* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-user-select: none; /* Safari */
    -ms-user-select: none; /* IE 10 and IE 11 */
    user-select: none; /* Standard syntax *//* CSS user-select Property */
    outline: none;
    outline-color: transparent;
    border: none;
    border-color: transparent;
}

*::-moz-focus-inner {
    border-style: none; /* Remove the inner border in Firefox. */
}

/*  Certain types of motion-based animations can cause discomfort for some users. In particular, people with vestibular disorders have sensitivity to certain motion triggers.
*   The @media at-rule has a media feature called prefers-reduced-motion to set CSS based on the user's preferences. It can take one of the following values:
*       reduce
*       no-preference
*/
@media (prefers-reduced-motion: no-preference) {
  * {
    scroll-behavior: smooth;
  }
}

html {
    font-size: 24px;
    height: auto; /* It will automatically adjust the height to allow the content to be displayed correctly. */
    text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
    -webkit-text-size-adjust: 100%; /* -webkit- vendor prefix for Safari*/
    -moz-text-size-adjust: 100%;  /* -moz- vendor prefix for Firefox */
    scroll-behavior: smooth; /* To add a smooth scrolling effect to the page. */
    overscroll-behavior: none;
    overflow-x: hidden;
    overflow-y: scroll; /* Add vertical scrollbar */
}

body {
    background-color: hsl(53, 29%, 89%); /* RYB colors */
    font-family: "Helvetica Neue",Helvetica, Arial, sans-serif;
    text-align: center;
    color: #10091c;
}

/* The Flexible Box Layout Module, makes it easier to design flexible responsive layout structure 
*  without using float or positioning.*/
/* Flexbox helps me design my webpage so that it looks good on any screen size. */
.flexBox {
    display: flex;
    display: -webkit-flex;
    align-items: center;
    justify-content: center;
    flex-flow: column nowrap; /* The "flex-direction: column;" stacks the flex items vertically (from top to bottom) */
}

.rowGap {
    row-gap: 2rem;
}

/*  To create space when needed. */
.whiteSpace {
    display: inline-block;
    width: 0.5rem;
    height: 0.5rem;
}

/* div container | flex box 
===========================
===========================*/
#about-art {
  padding: 32px 0 128px 0;
  text-align: center;
  position: relative;
  color: black;
}

/*  Design logo 
===============*/
.container-logo {
    width: 150px;
    height: 150px;
    position: fixed;
    z-index: 1;
    top:32px;
    left:16px;
}

[id="design"]{ 
    display: flex;
    display: -webkit-flex;
    flex-flow: row wrap;
    position: relative;
    width: 116px;
    padding: .4rem;
    background-color: darkkhaki;
    background-origin: border-box;
    -webkit-background-origin: border-box;
    box-shadow: 5px 5px gray, 10px 10px darkgray, 15px 15px gainsboro;
}

/*  Arial is the most widely used font for both online and printed media. */
[class*="keywords"]:nth-of-type(1) {
    font: 400 1rem Arial, sans-serif;
    writing-mode: vertical-lr;
}

/*  offsetdiv#design */
/*  The following elements are positioned so that the design looks correct on iPads and iPhones.*/
/*  Georgia is an elegant serif font. */
[class*="keywords"]:nth-of-type(2) {
    font: 500 2rem Georgia, serif;
    height: 2.75rem;
    border-bottom: 10px solid black;
    position: absolute;
    right: 0.53rem;
    width: 68px; 
}

/*  offsetdiv#design */
[class*="keywords"]:nth-of-type(3) {
    font: 400 0.73rem Georgia, serif;
    letter-spacing: -0.022em;
    position: absolute;
    bottom: 0.47rem;
    right: 0.53rem;
    width: 68px; 
}

/*  header */
#titleApp {
    margin: 0 auto;
    width: 100%;
    padding: 1rem 1rem 2rem 1rem;
    border-bottom: 5px groove gray;
}

/*  Georgia is an elegant serif font. It is very readable at different font sizes, so it is a good candidate for mobile-responsive design. It is a little larger than Times New Roman, but works well on most Windows machines (99.4%) and Mac machines (97.5%)  
    ===============================*/
#titleApp h1 {
    font: bold 2.5rem Georgia, serif;
}

#titleApp h2 {
    width: 100%;
    max-width: 1100px;
    font: 1.1rem/1.5 "Helvetica Neue", Arial, sans-serif;
    text-transform: capitalize;
    padding: 0 0 0.5rem 0;
}

.special-mask {
    display: inline-block;
    background-color: darkkhaki;
    border-top: 4px dashed khaki;
    box-shadow: 0 0 0 5px khaki;
    padding: 0 4px;
    margin: 16px 0 0 0;
}

