/*
 * CSIR NET Chemical Science Study Plan - Styles
 * ============================================
 * Main stylesheet for the study planner website
 * 
 * COLOR SCHEME:
 * - Primary: Indigo/Purple gradient (#6366f1 to #8b5cf6)
 * - Background: Dark slate theme (#0f172a primary, #1e293b secondary)
 * - Accent: Green for success, Red for danger
 * 
 * LAYOUT:
 * - Sidebar: Fixed 240px width navigation
 * - Main content: Fluid layout with responsive grid
 * - Mobile-first responsive design
 */

/* CSS Variables - Easy to customize colors and spacing */
:root {
    /* Color Palette */
    --primary-color: #6366f1;      /* Main indigo */
    --primary-dark: #4f46e5;       /* Darker indigo for hover */
    --primary-light: #818cf8;      /* Lighter indigo for accents */
    --secondary-color: #8b5cf6;    /* Purple for gradients */
    --success-color: #10b981;      /* Green for completed */
    --danger-color: #ef4444;       /* Red for warnings */
    --warning-color: #f59e0b;      /* Amber for alerts */
    
    /* Background Colors */
    --bg-primary: #0f172a;         /* Main dark background */
    --bg-secondary: #1e293b;       /* Sidebar/card background */
    --bg-card: #1e293b;            /* Card background */
    
    /* Text Colors */
    --text-primary: #f8fafc;       /* Main text (white) */
    --text-secondary: #cbd5e1;     /* Secondary text (gray) */
    --border-color: #334155;       /* Border color */
    
    /* Layout Dimensions */
    --sidebar-width: 240px;        /* Sidebar width */
    --transition: all 0.3s ease;   /* Default transition */
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ============================================
   SIDEBAR NAVIGATION STYLES
   Fixed left sidebar with navigation menu
============================================ */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    padding: 1rem 0.75rem;
    overflow-y: auto;
    z-index: 1000;
    transition: var(--transition);
}

.sidebar-header {
    text-align: center;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 1rem;
}

.sidebar-header h1 {
    font-size: 1.5rem;
    color: var(--primary-light);
    margin-bottom: 0.25rem;
}

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

/* Progress Summary */
.progress-summary {
    background: var(--bg-card);
    border-radius: 8px;
    padding: 0.75rem;
    margin-bottom: 1rem;
}

.progress-bar-container {
    margin-bottom: 0.5rem;
}

.progress-bar {
    width: 100%;
    height: 20px;
    background: var(--bg-primary);
    border-radius: 10px;
    overflow: hidden;
    position: relative;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 10px;
    transition: width 0.5s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: bold;
    color: var(--text-primary);
}

.progress-text {
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Navigation Menu */
.nav-menu {
    list-style: none;
}

.nav-item {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 6px;
    margin-bottom: 0.25rem;
    transition: var(--transition);
    position: relative;
}

.nav-item:hover {
    background: var(--bg-card);
    color: var(--primary-light);
}

.nav-item.active {
    background: var(--primary-color);
    color: var(--text-primary);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.nav-item .icon {
    margin-right: 0.75rem;
    font-size: 1.1rem;
}

/* Sidebar Footer */
.sidebar-footer {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.motivation-quote {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-style: italic;
    text-align: center;
    line-height: 1.4;
}

/* ============================================
   MAIN CONTENT AREA
   Container for all section content
============================================ */
.main-content {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
    padding: 1.5rem;
    transition: var(--transition);
}

.content-section {
    display: none;
    animation: fadeIn 0.5s ease;
}

.content-section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-header {
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.section-header h2 {
    font-size: 1.75rem;
    color: var(--text-primary);
}

.current-day {
    font-size: 1.25rem;
    color: var(--primary-light);
    font-weight: bold;
}

/* ============================================
   INFO CARDS (OVERVIEW SECTION)
   Metric cards showing key statistics
============================================ */
.info-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    text-align: center;
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.2);
}

.card h3 {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.big-number {
    font-size: 2rem;
    font-weight: bold;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Exam Info */
.exam-info {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.25rem;
    margin-bottom: 1.5rem;
}

