:root {
    --bg-color: #0D1164;
    --bg-gradient: radial-gradient(circle at top left, #640D5F, #0D1164 60%);
    --surface: rgba(255, 255, 255, 0.05);
    --surface-hover: rgba(255, 255, 255, 0.1);
    --border: rgba(255, 255, 255, 0.15);
    --primary: #EA2264;
    --primary-hover: #d11f5a;
    --primary-glow: rgba(234, 34, 100, 0.4);
    --accent: #F78D60;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --danger: #ef4444;
    --success: #10b981;
    --warning: #f59e0b;
    --glass-blur: blur(12px);
    
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-color);
    background-image: var(--bg-gradient);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Glassmorphism utility */
.glass {
    background: var(--surface);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

.glass-dark {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    padding: 1rem;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: rgba(11, 15, 25, 0.8);
    backdrop-filter: var(--glass-blur);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 2rem 1.5rem;
    z-index: 10;
}

.brand {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.brand i {
    color: var(--primary);
    filter: drop-shadow(0 0 8px var(--primary-glow));
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    flex-grow: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.2rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 500;
    font-family: inherit;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.nav-item:hover {
    background: var(--surface-hover);
    color: var(--text-primary);
}

.nav-item.active {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    box-shadow: 0 4px 15px var(--primary-glow);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--surface);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.user-info {
    display: flex;
    flex-direction: column;
}

.user-info .name {
    font-weight: 600;
    font-size: 0.95rem;
}

.user-info .status {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Main Content */
.main-content {
    flex-grow: 1;
    position: relative;
    overflow-y: auto;
    padding: 2rem 3rem;
}

.view {
    display: none;
    animation: fadeIn 0.4s ease-out forwards;
}

.view.active {
    display: block;
}

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

.view-header {
    margin-bottom: 2.5rem;
}

.view-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.view-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.header-split {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Buttons */
.btn {
    padding: 0.8rem 1.5rem;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    box-shadow: 0 4px 15px rgba(234, 34, 100, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(234, 34, 100, 0.5);
}

.btn-secondary {
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--surface-hover);
}

.btn-icon {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
}

.btn-icon:hover {
    background: var(--surface-hover);
    color: var(--primary);
}

.btn-danger {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
}
.btn-danger:hover {
    background: rgba(239, 68, 68, 0.2);
}

.btn-icon-small {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 0.9rem;
    transition: var(--transition);
}

.btn-danger-text:hover {
    color: var(--danger);
}

.w-100 { width: 100%; }
.mt-4 { margin-top: 1rem; }

/* Dashboard Cards */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    transition: transform 0.3s;
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, rgba(234, 34, 100, 0.2), rgba(247, 141, 96, 0.2));
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
}

.stat-details h3 {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 0.2rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
}

/* Progress Tracker */
.progress-section {
    padding: 2rem;
}
.progress-section h2 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.progress-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.progress-item {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.progress-title {
    font-weight: 600;
    font-size: 1.1rem;
}

.progress-stats {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.progress-bar-bg {
    width: 100%;
    height: 10px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 5px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 5px;
    transition: width 1s ease-out;
}

.topic-progress-list {
    margin-top: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding-left: 1rem;
    border-left: 2px solid var(--border);
}

.topic-progress-item {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
}

/* Grids */
.subjects-grid, .exams-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.subject-card, .exam-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.subject-card:hover, .exam-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
    border-color: rgba(255, 255, 255, 0.2);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.subject-color-indicator {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    display: inline-block;
    margin-right: 0.5rem;
    box-shadow: 0 0 10px currentColor;
}

.topic-list {
    margin-top: 1rem;
    list-style: none;
}

.topic-item {
    padding: 0.5rem;
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-sm);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    display: flex;
    justify-content: space-between;
}

/* Calendar */
.calendar-container {
    padding: 1.5rem;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.calendar-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.calendar-grid-header {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    text-align: center;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border);
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.5rem;
}

.calendar-day {
    aspect-ratio: 1;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    padding: 0.5rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    position: relative;
}

.calendar-day:hover {
    background: var(--surface-hover);
    border-color: var(--border);
}

.calendar-day.today {
    border-color: var(--primary);
    background: rgba(234, 34, 100, 0.15);
}

