.app-container {
    display: flex;
    min-height: 100vh;
    max-width: 1600px;
    margin: 0 auto;
    box-shadow: 0 0 30px rgba(0,0,0,0.1);
    background: white;
}

.sidebar {
    width: 250px;
    background: linear-gradient(180deg, var(--tech-blue-mid) 0%, var(--tech-blue-light) 100%);
    color: white;
    transition: all 0.3s;
    box-shadow: 4px 0 20px rgba(10, 38, 71, 0.3);
    position: relative;
    z-index: 100;
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

.sidebar::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 30%, rgba(65, 180, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(65, 180, 255, 0.08) 0%, transparent 50%);
    pointer-events: none;
}

.main-content {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
    background: linear-gradient(135deg, #f5f9fc 0%, #fafdff 50%, #f0f8ff 100%);
}

.page-content {
    animation: fadeIn 0.3s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.page-header {
    padding-bottom: 15px;
    margin-bottom: 25px;
    border-bottom: 2px solid transparent;
    background: linear-gradient(to right, #e0f2ff, transparent) bottom / 100% 2px no-repeat;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
}

.page-header h2 {
    color: var(--tech-blue-mid);
    font-weight: 600;
    position: relative;
    display: inline-block;
}

.page-header h2::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 40%;
    height: 3px;
    background: linear-gradient(90deg, var(--tech-blue-accent), transparent);
    border-radius: 2px;
}