:root {
    --primary-color: #0f172a;
    --secondary-color: #3b82f6;
    --accent-color: #f59e0b;
    --text-color: #334155;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --transition: all 0.3s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: 'Inter', sans-serif; color: var(--text-color); line-height: 1.6; background-color: var(--bg-light); }
h1, h2, h3 { color: var(--primary-color); line-height: 1.2; }
a { text-decoration: none; color: inherit; }

.container { width: 90%; max-width: 1200px; margin: 0 auto; }
section { padding: 4rem 0; }

/* Navigation */
nav { background-color: var(--bg-white); box-shadow: 0 2px 10px rgba(0,0,0,0.05); position: fixed; width: 100%; top: 0; z-index: 1000; }
.nav-container { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo { font-weight: 700; font-size: 1.2rem; color: var(--primary-color); }
.nav-links { display: none; }
.hamburger { display: block; cursor: pointer; }
.hamburger .line { width: 25px; height: 3px; background-color: var(--primary-color); margin: 5px 0; transition: var(--transition); }

/* Language Switcher Navbar Button */
.lang-btn { background: none; border: none; font-size: 1rem; font-weight: 600; color: var(--text-color); cursor: pointer; display: flex; align-items: center; gap: 0.4rem; font-family: inherit; transition: var(--transition); }
.lang-btn:hover { color: var(--secondary-color); }
.flag { font-size: 1.2rem; }
.arrow { font-size: 0.7rem; color: #94a3b8; }

/* Mobile Menu Active State */
.nav-links.active { display: flex; flex-direction: column; position: absolute; top: 70px; left: 0; width: 100%; background-color: var(--bg-white); box-shadow: 0 5px 10px rgba(0,0,0,0.05); padding: 1rem 0; text-align: center; }
.nav-links li { list-style: none; margin: 1rem 0; }
.nav-links a:hover { color: var(--secondary-color); }

/* Hero Section */
#home { padding-top: 120px; text-align: center; background: linear-gradient(to bottom right, var(--bg-white), #e2e8f0); min-height: 80vh; display: flex; flex-direction: column; justify-content: center; }
.hero-title { font-size: 2.5rem; margin-bottom: 1rem; }
.hero-subtitle { font-size: 1.1rem; margin-bottom: 2rem; color: #475569; }
.btn { display: inline-block; background-color: var(--secondary-color); color: white; padding: 0.8rem 2rem; border-radius: 5px; font-weight: 600; transition: var(--transition); }
.btn:hover { background-color: #2563eb; transform: translateY(-2px); }

/* About & Expertise */
#about { background-color: var(--bg-white); }
.section-title { text-align: center; font-size: 2rem; margin-bottom: 2rem; position: relative; }
.section-title::after { content: ''; display: block; width: 50px; height: 3px; background-color: var(--secondary-color); margin: 10px auto 0; }
.about-text { font-size: 1.1rem; text-align: center; max-width: 800px; margin: 0 auto; }

.grid { display: grid; grid-template-columns: 1fr; gap: 2rem; margin-top: 2rem; }
.card { background-color: var(--bg-white); padding: 2rem; border-radius: 8px; box-shadow: 0 4px 6px rgba(0,0,0,0.05); border-top: 4px solid var(--secondary-color); transition: var(--transition); }
.card:hover { transform: translateY(-5px); box-shadow: 0 10px 15px rgba(0,0,0,0.1); }
.card h3 { margin-bottom: 1rem; font-size: 1.25rem; }

/* Footer */
footer { background-color: var(--primary-color); color: white; padding: 3rem 0; text-align: center; }
footer h2 { color: white; margin-bottom: 1rem; }
.contact-info { list-style: none; margin-top: 2rem; font-size: 1.1rem;}
.contact-info li { margin-bottom: 1rem; }
.contact-info span { font-weight: 600; color: var(--accent-color); }
.contact-link { color: white; transition: color 0.3s ease; }
.contact-link:hover { color: var(--secondary-color); }

/* Language Modal Popup */
.lang-modal { display: none; position: fixed; z-index: 2000; left: 0; top: 0; width: 100%; height: 100%; background-color: rgba(15, 23, 42, 0.4); backdrop-filter: blur(4px); opacity: 0; transition: opacity 0.3s ease; }
.lang-modal.show { display: flex; justify-content: center; align-items: center; opacity: 1; }
.lang-modal-content { background-color: var(--bg-white); padding: 2rem; border-radius: 12px; width: 90%; max-width: 400px; box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1); transform: translateY(-20px); transition: transform 0.3s ease; }
.lang-modal.show .lang-modal-content { transform: translateY(0); }
.lang-modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.5rem; }
.lang-modal-header h3 { font-size: 1.2rem; margin: 0; }
.close-btn { background: none; border: none; font-size: 1.8rem; cursor: pointer; color: #64748b; line-height: 1; }
.close-btn:hover { color: var(--primary-color); }
.lang-grid { display: grid; grid-template-columns: 1fr; gap: 0.8rem; }
.lang-option { display: flex; align-items: center; gap: 1rem; padding: 0.8rem 1.2rem; border-radius: 8px; font-weight: 500; border: 1px solid #e2e8f0; transition: var(--transition); }
.lang-option:hover { background-color: var(--bg-light); border-color: var(--secondary-color); color: var(--secondary-color); }
.lang-option.active { background-color: #eff6ff; border-color: var(--secondary-color); color: var(--secondary-color); }

/* Desktop Media Query */
@media (min-width: 768px) {
    .hamburger { display: none; }
    .nav-links { display: flex; align-items: center; }
    .nav-links li { margin: 0 0 0 2rem; }
    .hero-title { font-size: 3.5rem; }
    .grid { grid-template-columns: repeat(2, 1fr); }
}

/* Animations */
.fade-in { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease-out, transform 0.6s ease-out; }
.fade-in.appear { opacity: 1; transform: translateY(0); }