/**
 * ============================================
 * ADVANCED FEATURES STYLES
 * ============================================
 * Styles for:
 * 1. Streak System
 * 2. Topic Mastery
 * 3. Goal Tracker
 * 4. Daily Challenge
 * 5. Calendar View
 */

/* ============================================
   1. STREAK SYSTEM 🔥
   ============================================ */

.streak-widget {
    background: linear-gradient(135deg, #ff6b6b 0%, #ff8e53 100%);
    border-radius: 16px;
    padding: 24px;
    color: white;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: 0 4px 12px rgba(255, 107, 107, 0.3);
    margin-bottom: 24px;
    position: relative;
    overflow: hidden;
}

.streak-widget::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 200px;
    height: 200px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
}

.streak-icon {
    font-size: 48px;
    animation: flameFlicker 2s infinite;
}

@keyframes flameFlicker {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.streak-info {
    flex: 1;
}

.streak-current {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 4px;
}

.streak-longest {
    font-size: 14px;
    opacity: 0.9;
}

.streak-badge {
    background: rgba(255, 255, 255, 0.2);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    white-space: nowrap;
}

/* Dark mode */
body.dark-mode .streak-widget {
    background: linear-gradient(135deg, #dc2626 0%, #ea580c 100%);
}

/* ============================================
   2. TOPIC MASTERY PROGRESS 📊
   ============================================ */

.topic-mastery-container {
    background: var(--bg-secondary);
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 24px;
}

.topic-mastery-container h3 {
    margin: 0 0 20px 0;
    color: var(--text-primary);
    font-size: 20px;
}

.mastery-item {
    margin-bottom: 20px;
}

.mastery-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.mastery-topic {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 14px;
}

.mastery-stats {
    font-size: 13px;
    color: var(--text-muted);
    font-weight: 500;
}

.mastery-bar-container {
    width: 100%;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 6px;
}

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

.mastery-level {
    font-size: 12px;
    font-weight: 600;
    text-align: right;
}

/* ============================================
   3. GOAL TRACKER 🎯
   ============================================ */

.goal-widget {
    background: var(--bg-secondary);
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 24px;
}

.goal-widget-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.goal-widget-header h3 {
    margin: 0;
    color: var(--text-primary);
    font-size: 20px;
}

.goal-counter {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 700;
    box-shadow: 0 2px 8px rgba(79, 70, 229, 0.3);
}

.no-goals {
    text-align: center;
    color: var(--text-muted);
    padding: 20px 0;
    font-size: 14px;
}

.goal-item {
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 18px;
    margin-bottom: 14px;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.goal-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    opacity: 0;
    transition: opacity 0.3s;
}

.goal-item:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.1);
}

.goal-item:hover::before {
    opacity: 1;
}

.goal-item.urgent {
    border-color: #ef4444;
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.05), rgba(239, 68, 68, 0.02));
}

.goal-item.urgent::before {
    background: linear-gradient(135deg, #ef4444, #dc2626);
    opacity: 1;
}

.goal-item.almost-done {
    border-color: #10b981;
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.05), rgba(16, 185, 129, 0.02));
}

.goal-item.almost-done::before {
    background: linear-gradient(135deg, #10b981, #059669);
}

.goal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 14px;
    gap: 12px;
}

.goal-title {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 15px;
    flex: 1;
    display: flex;
    align-items: center;
    gap: 8px;
}

.goal-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.goal-days {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    padding: 5px 12px;
    border-radius: 16px;
    white-space: nowrap;
}

.goal-days.urgent-badge {
    background: #ef4444;
    color: white;
    animation: pulse 2s infinite;
}

.goal-delete-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 6px 8px;
    border-radius: 6px;
    transition: all 0.2s;
    font-size: 14px;
}

.goal-delete-btn:hover {
    background: #fee2e2;
    color: #dc2626;
    transform: scale(1.1);
}

body.dark-mode .goal-delete-btn:hover {
    background: rgba(239, 68, 68, 0.2);
    color: #ef4444;
}

