/*-----------------------------------*\
  #style.css
\*-----------------------------------*/

/**
 * copyright 2022 codewithsadee
 */





/*-----------------------------------*\
  #CUSTOM PROPERTY
\*-----------------------------------*/

:root {

  /**
   * colors
   */

  --chinese-violet_30: hsla(34, 58%, 30%, 0.3);
  --chinese-violet: hsl(34, 58%, 30%);
  --sonic-silver: hsl(208, 7%, 46%);
  --old-rose_30: hsla(42, 76%, 44%, 0.22);
  --ghost-white: hsl(42, 30%, 94%);
  --light-pink: hsl(44, 62%, 78%);
  --light-gray: hsl(0, 0%, 88%);
  --old-rose: hsl(42, 76%, 44%);
  --seashell: hsl(42, 34%, 95%);
  --charcoal: hsl(32, 24%, 20%);
  --white: hsl(0, 0%, 100%);

  /**
   * typography
   */

  --ff-philosopher: 'Philosopher', sans-serif;
  --ff-poppins: 'Poppins', sans-serif;

  --fs-1: 4rem;
  --fs-2: 3.2rem;
  --fs-3: 2.7rem;
  --fs-4: 2.4rem;
  --fs-5: 2.2rem;
  --fs-6: 2rem;
  --fs-7: 1.8rem;

  --fw-500: 500;
  --fw-700: 700;

  /**
   * spacing
   */

  --section-padding: 92px;

  /**
   * shadow
   */

  --shadow-1: 0 12px 30px hsla(32, 24%, 20%, 0.08);
  --shadow-2: 0 18px 40px hsla(32, 24%, 20%, 0.08);
  --shadow-3: 0 10px 24px hsla(34, 58%, 30%, 0.16);
  --shadow-4: 0 20px 48px hsla(34, 58%, 30%, 0.18);

  /**
   * radius
   */

  --radius-5: 16px;
  --radius-10: 28px;

  /**
   * clip path
   */

  --polygon: polygon(100% 29%,100% 100%,19% 99%,0 56%);

  /**
   * transition
   */

  --transition-1: 0.25s ease;
  --transition-2: 0.5s ease;
  --cubic-out: cubic-bezier(0.33, 0.85, 0.4, 0.96);

}





/*-----------------------------------*\
  #RESET
\*-----------------------------------*/

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

li { list-style: none; }

a,
img,
span,
data,
input,
button,
textarea,
ion-icon { display: block; }

a {
  color: inherit;
  text-decoration: none;
}

img { height: auto; }

input,
button,
textarea {
  background: none;
  border: none;
  font: inherit;
}

input,
textarea { width: 100%; }

button { cursor: pointer; }

address { font-style: normal; }

ion-icon { pointer-events: none; }

html {
  font-family: var(--ff-poppins);
  font-optical-sizing: auto;
  font-size: 10px;
  scroll-behavior: smooth;
}

body {
  background:
    radial-gradient(circle at top left, hsla(42, 72%, 58%, 0.12), transparent 24%),
    radial-gradient(circle at 85% 10%, hsla(38, 68%, 46%, 0.08), transparent 22%),
    radial-gradient(circle at 50% 100%, hsla(46, 80%, 62%, 0.06), transparent 28%),
    linear-gradient(180deg, hsl(42, 45%, 99%) 0%, hsl(44, 34%, 97%) 52%, hsl(40, 28%, 95%) 100%);
  color: var(--sonic-silver);
  font-size: 1.6rem;
  line-height: 1.8;
}

:focus-visible { outline-offset: 4px; }

::selection {
  background-color: var(--old-rose);
  color: var(--white);
}

::-webkit-scrollbar { width: 10px; }

::-webkit-scrollbar-track { background-color: hsl(0, 0%, 98%); }

::-webkit-scrollbar-thumb { background-color: hsl(0, 0%, 80%); }

::-webkit-scrollbar-thumb:hover { background-color: hsl(0, 0%, 70%); }





/*-----------------------------------*\
  #REUSED STYLE
\*-----------------------------------*/

.container { padding-inline: 18px; }

.section { padding-block: var(--section-padding); }

.section:nth-child(odd) { background-color: hsla(0, 0%, 100%, 0.42); }

.section-subtitle {
  color: var(--old-rose);
  text-transform: uppercase;
  font-weight: var(--fw-700);
  letter-spacing: 3px;
  text-align: center;
}

.h1,
.h2,
.h3,
.tab-text {
  color: var(--charcoal);
  font-family: var(--ff-philosopher);
  line-height: 1.2;
}

.h1 { font-size: var(--fs-2); }

.h2 { font-size: var(--fs-3); }

.h3 { font-size: var(--fs-5); }

.section-text { font-size: var(--fs-7); }

.w-100 { width: 100%; }

.has-before,
.has-after {
  position: relative;
  z-index: 1;
}

.has-before::before,
.has-after::after {
  content: "";
  position: absolute;
}

.section-title { text-align: center; }

.card-text {
  color: hsl(30, 16%, 34%);
}

.grid-list {
  display: grid;
  gap: 25px;
}

.btn-link {
  color: var(--old-rose);
  font-weight: var(--fw-500);
  display: flex;
  align-items: center;
  gap: 5px;
  transition: var(--transition-1);
}

.btn-link:is(:hover, :focus) { color: var(--chinese-violet); }

.has-underline {
  position: relative;
  margin-block-end: 60px;
}

.has-underline .span {
  height: 2px;
  background-color: var(--old-rose_30);
  width: 200px;
  margin-inline: auto;
  margin-block-start: 30px;
}

