/* ===== ГОСТ-AI Premium ===== */
:root {
  --bg: #0a1929;
  --bg-elevated: #112240;
  --glass: rgba(255, 255, 255, 0.06);
  --glass-border: rgba(255, 255, 255, 0.1);
  --text-primary: #f0f6ff;
  --text-muted: #94a3b8;
  --accent: #2ecc71;
  --accent-glow: rgba(46, 204, 113, 0.25);
  --danger: #e74c3c;
  --radius: 16px;
  --shadow: 0 8px 40px rgba(0, 0, 0, 0.25);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(circle at 20% 0%, rgba(46, 204, 113, 0.08), transparent 40%),
    radial-gradient(circle at 80% 20%, rgba(30, 144, 255, 0.08), transparent 40%);
}

/* Стеклянная шапка */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 25, 41, 0.7);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
}

.header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
  padding: 0 32px;
  max-width: 1400px;
  margin: 0 auto;
}

/* Логотип */
.logo {
  font-size: 24px;
  font-weight: 900;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, #ffffff, #9ca3af);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  transition: transform 0.2s ease;
}

.logo:hover { transform: scale(1.03); }

/* Навигация */
.nav {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav a:not(.btn) {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 15px;
  text-decoration: none;
  transition: color 0.2s, transform 0.2s;
}

.nav a:not(.btn):hover { color: var(--text-primary); animation: pulse 0.3s; }

/* Кнопки */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border: none;
  border-radius: 14px;
  font-family: var(--font);
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.btn--primary {
  background: linear-gradient(135deg, #2ecc71, #27ae60);
  color: #fff;
  box-shadow: 0 4px 20px var(--accent-glow);
}

.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px var(--accent-glow); }
.btn--primary:active { transform: scale(0.95); }

.btn--outline {
  background: transparent;
  border: 1.5px solid var(--glass-border);
  color: var(--text-primary);
}

.btn--outline:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.btn--outline:active { transform: scale(0.95); }

.btn--ghost {
  background: transparent;
  color: var(--text-muted);
}

.btn--ghost:hover { color: var(--text-primary); background: rgba(255,255,255,0.05); }
.btn--ghost:active { transform: scale(0.95); }

.btn--danger {
  background: transparent;
  border: 1.5px solid rgba(231, 76, 60, 0.5);
  color: var(--danger);
}

.btn--danger:hover { background: rgba(231, 76, 60, 0.1); border-color: var(--danger); }

.btn--lg { padding: 16px 36px; font-size: 16px; border-radius: 16px; }
.btn--full { width: 100%; }

/* ===== Hero ===== */
.hero {
  padding: 140px 0 120px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero__inner { max-width: 800px; margin: 0 auto; padding: 0 24px; }

.hero__title {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -2px;
  background: linear-gradient(135deg, #ffffff 0%, #e2e8f0 50%, #2ecc71 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 24px;
  animation: fadeInUp 0.8s ease both;
}

.hero__subtitle {
  font-size: clamp(18px, 2.5vw, 22px);
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto 48px;
  animation: fadeInUp 0.8s 0.15s ease both;
}

.hero__actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s 0.3s ease both;
}

/* ===== Секции ===== */
.section { padding: 100px 0; }

.section-title {
  font-size: clamp(32px, 4vw, 44px);
  font-weight: 800;
  letter-spacing: -1px;
  text-align: center;
  margin-bottom: 64px;
  color: var(--text-primary);
}

/* ===== Премиум-карточки ===== */
.card {
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  font-weight: 500;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: default;
}

.card:hover {
  transform: translateY(-6px) scale(1.02);
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--accent);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4), 0 0 40px var(--accent-glow);
}

/* ===== Features grid ===== */
.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  padding: 0 24px;
  max-width: 1200px;
  margin: 0 auto;
}

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

/* ===== Pricing cards ===== */
.pricing__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

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

.price-card {
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 40px;
  text-align: center;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.price-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  transition: opacity 0.4s;
}

.price-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.4), 0 0 40px var(--accent-glow);
}

