:root {
    --bg-color: #f8fafc;
    --text-color: #0f172a;
    --card-bg: #ffffff;
    --primary-color: #2563eb;
    --border-color: rgba(0, 0, 0, 0.08);
}

.dark-theme {
    --bg-color: #020617;
    --text-color: #f1f5f9;
    --card-bg: #1e293b;
    --primary-color: #38bdf8;
    --border-color: rgba(255, 255, 255, 0.1);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; transition: 0.3s ease; }
html { scroll-behavior: smooth; }
body { background-color: var(--bg-color); color: var(--text-color); line-height: 1.6; overflow-x: hidden; }

/* Navigation & Header Hover Effects */
nav { display: flex; justify-content: space-between; align-items: center; padding: 1.2rem 10%; background: var(--bg-color); position: sticky; top: 0; z-index: 1000; border-bottom: 1px solid var(--border-color); }
.logo { font-weight: 800; letter-spacing: 1px; color: var(--primary-color); }

.nav-links { display: flex; list-style: none; }
.nav-links li { margin: 0 15px; position: relative; }

.nav-links a { 
    text-decoration: none; 
    color: var(--text-color); 
    font-weight: 500; 
    padding: 5px 0;
    transition: color 0.3s ease;
}

.nav-links a:hover { color: var(--primary-color); }

/* Navigation Underline Animation */
.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-links a:hover::after { width: 100%; }

.toggle-btn { background: var(--card-bg); border: 1px solid var(--border-color); width: 40px; height: 40px; border-radius: 50%; cursor: pointer; color: var(--primary-color); display: flex; align-items: center; justify-content: center; }

/* Sidebar */
.sidebar { position: fixed; top: 0; left: -300px; width: 280px; height: 100%; background: var(--card-bg); z-index: 2000; padding: 2rem; transition: 0.4s ease; box-shadow: 5px 0 15px rgba(0,0,0,0.1); }
.sidebar.active { left: 0; }
.sidebar-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 1999; display: none; }
.sidebar-overlay.active { display: block; }
.close-btn { font-size: 2.5rem; position: absolute; top: 10px; right: 20px; cursor: pointer; }

.sidebar-links { list-style: none; margin-top: 50px; }
.sidebar-links a { 
    text-decoration: none; 
    color: var(--text-color); 
    display: block; 
    padding: 12px; 
    border: 1px solid var(--border-color); 
    border-radius: 10px; 
    margin: 10px 0; 
    transition: 0.3s;
}

.sidebar-links a:hover { 
    background: var(--primary-color); 
    color: white !important; 
    transform: translateX(10px); 
    padding-left: 20px;
}

/* Hero Section */
header { min-height: 90vh; display: flex; align-items: center; justify-content: center; text-align: center; padding: 20px; }
.profile-img { width: 280px; height: 280px; border-radius: 50%; object-fit: cover; border: 8px solid var(--card-bg); box-shadow: 0 15px 45px rgba(0,0,0,0.2); margin-bottom: 30px; }
.highlight { color: var(--primary-color); font-weight: 800; font-size: 3.5rem; }

/* Expertise Cards with Advanced Hover */
.section { padding: 80px 10%; text-align: center; }
.skills-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; margin-top: 40px; }

.skill-item { 
    background: var(--card-bg); 
    padding: 35px 25px; 
    border-radius: 25px; 
    border: 1px solid var(--border-color); 
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); 
    cursor: pointer;
}

.skill-item:hover {
    transform: translateY(-12px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
    border-color: var(--primary-color);
}

.skill-icon { font-size: 2.5rem; color: var(--primary-color); margin-bottom: 15px; transition: transform 0.3s ease; }
.skill-item:hover .skill-icon { transform: scale(1.1) rotate(5deg); }

.skill-badges { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 15px; }
.badge { display: flex; align-items: center; gap: 6px; padding: 6px 12px; border-radius: 6px; font-size: 0.85rem; font-weight: bold; color: white; }

.html { background: #E34F26; } .css { background: #1572B6; } .js { background: #F7DF1E; color: #000; }
.java { background: #007396; } .python { background: #3776AB; } .gold { background: #FFD700; color: #000; }
.analysis { background: #2ECC71; } .mt5 { background: #4A90E2; } .ps { background: #31A8FF; }
.ui { background: #8B5CF6; } .brand { background: #EC4899; }

/* Project Cards */
.project-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 30px; margin-top: 40px; }
.project-card { 
    background: var(--card-bg); 
    padding: 40px; 
    border-radius: 20px; 
    border: 1px solid var(--border-color); 
    text-decoration: none; 
    color: inherit; 
    display: block; 
    transition: all 0.4s ease;
}

.project-card:hover { 
    transform: translateY(-10px); 
    box-shadow: 0 15px 35px rgba(0,0,0,0.15);
    border-color: var(--primary-color);
}

.view-link { color: var(--primary-color); font-weight: bold; display: block; margin-top: 15px; }

/* Contact Form */
.contact-container { max-width: 700px; margin: 40px auto; background: var(--card-bg); padding: 40px; border-radius: 25px; border: 1px solid var(--border-color); }
.form-body { display: flex; flex-direction: column; gap: 20px; }
.input-group { display: flex; gap: 20px; }
.form-body input, .form-body textarea { width: 100%; padding: 15px; border-radius: 12px; border: 1px solid var(--border-color); background: var(--bg-color); color: var(--text-color); font-size: 1rem; outline: none; }
.form-body input:focus, .form-body textarea:focus { border-color: var(--primary-color); box-shadow: 0 0 10px rgba(37, 99, 235, 0.1); }
.send-btn { width: 100%; cursor: pointer; border: none; display: flex; align-items: center; justify-content: center; gap: 10px; font-size: 1.1rem; }

/* Footer & Socials */
.socials { display: flex; justify-content: center; gap: 15px; margin-top: 10px; }
.social-card { width: 55px; height: 55px; background: var(--card-bg); border: 1px solid var(--border-color); border-radius: 12px; color: var(--text-color); font-size: 1.6rem; display: flex; align-items: center; justify-content: center; transition: 0.4s; }
.social-card:hover { background: var(--primary-color); color: white; transform: translateY(-8px) rotate(8deg); }

.btn { padding: 12px 30px; background: var(--primary-color); color: white; text-decoration: none; border-radius: 10px; display: inline-block; margin: 10px; font-weight: 600; }
.btn-outline { background: transparent; border: 2px solid var(--primary-color); color: var(--primary-color); }

footer { padding: 40px 10%; text-align: center; border-top: 1px solid var(--border-color); }
.copyright { margin-top: 20px; opacity: 0.7; font-size: 0.9rem; }

@media (max-width: 768px) { 
    .nav-links { display: none; } 
    .highlight { font-size: 2.4rem; } 
    .input-group { flex-direction: column; } 
}