:root {
  --color-site: #119bda;
  --color-site-light: #38bdf8;
  --color-site-dark: #0878ac;
  --color-background: #000000;
  --color-surface: #071019;
  --color-text-primary: #e8eef4;
  --color-text-secondary: #a7b6c4;
  --color-muted: #718495;
  --color-success: #36d399;
  --color-error: #fb7185;
  --color-warning: #fbbf24;
  --color-aurora-purple: #a855f7;
  --color-aurora-blue: #3b82f6;
  --color-aurora-cyan: #06b6d4;
  --color-surface-soft: rgba(255, 255, 255, 0.035);
  --color-surface-active: rgba(17, 155, 218, 0.08);
  --color-border-soft: rgba(255, 255, 255, 0.08);
  --color-border-active: rgba(17, 155, 218, 0.55);
  --header-height: 74px;
  --container-width: 1180px;
  --article-width: 850px;
  --transition: 0.28s cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 112px;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  font-family: "Vazirmatn", sans-serif;
  background: var(--color-background);
  color: var(--color-text-primary);
}

body.toc-is-open {
  overflow: hidden;
}

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

img {
  display: block;
  max-width: 100%;
}

button,
input,
textarea {
  font: inherit;
}

button {
  color: inherit;
}

::selection {
  background: rgba(17, 155, 218, 0.3);
  color: #ffffff;
}

/* Aurora */

.aurora-bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  pointer-events: none;
}

.aurora-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(
      circle at 50% 0%,
      rgba(17, 155, 218, 0.12),
      transparent 38%
    ),
    linear-gradient(
      to bottom,
      rgba(0, 0, 0, 0.12),
      rgba(0, 0, 0, 0.94) 78%
    );
}

.aurora-effect {
  position: absolute;
  width: 760px;
  height: 760px;
  border-radius: 50%;
  filter: blur(92px);
  will-change: transform, opacity;
}

.aurora-effect--purple {
  background:
    radial-gradient(
      circle,
      var(--color-aurora-purple) 0%,
      transparent 68%
    );
  animation: aurora-purple 17s ease-in-out infinite;
}

.aurora-effect--blue {
  background:
    radial-gradient(
      circle,
      var(--color-aurora-blue) 0%,
      transparent 68%
    );
  animation: aurora-blue 14s ease-in-out infinite;
  animation-delay: -5s;
}

.aurora-effect--cyan {
  width: 520px;
  height: 520px;
  background:
    radial-gradient(
      circle,
      var(--color-aurora-cyan) 0%,
      transparent 70%
    );
  animation: aurora-cyan 19s ease-in-out infinite;
  animation-delay: -9s;
}

@keyframes aurora-purple {
  0%,
  100% {
    transform: translate(-24%, -30%) scale(1);
    opacity: 0.34;
  }

  35% {
    transform: translate(28vw, 12vh) scale(1.08);
    opacity: 0.44;
  }

  70% {
    transform: translate(48vw, -12vh) scale(0.92);
    opacity: 0.25;
  }
}

@keyframes aurora-blue {
  0%,
  100% {
    transform: translate(66vw, 42vh) scale(0.92);
    opacity: 0.3;
  }

  42% {
    transform: translate(35vw, -18vh) scale(1.14);
    opacity: 0.42;
  }

  76% {
    transform: translate(72vw, 20vh) scale(1);
    opacity: 0.46;
  }
}

@keyframes aurora-cyan {
  0%,
  100% {
    transform: translate(16vw, 78vh) scale(0.9);
    opacity: 0.16;
  }

  50% {
    transform: translate(62vw, 40vh) scale(1.15);
    opacity: 0.28;
  }
}

/* Icons */

.masked-icon {
  display: inline-block;
  width: 20px;
  height: 20px;
  flex: 0 0 auto;
  background: currentColor;
  -webkit-mask-position: center;
  mask-position: center;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-size: contain;
  mask-size: contain;
}

.icon-arrow-right {
  -webkit-mask-image: url("assets/icons/arrow-right.svg");
  mask-image: url("assets/icons/arrow-right.svg");
}

.icon-list {
  -webkit-mask-image: url("assets/icons/list.svg");
  mask-image: url("assets/icons/list.svg");
}