.price-card:hover::before { opacity: 1; }

.price-card--featured {
  border: 1.5px solid var(--accent);
  box-shadow: 0 0 60px var(--accent-glow);
}

.price-card--featured::after {
  content: 'Популярный';
  position: absolute;
  top: 16px;
  right: 16px;
  background: var(--accent);
  color: #0a1929;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 20px;
  text-transform: uppercase;
}

.price-card h3 { font-size: 24px; font-weight: 700; margin-bottom: 8px; }

.price {
  font-size: 48px;
  font-weight: 900;
  letter-spacing: -2px;
  background: linear-gradient(135deg, #2ecc71, #27ae60);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin: 16px 0 24px;
}

.price-card ul {
  list-style: none;
  margin-bottom: 32px;
  color: var(--text-muted);
  font-size: 15px;
}

.price-card li {
  padding: 8px 0;
  border-bottom: 1px solid rgba(255,255,255,0.05);
}

.price-card li:last-child { border-bottom: none; }

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--glass-border);
  background: rgba(10, 25, 41, 0.6);
  backdrop-filter: blur(12px);
  padding: 24px 0;
  margin-top: auto;
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 32px;
  color: var(--text-muted);
  font-size: 14px;
}

/* ===== Анимации ===== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* ===== Модальное окно ===== */
.modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(8px);
  z-index: 1000;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal--open {
  display: flex;
  animation: fadeInUp 0.3s ease;
}

.modal__content {
  background: var(--bg-elevated);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 48px;
  width: 100%;
  max-width: 420px;
  position: relative;
  box-shadow: 0 32px 80px rgba(0, 0, 0, 0.5);
}

.modal__close {
  position: absolute;
  top: 16px;
  right: 20px;
  font-size: 28px;
  cursor: pointer;
  color: var(--text-muted);
  background: none;
  border: none;
  transition: color 0.2s, transform 0.2s;
  line-height: 1;
}

.modal__close:hover { color: var(--danger); transform: scale(1.1); }

.modal__content h2 {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 32px;
  text-align: center;
}

.modal__error {
  color: var(--danger);
  margin-top: 16px;
  text-align: center;
  font-size: 14px;
}

/* ===== Формы ===== */
input[type="email"],
input[type="password"],
input[type="number"] {
  width: 100%;
  padding: 14px 16px;
  margin: 8px 0 24px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--glass-border);
  border-radius: 14px;
  color: var(--text-primary);
  font-size: 16px;
  font-family: var(--font);
  transition: all 0.3s;
}

input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 20px var(--accent-glow);
}

/* ===== Дашборд ===== */
.dashboard { padding: 60px 24px; max-width: 1200px; margin: 0 auto; }

.dashboard__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

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

.card--full { grid-column: 1 / -1; }

.balance-large {
  font-size: 56px;
  font-weight: 900;
  letter-spacing: -2px;
  background: linear-gradient(135deg, #2ecc71, #27ae60);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin: 20px 0;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid var(--glass-border);
  color: var(--text-muted);
}

.stat-row b { color: var(--text-primary); }

.history-list {
  list-style: none;
  margin-top: 16px;
}

.history-list li {
  padding: 14px;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-radius: 8px;
  transition: background 0.2s;
}

.history-list li:hover { background: rgba(255,255,255,0.03); }

.history-list li span { color: var(--text-muted); font-size: 13px; }

/* ===== Чат ===== */
.chat-page { display: flex; flex-direction: column; min-height: 100vh; }

.toolbar {
  background: rgba(10, 25, 41, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  padding: 12px 0;
}

.toolbar__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 32px;
  flex-wrap: wrap;
  gap: 12px;
}

.toolbar__title {
  font-weight: 700;
  font-size: 18px;
  background: linear-gradient(135deg, #2ecc71, #27ae60);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.toolbar__actions { display: flex; gap: 12px; flex-wrap: wrap; }

.chat-frame-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 16px 24px;
}

.chat-frame {
  flex: 1;
  width: 100%;
  border: 1px solid var(--glass-border);
  border-radius: 18px;
  background: #f8fafc;
  min-height: 600px;
  box-shadow: var(--shadow);
}

