/* Modern Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary: #2563eb;
    --primary-light: #3b82f6;
    --text: #1f2937;
    --text-light: #4b5563;
    --background: #ffffff;
    --background-alt: #f8fafc;
    --border: #e2e8f0;
    --shadow: rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

/* Dark Mode Colors */
[data-theme="dark"] {
    --primary: #60a5fa;
    --primary-light: #93c5fd;
    --text: #f1f5f9;
    --text-light: #cbd5e1;
    --background: #0f172a;
    --background-alt: #1e293b;
    --border: #334155;
    --shadow: rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', 'Poppins', sans-serif;
    background-color: var(--background);
    color: var(--text);
    line-height: 1.6;
    transition: var(--transition);
}

/* Dark Mode Toggle */
#darkModeToggle {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--background-alt);
    border: 2px solid var(--border);
    color: var(--text);
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    z-index: 1000;
    box-shadow: 0 4px 12px var(--shadow);
}

#darkModeToggle:hover {
    transform: scale(1.1);
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* Back to Home Button */
.back-home {
    position: fixed;
    top: 20px;
    left: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--background-alt);
    border: 2px solid var(--border);
    color: var(--text);
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    z-index: 1000;
    box-shadow: 0 4px 12px var(--shadow);
    text-decoration: none;
}

.back-home:hover {
    transform: scale(1.1);
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* Header */
header {
    background: var(--background-alt);
    padding: 4rem 2rem;
    text-align: center;
    margin-bottom: 3rem;
    border-bottom: 1px solid var(--border);
}

header h1 {
    font-size: 2.5rem;
    color: var(--text);
    margin-bottom: 1rem;
    font-weight: 700;
}

header p {
    color: var(--text-light);
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Main Content */
main {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

/* Project Cards */
.project-card {
    background: var(--background-alt);
    border-radius: 15px;
    padding: 2rem;
    border: 1px solid var(--border);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(20px);
    box-shadow: 0 2px 8px var(--shadow);
}

.project-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px var(--shadow);
    border-color: var(--primary);
}

.project-header {
    margin-bottom: 1.5rem;
}

.project-header h2 {
    color: var(--primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.project-tech {
    display: flex;
    gap: 0.8rem;
    flex-wrap: wrap;
}

.project-tech span {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--background);
    color: var(--primary);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.9rem;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.project-tech span:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
    border-color: var(--primary);
}

.project-card p {
    color: var(--text);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-btn {
    flex: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.8rem 1.2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

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

.demo-btn:hover {
    background: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

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

.source-btn:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

/* Footer */
footer {
    background: var(--background-alt);
    padding: 3rem;
    text-align: center;
    margin-top: 4rem;
    border-top: 1px solid var(--border);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.social-links a {
    background: var(--background);
    color: var(--text);
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    border: 2px solid var(--border);
}

.social-links a:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-5px);
    border-color: var(--primary);
}

footer h3 {
    color: var(--text-light);
    font-size: 1.1rem;
}

footer .fa-heart {
    color: #ef4444;
    margin: 0 0.2rem;
}

/* Loading Animation */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--background);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: 0.5s;
}

.loading.fade-out {
    opacity: 0;
}

.loader {
    width: 50px;
    height: 50px;
    border: 3px solid var(--border);
    border-radius: 50%;
    border-top-color: var(--primary);
    animation: spin 1s linear infinite;
}

@keyframes spin {
    100% {
        transform: rotate(360deg);
    }
}

/* Scroll to Top Button */
.scroll-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 45px;
    height: 45px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 1000;
}

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

.scroll-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 12px var(--shadow);
}

/* Media Queries */
@media (max-width: 768px) {
    header {
        padding: 3rem 1rem;
    }

    header h1 {
        font-size: 2rem;
    }

    main {
        padding: 0 1rem;
        grid-template-columns: 1fr;
    }

    .project-links {
        flex-direction: column;
    }

    .back-home, #darkModeToggle {
        width: 45px;
        height: 45px;
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.8rem;
    }

    header p {
        font-size: 1rem;
    }

    .project-tech {
        gap: 0.5rem;
    }

    .project-tech span {
        padding: 0.3rem 0.6rem;
        font-size: 0.8rem;
    }

    .social-links {
        gap: 1rem;
    }

    .social-links a {
        width: 40px;
        height: 40px;
    }
}