:root {
  /* FONT SIZE : Scale= 16 x1.25 */
  --text-sm: 1.4rem; /* 1.28rem*/
  --text-link: 1.6rem; /* 1.4rem */
  --text-paragraph: 1.8rem; /* 1.6rem */
  --text-h6: 2.3rem;
  --text-h5: 2.5rem;
  --text-h4: 3.125rem;
  --text-h3: 3.906rem;
  --text-h2: 4.883rem;
  --text-h1: 6.104rem;

  /* SPACING */
  --space-xs: 0.4rem; /* 4px */
  --space-sm: 0.8rem; /* 8px */
  --space-md: 1.6rem; /* 16px */
  --space-lg: 3.2rem; /* 32px */
  --space-xl: 6.4rem; /* 64px */
  --space-2xl: 12.8rem; /* 128px */
  /* Guidance:
  Use:
    --space-lg or xl for section spacing
    --space-md for card/grid gap
    --space-sm for text or button spacing */

  /* FONT WEIGHT */
  --fw-light: 300;
  --fw-normal: 400;
  --fw-medium: 600;

  /* LINE HEIGHT */
  --line-height-tight: 1.2;
  --line-height-normal: 1.5;

  /* LETTER SPACING : for big letter gap of heading tags*/
  /* --letter-spacing-tight: -2px; */

  /* FONT FAMILY */
  --ff-body: "Outfit", sans-serif;

  /* COLOR : Tint / Base / Shade */
  /* Use website: maketintsandshades.com */
  --Blue-500: hsl(215, 51%, 70%);
  --Cyan-400: rgb(0, 255, 247);

  --Blue-950-bg: hsl(217, 54%, 11%);
  --Blue-900-card: hsl(216, 50%, 16%);
  --Blue-800-line: rgb(47, 65, 91);
  --White: hsl(0, 0%, 100%);
}
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  /* 62.5% of 16px = 10px */
  /* 62.5% of 24px = 15px */
  /* When browser change font-size it will scale base on browser font-size */
  font-size: 62.5%;
}

body {
  font-family: var(--ff-body);
  font-weight: var(--fw-normal);
  line-height: var(--line-height-normal);
  color: var(--Blue-500);
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: var(--fw-medium);
  line-height: var(--line-height-tight);
  /* letter-spacing: -2px; NOTE: depend on font */
  /* color: black; depend on style*/
}

/* use website Typescale.com */
h1 {
  font-size: var(--text-h1);
}

h2 {
  font-size: var(--text-h2);
}

h3 {
  font-size: var(--text-h3);
}

h4 {
  font-size: var(--text-h4);
}

h5 {
  font-size: var(--text-h5);
}

h6 {
  font-size: var(--text-h6);
}

p {
  /* font size 16px or 20px base on text readability */
  font-size: var(--text-paragraph);
}

a {
  text-decoration: none;
  font-size: var(--text-link);
  display: inline-block;
}

ul {
  list-style: none;
}

span {
  display: inline-block;
}

/* ===== Style layout ====== */

.container {
  min-height: 100vh;
  background-color: var(--Blue-950-bg);

  display: flex;
  justify-content: center;
  align-items: center;
}
.card {
  display: flex;
  flex-direction: column;

  max-width: 350px;
  padding: 2.4rem;
  background-color: var(--Blue-900-card);
  border-radius: 1.2rem;
  gap: var(--space-md);
}
.group-image {
  border-radius: var(--space-sm);
  overflow: hidden;
  position: relative;
}
.group-image img {
  width: 100%;
  display: block;
}
.overlay {
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: var(--Cyan-400);
  top: 0;
  right: 0;

  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
  transition: 0.3s;
  cursor: pointer;
}
.overlay img {
  width: 45px;
  height: auto;
}
.group-image:hover .overlay {
  opacity: 1;
  background-color: rgba(0, 255, 247, 0.4);
}
.card-heading {
  font-size: 2.4rem;
  font-weight: var(--fw-medium);
  color: var(--White);
  transition: 0.15s;
  cursor: pointer;
}
.card-heading:hover {
  color: var(--Cyan-400);
}
.card-description {
  font-weight: var(--fw-light);
}
.group-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.card-info {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}
.eth {
  color: var(--Cyan-400);
}
.date {
  font-weight: var(--fw-light);
}
.card-profile {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--Blue-800-line);
}
.profile {
  width: 35px;
  border: 1px solid var(--White);
  border-radius: 50%;
}
.name {
  font-weight: var(--fw-light);
}
.name span {
  color: var(--White);
  font-weight: var(--fw-normal);
  transition: 0.15s;
  cursor: pointer;
}
.name span:hover {
  color: var(--Cyan-400);
}
.attribution {
  padding: var(--space-md);
  text-align: center;
  color: black;
}