.icon-close {
  -webkit-mask-image: url("assets/icons/close.svg");
  mask-image: url("assets/icons/close.svg");
}

.icon-route {
  -webkit-mask-image: url("assets/icons/route.svg");
  mask-image: url("assets/icons/route.svg");
}

.icon-spark {
  -webkit-mask-image: url("assets/icons/spark.svg");
  mask-image: url("assets/icons/spark.svg");
}

.icon-layers {
  -webkit-mask-image: url("assets/icons/layers.svg");
  mask-image: url("assets/icons/layers.svg");
}

.icon-code {
  -webkit-mask-image: url("assets/icons/code.svg");
  mask-image: url("assets/icons/code.svg");
}

.icon-terminal {
  -webkit-mask-image: url("assets/icons/terminal.svg");
  mask-image: url("assets/icons/terminal.svg");
}

.icon-brain {
  -webkit-mask-image: url("assets/icons/brain.svg");
  mask-image: url("assets/icons/brain.svg");
}

.icon-warning {
  -webkit-mask-image: url("assets/icons/warning.svg");
  mask-image: url("assets/icons/warning.svg");
}

.icon-book {
  -webkit-mask-image: url("assets/icons/book.svg");
  mask-image: url("assets/icons/book.svg");
}

.icon-rocket {
  -webkit-mask-image: url("assets/icons/rocket.svg");
  mask-image: url("assets/icons/rocket.svg");
}

.icon-message {
  -webkit-mask-image: url("assets/icons/message.svg");
  mask-image: url("assets/icons/message.svg");
}

.icon-shield {
  -webkit-mask-image: url("assets/icons/shield.svg");
  mask-image: url("assets/icons/shield.svg");
}

.icon-check {
  -webkit-mask-image: url("assets/icons/check.svg");
  mask-image: url("assets/icons/check.svg");
}

/* Header */

.article-header {
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 14px 18px 0;
  background: linear-gradient(
    to bottom,
    rgba(0, 0, 0, 0.78),
    transparent
  );
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.article-header__inner {
  width: min(var(--container-width), 100%);
  min-height: var(--header-height);
  margin: 0 auto;
  padding: 0 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--color-border-soft);
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.site-brand__logo {
  width: 42px;
  height: 42px;
  object-fit: contain;
}

.site-brand__name {
  font-size: 1rem;
  font-weight: 800;
  white-space: nowrap;
}

.article-header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.back-btn,
.toc-open-btn {
  min-height: 42px;
  padding: 0 15px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--color-text-primary);
  cursor: pointer;
  transition:
    color var(--transition),
    background var(--transition),
    transform var(--transition);
}

.back-btn:hover,
.toc-open-btn:hover {
  color: var(--color-site-light);
  background: rgba(255, 255, 255, 0.035);
  transform: translateY(-2px);
}

.back-btn:focus-visible,
.toc-open-btn:focus-visible,
.mobile-toc__close:focus-visible,
.scroll-top:focus-visible {
  outline: 2px solid var(--color-site);
  outline-offset: 3px;
}

.toc-open-btn {
  display: none;
}

/* Layout */

.article-shell {
  width: min(var(--container-width), calc(100% - 32px));
  margin: 0 auto;
  padding: 58px 0 120px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 56px;
  align-items: start;
}

.article-content {
  order: 1;
  min-width: 0;
}

.desktop-toc {
  order: 2;
}

.desktop-toc__sticky {
  position: fixed;
  top: 112px;
  /* max-height: calc(100vh - 140px); */
  overflow-y: auto;
  padding-right: 18px;
  border-right: 1px solid var(--color-border-soft);
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-active) transparent;
  overflow-x: hidden;
}

.desktop-toc__title {
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-text-primary);
  font-weight: 800;
}

.toc-nav {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.toc-nav a {
  position: relative;
  display: block;
  padding: 8px 0;
  color: var(--color-muted);
  font-size: 0.87rem;
  line-height: 1.7;
  transition:
    color var(--transition),
    transform var(--transition);
}

.toc-nav a:hover,
.toc-nav a.is-active {
  color: var(--color-site-light);
  transform: translateX(-4px);
}

.toc-nav a.is-active::before {
  content: "";
  position: absolute;
  top: 50%;
  right: -19px;
  width: 2px;
  height: 24px;
  border-radius: 999px;
  background: var(--color-site);
  transform: translateY(-50%);
}

