:root {
    --bg-dark: #0a0b10;
    --panel-dark: #151921;
    --panel-glass: rgba(21, 25, 33, 0.8);
    --text-primary: #ffffff;
    --text-secondary: #a0a0c0;
    --neon-blue: #00d2ff;
    --neon-green: #39ff14;
    --neon-purple: #9d50bb;
    --neon-orange: #ff9a00;
    --neon-red: #ff3131;
    --accent: #6e00ff;
    --sidebar-width: 260px;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    overflow-x: hidden;
}

h1, h2, h3, .logo-text {
    font-family: 'Outfit', sans-serif;
}

.dark-theme {
    background: radial-gradient(circle at top right, #1a1a2e, #0a0b10);
}

/* Layout */
.app-container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--panel-dark);
    border-right: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    padding: 2rem 1.5rem;
    position: fixed;
    height: 100vh;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
}

.accent { color: var(--neon-blue); }

.nav-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: auto;
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 1rem;
    border-radius: 12px;
    text-align: left;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.nav-btn:hover, .nav-btn.active {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.nav-btn.active {
    border-left: 4px solid var(--neon-blue);
    background: linear-gradient(90deg, rgba(0, 210, 255, 0.1), transparent);
}

.user-stats {
    background: rgba(255, 255, 255, 0.03);
    padding: 1.2rem;
    border-radius: 16px;
    margin-top: 2rem;
}

.xp-bar-container {
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    margin: 0.8rem 0;
    overflow: hidden;
}

.xp-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--neon-blue), var(--accent));
    transition: width 0.5s ease;
}

.rank-badge {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--neon-blue);
}

.sync-actions {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.text-link {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.7rem;
    cursor: pointer;
    transition: var(--transition);
    padding: 2px 4px;
}

.text-link:hover {
    color: var(--neon-blue);
    text-decoration: underline;
}

.streak-panel {
    margin-top: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: linear-gradient(135deg, rgba(255, 154, 0, 0.1), transparent);
    border-radius: 16px;
    border: 1px solid rgba(255, 154, 0, 0.1);
}

.streak-icon { font-size: 1.5rem; }

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 2rem 3rem;
}

.top-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    position: sticky;
    top: 0;
    background: var(--bg-dark);
    padding: 1rem 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
}

.mini-stat-card {
    background: var(--panel-glass);
    backdrop-filter: blur(10px);
    padding: 0.8rem 1.5rem;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.stat-title {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.stat-count {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--neon-blue);
}

/* Day Navigation */
.day-navigation {
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.day-navigation h2 {
    font-size: 2rem;
}

.icon-btn {
    background: var(--panel-glass);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.icon-btn:hover {
    background: var(--accent);
}

/* Tasks Grid */
.tasks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.task-card {
    background: var(--panel-glass);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.task-card:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 210, 255, 0.3);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.task-card.completed {
    border-color: var(--neon-green);
    background: linear-gradient(135deg, rgba(57, 255, 20, 0.05), transparent);
}

.category-tag {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 0.3rem 0.6rem;
    border-radius: 6px;
    margin-bottom: 1rem;
    display: inline-block;
}

.tag-dsa { background: rgba(0, 210, 255, 0.1); color: var(--neon-blue); }
.tag-core { background: rgba(157, 80, 187, 0.1); color: var(--neon-purple); }
.tag-ai { background: rgba(255, 154, 0, 0.1); color: var(--neon-orange); }
.tag-aptitude { background: rgba(57, 255, 20, 0.1); color: var(--neon-green); }
.tag-projects { background: rgba(255, 49, 49, 0.1); color: var(--neon-red); }

.task-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: block;
    background: rgba(255, 255, 255, 0.03);
    border: 1px dashed rgba(255, 255, 255, 0.1);
    color: white;
    width: 100%;
    padding: 0.4rem;
    border-radius: 8px;
    transition: var(--transition);
    cursor: text;
}

.task-title:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--neon-blue);
}

.task-title:focus {
    border-color: var(--neon-blue);
    border-style: solid;
    outline: none;
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 10px rgba(0, 210, 255, 0.2);
}

.task-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.complete-btn {
    background: transparent;
    border: 1px solid var(--neon-blue);
    color: var(--neon-blue);
    padding: 0.5rem 1.2rem;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.complete-btn:hover {
    background: var(--neon-blue);
    color: var(--bg-dark);
}

.task-card.completed .complete-btn {
    background: var(--neon-green);
    border-color: var(--neon-green);
    color: var(--bg-dark);
}

.edit-notes {
    background: rgba(255,255,255,0.05);
    border: none;
    color: white;
    width: 100%;
    padding: 0.5rem;
    border-radius: 8px;
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Progress Ring */
.completion-ring-container {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.ring-text {
    position: absolute;
    font-size: 1.2rem;
    font-weight: 700;
}

.progress-ring__circle {
    transition: stroke-dashoffset 0.35s;
    transform: rotate(-90deg);
    transform-origin: 50% 50%;
    stroke-dasharray: 326.72;
    stroke-dashoffset: 326.72;
}

/* Dashboard */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.dash-card {
    padding: 2rem;
    min-height: 300px;
}

.dash-card.wide {
    grid-column: span 2;
}

.glass-panel {
    background: var(--panel-glass);
    backdrop-filter: blur(10px);
    border-radius: 24px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

/* Heatmap */
.heatmap-grid {
    display: grid;
    grid-template-columns: repeat(20, 1fr);
    gap: 8px;
    margin-top: 1.5rem;
}

.heatmap-cell {
    width: 15px;
    height: 15px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.05);
}

.heatmap-cell.level-1 { background: #0e4429; }
.heatmap-cell.level-2 { background: #006d32; }
.heatmap-cell.level-3 { background: #26a641; }
.heatmap-cell.level-4 { background: #39d353; }

/* Views Toggle */
.view-container {
    display: none;
}

.view-container.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar { width: 80px; padding: 2rem 0.5rem; }
    .logo-text, .nav-btn span:not(.icon), .user-stats, .streak-panel { display: none; }
    .main-content { margin-left: 80px; }
    .dashboard-grid { grid-template-columns: 1fr; }
    .dash-card.wide { grid-column: auto; }
}