/* ==========================================================================
   Main Styles - Video Streaming Integration Project
   Programmer-inspired theme with dark/light mode support
   ========================================================================== */

/* CSS Variables for Theme */
:root {
    /* Light Mode Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #e8e8e8;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-tertiary: #999999;
    
    /* Accent Colors (Ocean Blue Theme) */
    --accent-primary: #00d4ff;
    --accent-secondary: #00a8cc;
    --accent-tertiary: #0088aa;
    --accent-glow: rgba(0, 212, 255, 0.3);
    
    /* Ocean-style blues */
    --ocean-blue: #00d4ff;
    --ocean-dark: #003d4d;
    --ocean-light: #5de4ff;
    
    /* Semantic Colors */
    --success: #00d4ff;
    --warning: #ffaa00;
    --error: #ff4444;
    --info: #00aaff;
    
    /* UI Elements */
    --border-color: #dddddd;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --shadow-glow: 0 0 20px var(--accent-glow);
    
    /* Typography */
    --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', 'Droid Sans Mono', 'Source Code Pro', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Dark Mode Variables */
.dark-mode {
    --bg-primary: #0a0e12;
    --bg-secondary: #0f1419;
    --bg-tertiary: #1a1f26;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --text-tertiary: #707070;
    --border-color: #2a2f35;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.6);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.8);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
}

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

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

code {
    font-family: var(--font-mono);
    background-color: var(--bg-tertiary);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn svg {
    width: 20px;
    height: 20px;
    stroke-width: 2;
}

.btn-primary {
    background-color: var(--accent-primary);
    color: #000;
    box-shadow: 0 0 20px var(--accent-glow);
}

.btn-primary:hover {
    background-color: var(--accent-secondary);
    transform: translateY(-2px);
    box-shadow: 0 0 30px var(--accent-glow);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 2px solid var(--accent-primary);
}

.btn-secondary:hover {
    background-color: var(--accent-primary);
    color: #000;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

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

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

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
}

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

/* Enhanced Navigation Buttons */
.nav-btn-primary,
.nav-btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.nav-btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: #000;
    box-shadow: 0 4px 15px rgba(0, 212, 255, 0.3);
}

.nav-btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s;
}

.nav-btn-primary:hover::before {
    left: 100%;
}

.nav-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0, 212, 255, 0.5);
    color: #000;
}

.nav-btn-primary:active {
    transform: translateY(0);
}

.nav-btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.nav-btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    transform: translateY(-2px);
}

.nav-btn-secondary:active {
    transform: translateY(0);
}

.btn-icon {
    width: 20px;
    height: 20px;
    transition: transform var(--transition-fast);
}

.nav-btn-primary:hover .btn-icon,
.nav-btn-secondary:hover .btn-icon {
    transform: scale(1.1);
}

.nav-btn-primary .btn-icon {
    animation: pulse-play 2s infinite;
}

@keyframes pulse-play {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.theme-toggle {
    background: transparent;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    padding: 0;
}

.theme-toggle:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
    stroke-width: 2;
    color: var(--text-primary);
}

.sun-icon {
    display: none;
}

.dark-mode .sun-icon {
    display: block;
}

.moon-icon {
    display: block;
}

.dark-mode .moon-icon {
    display: none;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    transition: all var(--transition-fast);
}

/* Mobile Navigation */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background-color: var(--bg-primary);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        border-bottom: 1px solid var(--border-color);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all var(--transition-normal);
    }
    
    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }
    
    .nav-btn-primary,
    .nav-btn-secondary {
        width: 100%;
        justify-content: center;
        padding: 1rem 1.5rem;
        font-size: 1rem;
    }
    
    .nav-btn-primary {
        box-shadow: 0 4px 20px rgba(0, 212, 255, 0.4);
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
}

/* Sections */
.section {
    padding: 6rem 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    font-family: var(--font-mono);
    color: var(--accent-primary);
    font-size: 0.9rem;
    display: block;
    margin-bottom: 1rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Gradient Text */
.gradient-text {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-tertiary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: var(--accent-primary);
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer-section ul li a:hover {
    color: var(--accent-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-tertiary);
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

.instructor-credit {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.instructor-credit strong {
    color: var(--accent-primary);
    font-weight: 600;
}

/* Technology Icons */
.tech-icons {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.tech-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tech-icon:hover {
    background-color: var(--accent-primary);
    border-color: var(--accent-primary);
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 4px 12px var(--accent-glow);
}

.tech-icon svg {
    width: 24px;
    height: 24px;
    color: var(--text-primary);
    transition: color var(--transition-fast);
}

.tech-icon:hover svg {
    color: #000;
}

/* Instructor Section */
.instructor-info {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
    align-items: flex-start;
}

.instructor-avatar {
    width: 60px;
    height: 60px;
    min-width: 60px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px var(--accent-glow);
}

.instructor-avatar svg {
    width: 32px;
    height: 32px;
    color: #000;
}

.instructor-details {
    flex: 1;
}

.instructor-name {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: 0.25rem;
}

.instructor-title {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-style: italic;
}

.instructor-bio {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes glow {
    0%, 100% {
        box-shadow: 0 0 20px var(--accent-glow);
    }
    50% {
        box-shadow: 0 0 40px var(--accent-glow);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 12px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}

/* Selection */
::selection {
    background-color: var(--accent-primary);
    color: #000;
}