 6px */
    --radius-md: 0.5rem;     /* 8px */
    --radius-lg: 0.75rem;    /* 12px */
    --radius-xl: 1rem;       /* 16px */
    --radius-2xl: 1.5rem;    /* 24px */
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 0.15s cubic-bezier(0.4, 0.0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0.0, 0.2, 1);
    
    /* Layout */
    --container-max-width: 1200px;
    --header-height: 80px;
    
    /* Glassmorphism */
    --glass-background: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.2);
    --glass-backdrop: blur(20px);

    /* Extended Theme Tokens */
    --text-primary: var(--color-gray-900);
    --text-secondary: var(--color-gray-600);
    --text-tertiary: var(--color-gray-500);
    --border-color: rgba(15, 23, 42, 0.08);
    --glass-bg: rgba(255, 255, 255, 0.65);
    --bg-secondary: rgba(255, 255, 255, 0.75);
    --surface-elevated: rgba(255, 255, 255, 0.92);

    color-scheme: light;
}

/* Force light theme even when the OS requests dark mode */
@media (prefers-color-scheme: dark) {
    :root {
        color-scheme: light;
    }

    html,
    body {
        background-color: var(--color-white);
        color: var(--text-primary);
    }
}

/* Dark mode support */
html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background-color: var(--color-white);
    color-scheme: light;
}

body {
    font-family: var(--font-family-primary);
    font-weight: var(--font-weight-regular);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--color-white);
    overflow-x: hidden;
    color-scheme: light;
}

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

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }
}

.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;
}

/* ===== NAVIGATION ===== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--glass-background);
    backdrop-filter: var(--glass-backdrop);
    -webkit-backdrop-filter: var(--glass-backdrop);
    border-bottom: 1px solid var(--glass-border);
    transition: all var(--transition-normal);
}

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

.nav-logo-link {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-bold);
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-2xl);
    margin: 0;
    padding: 0;
}

.nav-link {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    color: var(--text-secondary);
    text-decoration: none;
    position: relative;
    transition: color var(--transition-fast);
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: width var(--transition-normal);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.nav-toggle-line {
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-normal);
}

@media (max-width: 768px) {
    .nav {
        position: sticky;
        top: 0;
        left: 0;
        right: 0;
        background: var(--color-white);
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-sm);
        backdrop-filter: none;
        -webkit-backdrop-filter: none;
    }

    .nav-container {
        justify-content: center;
        padding: 0 var(--spacing-md);
        height: 64px;
    }

    .nav-logo {
        flex: 1;
        display: flex;
        justify-content: center;
    }

    .nav-logo-link {
        text-align: center;
        font-size: var(--font-size-lg);
    }

    .nav-menu,
    .nav-toggle {
        display: none !important;
    }
}

/* ===== HERO SECTION ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--color-gray-50) 0%, var(--color-white) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 30% 20%, rgba(0, 122, 255, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 70% 80%, rgba(88, 86, 214, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--spacing-5xl) var(--spacing-lg);
    position: relative;
    z-index: 1;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-4xl);
    align-items: center;
    justify-items: center;
    text-align: center;
}

.hero-title {
    font-size: var(--font-size-6xl);
    font-weight: var(--font-weight-black);
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
}

.hero-title-line {
    display: block;
    color: var(--color-gray-600);
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-medium);
    margin-bottom: var(--spacing-sm);
}

.hero-title-name {
    display: block;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: transparent;
}

.hero-text {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.hero-description {
    font-size: var(--font-size-xl);
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-2xl);
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    justify-content: center;
}

.hero-accent {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    padding: 2rem;
}

.accent-box {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-xl);
    position: relative;
    animation: float 6s ease-in-out infinite;
}

.accent-primary {
    background: linear-gradient(135deg, #1d4ed8, #3b82f6);
    animation-delay: 0s;
}

.accent-secondary {
    background: linear-gradient(135deg, #9333ea, #c084fc);
    animation-delay: 2s;
}

