styles.css

:root {
    --white: #fffbfb;
    --black: #050505;
    --page-color: #f2eecb;
    --light-brown: #dcbe87;
    --brown: #ad6a34;
    --dark-brown: #4e1d04;
    --darker-green: #325453;
    --green: #508988;
    --light-green: #9fff9c;
    --light-red: #ff9c9c;
    --border-radius: 8px;
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-lg: 20px;
    --spacing-xl: 40px;
    --container-width: 1200px;
    --shadow: rgba(0, 0, 0, 0.16) 0px 1px 4px;
}

/* GENERAL */
*,
*::before,
*::after {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

body {
    background-color: var(--light-brown);
    color: var(--black);
    font-family: 'Poppins', sans-serif;
    font-size: 18px;
    font-weight: 500;
    word-wrap: break-word;
    margin: 0;
}

button, input {
    border: none;
    color: inherit;
    font-family: inherit;
    font-size: inherit;
    font-weight: inherit;
    cursor: pointer;
    outline: none;
}

input[type='text'], input[type='number'] {
    cursor: text;
}

/* UTILS */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
}

.btn {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    transition: filter 0.15s ease-in-out;
}

.btn:hover {
    filter: brightness(90%);
}

.btn:active {
    transform: scale(0.9);
}

.btn-add {
    font-size: 24px;
    font-weight: 600;
    background-color: var(--brown);
    color: var(--white);
}

.btn-add:hover {
    background-color: var(--dark-brown);
}

.btn-light-green {
    background-color: var(--light-green);
    color: var(--black);
}

.btn-light-red {
    background-color: var(--light-red);
}

.btn-log-in, .btn-log-out {
    background-color: var(--light-brown);
    color: var(--darker-green);
    border: 1.5px solid var(--light-brown);
}

.btn-log-in:hover, .btn-log-out:hover {
    background-color: var(--darker-green);
    color: var(--light-brown);
    border: 1.5px solid var(--light-brown);
}

/* HEADER */
.header {
    background-color: var(--darker-green);
    box-shadow: var(--shadow);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.header .container > div > div {
    display: flex;
}

.header .title {
    position: absolute;
    left: var(--spacing-lg);
    top: var(--spacing-lg)*2;
    color: var(--light-brown);
}

.header .book-count {
    color: var(--light-brown);
    font-weight: 600;
}

.header .total_books {
    display: flex;
    justify-content: center;
}

.header .total_read {
    display: flex;
    justify-content: center;
}

.header .total_unread {
    display: flex;
    justify-content: center;
}

.logged-out, .logged-in {
    position: absolute;
    right: var(--spacing-lg);
    top: var(--spacing-lg)*2;
    visibility: hidden;
}

.logged-in {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.logged-in .active, .logged-out .active {
    visibility: visible;
}

.greeting {
    color: var(--light-brown);
    font-weight: 600;
    visibility: hidden;
}

/* MAIN */
.main {
    margin-top: var(--spacing-xs);
    text-align: center;
    padding: var(--spacing-xl);
;}

.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.book-card {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    font-size: 20px;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    background-color: var(--page-color);
    box-shadow: var(--shadow);
    line-height: 1;
    color: var(--dark-brown);
}

.button-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    color: var(--black);
}

/* FORM */
.form-container {
    position: fixed;
    z-index: 1;
    top: 50%;
    left: 50%;
    width: 300px;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    background-color: var(--green);
    color: var(--white);
    text-align: center;
    transform: translate(-50%, -50%) scale(0);
    transition: 0.2s ease-in-out;
}

.form-container.active {
    transform: translate(-50%, -50%) scale(1);
}

.add-book-form {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
}

.add-book-form button {
    width: 100%;
}

.input {
    width: 100%;
    padding: 10px;
    border-radius: var(--border-radius);
    color: var(--dark-brown);
}

.is-read {
    display: flex;
    gap: var(--spacing-md);
}

.checkbox {
    width: 20px;
    height: 20px;
    margin-top: 4px;
    accent-color: var(--white);
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    display: none;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
}

.overlay.active {
    display: block;
}

/* MEDIA QUERIES */
@media (max-width: 400px) {
    .header .container {
      flex-direction: column;
      gap: var(--spacing-md);
      padding-top: var(--spacing-sm);
    }

    .header .title {
        font-size: 1.5em;
    }

    .book-count div {
        font-size: 15px;
    }

    .btn-log-in, .btn-log-out {
        font-size: 15px;
    }
  
    .main {
      margin-top: 0;
    }
  
    :root {
      --spacing-xl: 20px;
    }
  }