<s>
Flat	B-Application
design	I-Application
is	O
a	O
minimalist	B-Device
design	O
language	O
or	O
design	O
style	O
commonly	O
used	O
in	O
graphical	B-Application
user	I-Application
interfaces	I-Application
(	O
GUI	B-Application
)	O
(	O
such	O
as	O
web	B-Application
applications	I-Application
and	O
mobile	B-Application
apps	I-Application
)	O
,	O
and	O
also	O
in	O
graphical	O
materials	O
such	O
as	O
posters	O
,	O
arts	O
,	O
guide	O
documents	O
and	O
publishing	O
products	O
.	O
</s>
<s>
Flat	B-Application
design	I-Application
is	O
a	O
style	O
of	O
interface	O
design	O
emphasizing	O
minimalist	B-Device
use	O
of	O
simple	O
elements	O
,	O
typography	B-Application
,	O
and	O
flat	O
colors	O
.	O
</s>
<s>
Designers	O
may	O
prefer	O
flat	B-Application
design	I-Application
because	O
it	O
allows	O
interface	O
designs	O
to	O
be	O
more	O
streamlined	O
and	O
efficient	O
.	O
</s>
<s>
Additionally	O
,	O
it	O
makes	O
it	O
easier	O
to	O
design	O
an	O
interface	O
that	O
is	O
responsive	B-General_Concept
to	O
changes	O
in	O
browser	O
size	O
across	O
different	O
devices	O
.	O
</s>
<s>
Flat	B-Application
design	I-Application
is	O
primarily	O
influenced	O
by	O
the	O
International	O
Typographic	O
Style	O
(	O
also	O
known	O
as	O
Swiss	O
Style	O
)	O
,	O
text	B-Application
user	I-Application
interfaces	I-Application
,	O
modernism	O
,	O
and	O
the	O
styles	O
emerging	O
from	O
Bauhaus	O
.	O
</s>
<s>
The	O
International	O
Typographic	O
style	O
is	O
often	O
considered	O
the	O
most	O
substantial	O
influence	O
on	O
flat	B-Application
design	I-Application
,	O
and	O
its	O
emergence	O
and	O
popularization	O
during	O
the	O
1950s	O
and	O
1960s	O
is	O
regarded	O
as	O
the	O
starting	O
point	O
of	O
flat	B-Application
design	I-Application
,	O
although	O
it	O
would	O
not	O
make	O
an	O
appearance	O
in	O
the	O
digital	O
world	O
for	O
some	O
time	O
thereafter	O
.	O
</s>
<s>
In	O
2002	O
,	O
Microsoft	O
released	O
Windows	B-Device
Media	I-Device
Center	I-Device
,	O
and	O
in	O
2006	O
,	O
the	O
Zune	B-Library
MP3	O
player	O
,	O
both	O
of	O
which	O
contained	O
elements	O
of	O
flat	B-Application
design	I-Application
.	O
</s>
<s>
The	O
design	O
of	O
the	O
Zune	B-Library
was	O
clean	O
and	O
simple	O
,	O
with	O
a	O
focus	O
on	O
large	O
lower	O
case	O
typography	B-Application
,	O
silhouette-style	O
logos	O
,	O
and	O
monochromatic	O
font	O
colors	O
.	O
</s>
<s>
Microsoft	O
continued	O
this	O
style	O
of	O
design	O
with	O
the	O
2010	O
release	O
of	O
Windows	B-Protocol
Phone	I-Protocol
7	O
,	O
which	O
built	O
on	O
the	O
flat	B-Application
design	I-Application
elements	O
introduced	O
with	O
the	O
Zune	B-Library
,	O
formalized	O
as	O
the	O
"	O
Metro	O
design	O
language	O
"	O
.	O
</s>
<s>
The	O
design	O
was	O
dominated	O
by	O
large	O
and	O
bright	O
shapes	O
accompanied	O
by	O
sans-serif	O
typography	B-Application
from	O
the	O
Segoe	O
font	O
family	O
,	O
flat	O
images	O
,	O
and	O
a	O
menu	O
with	O
a	O
grid-like	O
pattern	O
.	O
</s>
<s>
Metro	O
was	O
subsequently	O
adopted	O
by	O
all	O
Microsoft	O
software	O
lines	O
,	O
including	O
the	O
Windows	B-Application
8	I-Application
PC	B-Device
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Android	B-Application
