:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --accent: #60a5fa;
    --bg-base: #0f172a;
    --bg-surface: rgba(30, 41, 59, 0.6);
    --border: rgba(255, 255, 255, 0.1);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --success: #10b981;
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; }
body { background: var(--bg-base); color: var(--text-main); min-height: 100vh; overflow-x: hidden; }

/* Utilities */
.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.text-accent { color: var(--accent); }
.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }
.text-sm { font-size: 0.875rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }
.pt-4 { padding-top: 1rem; }
.ml-2 { margin-left: 0.5rem; }
.mx-auto { margin-left: auto; margin-right: auto; }
.border-t { border-top: 1px solid var(--border); }
.flex-between { display: flex; justify-content: space-between; }
.align-center { align-items: center; }
.hidden { display: none !important; }

.text-gradient {
    background: linear-gradient(135deg, #60a5fa, #c084fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Background glows */
.bg-glow { position: absolute; border-radius: 50%; filter: blur(100px); z-index: -1; opacity: 0.4; }
.bg-glow-1 { top: -10%; left: -10%; width: 500px; height: 500px; background: rgba(59, 130, 246, 0.4); }
.bg-glow-2 { bottom: 0%; right: 0%; width: 600px; height: 600px; background: rgba(192, 132, 252, 0.2); }

/* Glass Card */
.glass-card {
    background: var(--bg-surface);
    backdrop-filter: blur(16px);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s, border-color 0.3s;
}
.glass-card:hover { transform: translateY(-3px); }
.border-accent { border-color: rgba(96, 165, 250, 0.4); }

/* Buttons */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem;
    padding: 0.75rem 1.25rem; border-radius: 8px; font-weight: 500; font-family: 'Outfit';
    border: none; cursor: pointer; transition: all 0.3s ease; text-decoration: none; font-size: 1rem;
}
.btn-primary { background: linear-gradient(135deg, var(--primary), var(--accent)); color: white; }
.btn-primary:hover { box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4); filter: brightness(1.1); }
.btn-outline { background: transparent; border: 1px solid var(--border); color: var(--text-main); }
.btn-outline:hover { border-color: var(--accent); }
.btn-ghost { background: transparent; color: var(--text-main); }
.btn-ghost:hover { color: var(--accent); }
.btn-full { width: 100%; }
.btn-lg { padding: 1rem 1.5rem; font-size: 1.1rem; }

/* Navbar */
.navbar { padding: 1.5rem 0; position: sticky; top: 0; backdrop-filter: blur(10px); z-index: 100; border-bottom: 1px solid var(--border); }
.nav-container { display: flex; justify-content: space-between; align-items: center; }
.logo { display: flex; align-items: center; gap: 0.5rem; font-family: 'Outfit'; font-size: 1.5rem; font-weight: 700; text-decoration: none; color: white; }
.logo i { font-size: 2rem; }
.nav-links { display: flex; gap: 2rem; }
.nav-link { color: var(--text-muted); text-decoration: none; transition: color 0.3s; font-weight: 500; }
.nav-link:hover, .nav-link.active { color: white; }

/* Typography */
h1, h2, h3 { font-family: 'Outfit', sans-serif; }
.page-title { font-size: 3rem; font-weight: 800; line-height: 1.1; }
.page-subtitle { font-size: 1.25rem; color: var(--text-muted); max-width: 600px; }

/* Page Specific: Directory / Grid */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.5rem; }
.user-card { position: relative; text-align: center; display: flex; flex-direction: column; align-items: center; }
.avatar-lg { width: 90px; height: 90px; border-radius: 50%; margin-bottom: 1rem; border: 2px solid var(--accent); object-fit: cover; }
.avatar-sm { width: 45px; height: 45px; border-radius: 50%; object-fit: cover;}
.user-name { font-size: 1.25rem; font-weight: 600; }
.user-major { font-size: 0.9rem; margin-top: 0.25rem; }
.user-job { display: flex; align-items: center; gap: 0.5rem; color: var(--text-main); font-size: 0.95rem; }
.mentor-badge { position: absolute; top: 1rem; right: 1rem; background: rgba(139, 92, 246, 0.2); color: #c4b5fd; padding: 0.25rem 0.75rem; border-radius: 20px; font-size: 0.75rem; display: flex; align-items: center; gap: 0.25rem; border: 1px solid #8b5cf6;}

/* Page Specific: Tags */
.tag { background: rgba(59, 130, 246, 0.1); color: var(--accent); padding: 0.3rem 0.8rem; border-radius: 20px; font-size: 0.8rem; border: 1px solid rgba(59,130,246,0.3); margin-right: 0.5rem; margin-top: 0.5rem; display: inline-block;}

/* Page Specific: Q&A */
.qa-grid { display: flex; flex-direction: column; gap: 1.5rem; }
.qa-card { text-align: left; }
.qa-header { display: flex; align-items: center; gap: 1rem; }
.author-name { font-weight: 600; font-family: 'Outfit'; }
.qa-title { font-size: 1.3rem; margin-top: 1rem;}
.qa-body { line-height: 1.6; }

/* Center Page (Login) */
.center-content { display: flex; flex-direction: column; justify-content: center; align-items: center; min-height: 100vh; position: relative;}
.absolute-top-left { position: absolute; top: 2rem; left: 2rem; }
.auth-box { width: 100%; max-width: 500px; padding: 2.5rem; }
.auth-tabs { display: flex; border-bottom: 1px solid var(--border); }
.tab-btn { flex: 1; background: none; border: none; color: var(--text-muted); padding: 1rem; font-family: 'Outfit'; font-size: 1.1rem; cursor: pointer; border-bottom: 2px solid transparent; transition: all 0.3s;}
.tab-btn.active { color: white; border-bottom-color: var(--accent); }
.form-title { font-size: 2rem; }
.form-group { display: flex; flex-direction: column; gap: 0.5rem; margin-bottom: 1.25rem; }
.form-group label { font-size: 0.9rem; font-weight: 500; color: var(--text-muted); }
.grid-2-col { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-bottom: 0;}
input { background: rgba(15, 23, 42, 0.5); border: 1px solid var(--border); color: white; padding: 0.85rem 1rem; border-radius: 8px; font-size: 1rem; outline: none; transition: border-color 0.3s; width: 100%;}
input:focus { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(96, 165, 250, 0.2); }