/* Typography */

.hero {
  min-height: 510px;
  padding-bottom: 64px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero__eyebrow {
  width: fit-content;
  margin-bottom: 18px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--color-site-light);
  font-size: 0.94rem;
  font-weight: 800;
}

.hero h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(2.15rem, 6vw, 4.7rem);
  line-height: 1.28;
  letter-spacing: -0.055em;
}

.hero__description {
  max-width: 760px;
  margin: 24px 0 0;
  color: var(--color-text-secondary);
  font-size: 1.09rem;
  line-height: 2.15;
}

.hero__meta {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  color: var(--color-muted);
  font-size: 0.87rem;
}

.hero__message {
  max-width: 730px;
  margin-top: 34px;
  padding: 18px 22px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  border-right: 2px solid var(--color-site);
  background: linear-gradient(
    to left,
    rgba(17, 155, 218, 0.1),
    transparent
  );
}

.hero__message .masked-icon {
  width: 22px;
  height: 22px;
  margin-top: 8px;
  color: var(--color-site-light);
}

.hero__message p {
  margin: 0;
  color: var(--color-text-primary);
}

.article-section {
  padding: 58px 0;
  border-top: 1px solid var(--color-border-soft);
}

.article-introduction {
  padding-top: 0;
  border-top: 0;
}

.section-heading {
  margin-bottom: 20px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  color: var(--color-site);
}

.section-heading .masked-icon {
  width: 26px;
  height: 26px;
  margin-top: 8px;
}

.section-heading h2,
.lesson-heading h2 {
  margin: 0;
  color: var(--color-text-primary);
  font-size: clamp(1.45rem, 3vw, 2.2rem);
  line-height: 1.55;
  letter-spacing: -0.03em;
}

h3 {
  margin: 26px 0 10px;
  color: var(--color-site-light);
  font-size: 1.08rem;
}

p {
  margin: 0 0 18px;
  color: var(--color-text-secondary);
  font-size: 1.02rem;
  line-height: 2.15;
}

strong {
  color: var(--color-text-primary);
}

.latin {
  display: inline-block;
  direction: ltr;
  unicode-bidi: isolate;
  color: var(--color-text-primary);
  font-family:
    ui-monospace,
    SFMono-Regular,
    Menlo,
    Monaco,
    Consolas,
    monospace;
}

/* Content blocks */

.highlight-quote {
  margin: 30px 0;
  padding: 24px 26px;
  display: flex;
  align-items: flex-start;
  gap: 15px;
  border-right: 3px solid var(--color-site);
  background:
    linear-gradient(
      to left,
      rgba(17, 155, 218, 0.1),
      rgba(17, 155, 218, 0.015)
    );
}

.highlight-quote .masked-icon {
  width: 28px;
  height: 28px;
  margin-top: 7px;
  color: var(--color-site-light);
}

.highlight-quote p {
  margin: 0;
  color: var(--color-text-primary);
  font-size: 1.08rem;
}

.question-block {
  margin: 28px 0;
  padding: 25px 28px;
  border: 1px solid var(--color-border-active);
  border-radius: 18px;
  background: rgba(17, 155, 218, 0.06);
}

.question-block span {
  display: block;
  margin-bottom: 9px;
  color: var(--color-site-light);
  font-size: 0.82rem;
  font-weight: 800;
}

.question-block strong {
  display: block;
  font-size: clamp(1.07rem, 2vw, 1.28rem);
  line-height: 1.9;
}

.article-figure {
    max-width: 400px;
  width: min(680px, 100%);
  margin: 40px auto;
}

.article-figure__frame {
  position: relative;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border: 1px solid var(--color-border-soft);
  border-radius: 22px;
  background: var(--color-surface-soft);
  box-shadow:
    0 32px 90px rgba(0, 0, 0, 0.42),
    0 0 80px rgba(17, 155, 218, 0.06);
}

.article-figure__frame::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: inherit;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.03);
  pointer-events: none;
}

.article-figure img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: rgba(0, 0, 0, 0.35);
}

.article-figure figcaption {
  margin-top: 14px;
  color: var(--color-muted);
  font-size: 0.88rem;
  text-align: center;
  line-height: 1.8;
}