.has-underline .has-before::before {
  width: 18px;
  height: 18px;
  top: 2px;
  left: 45%;
  transform: translateY(-50%) rotate(45deg);
  background-color: var(--old-rose_30);
  box-shadow: 7px -7px var(--old-rose_30);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-height: 54px;
  padding: 15px 25px;
  border-radius: 15px;
  border: 1px solid transparent;
  position: relative;
  z-index: 1;
  overflow: hidden;
  font-weight: var(--fw-700);
  letter-spacing: 0.01em;
  box-shadow: 4px 8px 19px -3px hsla(32, 24%, 20%, 0.2);
  transition: color 250ms ease, transform 250ms ease, box-shadow 250ms ease, border-color 250ms ease;
}

.btn::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 0;
  border-radius: inherit;
  z-index: -1;
  transition: width 250ms ease;
}

.btn::after {
  content: "";
  position: absolute;
  top: -20%;
  left: -55%;
  width: 42%;
  height: 140%;
  border-radius: inherit;
  background: linear-gradient(
    105deg,
    transparent 0%,
    hsla(44, 78%, 72%, 0.08) 25%,
    hsla(47, 95%, 78%, 0.72) 50%,
    hsla(38, 72%, 58%, 0.2) 72%,
    transparent 100%
  );
  transform: skewX(-24deg);
  opacity: 0;
  pointer-events: none;
}

.btn-primary {
  background: hsl(42, 32%, 92%);
  color: hsl(32, 24%, 18%);
  border-color: hsla(34, 58%, 30%, 0.18);
}

.btn-primary::before {
  background: linear-gradient(135deg, hsl(34, 58%, 30%), hsl(28, 54%, 24%));
}

.hero-amazon-btn,
.btn-secondary {
  background-color: hsl(0, 0%, 96%);
  border-color: hsla(34, 58%, 30%, 0.18);
  color: hsl(32, 24%, 18%);
}

.hero-amazon-btn::before,
.btn-secondary::before {
  background: hsl(32, 24%, 18%);
}

.cta-glow-btn::before {
  background: linear-gradient(135deg, hsl(45, 78%, 62%), hsl(40, 82%, 50%));
}

.btn:is(:hover, :focus-visible) {
  color: hsl(42, 40%, 94%);
  transform: translateY(-0.335rem);
  box-shadow: 0 18px 30px -8px hsla(32, 24%, 20%, 0.28);
}

.btn:is(:hover, :focus-visible)::before {
  width: 100%;
}

.cta-glow-btn:is(:hover, :focus-visible)::before {
  width: 100%;
  background: linear-gradient(135deg, hsl(46, 79%, 56%), hsl(40, 92%, 44%));
}

.cta-glow-btn:is(:hover, :focus-visible) {
  color: hsl(32, 24%, 8%);
  border-color: hsla(43, 86%, 52%, 0.52);
  box-shadow:
    0 18px 30px -8px hsla(32, 24%, 20%, 0.28),
    0 0 0 1px hsla(44, 75%, 58%, 0.24),
    0 0 22px hsla(43, 86%, 62%, 0.24);
}

.cta-glow-btn::after {
  opacity: 1;
  animation: cta-sheen 2.8s ease-in-out infinite;
}

@keyframes cta-sheen {
  0% {
    left: -55%;
  }

  55% {
    left: 130%;
  }

  100% {
    left: 130%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cta-glow-btn::after {
    animation: none;
    opacity: 0.35;
  }
}

.img-holder {
  aspect-ratio: var(--width) / var(--height);
  background-color: var(--light-gray);
}

.img-cover {
  width: 100%;
  height: 100%;
  object-fit: cover;
}





/*-----------------------------------*\
  #HEADER
\*-----------------------------------*/

.header {
  background-color: hsla(0, 0%, 100%, 0.72);
  backdrop-filter: blur(16px);
  position: absolute;
  top: 10px;
  right: 10px;
  left: 10px;
  padding-block: 12px;
  z-index: 4;
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  border-radius: 999px;
  transition: var(--transition-2);
}

.header.active {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  filter: drop-shadow(var(--shadow-1));
  transform: translateY(-100%);
  transition: none;
  border-radius: 0;
  animation: slideIn 0.5s ease forwards;
}

@keyframes slideIn {
  0% { transform: translateY(-100%); }
  100% { transform: translateY(0); }
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.logo {
  font-family: var(--ff-philosopher);
  font-size: 1.85rem;
  color: var(--charcoal);
  line-height: 1.12;
  max-width: 16ch;
}

.nav-toggle-btn {
  font-size: 40px;
  color: var(--charcoal);
}

.nav-toggle-btn ion-icon { --ionicon-stroke-width: 20px; }

.nav-toggle-btn.active .open,
.nav-toggle-btn .close { display: none; }

.nav-toggle-btn .open,
.nav-toggle-btn.active .close { display: block; }

.navbar {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  background-color: var(--white);
  padding-inline: 15px;
  max-height: 0;
  overflow: hidden;
  visibility: hidden;
  transition: 0.25s var(--cubic-out);
}

.navbar.active {
  max-height: 300px;
  visibility: visible;
  transition-duration: 0.5s;
}

.navbar-list { margin-block-end: 10px; }

.navbar-link {
  color: var(--charcoal);
  padding-block: 10px;
  line-height: 1.5;
  font-weight: var(--fw-500);
  letter-spacing: 0.01em;
  transition: var(--transition-1);
}

