/* ==========================================================================
   Chess2grow Landingpage – Design System
   ========================================================================== */

:root {
  --color-bg: #0f1419;
  --color-bg-alt: #161d26;
  --color-bg-card: #1c2530;
  --color-border: #2a3544;
  --color-text: #e8ecf1;
  --color-text-muted: #9aa8b8;
  --color-accent: #c9a227;
  --color-accent-hover: #dbb42e;
  --color-green: #2d4a3e;
  --color-green-light: #3d6b58;
  --color-error: #e05c5c;

  --font-sans: "DM Sans", system-ui, sans-serif;
  --font-serif: "Fraunces", Georgia, serif;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.35);
  --transition: 0.2s ease;

  --max-width: 72rem;
  --header-height: 4.5rem;
}

/* Reset & Base */

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent-hover);
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

h1, h2, h3 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.2;
  margin: 0 0 var(--space-sm);
}

p {
  margin: 0 0 var(--space-sm);
}

ul {
  margin: 0;
  padding: 0;
}

/* Layout */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.container--narrow {
  max-width: 40rem;
}

/* Header & Navigation */

.header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(15, 20, 25, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--color-text);
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.15rem;
}

.logo:hover {
  color: var(--color-accent);
}

.logo__icon {
  font-size: 1.5rem;
  color: var(--color-accent);
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  background: transparent;
  border: none;
  cursor: pointer;
  z-index: 110;
}

.nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav {
  position: fixed;
  inset: 0;
  top: var(--header-height);
  background: var(--color-bg);
  padding: var(--space-lg) var(--space-md);
  transform: translateX(100%);
  transition: transform 0.3s ease;
  overflow-y: auto;
}

.nav.is-open {
  transform: translateX(0);
}

.nav__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.nav__link {
  display: block;
  padding: var(--space-sm);
  color: var(--color-text);
  font-size: 1.125rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
}

.nav__link:hover {
  color: var(--color-accent);
  background: var(--color-bg-card);
}

.nav__link--cta {
  color: var(--color-bg);
  background: var(--color-accent);
  text-align: center;
  margin-top: var(--space-sm);
}

.nav__link--cta:hover {
  background: var(--color-accent-hover);
  color: var(--color-bg);
}

@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }

  .nav {
    position: static;
    inset: auto;
    padding: 0;
    transform: none;
    background: transparent;
    overflow: visible;
  }

  .nav__list {
    flex-direction: row;
    align-items: center;
    gap: var(--space-xs);
  }

  .nav__link {
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.95rem;
  }

  .nav__link--cta {
    margin-top: 0;
    margin-left: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
  }
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
  text-decoration: none;
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-bg);
  border-color: var(--color-accent);
}

.btn--primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  color: var(--color-bg);
}

.btn--secondary {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn--secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn--block {
  width: 100%;
}

/* Hero */

.hero {
  padding: var(--space-xl) 0 var(--space-2xl);
  background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
  overflow: hidden;
}

.hero__inner {
  display: grid;
  gap: var(--space-xl);
  align-items: center;
}

.hero__eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-green-light);
  margin-bottom: var(--space-sm);
}

.hero__title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  margin-bottom: var(--space-md);
}

.hero__text {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  max-width: 32rem;
  margin-bottom: var(--space-lg);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.hero__visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 240px;
}

.chess-board {
  display: grid;
  grid-template-columns: repeat(2, 80px);
  grid-template-rows: repeat(2, 80px);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transform: rotate(-3deg);
}

.chess-board__square--light {
  background: #e8e0d0;
}

.chess-board__square--dark {
  background: var(--color-green);
}

.hero__piece {
  position: absolute;
  font-size: 5rem;
  color: var(--color-accent);
  text-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
  transform: translate(40px, -20px);
}

@media (min-width: 768px) {
  .hero__inner {
    grid-template-columns: 1fr 1fr;
  }
}

/* Sections */

.section {
  padding: var(--space-2xl) 0;
}

.section--alt {
  background: var(--color-bg-alt);
}

.section__header {
  text-align: center;
  margin-bottom: var(--space-xl);
  max-width: 36rem;
  margin-left: auto;
  margin-right: auto;
}

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
}

.section__subtitle {
  color: var(--color-text-muted);
  font-size: 1.0625rem;
  margin-bottom: 0;
}

/* Cards */

.cards {
  display: grid;
  gap: var(--space-md);
}

.cards--three {
  grid-template-columns: 1fr;
}

.cards--single {
  max-width: 36rem;
  margin: 0 auto;
}

.card--highlight {
  border-color: var(--color-green-light);
}

.card__list--columns {
  display: grid;
  gap: var(--space-xs);
}

@media (min-width: 480px) {
  .card__list--columns {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 640px) {
  .cards--three {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .cards--three {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  transition: border-color var(--transition), transform var(--transition);
}

.card:hover {
  border-color: var(--color-green-light);
}

.card__icon {
  font-size: 2rem;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
  line-height: 1;
}