.calendar-day.other-month {
    opacity: 0.3;
}

.day-number {
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 0.2rem;
}

.day-events {
    display: flex;
    flex-direction: column;
    gap: 2px;
    overflow-y: auto;
    flex-grow: 1;
}
.day-events::-webkit-scrollbar { width: 2px; }
.day-events::-webkit-scrollbar-thumb { background: var(--border); }

.event-dot {
    font-size: 0.7rem;
    padding: 2px 4px;
    border-radius: 4px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.event-exam { background: rgba(245, 158, 11, 0.2); color: var(--warning); border-left: 2px solid var(--warning); }
.event-study { background: rgba(16, 185, 129, 0.2); color: var(--success); border-left: 2px solid var(--success); }

/* Modals */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
    z-index: 100;
}

.modal.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-content {
    width: 90%;
    max-width: 400px;
    padding: 2rem;
    transform: translateY(20px) scale(0.95);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.modal-content.modal-lg {
    max-width: 600px;
}

.modal.active .modal-content {
    transform: translateY(0) scale(1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color 0.3s;
}

.close-btn:hover {
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group input[type="date"],
.form-group select {
    width: 100%;
    padding: 0.8rem 1rem;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(234, 34, 100, 0.2);
}

.form-group input[type="color"] {
    -webkit-appearance: none;
    border: none;
    width: 100%;
    height: 40px;
    border-radius: var(--radius-md);
    cursor: pointer;
    background: none;
}
.form-group input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
.form-group input[type="color"]::-webkit-color-swatch { border: 1px solid var(--border); border-radius: var(--radius-md); }

.topics-selector {
    max-height: 200px;
    overflow-y: auto;
}

.topic-checkbox-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem;
    border-bottom: 1px solid var(--border);
}
.topic-checkbox-item:last-child { border-bottom: none; }
.topic-checkbox-item input[type="checkbox"] {
    accent-color: var(--primary);
    width: 16px;
    height: 16px;
}
.topic-checkbox-item input[type="number"] {
    width: 80px;
    padding: 0.2rem 0.5rem;
    margin-left: auto;
}

.info-box {
    padding: 1rem;
    background: rgba(234, 34, 100, 0.1);
    border-left: 3px solid var(--primary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    display: none;
}

.events-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.event-list-item {
    padding: 1rem;
    background: rgba(0,0,0,0.2);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--primary);
}

/* Empty states */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
    font-style: italic;
}

/* Focus Mode */
#focus-background {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: #000;
    background-size: cover;
    background-position: center;
    z-index: 0;
}
#focus .focus-header {
    position: relative;
    z-index: 1;
}

/* Mobile Header */
.mobile-header {
    display: none;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: rgba(13, 17, 100, 0.8);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 20;
}

.mobile-header .brand {
    margin-bottom: 0;
}

.close-sidebar-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    position: absolute;
    top: 1rem;
    right: 1rem;
    cursor: pointer;
}

/* Media Queries for Mobile Responsiveness */
@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
    }
    
    .mobile-header {
        display: flex;
    }

    .sidebar {
        position: fixed;
        left: -100%;
        top: 0;
        height: 100vh;
        width: 280px;
        transition: left 0.3s ease;
        box-shadow: 5px 0 15px rgba(0,0,0,0.5);
    }

    .sidebar.open {
        left: 0;
    }

    .close-sidebar-btn {
        display: block;
    }

    .main-content {
        padding: 1rem;
    }

    .view-header h1 {
        font-size: 2rem;
    }
    
    .header-split {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .header-split .btn {
        width: 100%;
    }

    .calendar-grid-header div {
        font-size: 0.8rem;
    }
    
    .calendar-day {
        padding: 0.2rem;
    }
    
    .day-number {
        font-size: 0.8rem;
    }

    .event-dot {
        font-size: 0.6rem;
        padding: 1px 2px;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    .modal-content {
        padding: 1.5rem;
    }
}

/* Login Screen */
.login-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: var(--bg-color);
    background-image: var(--bg-gradient);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.5s;
}

.login-screen.active {
    opacity: 1;
    pointer-events: auto;
}

.login-card {
    padding: 3rem;
    width: 90%;
    max-width: 500px;
}

.users-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.user-btn {
    padding: 1.5rem;
    font-size: 1.2rem;
    text-align: center;
}

.user-btn:hover {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    border-color: transparent;
}