:root{--bg:#0d1117;--surface:#161b22;--surface2:#21262d;--border:#30363d;--text:#e6edf3;--text2:#8b949e;--accent:#58a6ff;--accent2:#1f6feb;--green:#3fb950;--yellow:#d29922;--red:#f85149;--purple:#bc8cff;--orange:#f0883e}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;background:var(--bg);color:var(--text);min-height:100vh}

/* ===== LAYOUT ===== */
body.has-sidebar{display:flex}
.sidebar{width:300px;background:var(--surface);border-right:1px solid var(--border);overflow-y:auto;position:fixed;top:0;left:0;bottom:0;z-index:100;transition:transform .3s}
.sidebar h1{padding:20px;font-size:18px;border-bottom:1px solid var(--border);display:flex;align-items:center;gap:8px}
.sidebar h1 span{font-size:24px}
.progress-bar{margin:12px 16px;background:var(--surface2);border-radius:8px;height:8px;overflow:hidden}
.progress-fill{height:100%;background:linear-gradient(90deg,var(--green),var(--accent));border-radius:8px;transition:width .3s}
.progress-text{padding:0 16px 12px;font-size:12px;color:var(--text2)}
.phase-label{padding:12px 16px 6px;font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:1px;color:var(--text2)}
.nav-item{display:flex;align-items:center;padding:8px 16px;cursor:pointer;border-left:3px solid transparent;transition:all .15s;font-size:13px;gap:8px;text-decoration:none;color:var(--text)}
.nav-item:hover{background:var(--surface2)}
.nav-item.active{background:var(--surface2);border-left-color:var(--accent);color:var(--accent)}
.nav-item .day-num{font-weight:700;min-width:20px}
.nav-item .nav-title{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.nav-item .day-pct{font-size:11px;color:var(--text2);min-width:32px;text-align:right}
.nav-item .day-pct.complete{color:var(--green)}
.nav-mini-bar{height:3px;background:var(--surface2);border-radius:2px;margin:0 16px 2px 46px;overflow:hidden}
.nav-mini-fill{height:100%;border-radius:2px;transition:width .3s}
.main{margin-left:300px;flex:1;max-width:960px;padding:32px 40px 80px}
.hamburger{display:none;position:fixed;top:12px;left:12px;z-index:200;background:var(--surface2);border:1px solid var(--border);color:var(--text);font-size:22px;padding:6px 10px;border-radius:8px;cursor:pointer}
.overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:99}

/* ===== TOP NAV (for standalone pages) ===== */
.top-nav{background:var(--surface);border-bottom:1px solid var(--border);padding:0 24px;display:flex;align-items:center;gap:0;position:sticky;top:0;z-index:100}
.top-nav .brand{font-weight:700;font-size:16px;padding:14px 16px 14px 0;border-right:1px solid var(--border);margin-right:8px;white-space:nowrap;display:flex;align-items:center;gap:8px}
.top-nav a{color:var(--text2);text-decoration:none;padding:14px 16px;font-size:13px;font-weight:500;border-bottom:2px solid transparent;transition:all .15s;white-space:nowrap}
.top-nav a:hover{color:var(--text);background:var(--surface2)}
.top-nav a.active{color:var(--accent);border-bottom-color:var(--accent)}
.page-main{max-width:1100px;margin:0 auto;padding:32px 40px 80px}

/* ===== CONTENT ===== */
.day-header{margin-bottom:24px}
.day-header h2{font-size:28px;margin-bottom:4px}
.day-header .meta{color:var(--text2);font-size:14px;display:flex;gap:16px;flex-wrap:wrap;align-items:center}
.day-header .meta span{display:flex;align-items:center;gap:4px}
.badge{display:inline-block;padding:2px 8px;border-radius:12px;font-size:11px;font-weight:600}
.badge.easy{background:#1a3a2a;color:var(--green)}.badge.medium{background:#3a2a0a;color:var(--yellow)}.badge.hard{background:#3a1a1a;color:var(--red)}.badge.mixed{background:#2a1a3a;color:var(--purple)}
section{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:24px;margin-bottom:20px}
section h3{font-size:18px;margin-bottom:16px;display:flex;align-items:center;gap:8px;color:var(--accent)}
section h4{font-size:15px;margin:16px 0 8px;color:var(--purple)}
section h5{font-size:13px;margin:12px 0 6px;color:var(--orange)}
section p,section li{line-height:1.7;color:var(--text);font-size:14px}
section ul,section ol{padding-left:20px}
section li{margin-bottom:4px}
pre{background:var(--bg);border:1px solid var(--border);border-radius:8px;padding:16px;overflow-x:auto;margin:12px 0;font-size:13px;line-height:1.5}
code{font-family:'Fira Code',Consolas,monospace;font-size:13px}
p code{background:var(--surface2);padding:2px 6px;border-radius:4px}
table{width:100%;border-collapse:collapse;margin:12px 0;font-size:13px}
th,td{border:1px solid var(--border);padding:8px 12px;text-align:left}
th{background:var(--surface2);font-weight:600}
tr:hover{background:rgba(88,166,255,.05)}