.accent-tertiary {
    background: linear-gradient(135deg, #f59e0b, #fbbf24);
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px) rotate(0deg);
    }
    33% {
        transform: translateY(-10px) rotate(2deg);
    }
    66% {
        transform: translateY(5px) rotate(-1deg);
    }
}

.hero-scroll-indicator {
    position: absolute;
    bottom: var(--spacing-2xl);
    left: 50%;
    transform: translateX(-50%);
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid var(--color-gray-400);
    border-bottom: 2px solid var(--color-gray-400);
    transform: rotate(45deg);
    animation: scroll-bounce 2s infinite;
}

@keyframes scroll-bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: rotate(45deg) translateY(0);
    }
    40% {
        transform: rotate(45deg) translateY(-10px);
    }
    60% {
        transform: rotate(45deg) translateY(-5px);
    }
}

@media (max-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
        text-align: center;
    }
    
    .hero-title {
        font-size: var(--font-size-4xl);
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-description {
        font-size: var(--font-size-lg);
        margin-left: auto;
        margin-right: auto;
    }

    .hero-text {
        align-items: center;
    }
    
    .hero-icon,
    .hero-visual-backdrop {
        width: 150px;
        height: 150px;
    }
    
    .hero-buttons {
        justify-content: center;
    }
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.btn:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.3);
}

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

.btn-primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-full {
    width: 100%;
}

/* ===== SECTIONS ===== */
section {
    padding: var(--spacing-5xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-4xl);
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: var(--font-size-xl);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== ABOUT SECTION ===== */
.about {
    background: var(--color-gray-50);
}

.about-description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2xl);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    max-width: 1000px;
    margin: 0 auto;
}

.skill-category {
    background: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

.skill-category-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skill-tag {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-gray-100);
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.skill-tag:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: scale(1.05);
}

/* ===== PROJECTS SECTION ===== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-2xl);
}

.project-card {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.project-icon {
    position: relative;
    aspect-ratio: 16/10;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, var(--bg-secondary), var(--glass-bg));
    border-bottom: 1px solid var(--border-color);
}

.project-icon-container {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
    color: var(--text-secondary);
    transition: all var(--transition-normal);
}

.project-header {
    padding: 1.5rem 1.5rem 0;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.project-category-badge {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.ml-badge {
    background: linear-gradient(135deg, #1d4ed8, #3b82f6);
    color: white;
}

.nlp-badge {
    background: linear-gradient(135deg, #9333ea, #c084fc);
    color: white;
}

.dl-badge {
    background: linear-gradient(135deg, #f59e0b, #fbbf24);
    color: white;
}

.analytics-badge {
    background: linear-gradient(135deg, #8b5cf6, #a78bfa);
    color: white;
}

.data-badge {
    background: linear-gradient(135deg, #06b6d4, #67e8f9);
    color: white;
}

.default-badge {
    background: linear-gradient(135deg, #6b7280, #9ca3af);
    color: white;
}

/* Filter Tabs */
.filter-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.filter-tab {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--border-color);
    background: transparent;
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.filter-tab:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.filter-tab.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

/* Loading and No Results */
.loading,
.no-results {
    text-align: center;
    padding: 3rem 0;
    color: var(--text-secondary);
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.project-modal {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    max-width: 800px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-2xl);
    border: 1px solid var(--border-color);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-title-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.modal-close:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.modal-body {
    padding: 2rem;
}

/* Enhanced Modal Styles */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(12px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10000;
    animation: modalFadeIn 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
}

.modal-container {
    background: var(--color-white);
    border-radius: var(--radius-2xl);
    max-width: 900px;
    width: 90%;
    max-height: 90vh;
    overflow: hidden;
    box-shadow: var(--shadow-2xl);
    animation: modalSlideIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    border: 1px solid var(--border-color);
}

.modal-header-section {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 2rem 2rem 1rem;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(135deg, var(--color-gray-50), var(--color-white));
}

