Examples of CSS properties practical usage opacity, overflow, etc.

-o-align-items
-o-animation
-o-animation-delay
-o-animation-name
-o-appearance
-o-background-clip
-o-background-size
-o-border-image
-o-border-radius
-o-box-align
-o-box-direction
-o-box-flex
-o-box-orient
-o-box-pack
-o-box-shadow
-o-box-sizing
-o-column-count
-o-column-gap
-o-filter
-o-flex-direction
-o-flex-wrap
-o-font-smoothing
-o-hyphens
-o-justify-content
-o-mask
-o-mask-image
-o-object-fit
-o-opacity
-o-order
-o-origin
-o-padding-start
-o-perspective
-o-radius
-o-shadow
-o-tab-size
-o-text-overflow
-o-text-rendering
-o-text-shadow
-o-text-size-adjust
-o-transform
-o-transform-origin
-o-transform-style
-o-transition
-o-transition-delay
-o-user-drag
-o-user-select
-o-webkit-transform
OPEN
OT_Find_a_Table
OT_navLink
OUTLINE-COLOR
OUTLINE-STYLE
OUTLINE-WIDTH
OVERFLOW
OVERFLOW-X
OVERFLOW-Y
Object
OknoRwd
One
Opacity
Optional
Orange
Orientation
Oswald
Other
OtherTabs
Oxygen
o-animation
o-box-sizing
o-transform
o-transition
object
object-fit
object-position
ocogogfn
odd
oe_empty
oe_insert
of-type
oferta_menu
off
off-canvas-toggle
off-screen
offcanvas-menu
offcanvas-pusher
offer
offer-item
offer-ribbon
offers
offers-thumbnail
offersEmailTrigger
offersPrintTrigger
offerta
office--action
official
offline
offset
offset1
offset10
offset11
offset12
offset13
offset14
offset15
offset2
offset3
offset4
offset5
offset6
offset7
offset8
offset9
offsetxin
offsetxout
offsetyin
og-close
oi-select
old
old-price
older-nav
olive
olor
on--hover
on-off
on-primary-color
onComplete
onHoverStop
one
one-faq
one-fourth
one-half
one-side-wide
one-third
onePro
one_fifth
one_fourth
one_fourth_img
one_half
one_sixth
one_sixth_img
one_third
one_third_bg
onefifth
onethird
onework
online
onoffswitch-inner
onrequest
onsale
ont-family
ont-size
opacity
opacity-hover
opaity
open
open-btn
open-child
open-close
open-comment-form
open-menu
open-panel
open-sub
open-submenu
open-video-popup
openAnimationSpeed
openCloseToggle
openRightMenu
open_details
open_lightbox
open_sub_categories
open_video_lightbox
openblok
opencloselink
opened
opener
openid
openpanel
opensearch
opensleft
opensright
opera
opinion-box
opinion-box-hover
opt
optgroup
option
option--input
option-item
options
options-list
opus
oracle
orange
orange-btn
orange-button
orange-outline
orangeButton
orangebutton
orangered
orbit-container
orbit-next
orbit-prev
orbit-previous
orbit-wrapper
orbita
orchid
order
order-actions
order-btn
order-cancel
order-info
order-now
order-submit
order_details
organization
orientation
orig
origin
original
orphans
os-lb-close-btn
oshr
osition
osoba
other
other-news
our-clients-item
our-doctors-blogs
our-process-item
our-team
our-team-box
ourteam-item
out
out-of-stock
outOfBandOnce
outer
outer-wrap
outline
outline-bg-btn
outline-btn
outline-color
outline-inward
outline-offset
outline-outward
outline-style
outline-width
outlined
output
outroaction-core
oveflow
over
over-flow
overdefult
overflow
overflow-Y
overflow-scrolling
overflow-wrap
overflow-x
overflow-y
overlap
overlay
overlay-close
overlay-container
overlay-dark
overlay-fade-in
overlay-icon
overlay-menu
overlay-navigation
overlay-parent
overlayColor
overlayOpacity
overlay_a
overlayed
override
overview
overwrites
ow_button
owl-buttons
owl-carousel
owl-controls
owl-dot
owl-dots
owl-inner-nav
owl-item
owl-main
owl-next
owl-outer-nav
owl-page
owl-pagination
owl-prev
owl-stage
owl-stage-outer
owl-theme
owl-ui-lg
owl-ui-md
owl-video-play-icon
owl-wrapper
owl-wrapper-outer
owl_carousel
owlid
owner_name