/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-family); color: var(--color-text); line-height: 1.6; -webkit-font-smoothing: antialiased; }
img { max-width: 100%; display: block; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
ul { list-style: none; }

/* ===== Variables ===== */
:root {
  --color-primary: #0DC2B0;
  --color-primary-hover: #0AB3A2;
  --color-dark: #1A1A2E;
  --color-light: #F8F9FA;
  --color-text: #2D2D2D;
  --color-text-light: #FFFFFF;
  --color-status-available: #0DC2B0;
  --color-status-beta: #F5A623;
  --color-status-coming: #999999;
  --color-muted: #6B7280;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --max-width: 1100px;
  --radius: 8px;
}

/* ===== Utility ===== */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }

/* ===== Typography ===== */
h1 { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 800; line-height: 1.2; }
h2 { font-size: clamp(1.5rem, 3vw, 2.2rem); font-weight: 700; margin-bottom: 1rem; }
h3 { font-size: 1.25rem; font-weight: 600; }

/* ===== Buttons ===== */
.btn {
  display: inline-block; padding: 14px 32px; border: none; border-radius: var(--radius);
  font-size: 0.95rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px;
  cursor: pointer; transition: all 0.2s; text-align: center;
}
.btn-primary { background: var(--color-primary); color: var(--color-text-light); }
.btn-primary:hover { background: var(--color-primary-hover); text-decoration: none; }
.btn-outline {
  background: transparent; color: var(--color-text-light);
  border: 2px solid rgba(255,255,255,0.3);
}
.btn-outline:hover { border-color: var(--color-primary); color: var(--color-primary); text-decoration: none; }
.btn-muted { background: var(--color-muted); color: var(--color-text-light); cursor: default; }
.btn-muted:hover { text-decoration: none; }

/* ===== Header ===== */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--color-dark); padding: 16px 0; transition: background 0.3s;
}
.header.scrolled { background: rgba(26, 26, 46, 0.95); backdrop-filter: blur(10px); }
.header .container { display: flex; align-items: center; justify-content: space-between; }
.header__logo { font-size: 1.25rem; font-weight: 700; color: var(--color-text-light); }
.header__logo a { color: var(--color-text-light); }
.header__logo a:hover { color: var(--color-primary); text-decoration: none; }
.header__nav { display: flex; gap: 32px; }
.header__nav a { color: rgba(255,255,255,0.7); font-size: 0.9rem; font-weight: 500; transition: color 0.2s; }
.header__nav a:hover, .header__nav a.active { color: var(--color-primary); text-decoration: none; }

/* Burger */
.header__burger { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 4px; }
.header__burger span { display: block; width: 24px; height: 2px; background: var(--color-text-light); transition: all 0.3s; }
.header__burger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.header__burger.active span:nth-child(2) { opacity: 0; }
.header__burger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

@media (max-width: 768px) {
  .header__burger { display: flex; }
  .header__nav {
    position: fixed; top: 60px; left: 0; right: 0; flex-direction: column;
    background: var(--color-dark); padding: 24px; gap: 16px;
    transform: translateY(-120%); transition: transform 0.3s;
  }
  .header__nav.open { transform: translateY(0); }
}

/* ===== Hero ===== */
.hero {
  background: var(--color-dark); color: var(--color-text-light);
  padding: 160px 0 100px; text-align: center;
}
.hero h1 { margin-bottom: 16px; }
.hero__subtitle { font-size: 1.2rem; color: rgba(255,255,255,0.7); margin-bottom: 8px; }
.hero__tagline { font-size: 1.5rem; font-weight: 600; color: var(--color-primary); margin-bottom: 40px; }

/* ===== Section backgrounds ===== */
.section-dark { background: var(--color-dark); color: var(--color-text-light); }
.section-light { background: var(--color-light); }
.section-white { background: #FFFFFF; }