/* ===== TASKS / CHECKBOXES ===== */
.task{display:flex;align-items:flex-start;gap:10px;padding:8px 12px;border-radius:8px;margin:4px 0;transition:background .15s}
.task:hover{background:var(--surface2)}
.task input[type=checkbox]{-webkit-appearance:none;-moz-appearance:none;appearance:none;width:18px;height:18px;border:2px solid var(--border);border-radius:4px;cursor:pointer;margin-top:2px;flex-shrink:0;position:relative;background:transparent;transition:all .15s}
.task input[type=checkbox]:checked{background:var(--green);border-color:var(--green)}
.task input[type=checkbox]:checked::after{content:'';position:absolute;left:5px;top:1px;width:5px;height:10px;border:solid var(--bg);border-width:0 2px 2px 0;transform:rotate(45deg)}
.task input[type=checkbox]:hover{border-color:var(--accent)}
.task label{cursor:pointer;font-size:14px;line-height:1.5}
.task.checked label{text-decoration:line-through;color:var(--text2)}
.task a{color:var(--accent);text-decoration:none}
.task a:hover{text-decoration:underline}
.tip-box{background:rgba(88,166,255,.08);border:1px solid rgba(88,166,255,.2);border-radius:8px;padding:16px;margin:12px 0}
.tip-box h4{color:var(--accent);margin:0 0 8px}

/* ===== BUTTONS ===== */
.btn{padding:8px 16px;border-radius:8px;border:1px solid var(--border);cursor:pointer;font-size:13px;transition:all .15s;display:inline-flex;align-items:center;gap:6px}
.btn-danger{background:rgba(248,81,73,.1);color:var(--red);border-color:rgba(248,81,73,.3)}
.btn-danger:hover{background:rgba(248,81,73,.2)}
.btn-primary{background:var(--accent2);color:white;border:none}
.btn-primary:hover{background:var(--accent)}
.btn-ghost{background:transparent;color:var(--text2);border-color:var(--border)}
.btn-ghost:hover{color:var(--text);background:var(--surface2)}
.day-progress-bar{height:6px;background:var(--surface2);border-radius:4px;overflow:hidden;margin:8px 0}
.day-progress-fill{height:100%;border-radius:4px;transition:width .3s}

/* ===== OVERVIEW CARDS ===== */
.overview-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:12px;margin:16px 0}
.overview-card{background:var(--surface2);border:1px solid var(--border);border-radius:10px;padding:16px;cursor:pointer;transition:all .15s}
.overview-card:hover{border-color:var(--accent);transform:translateY(-2px)}
.overview-card .card-day{font-size:12px;color:var(--text2);margin-bottom:4px}
.overview-card .card-title{font-size:15px;font-weight:600;margin-bottom:8px}
.overview-card .card-progress{font-size:12px;color:var(--text2)}
.overview-card .card-bar{height:4px;background:var(--bg);border-radius:4px;margin-top:6px;overflow:hidden}
.overview-card .card-bar-fill{height:100%;border-radius:4px}

/* ===== GRAPH COMMON ===== */
.graph-container{position:relative;background:var(--bg);border:1px solid var(--border);border-radius:12px;overflow:hidden;margin:16px 0}
.graph-container svg{display:block;width:100%;cursor:grab}
.graph-container svg:active{cursor:grabbing}
.graph-controls{position:absolute;top:12px;right:12px;display:flex;gap:6px;z-index:10}
.graph-controls button{width:32px;height:32px;border-radius:8px;border:1px solid var(--border);background:var(--surface);color:var(--text);cursor:pointer;font-size:16px;display:flex;align-items:center;justify-content:center;transition:all .15s}
.graph-controls button:hover{background:var(--surface2);border-color:var(--accent)}
.graph-legend{display:flex;gap:16px;padding:12px 16px;background:var(--surface);border-top:1px solid var(--border);font-size:12px;color:var(--text2);flex-wrap:wrap}
.graph-legend span{display:flex;align-items:center;gap:6px}
.graph-legend .dot{width:10px;height:10px;border-radius:50%}

