:root {
  --brand-primary: #2f7a5f;
  --brand-primary-strong: #23644d;
  --brand-accent: #7fc9a5;
  --brand-bg: #f4f8f5;
  --brand-surface: #ffffff;
  --brand-border: #dbe8df;
  --brand-text: #1f2a24;
  --brand-muted: #5f7268;
  --shadow-soft: 0 10px 30px rgba(47, 122, 95, 0.08);
  --danger: #d05f5f;
  --warning: #e6a23c;
  --sign-pos: #2f7a5f;
  --sign-neg: #c45c5c;
  --sign-zero: #8a9a94;
  --radius: 8px;
}

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

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: linear-gradient(180deg, #f7fbf8 0%, var(--brand-bg) 100%);
  color: var(--brand-text);
  min-height: 100vh;
}

.container { max-width: 1100px; margin: 0 auto; padding: 20px; }

header.app-header {
  background: var(--brand-surface);
  border: 1px solid var(--brand-border);
  box-shadow: var(--shadow-soft);
  border-radius: var(--radius);
  padding: 1rem 1.5rem;
  margin-bottom: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

header.app-header h1 {
  font-size: 1.35rem;
  color: var(--brand-primary-strong);
  font-weight: 600;
}

.brand-logos { display: flex; align-items: center; gap: 10px; }
.brand-logos img { height: 22px; width: auto; opacity: 0.95; }
.brand-logos-centered { justify-content: center; gap: 14px; margin-bottom: 0.35rem; }
.brand-logos-centered img { height: 34px; }
.app-header-home {
  flex-direction: column;
  align-items: center;
  text-align: center;
}
.app-header-home .nav-links {
  width: 100%;
  justify-content: center;
}
.brand-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
}
.brand-title {
  font-size: 1.1rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  line-height: 1.35;
}
.brand-subtitle {
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--brand-muted);
  text-transform: uppercase;
  margin-top: 0.1rem;
}

.panel, .card {
  background: var(--brand-surface);
  border: 1px solid var(--brand-border);
  box-shadow: var(--shadow-soft);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  border: 1px solid var(--brand-primary);
  background: var(--brand-primary);
  color: #fff;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
}

.btn:hover { background: var(--brand-primary-strong); transform: translateY(-1px); }
.btn-outline {
  background: #f8fcfa;
  color: var(--brand-text);
  border-color: var(--brand-border);
}
.btn-outline:hover { background: var(--brand-primary); color: #fff; }

.form-control {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--brand-border);
  border-radius: 4px;
  font-size: 1rem;
}
.form-control:focus {
  border-color: var(--brand-accent);
  box-shadow: 0 0 0 3px rgba(127, 201, 165, 0.25);
  outline: none;
}

.links { display: flex; flex-direction: column; gap: 0.6rem; }
.links a {
  display: block;
  padding: 0.85rem 1rem;
  background: #f8fcfa;
  border: 1px solid var(--brand-border);
  border-radius: var(--radius);
  color: var(--brand-text);
  text-decoration: none;
  transition: all 0.2s;
}
.links a:hover {
  background: var(--brand-primary);
  color: #fff;
  border-color: var(--brand-primary);
  transform: translateY(-1px);
}

.subtitle { color: var(--brand-muted); font-size: 0.9rem; }
.error { color: var(--danger); font-size: 0.9rem; margin-top: 0.5rem; }

.feedback-strip {
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  margin-top: 0.75rem;
  font-size: 0.95rem;
}
.feedback-strip.info { background: #f0f7f3; border: 1px solid var(--brand-border); }
.feedback-strip.success { background: #e8f5ee; border: 1px solid var(--brand-accent); color: var(--brand-primary-strong); }
.feedback-strip.warn { background: #fff8e6; border: 1px solid var(--warning); }
.feedback-strip.error { background: #fdeeee; border: 1px solid var(--danger); }

#numberLineSvg { width: 100%; height: 200px; display: block; }
.interval-zone { cursor: pointer; transition: opacity 0.25s; }
.interval-zone:hover { opacity: 0.85; }