/* ===== Оплата ===== */
.payment { padding: 60px 24px; max-width: 560px; margin: 0 auto; }

.payment__card {
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 40px;
}

.payment__quick {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin: 24px 0;
}

@media (max-width: 768px) {
  .payment__quick { grid-template-columns: repeat(2, 1fr); }
}

.payment__note {
  color: var(--text-muted);
  text-align: center;
  margin-top: 24px;
  font-size: 14px;
}

/* ===== Баланс в шапке ===== */
.balance {
  background: rgba(46, 204, 113, 0.12);
  border: 1px solid rgba(46, 204, 113, 0.3);
  color: var(--accent);
  padding: 6px 16px;
  border-radius: 20px;
  font-weight: 700;
  font-size: 14px;
  backdrop-filter: blur(8px);
}

/* ===== Анимации появления ===== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger задержки */
.reveal:nth-child(1) { transition-delay: 0.05s; }
.reveal:nth-child(2) { transition-delay: 0.1s; }
.reveal:nth-child(3) { transition-delay: 0.15s; }
.reveal:nth-child(4) { transition-delay: 0.2s; }
.reveal:nth-child(5) { transition-delay: 0.25s; }
.reveal:nth-child(6) { transition-delay: 0.3s; }

/* ===== Мобильная версия ===== */
@media (max-width: 768px) {
    .header__inner {
        height: 60px;
        padding: 0 16px;
    }
    .nav {
        gap: 10px;
    }
    .nav__link {
        display: none; /* скрываем "Возможности" и "Тарифы" на мобильных */
    }
    .btn {
        padding: 8px 16px;
        font-size: 14px;
        border-radius: 10px;
    }
    .logo {
        font-size: 20px;
    }
    .hero {
        padding: 80px 0 60px;
    }
    .hero__title {
        font-size: 32px;
    }
    .hero__subtitle {
        font-size: 16px;
        margin-bottom: 32px;
    }
    .hero__actions {
        flex-direction: column;
        align-items: center;
        gap: 12px;
    }
    .features__grid,
    .pricing__grid {
        grid-template-columns: 1fr;
    }
    .section-title {
        font-size: 28px;
        margin-bottom: 32px;
    }
    .footer__inner {
        flex-direction: column;
        gap: 8px;
        text-align: center;
        padding: 16px;
    }
    .dashboard__grid {
        grid-template-columns: 1fr;
    }
    .toolbar__inner {
        flex-direction: column;
        padding: 12px 16px;
    }
    .toolbar__actions {
        flex-wrap: wrap;
        justify-content: center;
    }
    .payment__card {
        padding: 24px;
    }
    .modal__content {
        padding: 24px;
    }
}

/* ===== Мобильная версия ===== */
@media (max-width: 768px) {
    .header__inner {
        height: 60px;
        padding: 0 16px;
    }
    .nav {
        gap: 10px;
    }
    .nav__link {
        display: none;
    }
    .btn {
        padding: 8px 16px;
        font-size: 14px;
        border-radius: 10px;
    }
    .logo {
        font-size: 20px;
    }
    .hero {
        padding: 80px 0 60px;
    }
    .hero__title {
        font-size: 32px;
    }
    .hero__subtitle {
        font-size: 16px;
        margin-bottom: 32px;
    }
    .hero__actions {
        flex-direction: column;
        align-items: center;
        gap: 12px;
    }
    .features__grid,
    .pricing__grid {
        grid-template-columns: 1fr;
    }
    .section-title {
        font-size: 28px;
        margin-bottom: 32px;
    }
    .footer__inner {
        flex-direction: column;
        gap: 8px;
        text-align: center;
        padding: 16px;
    }
    .dashboard__grid {
        grid-template-columns: 1fr;
    }
    .toolbar__inner {
        flex-direction: column;
        padding: 12px 16px;
    }
    .toolbar__actions {
        flex-wrap: wrap;
        justify-content: center;
    }
    .payment__card {
        padding: 24px;
    }
    .modal__content {
        padding: 24px;
    }
}