:root {
    --sidebar-bg: #1a2a3a;
    --accent: #00d2ff;
    --card-bg: #ffffff;
    --text-main: #333;
    --text-muted: #bdc3c7;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Segoe UI', Tahoma, sans-serif; background: #f0f2f5; color: var(--text-main); scroll-behavior: smooth; }

.app-container { display: flex; flex-wrap: nowrap; min-height: 100vh; }

/* Sidebar */
.sidebar {
    width: 280px;
    min-width: 280px;
    background: var(--sidebar-bg);
    color: white;
    padding: 1.5rem;
    position: sticky;
    top: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
    z-index: 100;
}

.img-container { width: 120px; height: 120px; margin: 0 auto 1rem; border-radius: 50%; overflow: hidden; border: 3px solid var(--accent); }
.profile-img { width: 100%; height: 100%; object-fit: cover; }

.user-name { font-size: 1.1rem; white-space: nowrap; text-align: center; margin-bottom: 5px; }
.headline { font-size: 0.75rem; color: var(--text-muted); text-align: center; margin-bottom: 1.5rem; }

.side-nav { flex-grow: 1; }
.side-nav a { display: block; color: #ecf0f1; text-decoration: none; padding: 10px 5px; font-size: 0.9rem; transition: 0.3s; }
.side-nav a i { width: 25px; color: var(--accent); }
.side-nav a:hover { background: rgba(255,255,255,0.05); border-radius: 5px; }

.btn-download {
    background: var(--accent);
    color: #1a2a3a;
    padding: 10px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: bold;
    display: block;
    text-align: center;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.contact-icon-row { display: flex; justify-content: space-between; gap: 8px; }
.contact-icon-row button, .contact-icon-row a {
    width: 35px; height: 35px; border-radius: 50%;
    background: rgba(255,255,255,0.1); color: white;
    border: none; cursor: pointer; display: grid; place-items: center;
    transition: 0.3s; font-size: 0.9rem;
}
.contact-icon-row a:hover, .contact-icon-row button:hover { background: var(--accent); color: var(--sidebar-bg); }

/* Main Content Area */
.main-content { flex-grow: 1; padding: 2rem 4rem; overflow-y: auto; max-width: calc(100% - 280px); }

.section-title { margin: 2rem 0 1rem; font-size: 1.4rem; color: var(--sidebar-bg); border-left: 4px solid var(--accent); padding-left: 10px; }

.card { background: white; padding: 1.5rem; border-radius: 8px; margin-bottom: 1rem; box-shadow: 0 4px 6px rgba(0,0,0,0.05); }

/* Toggle Description */
.btn-toggle-desc {
    background: transparent;
    border: 1px solid var(--accent);
    color: var(--sidebar-bg);
    padding: 4px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.75rem;
    margin-top: 10px;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: 0.3s;
}
.btn-toggle-desc:hover { background: var(--accent); color: white; }
.btn-toggle-desc i { transition: transform 0.3s; }
.btn-toggle-desc.active i { transform: rotate(180deg); }

.description-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-in-out;
}
.description-content.expanded { max-height: 500px; }
.description-content p { padding-top: 12px; font-size: 0.85rem; color: #666; line-height: 1.6; }

/* Skills Grid (4 Columns) */
.skill-card-container { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; align-items: start; }
.skill-group h4 { font-size: 0.8rem; margin-bottom: 12px; color: var(--sidebar-bg); border-bottom: 2px solid var(--accent); padding-bottom: 5px; min-height: 2.5rem; display: flex; align-items: center; }
.skill-item { font-size: 0.75rem; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.skill-item i { color: var(--accent); font-size: 0.9rem; width: 15px; text-align: center; }

/* Certification Buttons */
.cert-item { margin-bottom: 1.5rem; }
.cert-item:last-child { margin-bottom: 0; }
.btn-view-cert {
    display: inline-block;
    margin-top: 8px;
    padding: 5px 12px;
    font-size: 0.75rem;
    color: var(--sidebar-bg);
    border: 1px solid var(--accent);
    text-decoration: none;
    border-radius: 4px;
    transition: 0.3s;
}
.btn-view-cert:hover { background: var(--accent); color: white; }

/* Contact Grid (2 Columns) */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.contact-col { display: flex; flex-direction: column; gap: 12px; }
.contact-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 15px;
    background: rgba(0, 210, 255, 0.05);
    border: 1px solid var(--accent);
    color: var(--sidebar-bg);
    text-decoration: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: 0.3s;
    cursor: pointer;
}
.contact-btn:hover { background: var(--accent); color: white; }
.contact-btn i { font-size: 1.1rem; width: 20px; text-align: center; }

/* Toast */
.toast { position: fixed; bottom: 20px; right: 20px; background: #2ecc71; color: white; padding: 10px 20px; border-radius: 5px; display: none; z-index: 1000; }

/* Responsive */
@media (max-width: 1200px) { .skill-card-container { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 768px) {
    .app-container { flex-direction: column; }
    .sidebar { width: 100%; height: auto; position: relative; }
    .main-content { max-width: 100%; padding: 1.5rem; }
    .skill-card-container { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
}