.modal-title-area {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.modal-project-title {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    color: var(--text-primary);
    margin: 0;
    line-height: 1.2;
}

.modal-close-btn {
    background: var(--bg-secondary);
    border: none;
    border-radius: var(--radius-full);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.modal-close-btn:hover {
    background: var(--color-gray-200);
    color: var(--text-primary);
    transform: scale(1.05);
}

.modal-content-area {
    padding: 0;
    max-height: calc(90vh - 140px);
    overflow-y: auto;
}

.modal-description-section,
.modal-tech-section,
.modal-features-section,
.modal-challenges-section,
.modal-results-section,
.modal-links-section {
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-links-section {
    border-bottom: none;
    background: var(--bg-secondary);
}

.modal-section-title {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-semibold);
    color: var(--text-primary);
    margin: 0 0 1rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.modal-section-title::before {
    content: '';
    width: 4px;
    height: 20px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border-radius: var(--radius-full);
}

.modal-description-text {
    font-size: var(--font-size-base);
    line-height: 1.7;
    color: var(--text-secondary);
    margin: 0;
}

.modal-tech-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.modal-tech-tag {
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    color: var(--color-white);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.modal-tech-tag:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.modal-feature-list,
.modal-challenge-list,
.modal-result-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.modal-feature-item,
.modal-challenge-item,
.modal-result-item {
    position: relative;
    padding-left: 1.5rem;
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-secondary);
}

.modal-feature-item::before {
    content: '✓';
    position: absolute;
    left: 0;
    top: 0;
    width: 20px;
    height: 20px;
    background: var(--color-success);
    color: var(--color-white);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-bold);
}

.modal-challenge-item::before {
    content: '⚡';
    position: absolute;
    left: 0;
    top: 0;
    width: 20px;
    height: 20px;
    background: var(--color-warning);
    color: var(--color-white);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xs);
}

.modal-result-item::before {
    content: '🎯';
    position: absolute;
    left: 0;
    top: 0;
    width: 20px;
    height: 20px;
    background: var(--color-secondary);
    color: var(--color-white);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xs);
}

.modal-button-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.modal-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 1.5rem;
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

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

.modal-btn-primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.modal-btn-secondary:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Modal Animations */
@keyframes modalFadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(50px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* Additional inline modal animations for fallback */
@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes modalSlideIn {
    from { 
        opacity: 0; 
        transform: translateY(50px) scale(0.95); 
    }
    to { 
        opacity: 1; 
        transform: translateY(0) scale(1); 
    }
}

/* Responsive Modal Design */
@media (max-width: 768px) {
    .modal-container {
        width: 95%;
        max-height: 95vh;
        border-radius: var(--radius-xl);
    }
    
    .modal-header-section {
        padding: 1.5rem 1.5rem 1rem;
    }
    
    .modal-project-title {
        font-size: var(--font-size-2xl);
    }
    
    .modal-description-section,
    .modal-tech-section,
    .modal-features-section,
    .modal-challenges-section,
    .modal-results-section,
    .modal-links-section {
        padding: 1rem 1.5rem;
    }
    
    .modal-button-group {
        flex-direction: column;
    }
    
    .modal-btn {
        justify-content: center;
    }
}

.project-status {
    padding: 0.25rem 0.75rem;
    background: rgba(34, 197, 94, 0.1);
    color: #22c55e;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid rgba(34, 197, 94, 0.2);
}

.project-content {
    padding: 0 1.5rem 1.5rem;
}

.project-links {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-links {
    display: flex;
    gap: var(--spacing-md);
}

.project-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--color-white);
    color: var(--text-primary);
    border-radius: var(--radius-full);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.project-link:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: scale(1.1);
}

.project-content {
    padding: var(--spacing-xl);
}

.project-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.project-category {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-primary);
    color: var(--color-white);
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-semibold);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-radius: var(--radius-full);
}

