/* CSS Variables for Advanced Theming */
:root {
    --bg-color: #fafafa;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --accent: #2563eb;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;
    --hover-shadow: 0 10px 30px -10px rgba(0,0,0,0.1);
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-color: #0b0f19;
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --accent: #3b82f6;
    --card-bg: #111827;
    --border-color: #1f2937;
    --hover-shadow: 0 10px 30px -10px rgba(0,0,0,0.5);
}

* { 
    margin: 0; 
    padding: 0; 
    box-sizing: border-box; 
    /* Smooth transition for theme switching */
    transition: background-color 0.4s ease, color 0.4s ease, border-color 0.4s ease; 
}

body { 
    font-family: 'Inter', sans-serif; 
    background-color: var(--bg-color); 
    color: var(--text-primary); 
    line-height: 1.7; 
    -webkit-font-smoothing: antialiased;
}

/* Navigation (Glassmorphism Effect) */
.navbar { 
    position: fixed; 
    width: 100%; 
    top: 0; 
    backdrop-filter: blur(12px); 
    -webkit-backdrop-filter: blur(12px);
    background-color: rgba(var(--bg-color), 0.75); 
    border-bottom: 1px solid var(--border-color); 
    z-index: 1000; 
}

.nav-container { 
    max-width: 1100px; 
    margin: 0 auto; 
    padding: 20px; 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
}

.logo { 
    font-family: 'Playfair Display', serif; 
    font-size: 22px; 
    font-weight: 600; 
    letter-spacing: 1.5px; 
}

.nav-links { 
    display: flex; 
    gap: 35px; 
    list-style: none; 
}

.nav-links a { 
    text-decoration: none; 
    color: var(--text-secondary); 
    font-size: 14px; 
    text-transform: uppercase; 
    letter-spacing: 1px; 
    transition: color 0.3s ease;
}

.nav-links a:hover { color: var(--accent); }
.theme-btn { background: none; border: none; font-size: 20px; cursor: pointer; transition: transform 0.3s ease; }
.theme-btn:hover { transform: scale(1.1); }

/* Main Content Layout */
main { max-width: 1100px; margin: 140px auto 0; padding: 0 20px; }

/* Hero Section */
.hero { max-width: 850px; margin-bottom: 120px; }
.hero-greeting { font-size: 15px; font-weight: 500; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 2.5px; margin-bottom: 12px; }
.hero-title { font-family: 'Playfair Display', serif; font-size: 3.8rem; line-height: 1.15; margin-bottom: 24px; color: var(--text-primary); }
.accent-text { color: var(--accent); font-style: italic; }
.hero-description { font-size: 17px; color: var(--text-secondary); margin-bottom: 35px; max-width: 750px; }

/* Button & Contact Card */
.primary-btn { 
    padding: 14px 30px; 
    background-color: var(--text-primary); 
    color: var(--bg-color); 
    border: none; 
    border-radius: 6px; 
    font-size: 15px; 
    font-weight: 500;
    cursor: pointer; 
    transition: transform 0.2s ease, opacity 0.2s ease;
}
.primary-btn:hover { transform: translateY(-2px); opacity: 0.9; }

.contact-card { 
    margin-top: 25px; 
    padding: 24px; 
    background-color: var(--card-bg); 
    border: 1px solid var(--border-color); 
    border-radius: 8px; 
    max-width: 450px; 
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}
.hidden { display: none; }

/* Section Titles */
.section-title { 
    font-size: 13px; 
    font-weight: 600;
    text-transform: uppercase; 
    letter-spacing: 2px; 
    color: var(--text-secondary); 
    margin-bottom: 40px; 
    border-bottom: 1px solid var(--border-color); 
    padding-bottom: 12px; 
}

/* Experience List */
.experience-list { display: flex; flex-direction: column; gap: 24px; margin-bottom: 100px; }
.exp-card { 
    padding: 28px; 
    background-color: var(--card-bg); 
    border: 1px solid var(--border-color); 
    border-radius: 10px; 
    border-left: 4px solid var(--accent); 
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.exp-card:hover {
    transform: translateX(5px);
    box-shadow: var(--hover-shadow);
}
.exp-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.exp-header h3 { font-size: 20px; font-weight: 600; }
.exp-date { font-size: 14px; font-weight: 500; color: var(--accent); }
.exp-card h4 { font-size: 16px; font-weight: 400; color: var(--text-secondary); margin-bottom: 16px; }
.exp-card ul { margin-left: 20px; color: var(--text-secondary); font-size: 15px; }
.exp-card ul li { margin-bottom: 6px; }

/* Projects Grid */
.project-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 30px; margin-bottom: 80px; }
.project-card { 
    background-color: var(--card-bg); 
    border: 1px solid var(--border-color); 
    border-radius: 10px; 
    transition: transform 0.3s ease, box-shadow 0.3s ease; 
}
.project-card:hover { 
    transform: translateY(-8px); 
    box-shadow: var(--hover-shadow);
}
.project-content { padding: 28px; }
.project-content h3 { font-size: 20px; font-weight: 600; margin-bottom: 12px; }
.project-content p { color: var(--text-secondary); font-size: 15px; margin-bottom: 24px; }

/* Skills Tags */
.skills-container { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 100px; }
.tech-tag { 
    display: inline-block; 
    padding: 8px 16px; 
    background-color: rgba(37, 99, 235, 0.08); 
    color: var(--accent); 
    border-radius: 30px; 
    font-size: 13px; 
    font-weight: 600; 
    transition: background-color 0.3s ease;
}
.tech-tag:hover { background-color: rgba(37, 99, 235, 0.15); }

footer { text-align: center; padding: 40px; color: var(--text-secondary); font-size: 14px; border-top: 1px solid var(--border-color); }

/* --- ANIMATION CLASSES --- */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title { font-size: 2.5rem; }
    .nav-links { display: none; }
    .exp-header { flex-direction: column; align-items: flex-start; gap: 5px; }
}