.goal-progress-bar {
    width: 100%;
    height: 24px;
    background: var(--bg-tertiary);
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 10px;
    position: relative;
}

.goal-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 12px;
    transition: width 0.5s ease;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 10px;
    position: relative;
}

.goal-progress::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.progress-text {
    color: white;
    font-size: 11px;
    font-weight: 700;
    position: relative;
    z-index: 1;
}

.goal-stats {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
}

.goal-current {
    font-weight: 600;
    color: var(--text-primary);
}

.goal-topic-tag {
    background: var(--bg-tertiary);
    padding: 4px 10px;
    border-radius: 12px;
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 500;
}

.goal-add-btn {
    width: 100%;
    margin-top: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-weight: 600;
}

.goal-limit-msg {
    text-align: center;
    color: var(--text-muted);
    font-size: 13px;
    padding: 12px;
    margin-top: 12px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

/* Goal Modal Enhancements */
#goalModal .form-group label {
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 6px;
}

#goalModal .form-group small {
    display: block;
    margin-top: 4px;
    color: var(--text-muted);
    font-size: 12px;
}

/* ============================================
   4. DAILY CHALLENGE MODE 🎮
   ============================================ */

.challenge-widget {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 16px;
    padding: 24px;
    color: white;
    margin-bottom: 24px;
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.3);
}

.challenge-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.challenge-header h3 {
    margin: 0;
    font-size: 18px;
    color: white;
}

.btn-icon {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

.btn-icon:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.btn-icon i {
    font-size: 14px;
}

.challenge-xp {
    background: rgba(255, 255, 255, 0.2);
    padding: 6px 12px;
    border-radius: 16px;
    font-size: 13px;
    font-weight: 600;
}

.challenge-content h4 {
    margin: 0 0 12px 0;
    font-size: 22px;
    font-weight: 700;
}

.challenge-meta {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.challenge-meta span {
    background: rgba(255, 255, 255, 0.15);
    padding: 6px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
}

.challenge-difficulty {
    font-weight: 700;
}

.challenge-start {
    background: white !important;
    color: #667eea !important;
    font-weight: 700;
    padding: 12px 24px;
    transition: all 0.3s;
}

.challenge-start:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(255, 255, 255, 0.3);
}

.challenge-completed {
    background: rgba(16, 185, 129, 0.2);
    border: 2px solid #10b981;
    padding: 12px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
}

.challenge-timer-container {
    margin-top: 16px;
}

.challenge-timer {
    background: rgba(255, 255, 255, 0.2);
    padding: 16px;
    border-radius: 12px;
    text-align: center;
}

.timer-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    gap: 16px;
}

.timer-display {
    font-size: 32px;
    font-weight: 700;
    font-family: 'Courier New', monospace;
    color: white;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.timer-remaining {
    font-size: 14px;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    background: rgba(255, 255, 255, 0.1);
    padding: 6px 12px;
    border-radius: 8px;
}

.timer-progress {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 16px;
}

.timer-progress-bar {
    height: 100%;
    background: #10b981;
    border-radius: 10px;
    transition: width 0.5s ease, background 0.3s ease;
    width: 0%;
}

.timer-controls {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-small {
    padding: 8px 16px;
    font-size: 13px;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.btn-small:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.btn-small:active {
    transform: translateY(0);
}

.btn-secondary {
    background: #64748b;
    color: white;
}

.btn-secondary:hover {
    background: #475569;
}

.btn-danger {
    background: #ef4444;
    color: white;
}

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

.btn-success {
    background: #10b981;
    color: white;
}

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

.btn-small i {
    font-size: 12px;
}

/* Dark mode */
body.dark-mode .challenge-widget {
    background: linear-gradient(135deg, #4338ca 0%, #6b21a8 100%);
}

body.dark-mode .timer-display {
    color: #e0e7ff;
}

/* ============================================
   5. CALENDAR VIEW 📅
   ============================================ */

.calendar-widget {
    background: var(--bg-secondary);
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 24px;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.calendar-header h3 {
    margin: 0;
    color: var(--text-primary);
    font-size: 20px;
}