.foundation-grid {
  margin: 28px 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.foundation-card {
  position: relative;
  padding: 27px;
  overflow: hidden;
  border: 1px solid var(--color-border-soft);
  border-radius: 18px;
  background:
    linear-gradient(
      145deg,
      rgba(17, 155, 218, 0.07),
      rgba(255, 255, 255, 0.015)
    );
}

.foundation-card__number {
  position: absolute;
  top: 18px;
  left: 20px;
  color: rgba(255, 255, 255, 0.14);
  font-size: 1.8rem;
  font-weight: 900;
}

.foundation-card h3 {
  margin-top: 0;
  direction: ltr;
  text-align: right;
}

.foundation-card p:last-child {
  margin-bottom: 0;
}

.section-separator {
  margin: 48px 0 16px;
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--color-text-primary);
  font-weight: 800;
}

.section-separator::before,
.section-separator::after {
  content: "";
  height: 1px;
  flex: 1;
  background: var(--color-border-soft);
}

.section-separator span {
  max-width: 420px;
  text-align: center;
  line-height: 1.9;
}

.responsibility-list {
  margin-top: 24px;
}

.responsibility-item {
  padding: 31px 0;
  border-bottom: 1px solid var(--color-border-soft);
}

.responsibility-item:last-child {
  border-bottom: 0;
}

.responsibility-item__heading {
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 13px;
}

.responsibility-item__heading h3 {
  margin: 0;
  direction: ltr;
  text-align: right;
  color: var(--color-text-primary);
  font-size: 1.13rem;
}

.responsibility-item__index {
  min-width: 34px;
  direction: ltr;
  color: var(--color-site);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.responsibility-item p {
  padding-right: 47px;
}

.responsibility-item p:last-child {
  margin-bottom: 0;
}

.note {
  margin: 30px 0;
  padding: 22px 25px;
  border-right: 3px solid var(--color-site);
  background:
    linear-gradient(
      to left,
      rgba(17, 155, 218, 0.09),
      transparent 76%
    );
}

.note p:last-child {
  margin-bottom: 0;
}

.note--warning {
  display: flex;
  align-items: flex-start;
  gap: 13px;
  border-right-color: var(--color-warning);
  background:
    linear-gradient(
      to left,
      rgba(251, 191, 36, 0.08),
      transparent 76%
    );
}

.note--warning .masked-icon {
  width: 24px;
  height: 24px;
  margin-top: 7px;
  color: var(--color-warning);
}

.story-block {
  margin: 30px 0;
  padding: 28px;
  border: 1px solid var(--color-border-soft);
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.025);
}

.story-block__label {
  display: block;
  width: fit-content;
  margin-bottom: 15px;
  color: var(--color-site-light);
  font-size: 0.85rem;
  font-weight: 900;
}

.story-block p:last-child {
  margin-bottom: 0;
}

.lesson-heading {
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.lesson-heading__number {
  direction: ltr;
  color: var(--color-site);
  font-size: 1.85rem;
  font-weight: 900;
  letter-spacing: 0.06em;
}

.lesson-heading__label {
  display: block;
  margin-bottom: 2px;
  color: var(--color-muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.rule-block {
  margin: 30px 0 0;
  padding: 22px 25px;
  display: flex;
  align-items: center;
  gap: 14px;
  border: 1px solid var(--color-border-active);
  border-radius: 17px;
  background: rgba(17, 155, 218, 0.07);
}

.rule-block .masked-icon {
  width: 28px;
  height: 28px;
  color: var(--color-site-light);
}

.rule-block strong {
  line-height: 2;
}

.code-example {
  margin: 36px 0 0;
  overflow: hidden;
  border: 1px solid var(--color-border-soft);
  border-radius: 20px;
  background: rgba(5, 10, 15, 0.72);
}

.code-example__header {
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
  border-bottom: 1px solid var(--color-border-soft);
  color: var(--color-text-primary);
  font-weight: 800;
}

.code-example__language {
  direction: ltr;
  color: var(--color-site-light);
  font-family:
    ui-monospace,
    SFMono-Regular,
    Menlo,
    Monaco,
    Consolas,
    monospace;
  font-size: 0.82rem;
}