.navbar-link:is(:hover, :focus) { color: var(--old-rose); }





/*-----------------------------------*\
  #HERO
\*-----------------------------------*/

.hero {
  padding-block-start: calc(var(--section-padding) + 60px);
  text-align: center;
}

.hero .container {
  display: grid;
  gap: 60px;
}

.hero .hero-title {
  font-size: 2.45rem;
  max-width: 17ch;
  margin: 10px auto 22px;
  letter-spacing: -0.03em;
  line-height: 1.04;
}

.hero .section-text {
  font-size: 1.95rem;
  color: hsl(30, 16%, 34%);
  max-width: 34ch;
  margin-inline: auto;
  line-height: 1.65;
}

.hero-cover-context {
  position: absolute;
  top: -12px;
  right: 10px;
  z-index: 2;
}

.hero-cover-mark {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 10px 7px 8px;
  border-radius: 999px;
  background: hsla(0, 0%, 100%, 0.94);
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  box-shadow: 0 16px 34px hsla(34, 58%, 30%, 0.14);
  backdrop-filter: blur(12px);
}

.hero-cover-logo {
  width: 48px;
  height: 48px;
  object-fit: contain;
  flex-shrink: 0;
}

.hero-cover-note {
  color: hsl(30, 16%, 34%);
  font-size: 1.1rem;
  font-weight: var(--fw-700);
  line-height: 1.2;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-actions {
  display: grid;
  gap: 14px;
  justify-items: center;
  margin-block: 30px 28px;
}

.hero-availability-label {
  color: hsl(30, 16%, 34%);
  font-size: 1.5rem;
  font-weight: var(--fw-700);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-retailers {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  width: min(100%, 560px);
}

.hero-retailer-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 108px;
  padding: 20px 24px;
  border-radius: 22px;
  background: linear-gradient(180deg, hsla(0, 0%, 100%, 0.98), hsla(42, 22%, 97%, 0.94));
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  box-shadow: 0 16px 34px hsla(32, 24%, 20%, 0.08);
  transition: transform 250ms ease, filter 250ms ease, opacity 250ms ease, box-shadow 250ms ease, border-color 250ms ease;
}

.hero-retailer-link:is(:hover, :focus-visible) {
  transform: translateY(-4px);
  filter: saturate(1.04);
  opacity: 0.96;
  border-color: hsla(42, 76%, 44%, 0.24);
  box-shadow: 0 22px 42px hsla(32, 24%, 20%, 0.12);
}

.hero-retailer-logo {
  display: block;
  width: 148px;
  max-width: 100%;
  height: auto;
  object-fit: contain;
}

.hero-retailer-logo--amazon {
  width: 154px;
}

.hero-retailer-logo--oreilly {
  width: 150px;
}

.hero-retailer-logo--barnes {
  width: 156px;
}

.hero-retailer-logo--target {
  width: 70px;
}

.hero-proof {
  display: grid;
  gap: 16px;
  margin-top: 18px;
}

.hero-proof li {
  list-style: none;
  height: 100%;
}

.hero-proof-link {
  display: grid;
  align-content: start;
  gap: 10px;
  height: 100%;
  min-height: 0;
  padding: 18px 18px 20px;
  border-radius: 26px;
  background:
    linear-gradient(180deg, hsla(0, 0%, 100%, 0.98), hsla(42, 30%, 97%, 0.94));
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  box-shadow: 0 18px 38px hsla(32, 24%, 20%, 0.08);
  position: relative;
  overflow: hidden;
  transition: transform var(--transition-1), box-shadow var(--transition-1), border-color var(--transition-1), background-color var(--transition-1);
}

.hero-proof-link::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at top right, hsla(42, 78%, 56%, 0.18), transparent 36%),
    linear-gradient(180deg, hsla(0, 0%, 100%, 0), hsla(0, 0%, 100%, 0));
  pointer-events: none;
}

.hero-proof-link::after {
  content: "\2192";
  position: absolute;
  right: 18px;
  top: 18px;
  color: hsla(34, 58%, 30%, 0.24);
  font-size: 1.6rem;
  line-height: 1;
  transition: transform var(--transition-1), color var(--transition-1);
}

.hero-proof-link:is(:hover, :focus-visible) {
  transform: translateY(-5px);
  border-color: hsla(42, 76%, 44%, 0.26);
  box-shadow: 0 22px 42px hsla(32, 24%, 20%, 0.12);
}

.hero-proof-link:is(:hover, :focus-visible)::after {
  transform: translateX(2px);
  color: hsla(34, 58%, 30%, 0.48);
}

.hero-proof-kicker {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  width: fit-content;
  padding-inline: 10px;
  border-radius: 999px;
  background-color: hsla(42, 76%, 44%, 0.1);
  color: hsl(32, 24%, 28%);
  font-size: 1.05rem;
  font-weight: var(--fw-700);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.hero-proof strong {
  color: var(--charcoal);
  font-size: 1.48rem;
  font-weight: var(--fw-700);
  line-height: 1.34;
  letter-spacing: -0.01em;
  max-width: none;
}

.hero-proof-link > span:not(.hero-proof-kicker) {
  color: hsl(30, 14%, 38%);
  font-size: 1.2rem;
  line-height: 1.6;
  max-width: none;
}

.hero-banner {
  padding-inline-start: 30px;
  padding-block-end: 30px;
  max-width: 420px;
  margin-inline: auto;
  overflow: visible;
}

