:root {
    --bg: #f8f9fa; --sidebar: #ffffff; --surface: #ffffff;
    --text: #2d3748; --text-muted: #a0aec0;
    --primary: #4c6ef5; --primary-light: #edf2ff;
    --border: #e2e8f0; --success: #38d9a9;
    --radius: 12px;
}
[data-theme="dark"] {
    --bg: #101113; --sidebar: #141517; --surface: #1A1B1E;
    --text: #c1c2c5; --text-muted: #5c5f66;
    --primary: #5c7cfa; --primary-light: #1c1e26;
    --border: #2C2E33;
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Inter', system-ui, sans-serif; }
body { background: var(--bg); color: var(--text); height: 100vh; overflow: hidden; }

/* Layout Grid */
.app-wrapper { display: flex; height: 100%; }
.hidden { display: none !important; }

/* Sidebar */
.sidebar { width: 240px; background: var(--sidebar); border-right: 1px solid var(--border); display: flex; flex-direction: column; padding: 1.5rem 1rem; flex-shrink: 0; transition: transform 0.3s; }
.brand { font-size: 1.2rem; font-weight: 800; color: var(--primary); margin-bottom: 2rem; display: flex; align-items: center; gap: 10px; }
.side-nav { flex: 1; display: flex; flex-direction: column; gap: 5px; overflow-y: auto; }
.nav-item { display: flex; align-items: center; gap: 12px; padding: 10px 12px; color: var(--text-muted); text-decoration: none; border-radius: 8px; cursor: pointer; border: none; background: none; width: 100%; text-align: left; font-size: 0.95rem; }
.nav-item:hover { background: var(--bg); color: var(--text); }
.nav-item.active { background: var(--primary-light); color: var(--primary); font-weight: 600; }
.side-footer { margin-top: auto; border-top: 1px solid var(--border); padding-top: 1rem; display: flex; flex-direction: column; gap: 10px; }
.btn-quick { background: var(--primary); color: white; border: none; padding: 10px; border-radius: 8px; cursor: pointer; font-weight: 600; display: flex; align-items: center; justify-content: center; gap: 8px; }

/* Main Content */
.main-content { flex: 1; display: flex; flex-direction: column; overflow: hidden; position: relative; }
.top-bar { padding: 1.5rem 2rem; display: flex; justify-content: space-between; align-items: center; background: var(--bg); }
.top-bar h1 { font-size: 1.5rem; }
.icon-btn { background: var(--surface); border: 1px solid var(--border); width: 36px; height: 36px; border-radius: 8px; color: var(--text); cursor: pointer; display: grid; place-items: center; }

#contentArea { flex: 1; overflow-y: auto; padding: 0 2rem 2rem 2rem; }
.view { display: none; animation: fadeIn 0.2s; }
.view.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }

/* --- HABIT MATRIX TABLE --- */
.calendar-controls { display: flex; align-items: center; gap: 15px; margin-bottom: 1rem; background: var(--surface); padding: 8px; border-radius: 8px; width: fit-content; border: 1px solid var(--border); }

.habit-table { background: var(--surface); border-radius: var(--radius); border: 1px solid var(--border); overflow: hidden; margin-bottom: 2rem; }
.ht-header { display: flex; background: var(--bg); padding: 12px; border-bottom: 1px solid var(--border); font-size: 0.8rem; font-weight: 600; color: var(--text-muted); }
.ht-col-name { flex: 1; }
.ht-days { display: grid; grid-template-columns: repeat(7, 1fr); gap: 5px; width: 240px; text-align: center; }

.ht-row { display: flex; align-items: center; padding: 12px; border-bottom: 1px solid var(--border); }
.ht-row:last-child { border-bottom: none; }
.ht-check-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 5px; width: 240px; }
.check-cell { display: flex; justify-content: center; }

/* Custom Checkbox */
.cb-matrix { appearance: none; width: 24px; height: 24px; border: 2px solid var(--border); border-radius: 6px; cursor: pointer; transition: 0.2s; }
.cb-matrix:checked { background: var(--primary); border-color: var(--primary); }
.cb-matrix.today { border-color: var(--primary); }

/* --- DASHBOARD --- */
.stats-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 20px; }
.stat-box { background: var(--surface); padding: 20px; border-radius: var(--radius); border: 1px solid var(--border); display: flex; flex-direction: column; }
.stat-box .lbl { font-size: 0.8rem; color: var(--text-muted); }
.stat-box .val { font-size: 2rem; font-weight: 800; color: var(--primary); }
/* .chart-box { background: var(--surface); padding: 20px; border-radius: var(--radius); border: 1px solid var(--border); height: 300px; margin-bottom: 20px; } */
.chart-box { 
    background: var(--surface); 
    padding: 20px; 
    border-radius: var(--radius); 
    border: 1px solid var(--border); 
    height: 350px; /* <--- Important for chart visibility */
    margin-bottom: 20px; 
    position: relative;
}

/* --- SETTINGS --- */
.settings-group { background: var(--surface); padding: 20px; border-radius: var(--radius); border: 1px solid var(--border); margin-bottom: 20px; }
.full-select { width: 100%; padding: 10px; border: 1px solid var(--border); border-radius: 8px; margin: 10px 0; background: var(--bg); color: var(--text); }
.items-list div { display: flex; justify-content: space-between; padding: 10px; border-bottom: 1px solid var(--border); align-items: center; }
.del-btn { color: var(--danger, #fa5252); background: none; border: none; cursor: pointer; }

/* Mobile */
@media (max-width: 768px) {
    .app-wrapper { flex-direction: column; }
    .sidebar { position: absolute; z-index: 100; height: 100%; transform: translateX(-100%); box-shadow: 2px 0 10px rgba(0,0,0,0.2); }
    .sidebar.open { transform: translateX(0); }
    .main-content { padding: 0; }
    .top-bar { padding: 1rem; }
    #contentArea { padding: 1rem; }
    .mobile-only { display: block; }
    .ht-days, .ht-check-grid { width: 200px; } /* Shrink calendar on mobile */
}
.mobile-only { display: none; }