:root {
    --bg: #0f1117;
    --bg-card: #1a1d27;
    --bg-input: #252830;
    --text: #e4e6eb;
    --text-muted: #8b8f9a;
    --accent: #4f8cff;
    --accent-hover: #6ba0ff;
    --success: #34d399;
    --danger: #f87171;
    --border: #2d3040;
    --radius: 8px;
    --shadow: 0 2px 8px rgba(0,0,0,0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
    min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }

#app { max-width: 1200px; margin: 0 auto; padding: 0 16px; }

/* Nav */
nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 24px;
}
nav .brand { font-size: 1.25rem; font-weight: 700; color: var(--text); }
nav .nav-links { display: flex; gap: 16px; align-items: center; }
nav .nav-links a { color: var(--text-muted); font-size: 0.9rem; }
nav .nav-links a:hover, nav .nav-links a.active { color: var(--accent); }
nav .user-info { color: var(--text-muted); font-size: 0.85rem; }

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: var(--shadow);
}

/* Forms */
input, select, textarea {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    padding: 10px 14px;
    font-size: 0.9rem;
    width: 100%;
    outline: none;
    transition: border-color 0.2s;
}
input:focus, select:focus, textarea:focus { border-color: var(--accent); }

label { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 4px; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: background 0.2s;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { background: #ef4444; }
.btn-sm { padding: 6px 12px; font-size: 0.8rem; }

/* Stats grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin-bottom: 20px;
}
.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
    text-align: center;
}
.stat-card .value { font-size: 1.5rem; font-weight: 700; color: var(--accent); }
.stat-card .label { font-size: 0.8rem; color: var(--text-muted); margin-top: 4px; }

/* Activity list */
.activity-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 16px;
    border-bottom: 1px solid var(--border);
    cursor: pointer;
    transition: background 0.2s;
}
.activity-item:hover { background: var(--bg-input); }
.activity-item:last-child { border-bottom: none; }
.activity-icon { font-size: 1.5rem; width: 40px; text-align: center; }
.activity-info { flex: 1; }
.activity-info .name { font-weight: 500; }
.activity-info .meta { font-size: 0.8rem; color: var(--text-muted); }
.activity-stats { text-align: right; font-size: 0.85rem; color: var(--text-muted); }

/* Sport type colors */
.sport-run { color: #34d399; }
.sport-bike { color: #fbbf24; }
.sport-hike { color: #a78bfa; }
.sport-swim { color: #60a5fa; }
.sport-walk { color: #f472b6; }
.sport-other { color: var(--text-muted); }

/* Upload area */
.upload-zone {
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 48px 24px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s;
}
.upload-zone:hover, .upload-zone.dragover {
    border-color: var(--accent);
    background: rgba(79, 140, 255, 0.05);
}

/* Map */
.map-container { height: 350px; border-radius: var(--radius); overflow: hidden; margin-bottom: 16px; }

/* Chart */
.chart-container { height: 200px; margin-bottom: 16px; }

/* Tabs */
.tabs { display: flex; gap: 4px; margin-bottom: 16px; }
.tab {
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 0.85rem;
    cursor: pointer;
    color: var(--text-muted);
    background: transparent;
    border: 1px solid transparent;
}
.tab:hover { color: var(--text); }
.tab.active { background: var(--bg-card); border-color: var(--border); color: var(--accent); }

/* Login */
.login-container {
    max-width: 360px;
    margin: 80px auto;
}
.login-container h1 { text-align: center; margin-bottom: 24px; }
.form-group { margin-bottom: 16px; }

/* Responsive */
@media (max-width: 768px) {
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .activity-stats { display: none; }
}

/* Toggle */
.toggle {
    position: relative;
    display: inline-block;
    width: 40px;
    height: 22px;
}
.toggle input { opacity: 0; width: 0; height: 0; }
.toggle .slider {
    position: absolute;
    inset: 0;
    background: var(--bg-input);
    border-radius: 22px;
    border: 1px solid var(--border);
    transition: 0.2s;
    cursor: pointer;
}
.toggle .slider:before {
    content: '';
    position: absolute;
    height: 16px;
    width: 16px;
    left: 2px;
    bottom: 2px;
    background: var(--text-muted);
    border-radius: 50%;
    transition: 0.2s;
}
.toggle input:checked + .slider { background: var(--accent); border-color: var(--accent); }
.toggle input:checked + .slider:before { transform: translateX(18px); background: #fff; }

.flex { display: flex; }
.gap-2 { gap: 8px; }
.gap-4 { gap: 16px; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.mt-2 { margin-top: 8px; }
.mt-4 { margin-top: 16px; }
.mb-2 { margin-bottom: 8px; }
.mb-4 { margin-bottom: 16px; }
.text-muted { color: var(--text-muted); }
.text-sm { font-size: 0.85rem; }