.code-example > p {
  padding: 0 22px;
}

.code-example > p:first-of-type {
  margin-top: 22px;
}

.code-example pre {
  margin: 25px 0;
  padding: 24px;
  overflow-x: auto;
  border-block: 1px solid var(--color-border-soft);
  background: #03070b;
  color: #dbeafe;
  font-size: 0.92rem;
  line-height: 1.9;
  text-align: left;
}

.code-example code {
  font-family:
    ui-monospace,
    SFMono-Regular,
    Menlo,
    Monaco,
    Consolas,
    monospace;
}

.code-selector {
  color: #c084fc;
}

.code-property {
  color: #7dd3fc;
}

.code-value {
  color: #86efac;
}

.code-example__caption {
  margin-bottom: 22px;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.checklist-block {
  margin: 30px 0;
  padding: 26px;
  border: 1px solid var(--color-border-soft);
  border-radius: 20px;
  background: var(--color-surface-soft);
}

.checklist-block h3 {
  margin: 0 0 18px;
  color: var(--color-text-primary);
}

.check-list {
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 20px;
  list-style: none;
}

.check-list li {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  color: var(--color-text-secondary);
  line-height: 1.9;
}

.check-list .masked-icon {
  width: 18px;
  height: 18px;
  margin-top: 9px;
  color: var(--color-success);
}

.start-callout {
  margin-top: 34px;
  padding: 30px;
  border-right: 4px solid var(--color-site);
  background:
    radial-gradient(
      circle at 100% 0%,
      rgba(17, 155, 218, 0.12),
      transparent 52%
    ),
    rgba(255, 255, 255, 0.025);
}

.start-callout__eyebrow {
  display: block;
  margin-bottom: 10px;
  color: var(--color-site-light);
  font-size: 0.82rem;
  font-weight: 900;
}

.start-callout strong {
  display: block;
  margin-bottom: 12px;
  font-size: 1.16rem;
  line-height: 2;
}

.start-callout p:last-child {
  margin-bottom: 0;
}

/* Contact form */

.contact-layout {
  margin-top: 34px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 30px;
  align-items: start;
}

.contact-form {
  /* padding: 28px; */
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
  /* border: 1px solid var(--color-border-soft); */
  border-radius: 22px;
  /* background: rgba(4, 10, 15, 0.58); */
  /* backdrop-filter: blur(12px); */
  /* -webkit-backdrop-filter: blur(12px); */
}

.form-field {
  min-width: 0;
}

.form-field--full {
  grid-column: 1 / -1;
}

.form-field label {
  display: block;
  margin-bottom: 9px;
  color: var(--color-text-primary);
  font-size: 0.91rem;
  font-weight: 800;
}

.form-field input,
.form-field textarea {
  width: 100%;
  border: 1px solid var(--color-border-soft);
  border-radius: 13px;
  outline: none;
  background: rgba(255, 255, 255, 0.035);
  color: var(--color-text-primary);
  transition:
    border-color var(--transition),
    background var(--transition),
    box-shadow var(--transition);
}

.form-field input {
  height: 50px;
  padding: 0 15px;
}

.form-field textarea {
  min-height: 160px;
  padding: 14px 15px;
  resize: vertical;
  line-height: 1.9;
}

.form-field input::placeholder,
.form-field textarea::placeholder {
  color: #607384;
}

.form-field input:focus,
.form-field textarea:focus {
  border-color: var(--color-site);
  background: rgba(17, 155, 218, 0.05);
  box-shadow: 0 0 0 3px rgba(17, 155, 218, 0.11);
}

.form-field input.is-invalid,
.form-field textarea.is-invalid {
  border-color: var(--color-error);
}

.field-error {
  min-height: 19px;
  margin-top: 6px;
  display: block;
  color: var(--color-error);
  font-size: 0.78rem;
  line-height: 1.7;
}

.field-meta {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.character-counter {
  margin-top: 6px;
  flex: 0 0 auto;
  color: var(--color-muted);
  font-size: 0.76rem;
}

.honeypot-field {
  position: fixed;
  top: -9999px;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
}

.form-status {
  grid-column: 1 / -1;
  min-height: 0;
  color: var(--color-text-secondary);
  font-size: 0.88rem;
  line-height: 1.8;
}

