/* shared.css — Unified CSS variables, nav, footer, and common utilities for all pages.
   Does NOT own page-specific layouts (backtest panels, settings forms, etc.). */

/* ── CSS VARIABLES (single source of truth) ─────────────────── */
:root {
  --bg: #080a14;
  --surface: #0e1120;
  --surface2: #141830;
  --surface3: #1c2040;
  --accent: #6366f1;
  --accent2: #06b6d4;
  --accent-glow: rgba(99, 102, 241, 0.25);
  --accent2-glow: rgba(6, 182, 212, 0.2);
  --gradient: linear-gradient(135deg, #6366f1, #06b6d4);
  --text: #eef0f6;
  --text-dim: rgba(238, 240, 246, 0.5);
  --text-muted: rgba(238, 240, 246, 0.3);
  --border: rgba(99, 102, 241, 0.12);
  --border-strong: rgba(99, 102, 241, 0.25);
  --high: #00e87a;
  --mid: #ffd166;
  --low: #ff6b6b;
  --risk-bg: rgba(239, 68, 68, 0.08);
  --risk-border: rgba(239, 68, 68, 0.3);
  --risk-text: #fca5a5;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --font-heading: 'Syne', sans-serif;
  --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
}

/* ── RESET ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  min-height: 100vh;
}

/* ── UNIFIED NAV ────────────────────────────────────────────── */
.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 48px;
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(8, 10, 20, 0.92);
}

.site-nav__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
}

.site-nav__name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.site-nav__links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.site-nav__link {
  font-size: 0.82rem;
  color: var(--text-dim);
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: color 0.2s;
  position: relative;
  padding-bottom: 2px;
}

.site-nav__link:hover { color: var(--text); }

.site-nav__link--active {
  color: var(--accent2);
  font-weight: 500;
}

.site-nav__link--active::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient);
  border-radius: 2px;
}

/* Hamburger button — hidden on desktop */
.site-nav__hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-direction: column;
  gap: 5px;
}

.site-nav__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-dim);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

/* Hamburger animation when open */
.site-nav__hamburger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.site-nav__hamburger.open span:nth-child(2) {
  opacity: 0;
}
.site-nav__hamburger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── UNIFIED FOOTER ─────────────────────────────────────────── */
.site-footer {
  padding: 0 48px 40px;
  border-top: 1px solid var(--border);
}

.site-footer__inner {
  max-width: 1200px;
  margin: 0 auto;
}

.site-footer__risk {
  background: var(--risk-bg);
  border: 1px solid var(--risk-border);
  border-radius: var(--radius-md);
  padding: 28px 32px;
  margin: 48px 0 40px;
  text-align: center;
}

.site-footer__risk-icon { font-size: 1.4rem; margin-bottom: 8px; }

.site-footer__risk-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1rem;
  color: var(--risk-text);
  margin-bottom: 8px;
}

.site-footer__risk-text {
  font-size: 0.85rem;
  color: var(--risk-text);
  line-height: 1.75;
  max-width: 720px;
  margin: 0 auto;
}

.site-footer__bottom {
  display: flex;
  align-items: center;
  gap: 24px;
}

.site-footer__brand {
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-footer__brand-name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.95rem;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.site-footer__tagline {
  font-size: 0.8rem;
  color: var(--text-dim);
  flex: 1;
}

.site-footer__copy {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ── COMMON CARD STYLES ──────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: border-color 0.25s, box-shadow 0.25s;
}

.card:hover {
  border-color: var(--border-strong);
  box-shadow: 0 8px 32px var(--accent-glow);
}

/* ── COMMON TOAST STYLES ─────────────────────────────────────── */
.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 14px 20px;
  border-radius: 10px;
  font-size: 0.88rem;
  z-index: 200;
  max-width: 420px;
  transform: translateX(500px);
  transition: transform 0.3s;
}
.toast.show { transform: translateX(0); }
.toast--error { background: var(--low); color: #fff; }
.toast--success { background: var(--high); color: #000; font-weight: 500; }
.toast--warn { background: var(--mid); color: #000; font-weight: 500; }

/* ── LOADING OVERLAY ─────────────────────────────────────────── */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}
.loading-overlay.hidden { display: none; }

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--accent2);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* ── RESPONSIVE ──────────────────────────────────────────────── */
@media (max-width: 768px) {
  .site-nav {
    padding: 14px 20px;
  }

  .site-nav__hamburger {
    display: flex;
  }

  .site-nav__links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(8, 10, 20, 0.97);
    backdrop-filter: blur(16px);
    flex-direction: column;
    padding: 16px 20px 24px;
    gap: 0;
    border-bottom: 1px solid var(--border);
  }

  .site-nav__links.open {
    display: flex;
  }

  .site-nav__link {
    display: block;
    padding: 12px 0;
    font-size: 0.92rem;
    border-bottom: 1px solid rgba(99, 102, 241, 0.06);
    width: 100%;
  }

  .site-nav__link:last-child {
    border-bottom: none;
  }

  .site-nav__link--active::after {
    display: none;
  }

  .site-footer {
    padding-left: 20px;
    padding-right: 20px;
  }

  .site-footer__bottom {
    flex-wrap: wrap;
    gap: 12px;
  }
}

@media (max-width: 480px) {
  .site-nav {
    padding: 12px 16px;
  }
}