/* ===== COMPLEXITY TABLE ===== */
.complexity-table{overflow-x:auto}
.complexity-table table{min-width:900px}
.complexity-table th{cursor:pointer;user-select:none;position:relative}
.complexity-table th:hover{background:var(--border)}
.complexity-table th .sort-arrow{margin-left:4px;font-size:10px}
.filter-bar{display:flex;gap:8px;margin-bottom:16px;flex-wrap:wrap}
.filter-btn{padding:4px 12px;border-radius:16px;font-size:12px;border:1px solid var(--border);background:transparent;color:var(--text2);cursor:pointer;transition:all .15s}
.filter-btn:hover,.filter-btn.active{background:var(--accent2);color:white;border-color:var(--accent2)}

/* ===== LEETCODE PAGE ===== */
.lc-filters{display:flex;gap:8px;margin-bottom:20px;flex-wrap:wrap;align-items:center}
.lc-filters input[type=text]{background:var(--surface2);border:1px solid var(--border);border-radius:8px;padding:6px 12px;color:var(--text);font-size:13px;flex:1;min-width:200px}
.lc-filters input[type=text]:focus{outline:none;border-color:var(--accent)}
.lc-stats{display:flex;gap:24px;margin-bottom:20px;flex-wrap:wrap}
.lc-stat{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:16px 20px;text-align:center;flex:1;min-width:120px}
.lc-stat .lc-stat-num{font-size:28px;font-weight:700}
.lc-stat .lc-stat-label{font-size:12px;color:var(--text2);margin-top:4px}
.lc-group{margin-bottom:24px}
.lc-group h4{font-size:15px;color:var(--purple);margin-bottom:12px;padding-bottom:8px;border-bottom:1px solid var(--border)}
.lc-problem{display:flex;align-items:center;gap:10px;padding:10px 14px;border-radius:8px;margin:2px 0;transition:background .15s}
.lc-problem:hover{background:var(--surface2)}
.lc-problem input[type=checkbox]{-webkit-appearance:none;-moz-appearance:none;appearance:none;width:18px;height:18px;border:2px solid var(--border);border-radius:4px;cursor:pointer;flex-shrink:0;position:relative;background:transparent;transition:all .15s}
.lc-problem input[type=checkbox]:checked{background:var(--green);border-color:var(--green)}
.lc-problem input[type=checkbox]:checked::after{content:'';position:absolute;left:5px;top:1px;width:5px;height:10px;border:solid var(--bg);border-width:0 2px 2px 0;transform:rotate(45deg)}
.lc-problem input[type=checkbox]:hover{border-color:var(--accent)}
.lc-problem.checked .lc-name{text-decoration:line-through;color:var(--text2)}
.lc-name{flex:1;font-size:14px}
.lc-name a{color:var(--accent);text-decoration:none}
.lc-name a:hover{text-decoration:underline}
.lc-day{font-size:11px;color:var(--text2);background:var(--surface2);padding:2px 8px;border-radius:10px;white-space:nowrap}
.lc-hint{font-size:12px;color:var(--text2);font-style:italic;margin-left:28px;padding:2px 0 6px}

/* ===== RESPONSIVE ===== */
@media(max-width:768px){
.sidebar{transform:translateX(-100%)}.sidebar.open{transform:translateX(0)}.overlay.open{display:block}
.main{margin-left:0;padding:20px 16px 80px}.hamburger{display:block}.day-header h2{font-size:22px}
.overview-grid{grid-template-columns:1fr}
.page-main{padding:20px 16px 80px}
.top-nav{overflow-x:auto;gap:0}
.top-nav a{padding:12px 10px;font-size:12px}
.top-nav .brand{font-size:14px;padding:12px 10px 12px 0}
.lc-stats{gap:8px}.lc-stat{padding:12px;min-width:80px}.lc-stat .lc-stat-num{font-size:22px}
}