.exam-info h3 {
    margin-bottom: 0.75rem;
    color: var(--primary-light);
}

.exam-info ul {
    list-style: none;
    padding-left: 0;
}

.exam-info li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
}

.exam-info ul ul {
    padding-left: 2rem;
    margin-top: 0.5rem;
}

/* Strategy Section */
.strategy-section {
    margin-top: 1.5rem;
}

.strategy-section h3 {
    margin-bottom: 1rem;
    color: var(--primary-light);
}

.strategy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.strategy-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    transition: var(--transition);
}

.strategy-item:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.strategy-icon {
    font-size: 2rem;
}

.strategy-item h4 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.strategy-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ============================================
   FILTER BUTTONS
   Phase filters for study plan
============================================ */
.filter-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
}

.filter-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-light);
}

.filter-btn.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--text-primary);
}

/* ============================================
   STUDY PLAN GRID
   Day cards displayed in responsive grid
============================================ */
.study-plan-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1rem;
}

.day-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.25rem;
    transition: var(--transition);
    cursor: pointer;
}

.day-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.2);
}

.day-card.completed {
    border-color: var(--success-color);
    background: rgba(16, 185, 129, 0.05);
}

.day-card.in-progress {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.day-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.day-number {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-light);
}

.day-phase {
    background: var(--primary-color);
    color: var(--text-primary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
}

.day-card h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.day-topics {
    margin-bottom: 1rem;
}

.day-topics ul {
    list-style: none;
    padding-left: 0;
}

.day-topics li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    display: flex;
    align-items: flex-start;
}

.day-topics li::before {
    content: "→";
    color: var(--primary-color);
    margin-right: 0.5rem;
    font-weight: bold;
}

.day-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
}

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.875rem;
    transition: var(--transition);
    flex: 1;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-complete {
    background: var(--success-color);
    color: var(--text-primary);
}

.btn-complete:hover {
    background: #059669;
}

.completed .btn-complete {
    display: none;
}

.checkmark {
    color: var(--success-color);
    font-size: 1.25rem;
}

/* ============================================
   TODAY'S FOCUS SECTION
   Detailed view of current day
============================================ */
.today-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
}

.today-focus-card {
    margin-bottom: 1.5rem;
}

.today-focus-card h3 {
    color: var(--primary-light);
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
}

.today-focus-card ul {
    list-style: none;
    padding-left: 0;
}

.today-focus-card li {
    padding: 1rem;
    background: var(--bg-primary);
    border-radius: 8px;
    margin-bottom: 0.5rem;
    border-left: 4px solid var(--primary-color);
}

/* ============================================
   PROGRESS TRACKING
   Progress indicators and stats
============================================ */
.progress-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
}

.stat-card h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.circular-progress {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto;
}

.circular-progress svg {
    transform: rotate(-90deg);
}

.bg-circle {
    fill: none;
    stroke: var(--bg-primary);
    stroke-width: 8;
}

.progress-circle {
    fill: none;
    stroke: url(#gradient);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 283;
    stroke-dashoffset: 283;
    transition: stroke-dashoffset 0.5s ease;
}

.progress-percentage {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 2rem;
    font-weight: bold;
    color: var(--text-primary);
}

.subject-progress {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.subject-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    background: var(--bg-primary);
    border-radius: 8px;
}

.subject-item span {
    color: var(--text-secondary);
}

.subject-bar {
    width: 60%;
    height: 8px;
    background: var(--bg-secondary);
    border-radius: 4px;
    overflow: hidden;
}

.subject-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
    transition: width 0.5s ease;
}

/* Recent Activity */
.recent-activity {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
}

.recent-activity h3 {
    margin-bottom: 0.75rem;
    color: var(--primary-light);
}

.activity-log {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.activity-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--bg-primary);
    border-radius: 6px;
}

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

/* ============================================
   RESOURCES SECTION
   Books and materials grid
============================================ */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
}

.resource-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.25rem;
    transition: var(--transition);
}

.resource-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.resource-card h3 {
    margin-bottom: 0.5rem;
    color: var(--primary-light);
}

.resource-card ul {
    list-style: none;
    padding-left: 0;
}

.resource-card li {
    padding: 0.4rem 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.resource-card li:last-child {
    border-bottom: none;
}