.form-status:empty {
  display: none;
}

.form-status.is-success {
  color: var(--color-success);
}

.form-status.is-error {
  color: var(--color-error);
}

.submit-btn {
  grid-column: 1 / -1;
  width: fit-content;
  min-height: 49px;
  padding: 0 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 11px;
  border: 0;
  border-radius: 999px;
  background: var(--color-site);
  color: #ffffff;
  font-weight: 800;
  cursor: pointer;
  transition:
    background var(--transition),
    transform var(--transition),
    box-shadow var(--transition);
}

.submit-btn:hover:not(:disabled) {
  background: var(--color-site-light);
  transform: translateY(-2px);
  box-shadow: 0 13px 36px rgba(17, 155, 218, 0.22);
}

.submit-btn:disabled {
  cursor: wait;
  opacity: 0.7;
}

.submit-btn__loader {
  display: none;
  width: 17px;
  height: 17px;
  border: 2px solid rgba(255, 255, 255, 0.4);
  border-top-color: #ffffff;
  border-radius: 50%;
  animation: loading-spin 0.75s linear infinite;
}

.submit-btn.is-loading .submit-btn__loader {
  display: inline-block;
}

@keyframes loading-spin {
  to {
    transform: rotate(360deg);
  }
}

.privacy-note {
  position: sticky;
  top: 118px;
  padding: 24px;
  display: flex;
  align-items: flex-start;
  gap: 13px;
  border-right: 2px solid var(--color-success);
  background:
    linear-gradient(
      to left,
      rgba(54, 211, 153, 0.07),
      transparent
    );
}

.privacy-note > .masked-icon {
  width: 26px;
  height: 26px;
  margin-top: 4px;
  color: var(--color-success);
}

.privacy-note h3 {
  margin: 0 0 9px;
  color: var(--color-text-primary);
}

.privacy-note p {
  margin-bottom: 12px;
  color: var(--color-muted);
  font-size: 0.87rem;
  line-height: 1.95;
}

.privacy-note p:last-child {
  margin-bottom: 0;
}

/* Summary */

.summary-section {
  padding-bottom: 0;
}

.final-message {
  margin-top: 38px;
  padding: 33px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 10px 18px;
  border-block: 1px solid var(--color-border-soft);
  background:
    radial-gradient(
      circle at 50% 50%,
      rgba(17, 155, 218, 0.09),
      transparent 70%
    );
  color: var(--color-text-secondary);
  font-size: clamp(1rem, 2.2vw, 1.2rem);
}

.final-message span:not(:last-of-type)::after {
  content: "•";
  margin-right: 18px;
  color: var(--color-site);
}

.final-message strong {
  color: var(--color-site-light);
}

/* Mobile TOC */

.mobile-toc-backdrop {
  position: fixed;
  inset: 0;
  z-index: 29;
  background: rgba(0, 0, 0, 0.62);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}

.mobile-toc-backdrop.is-open {
  opacity: 1;
  pointer-events: auto;
}

.mobile-toc {
  position: fixed;
  top: 0;
  right: 0;
  z-index: 30;
  width: min(370px, 88vw);
  height: 100dvh;
  padding: 22px;
  overflow: hidden;
  border-left: 1px solid var(--color-border-soft);
  background: rgba(5, 10, 15, 0.96);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transform: translateX(102%);
  visibility: hidden;
  transition:
    transform var(--transition),
    visibility var(--transition);
}

.mobile-toc.is-open {
  visibility: visible;
  transform: translateX(0);
}

.mobile-toc__header {
  margin-bottom: 10px;
  padding-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--color-border-soft);
}

.mobile-toc__close {
  width: 42px;
  height: 42px;
  padding: 0;
  display: inline-grid;
  place-items: center;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--color-text-primary);
  cursor: pointer;
}

.mobile-toc__nav {
  max-height: calc(100dvh - 100px);
  overflow-y: auto;
  padding-left: 4px;
}

/* Scroll top */

.scroll-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 15;
  width: 46px;
  height: 46px;
  padding: 0;
  display: grid;
  place-items: center;
  border: 1px solid var(--color-border-soft);
  border-radius: 50%;
  background: rgba(5, 10, 15, 0.82);
  color: var(--color-site-light);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition:
    opacity var(--transition),
    transform var(--transition),
    background var(--transition);
}

