@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap');

* {
    box-sizing: border-box; /*if we add border or padding, it doesn't affect the width of it. */
}

html {
    user-select: none;
}

:root {
    --color-gray-1: #6d6d6d;
    --color-gray-2: #4e4e4e;
    --color-gray-3: #999999;
    --color-gray-4: #e1e1e1;
    --color-gray-5: #cccccc;
    --color-white: #ffffff;
    --color-red: rgb(238, 69, 69);
    --color-green: rgb(24, 190, 24);
    --color-gradient-top: #7f00ff;
    --color-gradient-bottom: #e100ff;
}

body {
    font-family: 'Roboto', sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    overflow: hidden; /*don't want scroll bar to appear.*/
    margin: 0px;
}

main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border: 4px solid var(--color-gray-3);
    border-radius: 3px;
    z-index: 10;
}

#border {
    border: 5px solid;
    border-image: linear-gradient(to bottom, var(--color-gradient-top), var(--color-gradient-bottom));
    border-image-slice: 1;
}

#heading {
    padding: 0 1rem;
}

h1 {
    font-size: 1.7rem;
    color: var(--color-gray-3);
}

#text {
    background: linear-gradient(var(--color-gradient-top), var(--color-gradient-bottom));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* input */
#inputTime {
    padding-top: 3rem;
}

#inputTime span {
    margin: 1rem 0.5rem;
}

input {
    border: 1px solid var(--color-gray-1);
    color: var(--color-gray-1);
    font-size: 1rem;
    padding: 0.4rem;
    border-radius: 3px;
}
#inputTime label {
    color: var(--color-gray-3);
}

/* time */
.display-time {
    font-size: 3rem;
    padding: 0rem;
    margin: 3rem;
    color: var(--color-gray-2);
}

/* buttons */

#btns {
    padding: 1rem 1rem;
    width: 100%;
    display: flex;
}

#btn {
    margin: 0rem 0;
    cursor: pointer;
    flex-grow: 3;
    color: var(--color-green);
    border: none;
    border-radius: 2px;
    background-color: #efefef;
    box-shadow: 2px 2px 2px var(--color-gray-4);
}

#btn:active {
    background-color: var(--color-green);
    color: var(--color-white);
    outline: none;
    border: none;
}

#resetBtn {
    border: none;
    color: var(--color-red);
    padding: 0.3rem 0.6rem;
    cursor: pointer;
    margin-left: 3rem;
    border-radius: 2px;
    background-color: transparent;
}

#resetBtn:active {
    background-color: var(--color-red);
    color: var(--color-white);
    outline: none;
    border: none;
}

/* js style */
.invalid {
    border: 1px solid var(--color-red);
    outline: none;
    background-color: var(--color-red);
    color: var(--color-white);
}

.valid {
    border: 1px solid var(--color-green);
    outline: none;
    background-color: var(--color-green);
    color: var(--color-white);
}