/* ============================================
   TIPS SECTION
   Study tip cards
============================================ */
.tips-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
}

.tip-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.25rem;
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.tip-card:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.tip-card h3 {
    margin-bottom: 0.5rem;
    color: var(--primary-light);
}

.tip-card p {
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 0.9rem;
}

/* ============================================
   MOBILE RESPONSIVE
   Mobile menu toggle button
============================================ */
.mobile-toggle {
    display: none;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1001;
    background: var(--primary-color);
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 8px;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 4px;
    cursor: pointer;
}

.mobile-toggle span {
    width: 24px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* ============================================
   RESPONSIVE BREAKPOINTS
   Mobile and tablet styles
============================================ */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
        padding: 1rem;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .info-cards {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .study-plan-container {
        grid-template-columns: 1fr;
    }
    
    .strategy-grid {
        grid-template-columns: 1fr;
    }
    
    .filter-buttons {
        flex-direction: column;
    }
    
    .filter-btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .info-cards {
        grid-template-columns: 1fr;
    }
    
    .section-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .sidebar {
        width: 100%;
    }
}

/* Scrollbar Styles */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

/* SVG Gradient */
.main-content::before {
    content: '';
    display: block;
    height: 0;
    width: 0;
}

.main-content {
    position: relative;
}

.main-content::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 300px;
    background: radial-gradient(ellipse at top, rgba(99, 102, 241, 0.1), transparent);
    pointer-events: none;
    z-index: -1;
}

/* Accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    text-decoration: none;
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* ============================================
   MOCK TESTS SECTION
   Practice test cards and links
============================================ */
.tests-container {
    margin-top: 1rem;
}

.tests-intro {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.25rem;
    margin-bottom: 1.5rem;
}

.tests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1rem;
}

.test-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.25rem;
    transition: var(--transition);
}

.test-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.2);
    border-color: var(--primary-color);
}

.test-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 0.75rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.test-header h3 {
    color: var(--primary-light);
    flex: 1;
    margin: 0;
}

.test-badge {
    background: var(--primary-color);
    color: var(--text-primary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: bold;
}

.test-info {
    display: flex;
    gap: 1.5rem;
    margin: 0.75rem 0;
    padding: 0.75rem;
    background: var(--bg-primary);
    border-radius: 6px;
}

.test-stat {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.test-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.test-topics {
    margin-top: 0.75rem;
}

.test-topics ul {
    list-style: none;
    padding-left: 0;
    margin-top: 0.5rem;
}

.test-topics li {
    padding: 0.25rem 0;
    color: var(--text-secondary);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
}

.test-topics li::before {
    content: "•";
    color: var(--primary-color);
    margin-right: 0.5rem;
    font-weight: bold;
}

/* Additional Practice */
.additional-practice {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.practice-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1rem;
}

.practice-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.25rem;
    transition: var(--transition);
}

.practice-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.practice-card h4 {
    color: var(--primary-light);
    margin-bottom: 0.5rem;
}

.platform-type {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: bold;
    margin: 0.5rem 0;
}

.platform-type.free {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success-color);
}

.platform-type.paid {
    background: rgba(99, 102, 241, 0.2);
    color: var(--primary-light);
}

.practice-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--primary-light);
    text-decoration: none;
    font-weight: bold;
    transition: var(--transition);
}

.practice-link:hover {
    color: var(--primary-color);
    transform: translateX(5px);
}

/* ============================================
   SETTINGS SECTION
   Configuration and reset options
============================================ */
.settings-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.settings-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
}

.settings-card h3 {
    color: var(--primary-light);
    margin-bottom: 0.75rem;
}

.settings-card p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.settings-card small {
    display: block;
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.5rem;
}

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

.btn-danger:hover {
    background: #dc2626;
}

.quick-actions {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

/* Responsive adjustments for new sections */
@media (max-width: 768px) {
    .tests-grid,
    .practice-grid {
        grid-template-columns: 1fr;
    }
    
    .test-info {
        flex-direction: column;
        gap: 1rem;
    }
    
    .settings-container {
        grid-template-columns: 1fr;
    }
    
    .quick-actions {
        width: 100%;
    }
    
    .quick-actions .btn {
        width: 100%;
    }
}