/* ===== Cards (grid 2x2) ===== */
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
@media (max-width: 768px) {
  .cards { grid-template-columns: 1fr; }
}
.card {
  background: #FFFFFF; border-radius: var(--radius); padding: 32px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06); transition: box-shadow 0.2s;
}
.card:hover { box-shadow: 0 4px 24px rgba(0,0,0,0.1); }
.card__icon { font-size: 2rem; margin-bottom: 16px; }
.card h3 { margin-bottom: 8px; }
.card p { color: var(--color-muted); font-size: 0.95rem; margin-bottom: 20px; }

/* ===== Course card ===== */
.course-card { border: 1px solid #e5e7eb; }
.course-card .status { display: inline-block; padding: 4px 12px; border-radius: 20px; font-size: 0.8rem; font-weight: 600; margin-bottom: 12px; }
.status-available { background: rgba(13, 194, 176, 0.15); color: var(--color-status-available); }
.status-beta { background: rgba(245, 166, 35, 0.15); color: var(--color-status-beta); }
.status-coming { background: rgba(153, 153, 153, 0.15); color: var(--color-status-coming); }

/* ===== Science page numbers ===== */
.numbers { display: flex; justify-content: center; gap: 60px; flex-wrap: wrap; text-align: center; }
.number__value { font-size: 3rem; font-weight: 800; color: var(--color-primary); }
.number__label { font-size: 1rem; color: rgba(255,255,255,0.7); margin-top: 4px; }

/* ===== Problem section ===== */
.problem { text-align: center; }
.problem__text { max-width: 600px; margin: 0 auto; font-size: 1.1rem; color: var(--color-muted); }

/* ===== Solution list ===== */
.solution-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; text-align: center; }
@media (max-width: 768px) { .solution-list { grid-template-columns: 1fr; } }
.solution-list__item h3 { color: var(--color-primary); margin-bottom: 8px; }
.solution-list__item p { color: var(--color-muted); }

/* ===== Section title ===== */
.section__title { text-align: center; margin-bottom: 48px; }
.section__title p { color: var(--color-muted); font-size: 1.1rem; }

/* ===== Footer ===== */
.footer {
  background: var(--color-dark); color: var(--color-text-light); padding: 80px 0 40px; text-align: center;
}
.footer h2 { margin-bottom: 8px; }
.footer__subtitle { color: rgba(255,255,255,0.6); margin-bottom: 40px; }
.footer__cta { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin-bottom: 60px; }
.footer__subscribe {
  max-width: 500px; margin: 0 auto 60px; padding: 40px; border: 1px solid rgba(255,255,255,0.1); border-radius: var(--radius);
}
.footer__subscribe h3 { margin-bottom: 16px; }
.footer__form { display: flex; gap: 12px; }
@media (max-width: 500px) { .footer__form { flex-direction: column; } }
.footer__form input {
  flex: 1; padding: 14px 16px; border: 1px solid rgba(255,255,255,0.2); border-radius: var(--radius);
  background: rgba(255,255,255,0.05); color: var(--color-text-light); font-size: 0.95rem;
}
.footer__form input::placeholder { color: rgba(255,255,255,0.4); }
.footer__form .btn { white-space: nowrap; }
.footer__copy { color: rgba(255,255,255,0.3); font-size: 0.85rem; }

/* ===== Content page (metodika, nauka) ===== */
.content-page { padding: 140px 0 80px; }
.content-page .container { max-width: 800px; }
.content-page h2 { margin-top: 48px; margin-bottom: 16px; }
.content-page p { margin-bottom: 16px; font-size: 1.05rem; line-height: 1.8; color: #4b5563; }
.content-page ul { list-style: disc; padding-left: 24px; margin-bottom: 24px; }
.content-page ul li { margin-bottom: 8px; color: #4b5563; }

/* ===== Catalog page ===== */
.catalog-page { padding: 140px 0 80px; }

/* ===== Link to catalog ===== */
.section__link { text-align: center; margin-top: 32px; }
.section__link a { font-weight: 600; }