.card__title {
  font-size: 1.25rem;
  margin-bottom: var(--space-xs);
}

.card__text {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  margin-bottom: var(--space-md);
}

.card__list {
  list-style: none;
}

.card__list li {
  position: relative;
  padding-left: 1.25rem;
  margin-bottom: var(--space-xs);
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.card__list li::before {
  content: "♟";
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-size: 0.75rem;
}

/* Pricing cards */

.card--price {
  display: flex;
  flex-direction: column;
  text-align: center;
}

.card--featured {
  border-color: var(--color-accent);
  position: relative;
  transform: scale(1);
}

@media (min-width: 960px) {
  .card--featured {
    transform: scale(1.03);
  }
}

.card__badge {
  position: absolute;
  top: -0.75rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-accent);
  color: var(--color-bg);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
}

.card__price {
  margin: var(--space-md) 0 var(--space-xs);
}

.card__amount {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-accent);
}

.card__price-note {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
}

.card--price .card__list {
  flex: 1;
  text-align: left;
  margin-bottom: var(--space-lg);
}

.card--price .btn {
  margin-top: auto;
}

.pricing-note {
  text-align: center;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-top: var(--space-lg);
  margin-bottom: 0;
}

/* Steps */

.steps {
  list-style: none;
  display: grid;
  gap: var(--space-lg);
  max-width: 40rem;
  margin: 0 auto;
}

@media (min-width: 768px) {
  .steps {
    max-width: none;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xl);
  }
}

@media (min-width: 960px) {
  .steps {
    grid-template-columns: repeat(4, 1fr);
  }
}

.step {
  display: flex;
  gap: var(--space-md);
  align-items: flex-start;
}

.step__number {
  flex-shrink: 0;
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-green);
  color: var(--color-accent);
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.125rem;
  border-radius: 50%;
}

.step__title {
  font-size: 1.0625rem;
  margin-bottom: var(--space-xs);
}

.step__text {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

/* Trainer */

.trainer {
  display: grid;
  gap: var(--space-lg);
  align-items: center;
  max-width: 48rem;
  margin: 0 auto;
}

@media (min-width: 640px) {
  .trainer {
    grid-template-columns: 200px 1fr;
    max-width: none;
  }
}

.trainer__photo {
  aspect-ratio: 1;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--color-green) 0%, var(--color-bg-card) 100%);
  border: 2px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  max-width: 200px;
  margin: 0 auto;
}

.trainer__initials {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-accent);
  opacity: 0.9;
}

.trainer__name {
  font-size: 1.5rem;
  margin-bottom: var(--space-xs);
}

.trainer__meta {
  font-size: 0.9375rem;
  color: var(--color-accent);
  margin-bottom: var(--space-md);
}

.trainer__bio {
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.tag {
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.35rem 0.75rem;
  background: var(--color-green);
  color: var(--color-text);
  border-radius: 999px;
}

/* FAQ */

.faq {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.faq__item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--color-bg-card);
}

.faq__question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: transparent;
  border: none;
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  transition: background var(--transition);
}

.faq__question:hover {
  background: var(--color-bg-alt);
}

.faq__icon {
  flex-shrink: 0;
  width: 1.25rem;
  height: 1.25rem;
  position: relative;
}

.faq__icon::before,
.faq__icon::after {
  content: "";
  position: absolute;
  background: var(--color-accent);
  transition: transform var(--transition);
}

.faq__icon::before {
  width: 100%;
  height: 2px;
  top: 50%;
  left: 0;
  transform: translateY(-50%);
}

.faq__icon::after {
  width: 2px;
  height: 100%;
  left: 50%;
  top: 0;
  transform: translateX(-50%);
}

.faq__question[aria-expanded="true"] .faq__icon::after {
  transform: translateX(-50%) scaleY(0);
}

.faq__answer {
  padding: 0 var(--space-md) var(--space-md);
}

.faq__answer[hidden] {
  display: none;
}

.faq__answer p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  margin: 0;
}

/* Contact Form */

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.form__group label {
  display: block;
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: var(--space-xs);
}

.form__group input,
.form__group select,
.form__group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition);
}

.form__group input::placeholder,
.form__group textarea::placeholder {
  color: var(--color-text-muted);
  opacity: 0.7;
}

.form__group input:invalid:not(:placeholder-shown),
.form__group textarea:invalid:not(:placeholder-shown) {
  border-color: var(--color-error);
}

.form__group select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%239aa8b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

.form__hint {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin: 0;
  text-align: center;
}

.form__success {
  text-align: center;
  color: var(--color-green-light);
  font-weight: 600;
  margin: 0;
}

.form__group.is-error input,
.form__group.is-error select,
.form__group.is-error textarea {
  border-color: var(--color-error);
}

/* Footer */

.footer {
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-alt);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  text-align: center;
}

.footer__copy {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin: 0;
}

.footer__nav {
  display: flex;
  gap: var(--space-md);
}

.footer__nav a {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.footer__nav a:hover {
  color: var(--color-accent);
}

@media (min-width: 640px) {
  .footer__inner {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}