/*  main */
#container {
    margin: 0 auto;
    width: 100%;
    max-width: 1100px;
    padding: 0 1rem;
}

#greeting-card {
    width: 900px;
    aspect-ratio: 16/9;
    position: relative;
    background-color: #10091c;
    margin: 100px auto;
}

/* background | offset#greeting-card */
#space-comet {
    width: 900px;
    aspect-ratio: 16/9;
    position: absolute;
    top: 0;
    left: 0;
}
/* offset#space-comet | cream #ecd09c Y-G #b2ad732 RYB colors */
.comet{
    position: absolute;
    height: 40px;
    width: 80px;
    background: conic-gradient( from 64deg at 0% 100%, #fbfaf8,4deg,transparent,6deg, transparent, 355deg,#b2d732),#10091c;
    border-radius: 50% 50% 0 0; /* top-left | top-right */
    border-width: 2px;
    border-color: #10091c;
    border-style: dashed hidden hidden hidden;
    /*conic-gradient( from 64deg at 0% 100%, #ecd09c,4deg,#79736f,6deg, black, 355deg,#b2d732),#10091c;*/
    /*conic-gradient( from 64deg at 0% 100%, orange,4deg,#fc600a,6deg, black, 355deg,#b2d732),#10091c;*/
}

.position-top-left {
    top: 78px;
    left: 19px;
    transform: rotate(-90deg);
}

.position-bottom-right {
    bottom: 56px;
    right: 28px;
    transform: rotate(90deg);
}

#stars-planets {
    position: absolute;
    top: 28px;
    left: 50px;
    width: 800px;
    aspect-ratio: 16/9;
    background: 
    radial-gradient(circle at 55% 87%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 65% 5%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 95% 80%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 4% 25%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 8% 75%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 15% 40%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 9% 15%,khaki 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
    radial-gradient(circle at 55% 87%,khaki 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
    radial-gradient(circle at 15% 50%,#4424d6 .5%,hsl(48, 38%, 85%) .5%,transparent .5%),
    radial-gradient(circle at 35% 80%,#4424d6 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
    radial-gradient(circle at 80% 22%,#4424d6 .5%,hsl(48, 38%, 85%) .5%,transparent .5%),
    radial-gradient(circle at 63% 66%,#4424d6 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
	radial-gradient(circle at 90% 11%,darkkhaki 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
    radial-gradient(circle at 97% 57%,khaki 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
	radial-gradient(circle at 5% 90%,#342b09 2%,hsl(48, 38%, 85%) 2%,transparent 2%),
    radial-gradient(circle at 8% 55%,#fccb1a 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
    radial-gradient(circle at 65% 20%,#fccb1a 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
	radial-gradient(circle at 75% 90%,#fccb1a 1%,hsl(48, 38%, 85%) 1%,transparent 1%),
    radial-gradient(circle at 85% 65%,#fc600a .5%,hsl(48, 38%, 85%) .5%,transparent .5%),
	radial-gradient(circle at 95% 5%,#fc600a .5%,hsl(48, 38%, 85%) .5%,transparent .5%),
	radial-gradient(circle at 25% 85%,#fc600a .5%,hsl(48, 38%, 85%) .5%,transparent .5%), transparent;
}

/* background | offset#greeting-card */ 
#ursa-minor {
    position: absolute;
    top: 22px; /*36px;*/
    left: 50px;
    width: 800px;
    aspect-ratio: 16/9;
    background: 
    radial-gradient(circle at 27% 6%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 25% 16%,khaki .3%,hsl(48, 38%, 85%) .4%,transparent .7%),
	radial-gradient(circle at 29% 11%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 22% 11%,khaki .3%,hsl(48, 38%, 85%) .4%,transparent .7%),
	radial-gradient(circle at 38% 4%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 34% 7%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
	radial-gradient(circle at 17% 55%,khaki .3%,hsl(48, 38%, 85%) .3%,transparent .3%),
    radial-gradient(circle at 44% 8%,hsl(48, 38%, 85%) .5%,transparent 2%), transparent;
}

/* RYB colors  | offset */
.second-circle {
    position: absolute;
    left: 284px;
    top: 111px;
    border-radius: 50%;
    width:242px;
    height:242px; 
    background-image: 
    linear-gradient(to right, black 0%, transparent 50%, white 100%),
    linear-gradient(to bottom, #f7f0d4 0%, #0247fe 70%, #f7f0d4 100%);
    background-color: beige; /* rgb(245, 245, 220) hsl(60, 56%, 91%) safe color */
    mix-blend-mode: difference;
}