.hero-banner .w-100 { border-radius: 10px 30px; }

.hero-banner a {
  position: relative;
  display: block;
  border-radius: 18px 34px;
  overflow: visible;
  box-shadow: var(--shadow-4);
  transition: transform var(--transition-2), box-shadow var(--transition-2);
}

.hero-banner a:is(:hover, :focus-visible) {
  transform: translateY(-4px);
  box-shadow: 0 24px 56px hsla(34, 58%, 30%, 0.22);
}

.hero-banner::before {
  top: 30px;
  right: 30px;
  bottom: 0;
  left: 0;
  background-color: var(--light-pink);
  border-radius: var(--radius-10);
  z-index: -1;
}

.play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: var(--white);
  color: var(--chinese-violet);
  font-size: 22px;
  padding: 24px;
  border-radius: 50%;
  transition: var(--transition-1);
  animation: pulse 3s ease infinite;
}

.play-btn:is(:hover, :focus) { color: var(--old-rose); }

@keyframes pulse {
  0%,
  50% { box-shadow: 0 0 0 0 hsla(0, 0%, 100%, 0.5); }

  100% { box-shadow: 0 0 0 10px transparent; }
}





/*-----------------------------------*\
  #PREFACE
\*-----------------------------------*/

.preface {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(180deg, hsla(42, 40%, 98%, 0.94), hsla(40, 34%, 95%, 0.8));
}

.preface::before {
  content: "";
  position: absolute;
  inset: 30px auto auto -80px;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, hsla(42, 76%, 44%, 0.12) 0%, transparent 68%);
  pointer-events: none;
}

.preface::after {
  content: "";
  position: absolute;
  right: -90px;
  bottom: -10px;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, hsla(34, 58%, 30%, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.preface-letter {
  --preface-type-scale: 1.33;
  --preface-rule-start: calc(3.2rem * var(--preface-type-scale));
  --preface-rule-end: calc(3.35rem * var(--preface-type-scale));
  position: relative;
  z-index: 1;
  max-width: 760px;
  margin-inline: auto;
  padding: 42px 26px 36px 52px;
  border-radius: 22px;
  border: 1px solid hsla(32, 24%, 20%, 0.1);
  box-shadow: var(--shadow-2);
  background:
    linear-gradient(
      90deg,
      transparent 0,
      transparent 44px,
      hsla(3, 70%, 62%, 0.28) 44px,
      hsla(3, 70%, 62%, 0.28) 46px,
      transparent 46px
    ),
    repeating-linear-gradient(
      180deg,
      hsla(0, 0%, 100%, 0.98) 0,
      hsla(0, 0%, 100%, 0.98) var(--preface-rule-start),
      hsla(210, 34%, 74%, 0.36) var(--preface-rule-start),
      hsla(210, 34%, 74%, 0.36) var(--preface-rule-end)
    );
  animation: fadeUp 0.7s ease both;
}

.preface-note {
  color: hsl(30, 18%, 38%);
  font-size: calc(1.25rem * 1.33);
  font-weight: var(--fw-700);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.preface-greeting,
.preface-paragraph,
.preface-signoff,
.preface-signature {
  color: hsl(32, 22%, 24%);
  font-family: "Caveat", cursive;
  font-weight: 500;
}

.preface-greeting {
  font-size: calc(3.8rem * 1.33);
  line-height: 1.1;
  margin-bottom: 0.25em;
}

.preface-paragraph {
  font-size: calc(2.15rem * 1.33);
  line-height: 1.56;
  margin-top: 0.35em;
}

.preface-signoff {
  font-size: calc(2.25rem * 1.33);
  line-height: 1.5;
  margin-top: 1em;
}

.preface-signature {
  font-size: calc(3.3rem * 1.33);
  line-height: 1.1;
  margin-top: 0.1em;
}





/*-----------------------------------*\
  #BENEFITS
\*-----------------------------------*/

.benefits .section-text {
  text-align: center;
  margin-block: 8px 25px;
}

.benefits-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 28px;
  background: hsla(0, 0%, 100%, 0.82);
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  box-shadow: var(--shadow-2);
  border-radius: var(--radius-10);
  overflow: hidden;
  transition: var(--transition-2);
}

.benefits-card::before,
.benefits-card::after {
  bottom: 0;
  right: 0;
  clip-path: var(--polygon);
  transition: var(--transition-2);
}

.benefits-card::before {
  width: 80px;
  height: 80px;
  background-color: var(--old-rose_30);
  transform: translateY(60px);
}

.benefits-card::after {
  width: 70px;
  height: 70px;
  background-color: var(--chinese-violet_30);
  transform: translateY(65px);
}

.benefits-card:is(:hover, :focus-within) { transform: translateY(-8px); }

.benefits-card:is(:hover, :focus-within)::before,
.benefits-card:is(:hover, :focus-within)::after { transform: translateY(0); }

.benefits-card:is(:hover, :focus-within)::after { transition-delay: 0.1s; }

.benefits-card .card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(180deg, hsla(0, 0%, 100%, 0.95), hsla(42, 20%, 97%, 0.98));
  max-width: max-content;
  width: 58px;
  min-height: 58px;
  padding: 10px 14px;
  border-radius: 16px;
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  box-shadow: var(--shadow-2);
  transition: var(--transition-1);
}

.tech-logo {
  width: 28px;
  height: 28px;
  object-fit: contain;
  display: block;
}

.icon-label {
  color: var(--white);
  font-size: 1.3rem;
  font-weight: var(--fw-700);
  letter-spacing: 0.08em;
}