began	O
to	O
adopt	O
flat	B-Application
design	I-Application
trends	O
with	O
4.0	B-Application
"	I-Application
Ice	I-Application
Cream	I-Application
Sandwich	I-Application
"	I-Application
in	O
2011	O
;	O
Matias	O
Duarte	O
,	O
Google	B-Application
's	I-Application
vice	O
president	O
of	O
design	O
,	O
felt	O
that	O
Apple	O
's	O
iOS	B-Application
was	O
too	O
skeuomorphic	O
,	O
Windows	B-Protocol
Phone	I-Protocol
looked	O
like	O
"	O
airport	O
lavatory	O
signage	O
"	O
,	O
and	O
that	O
both	O
interfaces	O
were	O
too	O
rigidly	O
standardized	O
with	O
limited	O
flexibility	O
for	O
designers	O
.	O
</s>
<s>
The	O
platform	O
's	O
new	O
"	O
Holo	O
"	O
interface	O
was	O
designed	O
to	O
appear	O
more	O
simplistic	O
than	O
past	O
Android	B-Application
versions	O
,	O
with	O
neon-blue	O
accents	O
,	O
hard	O
edges	O
,	O
and	O
drop	O
shadows	O
for	O
depth	O
.	O
</s>
<s>
In	O
2013	O
,	O
Apple	O
unveiled	O
iOS	B-Operating_System
7	I-Operating_System
,	O
which	O
shifted	O
to	O
a	O
flat	B-Application
UI	I-Application
design	I-Application
with	O
use	O
of	O
brighter	O
colors	O
,	O
typography	B-Application
,	O
as	O
well	O
as	O
blurred	O
,	O
translucent	O
overlays	O
.	O
</s>
<s>
The	O
following	O
year	O
,	O
OS	B-Device
X	I-Device
Yosemite	I-Device
introduced	O
the	O
iOS	O
7-styled	O
user	O
interface	O
to	O
Apple	O
's	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Google	B-Application
began	O
to	O
introduce	O
its	O
own	O
flat	B-Application
design	I-Application
language	O
known	O
as	O
"	O
Material	B-Application
Design	I-Application
"	O
for	O
Android	B-Application
(	O
beginning	O
on	O
Android	B-Application
Lollipop	I-Application
)	O
and	O
its	O
other	O
platforms	O
,	O
which	O
is	O
based	O
on	O
index	O
card-like	O
sheets	O
and	O
the	O
use	O
of	O
shadows	O
to	O
promote	O
depth	O
and	O
hierarchy	O
,	O
as	O
well	O
as	O
smooth	O
animations	O
and	O
transitions	O
.	O
</s>
<s>
In	O
2017	O
,	O
Microsoft	O
unveiled	O
the	O
Fluent	B-Application
Design	I-Application
System	I-Application
,	O
a	O
new	O
flat	O
user	O
interface	O
.	O
</s>
<s>
Flat	B-Application
design	I-Application
has	O
been	O
criticized	O
for	O
making	O
user	O
interfaces	O
unintuitive	O
and	O
less	O
usable	O
.	O
</s>
<s>
Research	O
has	O
shown	O
that	O
flat	B-Application
design	I-Application
is	O
more	O
popular	O
with	O
young	O
adults	O
than	O
older	O
adults	O
.	O
</s>
<s>
Research	O
also	O
showed	O
that	O
,	O
while	O
young	O
people	O
seem	O
faster	O
at	O
navigating	O
flat	B-Application
designs	I-Application
,	O
they	O
also	O
have	O
trouble	O
with	O
understanding	O
the	O
user	O
interface	O
.	O
</s>
<s>
In	O
2013	O
Jakob	O
Nielsen	O
,	O
an	O
expert	O
in	O
user	O
interface	O
design	O
and	O
usability	O
,	O
dubbed	O
flat	B-Application
design	I-Application
as	O
a	O
"	O
threat	O
to	O
tablet	O
usability	O
"	O
.	O
</s>
<s>
Nielsen	O
also	O
proposed	O
an	O
alternative	O
,	O
namely	O
a	O
middle-ground	O
between	O
skeuomorphism	O
and	O
flat	B-Application
design	I-Application
.	O
</s>
<s>
Nielsen	O
group	O
conducted	O
research	O
in	O
2017	O
that	O
showed	O
that	O
use	O
of	O
interfaces	O
using	O
flat	B-Application
design	I-Application
was	O
22%	O
slower	O
on	O
average	O
.	O
</s>