.first-circle {
    z-index: 1; /* important for seeing it */
    position: absolute;
    left: 295px;
    top: 113px;
    border-radius: 50%;
    width:210px;
    height:210px;
    background-color: khaki; /* rgb(240, 230, 140) hsl(54, 77%, 75%) safe color */
    mix-blend-mode: difference;
}

.greetings  {
    font: 900 85px "Brush Script MT", cursive; 
    position: absolute;
    bottom: 239px;
    left: 294px; /* before 257px */
    color: #f7f0d4; /* rgb(247, 240, 212) hsl(48, 69%, 90%) RYB colors */;
    padding: 0 10px; /* so that the text is inside the box */
    mix-blend-mode: difference;
}

/* mask */
#mask {
    position: absolute;
    top: 0;
    left: 0;
    width: 900px;
    aspect-ratio: 16/9;
    background-color: transparent;
    border-width: 10px 22px 5px 18px;
    border-color: #807453;
    border-style: double groove dashed double;
    outline-color: #b5b77c;
    outline-width: 20px;
    outline-style: groove;
    outline-offset: 20px;
    box-shadow: 0 0 0 2rem #10091c; /* spread  radius */
}

/*
#author-name {
    position: absolute;
    font: 12px Georgia, serif;
    bottom: 30px;
    right: -1px;
    color: #ece28e;
    writing-mode: vertical-lr;
}
*/
/*  For specific use on certain pages. */
/*  blockquote tag 
============================*/
/*  blocquote | with author */
#quote-author {
    font: 600 1.3rem  "Helvetica Neue", sans-serif;
    text-align: left;
    padding: 0 1rem;
}

#quote-author h2 {
    font: 400 .9rem  "Helvetica Neue", sans-serif;
    text-align: right;
    padding: 0.5rem 0 0 0;
}

/* Since it's a design with many positioned elements, I've placed a responsive image so that it can be seen.*/
#contaimer-greeting-image {
    display: none;
}

/*  All images */
.responsive {
    display: block;
    width: 100%;
    height: auto;
    margin-inline: auto;
    background-color: var(--White);
    pointer-events: none; /* The pointer-events property defines whether or not an element reacts to pointer events. | Do not allow copying or downloading an image. */
    object-fit: cover;
}

.boxMultipleShadows {
    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19); /* This value belongs to w3Schools | to create paper-like cards */
    -webkit-box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
    -moz-box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
}

/*  footer 
    =====*/
#information {grid-area: info;}
#signature {grid-area: signature;}

[class="authorship"] {
    font: 400 16px/1.5 Helvetica, sans-serif; /* Web Safe Fonts. */
    display: grid;
    column-gap: 1.13rem;
    grid-template-areas:'info   signature';
    grid-template-columns:  1fr auto;
    grid-template-rows: auto;
    padding: 32px 16px;
    color: white;
    background-color: hsl(209, 12%, 35%);
    text-align: right;
    position: relative;
}

#information {
    font-style: normal;
}

#information time {
    color: white;
}

#signature {
    max-width: 100px;
    align-self: center;
    margin: 0 0.7rem 0 0;
}

/* button tag to open tab preview */
#open-tab-preview {
    font-size: 16px;
    padding: 6px;
    border-radius: 10px;
    text-indent: 0;
    text-align: center;
    color: black;
    background-color: aliceblue;
    background-image: linear-gradient(180deg, aliceblue, hsl(209, 12%, 35%));
    cursor: pointer;
}

#open-tab-preview:hover {
    background-color: hsl(209, 12%, 20%);
    background-image: linear-gradient(180deg, hsl(209, 12%, 45%), hsl(209, 12%, 20%));
    color: white;
}

/*  Change background color */
@media screen and (max-width: 1200px) {
    /* Because the Brush Script font doesn't work with iPad and iPhone. */
    #greeting-card {
        display: none;
    }

    /* change position logo */  
    .container-logo {
        position: relative;
        top: 0;
    }

    #contaimer-greeting-image {
        display: flex;
        width: 100%;
        max-width: 900px;
        position: relative;
        background-color:  hsl(53, 29%, 89%);  /* RYB colors  */
        margin: 50px auto;
    }

    #greeting {
        max-width: 900px;
    }
}

/*  Mobile devices */
/*  Responsive layout - when the screen is less than 400px wide. */
@media screen and (max-width: 480px) {
    #titleApp {
        padding: .5rem;
    }

    #titleApp h1 {
        font: bold 2rem Georgia, serif;
    }   

    #titleApp h2 { 
        font: 0.9rem/1.5 "Helvetica Neue", Arial, sans-serif;
    }

    #container {
        padding: 0 0.5rem;
    }
    
    #quote-author {
        padding: 0;
    }
    
    /*  footer 
    =========*/
    [class="authorship"] {
        column-gap: 1rem;
    }
    
    #signature {
        margin: 0;
    }
}