.stage-dots { display: flex; gap: 0.5rem; margin-bottom: 1rem; flex-wrap: wrap; }
.stage-dot {
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--brand-border);
  transition: background 0.2s, transform 0.2s;
}
.stage-dot.active { background: var(--brand-primary); transform: scale(1.2); }
.stage-dot.done { background: var(--brand-accent); }

.sign-badge {
  display: inline-block;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
}
.sign-badge.pos { background: rgba(47,122,95,0.15); color: var(--sign-pos); }
.sign-badge.neg { background: rgba(196,92,92,0.15); color: var(--sign-neg); }

.prediction-grid { display: grid; gap: 0.75rem; margin-top: 0.75rem; }
.prediction-row {
  display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap;
  padding: 0.6rem; background: #f8fcfa; border-radius: 6px; border: 1px solid var(--brand-border);
}

.reveal-overlay {
  animation: revealIn 0.5s ease-out;
}
@keyframes revealIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

table { width: 100%; border-collapse: collapse; }
th, td { padding: 0.5rem; text-align: left; border-bottom: 1px solid #e5efe8; }
th { background: #f0f7f3; color: var(--brand-primary-strong); font-weight: 600; }

.lang-switch {
  display: inline-flex;
  border: 1px solid var(--brand-border);
  border-radius: 6px;
  overflow: hidden;
  background: #f7fbf8;
}
.lang-switch.vertical {
  flex-direction: column;
  width: 100%;
}
.lang-switch.vertical .lang-btn {
  width: 100%;
  text-align: center;
  border-bottom: 1px solid var(--brand-border);
  padding: 0.45rem 0.65rem;
}
.lang-switch.vertical .lang-btn:last-child { border-bottom: none; }
.lang-btn {
  padding: 0.35rem 0.65rem;
  border: none;
  background: transparent;
  color: var(--brand-muted);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
}
.lang-btn.active { background: var(--brand-primary); color: #fff; }
.lang-btn:hover:not(.active) { background: #eef6f1; }

.settings-wrap { position: relative; }
.settings-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.45rem 0.75rem;
  border-radius: 4px;
  border: 1px solid var(--brand-border);
  background: #f8fcfa;
  color: var(--brand-text);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
}
.settings-btn:hover { background: var(--brand-primary); color: #fff; border-color: var(--brand-primary); }
.settings-menu {
  display: none;
  position: absolute;
  right: 0;
  top: calc(100% + 6px);
  width: 300px;
  background: var(--brand-surface);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  padding: 0.6rem;
  z-index: 50;
}
.settings-menu.open { display: block; }
.settings-menu .settings-item {
  display: block;
  width: 100%;
  text-align: left;
  padding: 0.55rem 0.65rem;
  border: none;
  background: transparent;
  color: var(--brand-text);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  border-radius: 4px;
}
.settings-menu .settings-item:hover { background: #eef6f1; color: var(--brand-primary-strong); }
.settings-menu .settings-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--brand-muted);
  margin: 0.35rem 0 0.35rem;
}
.settings-divider {
  height: 1px;
  background: var(--brand-border);
  margin: 0.55rem 0;
}
.settings-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.45rem 0.65rem;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--brand-text);
  cursor: pointer;
  border-radius: 4px;
  line-height: 1.3;
}
.settings-toggle:hover { background: #eef6f1; }
.settings-toggle input {
  flex-shrink: 0;
  width: 1rem;
  height: 1rem;
  accent-color: var(--brand-primary);
  cursor: pointer;
}
.pw-cell {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.78rem;
  letter-spacing: 0.02em;
  word-break: break-all;
  background: #f3f7f5;
  padding: 0.15rem 0.35rem;
  border-radius: 3px;
  color: var(--brand-text);
}

.learning-pill {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--brand-primary-strong);
  background: #e8f5ee;
  border: 1px solid var(--brand-accent);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  margin-bottom: 0.5rem;
}

.admin-brand-eyebrow {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--brand-primary);
  margin-bottom: 0.25rem;
}
.admin-brand-title {
  font-size: 1.05rem !important;
  font-weight: 700 !important;
  letter-spacing: 0.03em;
  color: var(--brand-primary-strong) !important;
  line-height: 1.35;
  text-transform: uppercase;
}
.admin-brand-sep {
  color: var(--brand-accent);
  margin: 0 0.15rem;
  font-weight: 500;
}