.benefits-card:is(:hover, :focus) .card-icon { box-shadow: none; }

.benefits-card .card-title { margin-block: 20px 15px; }

.benefits-card .btn-link {
  margin-block-start: auto;
  padding-top: 15px;
}





/*-----------------------------------*\
  #CHAPTERS
\*-----------------------------------*/

.chapter-card {
  height: 100%;
  background-color: hsla(0, 0%, 100%, 0.88);
  padding: 28px;
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  border-radius: var(--radius-10);
  box-shadow: var(--shadow-2);
  transition: var(--transition-2);
}

.chapter-card:is(:hover, :focus-within) { transform: translateY(-10px); }

.chapter-card .card-title { margin-block-end: 15px; }





/*-----------------------------------*\
  #PREVIEW
\*-----------------------------------*/

.tab-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tab-card {
  position: relative;
  height: 60px;
  background-color: var(--seashell);
  border-radius: var(--radius-10);
  box-shadow: var(--shadow-3);
  display: grid;
  place-content: center;
  overflow: hidden;
  cursor: pointer;
  transition: var(--transition-1);
}

.tab-card .w-100 {
  pointer-events: none;
  opacity: 0;
  transition: var(--transition-2);
}

.tab-card.active .w-100 { opacity: 1; }

.tab-card.active {
  height: 40vh;
  box-shadow: none;
}

.tab-text {
  font-size: var(--fs-4);
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.tab-card.active .tab-heading { display: none; }

.author-preview-section .section-text {
  max-width: 62ch;
  margin-inline: auto;
  margin-bottom: 28px;
  text-align: center;
}

.author-preview-section .tab-list {
  flex-direction: column;
  gap: 14px;
}

.author-preview-section .tab-card {
  width: 100%;
  max-width: none;
  height: 72px;
  place-content: stretch;
  align-items: stretch;
  background: linear-gradient(180deg, hsla(0, 0%, 100%, 0.96), hsla(42, 25%, 96%, 0.98));
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  box-shadow: var(--shadow-2);
}

.author-preview-section .tab-card.active {
  height: auto;
  min-height: 320px;
  max-width: none;
}

.tab-heading {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 72px;
  padding: 12px 24px;
}

.author-preview-section .tab-text {
  position: static;
  transform: none;
  padding: 0;
  text-align: left;
  line-height: 1.2;
  white-space: normal;
  writing-mode: horizontal-tb;
  text-orientation: mixed;
}

.author-preview-panel {
  display: grid;
  gap: 14px;
  align-content: start;
  height: 100%;
  padding: 28px;
  transition: var(--transition-2);
  opacity: 0;
}

.tab-card.active .author-preview-panel { opacity: 1; }

.author-preview-role {
  color: var(--old-rose);
  font-size: 1.2rem;
  font-weight: var(--fw-700);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.author-preview-name {
  margin-block-end: 16px;
}

.author-preview-title {
  color: hsl(30, 10%, 48%);
  font-size: 1.5rem;
  font-style: italic;
  line-height: 1.35;
}

.author-preview-title-body {
  margin-top: -6px;
}

.author-preview-text {
  color: hsl(30, 16%, 34%);
  font-size: 1.6rem;
  line-height: 1.7;
}

.author-preview-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 6px;
}





/*-----------------------------------*\
  #PRICING
\*-----------------------------------*/

.pricing-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 42px 34px 36px;
  background:
    linear-gradient(180deg, hsla(0, 0%, 100%, 0.98), hsla(42, 18%, 97%, 0.94));
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  border-radius: var(--radius-10);
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 18px 36px hsla(32, 24%, 20%, 0.06);
  transition: transform var(--transition-2), box-shadow var(--transition-2), border-color var(--transition-2);
}

.pricing-card:is(:hover, :focus-within),
.pricing-card.bundle { box-shadow: var(--shadow-4); }

.pricing-card:is(:hover, :focus-within) {
  transform: translateY(-10px);
  border-color: hsla(42, 76%, 44%, 0.2);
}

.pricing-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 3px;
  background: linear-gradient(90deg, hsla(42, 76%, 44%, 0.15), hsla(34, 58%, 30%, 0.42));
}

.pricing-card .price {
  font-family: var(--ff-philosopher);
  font-size: 5.2rem;
  color: var(--charcoal);
  font-weight: var(--fw-700);
  margin-block: 10px 6px;
  letter-spacing: -0.04em;
}

.pricing-kicker {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 32px;
  padding: 0 12px;
  margin-bottom: 18px;
  border-radius: 999px;
  background-color: hsla(42, 76%, 44%, 0.1);
  color: var(--chinese-violet);
  font-size: 1.15rem;
  font-weight: var(--fw-700);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.pricing-card.bundle {
  background:
    linear-gradient(180deg, hsla(0, 0%, 100%, 1), hsla(42, 30%, 95%, 0.98));
  border-color: hsla(42, 76%, 44%, 0.22);
  box-shadow: 0 24px 46px hsla(34, 58%, 30%, 0.12);
}

.pricing-card.bundle .pricing-kicker {
  background-color: hsla(42, 76%, 44%, 0.16);
  color: var(--old-rose);
}

.pricing-card-list {
  margin-block: 24px 34px;
  text-align: left;
}

.pricing-card-list .card-item:not(:last-child) { border-block-end: 1px solid var(--ghost-white); }

.pricing-card .card-text {
  padding-block: 14px;
  color: hsl(30, 16%, 34%);
  line-height: 1.65;
}

.pricing-card .btn {
  width: 100%;
  margin-top: auto;
  margin-inline: auto;
}

.retailer-choice-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: auto;
  align-items: center;
}

