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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f8f9fa;
}

/* ── Nav ── */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: #2d6a4f;
    color: white;
}
nav a { color: white; text-decoration: none; }
.logo { font-size: 1.5rem; font-weight: bold; }
.nav-links { display: flex; gap: 1.5rem; align-items: center; }

/* ── Layout ── */
main { max-width: 960px; margin: 2rem auto; padding: 0 1rem; }

/* ── Buttons ── */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
}
.btn-primary { background: #2d6a4f; color: white; }
.btn-primary:hover { background: #1b4332; }
.btn-secondary { background: white; color: #2d6a4f; border: 2px solid #2d6a4f; }
.btn-small { background: none; border: 1px solid #aaa; padding: 0.3rem 0.6rem; font-size: 0.8rem; border-radius: 4px; cursor: pointer; margin-top: 0.3rem; }

/* ── Hero ── */
.hero { text-align: center; padding: 4rem 1rem 2rem; }
.hero h1 { font-size: 2.5rem; color: #2d6a4f; margin-bottom: 1rem; }
.hero p { font-size: 1.2rem; color: #666; margin-bottom: 2rem; }
.hero-stats { margin-bottom: 2rem; }
.hero-actions { display: flex; gap: 1rem; justify-content: center; }

/* ── Features ── */
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1.5rem; margin-top: 3rem; }
.feature { background: white; padding: 1.5rem; border-radius: 8px; text-align: center; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.feature-icon { font-size: 2rem; display: block; margin-bottom: 0.5rem; }
.feature h3 { color: #2d6a4f; margin-bottom: 0.5rem; }

/* ── Stats Grid ── */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 1rem; margin-bottom: 2rem; }
.stat-card { background: white; padding: 1.5rem; border-radius: 8px; text-align: center; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.stat-number { display: block; font-size: 2rem; font-weight: bold; color: #2d6a4f; }
.stat-label { display: block; font-size: 0.85rem; color: #666; margin-top: 0.3rem; }
.streak-card { background: #fff8e1; }

/* ── Walk Cards ── */
.walks-list { display: flex; flex-direction: column; gap: 0.75rem; }
.walk-card { background: white; padding: 1rem 1.5rem; border-radius: 8px; display: flex; justify-content: space-between; align-items: center; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.walk-info strong { color: #2d6a4f; font-size: 1.1rem; margin-right: 0.5rem; }
.walk-meta { display: flex; gap: 1rem; font-size: 0.85rem; color: #666; }
.empty { color: #999; text-align: center; padding: 2rem; }

/* ── Auth Pages ── */
.auth-page { max-width: 400px; margin: 3rem auto; }
.auth-page h1 { color: #2d6a4f; margin-bottom: 1.5rem; }
.auth-page form { display: flex; flex-direction: column; gap: 1rem; }
.auth-page input { padding: 0.75rem; border: 1px solid #ddd; border-radius: 6px; font-size: 1rem; }
.auth-page p { margin-top: 1rem; text-align: center; }
.auth-page a { color: #2d6a4f; }
.error { color: #d32f2f; margin-top: 0.5rem; }

/* ── Compare Page ── */
.compare-page { max-width: 700px; margin: 0 auto; }
.compare-page h1 { color: #2d6a4f; margin-bottom: 0.5rem; }
.form-row { display: flex; gap: 1rem; margin: 1.5rem 0; }
.form-group { flex: 1; display: flex; flex-direction: column; gap: 0.3rem; }
.form-group label { font-weight: 600; font-size: 0.9rem; }
.form-group input { padding: 0.75rem; border: 1px solid #ddd; border-radius: 6px; font-size: 1rem; }
.compare-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; margin: 1.5rem 0; }
.compare-card { padding: 2rem; border-radius: 8px; text-align: center; }
.walk-side { background: #e8f5e9; }
.drive-side { background: #fce4ec; }
.compare-card h3 { font-size: 1.3rem; margin-bottom: 0.5rem; }
.compare-value { font-size: 2.5rem; font-weight: bold; }
.compare-label { color: #666; margin-bottom: 1rem; }
.compare-detail { font-size: 0.95rem; margin-top: 0.3rem; }
.nudge { background: #fff8e1; padding: 1.5rem; border-radius: 8px; text-align: center; font-size: 1.1rem; margin-top: 1rem; }
.nudge strong { color: #2d6a4f; }

/* ── Achievements ── */
.achievements-page h1 { color: #2d6a4f; margin-bottom: 1.5rem; }
.badges-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 1rem; }
.badge-card { background: white; padding: 1.5rem; border-radius: 8px; text-align: center; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.badge-card.locked { opacity: 0.5; }
.badge-icon { font-size: 2rem; margin-bottom: 0.5rem; }
.badge-name { font-weight: bold; color: #2d6a4f; }
.badge-desc { font-size: 0.8rem; color: #666; margin-top: 0.3rem; }
.badge-date { font-size: 0.75rem; color: #999; margin-top: 0.5rem; }

/* ── Responsive ── */
@media (max-width: 600px) {
    .form-row { flex-direction: column; }
    .compare-grid { grid-template-columns: 1fr; }
    .hero-actions { flex-direction: column; align-items: center; }
    nav { flex-direction: column; gap: 0.5rem; }
}