.scroll-top .masked-icon {
  transform: rotate(-90deg);
}

.scroll-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.scroll-top:hover {
  background: rgba(17, 155, 218, 0.16);
}

/* Responsive */

@media (max-width: 1080px) {
  .article-shell {
    gap: 38px;
    grid-template-columns: minmax(0, 1fr) 235px;
  }
}

@media (max-width: 980px) {
  .article-shell {
    width: min(820px, calc(100% - 28px));
    padding-top: 36px;
    display: block;
  }

  .desktop-toc {
    display: none;
  }

  .toc-open-btn {
    display: inline-flex;
  }

  .hero {
    min-height: auto;
    padding: 58px 0 50px;
  }

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

  .privacy-note {
    position: static;
  }
}

@media (max-width: 720px) {
  .article-header {
    padding: 10px 12px 0;
  }

  .article-header__inner {
    min-height: 62px;
    padding: 0 4px;
  }

  .site-brand__name {
    display: none;
  }

  .back-btn,
  .toc-open-btn {
    min-height: 40px;
    padding: 0 10px;
    font-size: 0.88rem;
  }

  .article-shell {
    width: min(100% - 24px, 820px);
    padding-bottom: 82px;
  }

  .hero {
    padding-top: 48px;
  }

  .hero h1 {
    font-size: clamp(2rem, 11vw, 3.2rem);
    letter-spacing: -0.045em;
  }

  .hero__description,
  p {
    font-size: 0.98rem;
    line-height: 2.05;
  }

  .hero__message,
  .highlight-quote {
    padding: 19px;
  }

  .article-section {
    padding: 44px 0;
  }

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

  .foundation-card {
    padding: 23px;
  }

  .responsibility-item p {
    padding-right: 0;
  }

  .responsibility-item__heading {
    align-items: flex-start;
  }

  .section-separator::before,
  .section-separator::after {
    display: none;
  }

  .lesson-heading {
    align-items: flex-start;
  }

  .story-block,
  .checklist-block,
  .start-callout {
    padding: 22px;
  }

  .contact-form {
    padding: 21px;
    grid-template-columns: 1fr;
  }

  .form-field--full,
  .form-status,
  .submit-btn {
    grid-column: auto;
  }

  .submit-btn {
    width: 100%;
  }

  .final-message {
    padding: 27px 18px;
  }

  .final-message span:not(:last-of-type)::after {
    margin-right: 10px;
  }

  .scroll-top {
    right: 14px;
    bottom: 14px;
  }
}

@media (max-width: 420px) {
  .article-header__actions {
    gap: 3px;
  }

  .back-btn,
  .toc-open-btn {
    gap: 5px;
    padding-inline: 8px;
  }

  .hero__meta {
    flex-direction: column;
    gap: 7px;
  }

  .question-block,
  .code-example,
  .article-figure__frame,
  .contact-form {
    border-radius: 16px;
  }

  .final-message {
    justify-content: flex-start;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}


html {
  width: 100%;
  max-width: 100%;
  overflow-x: clip;
  scroll-behavior: smooth;
  scroll-padding-top: 112px;
}

body {
  width: 100%;
  max-width: 100%;
  min-height: 100vh;
  overflow-x: clip;
  font-family: "Vazirmatn", sans-serif;
  background: var(--color-background);
  color: var(--color-text-primary);
}

body.toc-is-open {
  overflow: hidden;
  overscroll-behavior: none;
}



.mobile-toc {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  z-index: 30;
  width: min(370px, 88vw);
  max-width: 100%;
  height: 100dvh;
  padding: 22px;
  overflow: hidden;
  contain: layout paint;
  border-left: 1px solid var(--color-border-soft);
  background: rgba(5, 10, 15, 0.96);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transform: translate3d(100%, 0, 0);
  visibility: hidden;
  pointer-events: none;
  transition:
    transform var(--transition),
    visibility var(--transition);
}

.mobile-toc.is-open {
  visibility: visible;
  pointer-events: auto;
  transform: translate3d(0, 0, 0);
}

.article-header,
.article-shell,
.mobile-toc-backdrop {
  max-width: 100vw;
}

@media (max-width: 720px) {
  .article-shell {
    width: min(calc(100% - 24px), 820px);
    padding-bottom: 82px;
  }
}