.retailer-choice-list--single {
  grid-template-columns: 1fr;
}

.retailer-choice {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 78px;
  padding: 14px 12px;
  transition: transform var(--transition-1), opacity var(--transition-1), filter var(--transition-1);
}

.retailer-choice--plain {
  background: none;
  border: 0;
  box-shadow: none;
}

.retailer-choice:is(:hover, :focus-visible) {
  transform: translateY(-3px);
  opacity: 0.9;
  filter: saturate(1.04);
}

.retailer-choice-logo {
  display: block;
  max-width: 100%;
  height: auto;
  object-fit: contain;
}

.retailer-choice-logo--amazon {
  width: 94px;
}

.retailer-choice-logo--barnes {
  width: 100px;
}

.retailer-choice-logo--target {
  width: 40px;
}

.retailer-choice-logo--oreilly {
  width: 120px;
}

.retailer-choice-logo--github {
  width: 126px;
}





/*-----------------------------------*\
  #AUTHOR
\*-----------------------------------*/

.author { background-color: var(--seashell); }

.author .container {
  display: grid;
  gap: 40px;
}

.author :is(.section-subtitle, .section-title) { text-align: left; }

.author-content {
  background-color: var(--white);
  padding: 30px;
}

.author-name {
  font-size: var(--fs-6);
  margin-block-end: 30px;
}

.author .section-text { font-size: unset; }

.author-text-only .container {
  display: block;
}

.author-text-only .author-content {
  margin-block-start: 0;
  margin-inline-start: 0;
}

.author-text-only .section-text p:not(:last-child) {
  margin-block-end: 18px;
}

.author-text-only .author-content {
  padding: 26px;
}

.author-bio:not(:last-child) {
  padding-bottom: 22px;
  margin-bottom: 22px;
  border-bottom: 1px solid hsla(32, 24%, 20%, 0.08);
}

.author-bio .author-name {
  margin-block-end: 12px;
}





/*-----------------------------------*\
  #ACHIEVEMENT
\*-----------------------------------*/

.section.achievement { background-color: var(--white); }

.achievement-card {
  background-color: hsla(0, 0%, 100%, 0.84);
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  box-shadow: var(--shadow-2);
  overflow: hidden;
  height: 100%;
  transition: var(--transition-2);
}

.achievement-card:is(:hover, :focus-within) { transform: translateY(-10px); }

.achievement-card .card-content {
  position: relative;
  padding: 15px;
}

.achievement-card .abs-img {
  position: absolute;
  top: 0;
  right: -5px;
  opacity: 0.3;
}

.achievement-text-only .grid-list {
  gap: 20px;
}

.achievement-text-only .achievement-card {
  display: block;
  box-shadow: var(--shadow-2);
}

.achievement-text-only .achievement-card > * {
  width: 100%;
}

.achievement-text-only .achievement-card .card-content {
  padding: 24px;
}

.achievement-text-only .timely-card .card-title {
  margin-block-end: 12px;
}





/*-----------------------------------*\
  #CONTACT
\*-----------------------------------*/

.contact .wrapper {
  display: grid;
  gap: 25px;
}

.contact-form {
  background-color: var(--seashell);
  padding: 20px;
}

.input-field {
  background-color: var(--white);
  padding: 16px 18px;
  margin-block-end: 15px;
  outline: none;
  border: 1px solid hsla(32, 24%, 20%, 0.12);
  border-radius: 16px;
  box-shadow: inset 0 1px 0 hsla(0, 0%, 100%, 0.6);
}

.input-field:focus {
  border-color: var(--old-rose);
  box-shadow: 0 0 0 4px hsla(42, 76%, 44%, 0.12);
}

textarea.input-field {
  resize: vertical;
  min-height: 120px;
  height: 120px;
  max-height: 200px;
}

.contact-form .btn { margin-inline: auto; }

.contact-card {
  background: linear-gradient(180deg, hsla(0, 0%, 100%, 0.95), hsla(42, 30%, 95%, 0.96));
  padding: 34px;
  border: 1px solid hsla(32, 24%, 20%, 0.08);
  border-radius: var(--radius-10);
  box-shadow: var(--shadow-2);
}

.newsletter-card {
  display: grid;
  gap: 20px;
}

.newsletter-wrapper {
  display: block;
  width: 100%;
}

.newsletter-wrapper .newsletter-card {
  width: 100%;
}

.newsletter-form {
  display: grid;
  gap: 12px;
  background-color: transparent;
  padding: 0;
}

.newsletter-card .section-text {
  max-width: 62ch;
  color: hsl(30, 16%, 34%);
}

.newsletter-card .card-text:last-child {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-top: 4px;
}

.newsletter-form .input-field {
  margin-block-end: 0;
}

.newsletter-form .btn {
  margin-inline: 0;
}

.newsletter-note {
  color: hsl(30, 12%, 42%);
  font-size: 1.35rem;
}

.contact-card .card-title {
  font-family: var(--ff-philosopher);
  text-transform: uppercase;
  font-weight: var(--fw-700);
}

.contact-card > li:not(:last-child) { margin-block-end: 30px; }

.contact-card .card-link {
  color: var(--chinese-violet);
  transition: var(--transition-1);
}

.contact-card .card-link:is(:hover, :focus) { color: var(--old-rose); }

.social-list-title {
  font-size: var(--fs-6);
  font-weight: var(--fw-700);
  margin-block-end: 15px;
}