.calendar-header button {
    background: var(--bg-tertiary);
    border: none;
    width: 36px;
    height: 36px;
    border-radius: 8px;
    color: var(--text-primary);
    cursor: pointer;
    font-size: 16px;
    transition: all 0.2s;
}

.calendar-header button:hover {
    background: var(--primary-color);
    color: white;
}

.calendar-grid {
    width: 100%;
}

.calendar-day-names {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 4px;
    margin-bottom: 8px;
}

.day-name {
    text-align: center;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-muted);
    padding: 8px 0;
}

.calendar-days {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 4px;
}

.calendar-day {
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
}

.calendar-day:hover {
    border-color: var(--primary-color);
    transform: scale(1.05);
}

.calendar-day.empty {
    background: transparent;
    border: none;
    cursor: default;
}

.calendar-day.today {
    border-color: var(--primary-color);
    background: rgba(79, 70, 229, 0.1);
}

.day-number {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.activity-dot {
    position: absolute;
    bottom: 4px;
    font-size: 10px;
    font-weight: 700;
    background: var(--accent-color);
    color: white;
    border-radius: 50%;
    width: 18px;
    height: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.calendar-day.no-activity {
    opacity: 0.5;
}

.calendar-day.has-activity .activity-dot {
    background: #10b981;
}

.calendar-day.high-activity .activity-dot {
    background: #f59e0b;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(245, 158, 11, 0.7);
    }
    50% {
        box-shadow: 0 0 0 6px rgba(245, 158, 11, 0);
    }
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 768px) {
    .streak-widget {
        flex-direction: column;
        text-align: center;
    }
    
    .streak-icon {
        font-size: 36px;
    }
    
    .challenge-meta {
        justify-content: center;
    }
    
    .calendar-day-names,
    .calendar-days {
        gap: 2px;
    }
    
    .day-number {
        font-size: 12px;
    }
    
    .activity-dot {
        width: 14px;
        height: 14px;
        font-size: 8px;
    }
    
    /* Goal widget responsive */
    .goal-widget-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .goal-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
    
    .goal-actions {
        width: 100%;
        justify-content: space-between;
    }
    
    .goal-stats {
        flex-direction: column;
        align-items: flex-start;
        gap: 6px;
    }
    
    .goal-progress-bar {
        height: 20px;
    }
    
    .progress-text {
        font-size: 10px;
    }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-bottom: 24px;
}

@media (max-width: 768px) {
    .feature-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   ANIMATIONS
   ============================================ */

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

.feature-widget {
    animation: slideInUp 0.5s ease-out;
}

/* ============================================
   MODAL FOR GOAL SETTING
   ============================================ */

.goal-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 10000;
}

.goal-modal.active {
    display: flex;
}

.goal-modal-content {
    background: var(--bg-primary);
    border-radius: 16px;
    padding: 32px;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.goal-modal-content h2 {
    margin: 0 0 24px 0;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-weight: 600;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.modal-actions {
    display: flex;
    gap: 12px;
    margin-top: 24px;
}

.modal-actions button {
    flex: 1;
    padding: 12px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

/* ============================================
   RESPONSIVE DESIGN FOR FEATURES
   ============================================ */

/* Tablets and Below (768px) */
@media (max-width: 768px) {
    /* Streak Widget */
    .streak-widget {
        padding: 16px;
        flex-direction: column;
        text-align: center;
        gap: 12px;
    }

    .streak-icon {
        font-size: 36px;
    }

    .streak-current {
        font-size: 20px;
    }

    .streak-longest {
        font-size: 12px;
    }

    /* Topic Mastery */
    .topic-mastery-container {
        padding: 16px;
    }

    .topic-mastery-container h3 {
        font-size: 18px;
    }

    .mastery-label {
        font-size: 13px;
    }

    .mastery-stats {
        font-size: 11px;
    }

    /* Goal Tracker */
    .goal-tracker-container {
        padding: 16px;
    }

    .goal-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .goal-header h3 {
        font-size: 18px;
    }

    .goal-card {
        padding: 14px;
    }

    .goal-meta {
        flex-direction: column;
        gap: 8px;
        font-size: 12px;
    }