.project-date {
    font-size: var(--font-size-sm);
    color: var(--text-tertiary);
    font-weight: var(--font-weight-medium);
}

.project-title {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-bold);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

.project-technologies {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.tech-tag {
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--color-gray-100);
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-sm);
}

/* ===== EXPERIENCE SECTION ===== */
.experience {
    background: var(--color-gray-50);
}

/* Education section background override */
.experience#study {
    background: var(--color-white);
}

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--color-gray-300);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-3xl);
    padding-left: var(--spacing-4xl);
}

.timeline-marker {
    position: absolute;
    left: 22px;
    top: 0;
    width: 16px;
    height: 16px;
    background: var(--color-primary);
    border: 3px solid var(--color-white);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-md);
}

.timeline-content {
    background: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

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

.timeline-period {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-semibold);
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-sm);
}

.timeline-title {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-bold);
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.timeline-company {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.timeline-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

.timeline-technologies {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

@media (max-width: 768px) {
    .timeline::before {
        left: 15px;
    }
    
    .timeline-item {
        padding-left: var(--spacing-2xl);
    }
    
    .timeline-marker {
        left: 7px;
    }
}

/* ===== CONTACT SECTION ===== */
.contact-content-centered {
    max-width: 800px;
    margin: 0 auto;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
    justify-items: center;
    max-width: 700px;
    margin: 0 auto;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    width: 100%;
    max-width: 300px;
    padding: var(--spacing-lg);
    background: var(--color-white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border: 1px solid var(--color-gray-200);
}

.contact-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

/* Icon-only link styles */
.contact-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    text-decoration: none;
    color: var(--text-primary);
}

.contact-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    border-radius: var(--radius-full);
    background: linear-gradient(180deg, var(--color-gray-50), var(--color-white));
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
}

.contact-icon svg {
    width: 28px;
    height: 28px;
    stroke: var(--text-secondary);
}

.contact-item:hover .contact-icon {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, rgba(0,122,255,0.08), rgba(88,86,214,0.06));
}

.contact-value,
.contact-label,
.contact-details { display: none; }

.contact-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: var(--color-white);
    border-radius: var(--radius-xl);
    flex-shrink: 0;
}

.contact-label {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-semibold);
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-xs);
}

.contact-value {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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



@media (max-width: 768px) {
    .contact-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
        max-width: 400px;
    }
    
    .contact-item {
        max-width: 100%;
    }
}

/* ===== FOOTER ===== */
.footer {
    background: var(--color-gray-900);
    color: var(--color-white);
    padding: var(--spacing-2xl) 0;
}

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

.footer-text {
    font-size: var(--font-size-sm);
    color: var(--color-gray-400);
}

.footer-social {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--color-gray-800);
    color: var(--color-gray-400);
    border-radius: var(--radius-full);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-2px);
}

@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
        padding: 0 var(--spacing-md);
    }
}

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

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Animation classes for JavaScript */
.animate-fade-in-up {
    animation: fadeInUp 0.6s ease-out forwards;
}

.animate-fade-in-left {
    animation: fadeInLeft 0.6s ease-out forwards;
}

.animate-fade-in-right {
    animation: fadeInRight 0.6s ease-out forwards;
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1024px) {
    .section-title {
        font-size: var(--font-size-3xl);
    }
    
    .projects-grid {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    }
}

@media (max-width: 768px) {
    :root {
        --spacing-4xl: 4rem;
        --spacing-5xl: 6rem;
    }
    
    .section-title {
        font-size: var(--font-size-2xl);
    }
    
    .section-subtitle {
        font-size: var(--font-size-lg);
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== ACCESSIBILITY ===== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .scroll-arrow {
        animation: none;
    }
}

/* Focus styles for better accessibility */
a:focus,
button:focus,
input:focus,
textarea:focus,
select:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --color-gray-600: #000000;
        --color-gray-700: #000000;
        --color-gray-900: #000000;
    }
}