.social-list {
  display: flex;
  gap: 10px;
}

.social-link {
  background-color: var(--old-rose);
  color: var(--white);
  font-size: 20px;
  padding: 5px;
  box-shadow: var(--shadow-3);
  transition: var(--transition-1);
}

.social-link:is(:hover, :focus) {
  background-color: var(--chinese-violet);
  box-shadow: none;
}





/*-----------------------------------*\
  #FOOTER
\*-----------------------------------*/

.footer {
  background-color: transparent;
  text-align: center;
  font-family: "Saira", sans-serif;
}

.footer-top {
  padding-block: 50px;
  border-block-end: 1px solid var(--chinese-violet_30);
}

.footer .logo { margin-block-end: 15px; }

.footer-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  column-gap: 20px;
}

.footer-link {
  color: var(--charcoal);
  transition: var(--transition-1);
}

.footer-link:is(:hover, :focus) { color: var(--old-rose); }

.footer-bottom {
  display: grid;
  justify-items: center;
  gap: 2px;
  padding-block: 28px 30px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-1), opacity var(--transition-1);
}

.footer-brand:is(:hover, :focus-visible) {
  transform: translateY(-2px);
  opacity: 0.9;
}

.footer-brand-logo {
  width: min(94px, 27vw);
  height: auto;
  object-fit: contain;
}

.copyright {
  color: hsl(30, 14%, 38%);
  font-family: "Saira", sans-serif;
  font-size: 1.35rem;
  letter-spacing: 0.02em;
}

.copyright-prefix {
  font-size: 1.25rem;
}

.footer-book-title {
  font-style: italic;
}

.footer-note {
  display: grid;
  justify-items: center;
  gap: 8px;
  margin-bottom: 24px;
  color: hsl(30, 14%, 38%);
  font-size: 1.28rem;
  line-height: 1.6;
}

.footer-note .footer-brand {
  align-self: center;
}

.footer-copyline {
  margin-top: 8px;
  color: hsl(30, 14%, 38%);
  font-size: 1.22rem;
  letter-spacing: 0.02em;
}

@media (max-width: 575px) {
  .footer-book-title {
    display: block;
    margin-top: 2px;
  }
}

.hero-content,
.benefits-card,
.chapter-card,
.pricing-card,
.achievement-card,
.newsletter-card {
  animation: fadeUp 0.7s ease both;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(14px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}





/*-----------------------------------*\
  #MEDIA QUERIES
\*-----------------------------------*/

/**
 * responsive for large than 575px screen
 */

@media (min-width: 575px) {

  /**
   * CUSTOM PROPERTY
   */

  :root {

    /**
     * typography
     */

    --fs-2: 4.5rem;
    --fs-3: 3.5rem;
    --fs-5: 2.5rem;

  }



  /**
   * REUSED STYLE
   */

  .container,
  .header,
  .navbar {
    max-width: 540px;
    width: 100%;
    margin-inline: auto;
  }

  .section-text { --fs-7: 2rem; }



  /**
   * HEADER
   */

  .header { top: 30px; }

  .header.active { max-width: unset; }

  .logo {
    font-size: 3.2rem;
    max-width: none;
    line-height: 1;
  }

  .navbar {
    left: 50%;
    transform: translateX(-50%);
  }



  /**
   * PREVIEW
   */

  .tab-card.active { height: 50vh; }



  /**
   * ACHIEVEMENT
   */

  .achievement-card { display: flex; }

  .achievement-card > * { width: 50%; }

  .achievement-text-only .achievement-card {
    display: block;
  }

  .achievement-text-only .achievement-card > * {
    width: 100%;
  }

  .achievement-card .card-content { padding-block: 30px; }

  .achievement-card .card-title { margin-block-end: 20px; }

  .achievement-text-only .achievement-card .card-content {
    padding: 30px 24px;
  }



  /**
   * CONTACT
   */

  .social-list-title { --fs-6: 2.2rem; }

  .newsletter-wrapper {
    display: block;
    width: 100%;
  }

  .social-link {
    font-size: 25px;
    padding: 8px;
  }

}





/**
 * responsive for large than 768px screen
 */

@media (min-width: 768px) {

  /**
   * CUSTOM PROPERTY
   */

  :root {

    /**
     * typography
     */

    --fs-2: 4.8rem;

  }



  /**
   * REUSED STYLE
   */

  .container,
  .header,
  .navbar { max-width: 720px; }

  .grid-list { grid-template-columns: 1fr 1fr; }



  /**
   * HERO
   */

  .hero {
    padding-block-start: calc(var(--section-padding) + 100px);
    text-align: left;
  }

  .hero .container {
    grid-template-columns: 1fr 0.8fr;
    align-items: center;
  }

  .hero .section-subtitle { text-align: left; }

  .hero .hero-title {
    font-size: var(--fs-2);
    max-width: none;
    margin-inline: 0;
  }

  .hero .section-text {
    margin-inline: 0;
  }

  .hero-cover-context {
    top: -18px;
    right: 14px;
  }

  .hero-cover-mark {
    gap: 8px;
    padding: 8px 12px 8px 10px;
  }

  .hero-cover-logo {
    width: 66px;
    height: 66px;
  }

  .hero-cover-note {
    font-size: 1.2rem;
  }

  .hero-actions {
    justify-items: start;
  }

  .hero-retailers {
    justify-content: flex-start;
  }

  .hero-proof {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .hero-proof-link {
    min-height: 108px;
    padding: 18px 20px;
  }