    .goal-actions {
        flex-direction: column;
        gap: 8px;
    }

    .goal-actions button {
        width: 100%;
        padding: 10px;
        font-size: 13px;
    }

    /* Daily Challenge */
    .challenge-container {
        padding: 16px;
    }

    .challenge-header h3 {
        font-size: 18px;
    }

    .challenge-meta {
        flex-direction: column;
        gap: 8px;
        font-size: 12px;
    }

    .challenge-actions {
        flex-direction: column;
        gap: 10px;
    }

    .challenge-actions button {
        width: 100%;
        padding: 12px;
        font-size: 13px;
    }

    .challenge-rewards {
        grid-template-columns: 1fr;
        gap: 10px;
        font-size: 12px;
    }

    /* Calendar View */
    .calendar-container {
        padding: 16px;
    }

    .calendar-header {
        flex-direction: column;
        gap: 12px;
    }

    .calendar-nav {
        width: 100%;
        justify-content: center;
    }

    .calendar-grid {
        grid-template-columns: repeat(7, 1fr);
        gap: 4px;
    }

    .calendar-day {
        padding: 6px;
        font-size: 11px;
        min-height: 45px;
    }

    .day-content {
        font-size: 12px;
    }

    .day-count {
        font-size: 10px;
    }

    /* Goal Modal */
    .goal-modal-content {
        max-height: 90vh;
        overflow-y: auto;
    }

    .modal-actions {
        flex-direction: column;
    }

    .modal-actions button {
        width: 100%;
    }

    /* Feature Grid */
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
}

/* Mobile Phones (480px and below) */
@media (max-width: 480px) {
    /* Streak Widget */
    .streak-widget {
        padding: 14px;
    }

    .streak-icon {
        font-size: 32px;
    }

    .streak-current {
        font-size: 18px;
    }

    .streak-badge {
        font-size: 11px;
        padding: 5px 10px;
    }

    /* Topic Mastery */
    .topic-mastery-container,
    .goal-tracker-container,
    .challenge-container,
    .calendar-container {
        padding: 12px;
    }

    .topic-mastery-container h3,
    .goal-header h3,
    .challenge-header h3,
    .calendar-header h2 {
        font-size: 16px;
    }

    .mastery-item {
        margin-bottom: 16px;
    }

    /* Goal Cards */
    .goal-card {
        padding: 12px;
    }

    .goal-title {
        font-size: 15px;
    }

    .goal-progress-text {
        font-size: 12px;
    }

    /* Daily Challenge */
    .challenge-problem {
        padding: 12px;
    }

    .challenge-title {
        font-size: 15px;
    }

    .challenge-badge {
        font-size: 10px;
        padding: 4px 8px;
    }

    /* Calendar */
    .calendar-day {
        padding: 4px;
        font-size: 10px;
        min-height: 40px;
    }

    .day-content {
        font-size: 11px;
    }

    .day-header {
        font-size: 10px;
        margin-bottom: 4px;
    }

    .calendar-nav button {
        padding: 8px 12px;
        font-size: 14px;
    }

    /* Progress Bars */
    .progress-bar,
    .goal-progress-bar {
        height: 6px;
    }

    /* Rewards Grid */
    .challenge-rewards .reward-item {
        padding: 10px;
    }
}

/* Very Small Devices (360px and below) */
@media (max-width: 360px) {
    .streak-widget,
    .topic-mastery-container,
    .goal-tracker-container,
    .challenge-container,
    .calendar-container {
        padding: 10px;
        border-radius: 12px;
    }

    .calendar-grid {
        gap: 2px;
    }

    .calendar-day {
        padding: 3px;
        min-height: 35px;
    }

    .day-content {
        font-size: 10px;
    }
}

/* Landscape Mode for Phones */
@media (max-width: 768px) and (orientation: landscape) {
    .calendar-grid {
        gap: 6px;
    }

    .calendar-day {
        min-height: 50px;
    }

    .streak-widget {
        flex-direction: row;
        text-align: left;
    }
}