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

:root {
  --bg:       #f8f8f6;
  --surface:  #ffffff;
  --border:   #e4e4e0;
  --text:     #111110;
  --muted:    #888884;
  --accent:   #146e3c;
  --accent-h: #0d4d2a;
}

html, body {
  height: 100%;
  background: var(--bg);
  font-family: 'Courier New', Courier, monospace;
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}

/* ── symbolsCol ── */
#symbolsCol {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
#symbolsCol canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* ── layout ── */
.page-wrapper {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* ── header ── */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 40px;
  border-bottom: 1px solid var(--border);
  background: rgba(248, 248, 246, 0.88);
  backdrop-filter: blur(10px);
}

.logo {
  display: flex;
  align-items: baseline;
  gap: 6px;
  text-decoration: none;
  color: var(--text);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}
.logo .xi  { font-size: 1.1rem; color: var(--accent); }
.logo .sep { color: var(--muted); font-weight: 400; }

nav { display: flex; gap: 8px; align-items: center; }

.btn {
  padding: 7px 18px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  cursor: pointer;
  text-decoration: none;
  transition: border-color 0.15s, color 0.15s;
  border-radius: 2px;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }

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

/* ── main ── */
main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 24px;
}

/* ── center card ── */
#centerCard {
  width: min(680px, 100%);
  background: transparent;
  border: none;
  padding: 56px 48px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.placeholder-hint {
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
  letter-spacing: 0.08em;
  border: 1px dashed var(--border);
  border-radius: 2px;
  padding: 72px 20px;
}

/* ── auth form ── */
.auth-header {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 8px;
}
.auth-title {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--text);
}
.auth-sub {
  font-size: 0.8rem;
  color: var(--muted);
  letter-spacing: 0.06em;
}

.auth-fields {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.field-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.field-group label {
  font-size: 0.75rem;
  letter-spacing: 0.07em;
  color: var(--muted);
  text-transform: uppercase;
}
.field-group .optional {
  font-size: 0.7rem;
  color: var(--border);
}
.field-group input {
  padding: 9px 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-size: 0.88rem;
  border-radius: 2px;
  outline: none;
  transition: border-color 0.15s;
}
.field-group input:focus {
  border-color: var(--accent);
}

.auth-status {
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  min-height: 1.2em;
}
.auth-status.error   { color: #c0392b; }
.auth-status.success { color: #27ae60; }

.auth-submit {
  width: 100%;
  padding: 10px;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-align: center;
  border-radius: 2px;
  cursor: pointer;
}

.auth-switch {
  text-align: center;
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 0.04em;
}
.auth-switch a {
  color: var(--accent);
  text-decoration: none;
}
.auth-switch a:hover {
  text-decoration: underline;
}