  .hero-proof-link::after {
    content: "\2192";
  }

  .hero-proof strong {
    font-size: 1.65rem;
    max-width: 12ch;
  }

  .hero-proof-link > span:not(.hero-proof-kicker) {
    font-size: 1.32rem;
    max-width: 22ch;
  }



  /**
   * PREFACE
   */

  .preface-letter {
    padding: 48px 34px 40px 60px;
  }



  /**
   * BENEFITS
   */

  .benefits :is(.section-title, .section-text) { text-align: left; }

  .benefits-content { grid-column: 1 / 3; }



  /**
   * CHAPTERS, PRICING
   */

  :is(.chapters, .pricing) .grid-list li:last-child {
    grid-column: 1 / 3;
    max-width: calc(50% - 12.5px);
    width: 100%;
    margin-inline: auto;
  }



  /**
   * PREVIEW
   */

  .tab-card.active { height: 70vh; }



  /**
   * AUTHOR
   */

  .author .h2 { --fs-3: 4.2rem; }



  /**
   * ACHIEVEMENT
   */

  .achievement-card { flex-direction: column; }

  .achievement-card > * { width: 100%; }



  /**
   * CONTACT
   */

  .contact .wrapper { grid-template-columns: 1fr 1fr; }

  .newsletter-wrapper {
    display: block;
  }

  .newsletter-form {
    grid-template-columns: 1fr auto;
    align-items: center;
  }

  .newsletter-form .btn {
    width: auto;
    min-width: 220px;
  }

}





/**
 * responsive for large than 992px screen
 */

@media (min-width: 992px) {

  /**
   * CUSTOM PROPERTY
   */

  :root {

    /**
     * typography
     */

    --fs-2: 5.4rem;
    --fs-3: 4rem;

  }



  /**
   * REUSED STYLE
   */

  .container,
  .header,
  .navbar { max-width: 960px; }

  .grid-list { grid-template-columns: repeat(3, 1fr); }



  /**
   * HEADER
   */

  .header .container { padding-inline: 20px 30px; }

  .nav-toggle-btn { display: none; }

  .navbar,
  .navbar.active { all: unset; }

  .navbar-list {
    margin-block-end: 0;
    display: flex;
    gap: 30px;
  }



  /**
   * PREFACE
   */

  .preface-letter {
    --preface-rule-start: 4.57rem;
    --preface-rule-end: 4.77rem;
    padding: 52px 40px 44px 68px;
  }

  .preface-greeting {
    font-size: calc(4.2rem * 1.33);
  }

  .preface-paragraph {
    font-size: calc(2.3rem * 1.33);
  }



  /**
   * BENEFITS
   */

  .benefits .grid-list {
    grid-template-columns: repeat(4, 1fr);
    align-items: stretch;
  }

  .benefits-content { max-width: 80%; }



  /**
   * CHAPTER, PRICING
   */

  :is(.chapters, .pricing) .grid-list li:last-child { all: unset; }



  /**
   * PREVIEW
   */

  .tab-list {
    flex-direction: row;
    gap: 20px;
  }

  .tab-text {
    text-orientation: upright;
    white-space: nowrap;
    writing-mode: vertical-lr;
  }

  .tab-card {
    height: 70vh;
    max-width: 60px;
  }

  .tab-card.active { max-width: 650px; }

  .author-preview-section .tab-list {
    flex-direction: column;
    gap: 14px;
  }

  .author-preview-section .tab-card {
    height: 72px;
    max-width: none;
  }

  .author-preview-section .tab-card.active {
    min-height: 320px;
    max-width: none;
  }

  .author-preview-section .tab-text {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    white-space: normal;
  }



  /**
   * AUTHOR
   */

  .author .container {
    grid-template-columns: 0.6fr 1fr;
    gap: 0;
  }

  .author-content {
    margin-block-start: 40px;
    margin-inline-start: -30px;
    padding-block-end: 70px;
  }

  .author-text-only .container {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .author-text-only .author-content {
    margin-block-start: 0;
    margin-inline-start: 0;
  }



  /**
   * ACHIEVEMENT
   */

  .achievement .grid-list { grid-template-columns: 1fr 1fr; }

  .achievement-card { flex-direction: row; }

  .achievement-card > * { width: 50%; }

  .achievement-text-only .achievement-card {
    flex-direction: column;
  }

  .achievement-text-only .achievement-card > * {
    width: 100%;
  }



  /**
   * CONTACT
   */

  .contact .wrapper { grid-template-columns: 1fr 0.5fr; }

  .contact .wrapper.newsletter-wrapper {
    display: block;
    grid-template-columns: 1fr;
    width: 100%;
  }

  .contact .wrapper.newsletter-wrapper .newsletter-card {
    width: 100%;
  }

  .contact-form { padding: 40px; }

}





/**
 * responsive for large than 1200px screen
 */

@media (min-width: 1200px) {

  /**
   * CUSTOM PROPERTY
   */

  :root {

    /**
     * typography
     */

    --fs-2: 6rem;
    --fs-3: 4.5rem;
    --fs-4: 3rem;
    --fs-5: 3rem;

  }



  /**
   * REUSED STYLE
   */

  .container,
  .header,
  .navbar { max-width: 1140px; }



  /**
   * PREVIEW
   */

  .tab-card { max-width: 75px; }

  .tab-card.active { max-width: 750px; }

  .author-preview-section .tab-card,
  .author-preview-section .tab-card.active {
    max-width: none;
  }



  /**
   * AUTHOR
   */

  .author-content { padding: 85px 60px 115px; }



  /**
   * FOOTER
   */

  .footer-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .footer .logo { margin-block-end: 0; }

}