:root {
    /* Colors */
    --bg-primary: #0a0a0a;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #2a2a2a;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --accent-green: #00ff88;
    --accent-blue: #00ccff;
    --accent-purple: #9d4edd;
    --success: #00ff88;
    --warning: #ffcc00;
    --danger: #ff4757;
    --border-radius: 20px;
    --transition: all 0.3s ease;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);
}

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

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

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Navigation */
.navbar {
    background: rgba(26, 26, 26, 0.95);
    backdrop-filter: blur(10px);
    padding: var(--spacing-md) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--bg-tertiary);
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(45deg, var(--accent-green), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.75rem 1rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    min-width: 80px;
    text-align: center;
}

.nav-btn:hover {
    color: var(--accent-green);
}

.nav-btn.active {
    color: var(--accent-green);
}

.nav-btn.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-green);
    border-radius: 2px;
}

/* Mobile Bottom Navigation */
.bottom-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-top: 1px solid var(--bg-tertiary);
    padding: var(--spacing-md) var(--spacing-sm);
    z-index: 1000;
}

.bottom-nav .nav-btn {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-xs);
    min-width: auto;
    font-size: 0.8rem;
}

.bottom-nav .nav-btn i {
    display: block;
    font-size: 1.2rem;
    margin-bottom: var(--spacing-xs);
}

/* Tablet and Mobile Styles */
@media (max-width: 768px) {
    .navbar {
        display: none;
    }
    
    .bottom-nav {
        display: flex;
    }
    
    .main-content {
        padding-bottom: 80px; /* Space for bottom nav */
    }
    
    .habits-list {
        margin-bottom: 140px; /* Extra space for submit button on mobile */
    }
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 2rem;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

/* Cards */
.card {
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    border: 1px solid var(--bg-tertiary);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-green), var(--accent-blue));
    opacity: 0.7;
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-green);
    box-shadow: 0 12px 40px rgba(0, 255, 136, 0.2);
}

.card h2 {
    color: var(--accent-green);
    margin-bottom: var(--spacing-md);
    font-size: 1.2rem;
    font-weight: 600;
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

/* Stats Card */
.level-display {
    text-align: center;
}

.level-number {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(45deg, var(--accent-green), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
    margin-bottom: 0.5rem;
}

.level-badge {
    background: var(--bg-tertiary);
    color: var(--accent-green);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    display: inline-block;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
}

/* XP Bar */
.xp-bar-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.xp-bar {
    flex: 1;
    height: 24px;
    background: var(--bg-tertiary);
    border-radius: 12px;
    overflow: hidden;
    position: relative;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

.xp-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-green), var(--accent-blue));
    border-radius: 12px;
    width: 0%;
    transition: width 0.5s ease;
    position: relative;
}

.xp-progress::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.1) 50%, transparent 70%);
    animation: shine 2s infinite;
}

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

.xp-text {
    font-weight: 600;
    color: var(--accent-green);
    min-width: 80px;
    text-align: right;
}

/* Streak Display */
.streak-display {
    text-align: center;
}

.streak-number {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(45deg, var(--accent-green), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
}

.streak-label {
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 1px;
}

/* Quote Card */
.quote-container {
    text-align: center;
    font-style: italic;
    color: var(--text-secondary);
    font-size: 1.1rem;
    line-height: 1.8;
}

/* Progress Circle */
.progress-circle {
    text-align: center;
}

.circular-chart {
    width: 100px;
    height: 100px;
    margin: 0 auto;
}

.circle-bg {
    fill: none;
    stroke: var(--bg-tertiary);
    stroke-width: 6;
}

.circle {
    fill: none;
    stroke-width: 6;
    stroke-linecap: round;
    stroke: url(#gradient);
    transition: stroke-dashoffset 0.5s ease;
}

.percentage {
    fill: var(--text-primary);
    font-size: 0.4em;
    font-weight: 600;
    text-anchor: middle;
    dominant-baseline: central;
}

/* Habits Container */
.habits-container h1 {
    color: var(--accent-green);
    margin-bottom: var(--spacing-lg);
    font-size: 2rem;
}

.habits-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: 80px; /* Space for submit button */
}

.submit-habits-container {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--spacing-lg);
    background: var(--bg-primary);
    border-top: 1px solid var(--bg-tertiary);
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.3);
    z-index: 100;
}

.submit-habits-btn {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: linear-gradient(90deg, var(--accent-green), var(--accent-blue));
    color: var(--bg-primary);
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

.submit-habits-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 255, 136, 0.4);
}

.submit-habits-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    box-shadow: var(--shadow-sm);
}

.habit-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    border: 1px solid var(--bg-tertiary);
    transition: var(--transition);
    min-height: 60px;
}

.habit-item:hover {
    border-color: var(--accent-green);
    background: rgba(42, 42, 42, 0.7);
}

.habit-checkbox {
    display: flex;
    align-items: center;
    flex: 1;
    cursor: pointer;
}

.habit-checkbox input[type="checkbox"] {
    opacity: 0;
    position: absolute;
}

.checkmark {
    width: 24px;
    height: 24px;
    border: 2px solid var(--text-secondary);
    border-radius: 6px;
    margin-right: 1rem;
    position: relative;
    transition: var(--transition);
}

.habit-checkbox input[type="checkbox"]:checked + .checkmark {
    background: var(--accent-green);
    border-color: var(--accent-green);
}

.habit-checkbox input[type="checkbox"]:checked + .checkmark::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--bg-primary);
    font-size: 14px;
    font-weight: bold;
}

.habit-text {
    flex: 1;
    color: var(--text-primary);
}

.xp-value {
    color: var(--accent-green);
    font-weight: 600;
    margin-left: 1rem;
}

.habit-slider {
    display: flex;
    align-items: center;
    flex: 1;
    cursor: pointer;
}

.habit-slider input[type="range"] {
    flex: 1;
    margin-left: 1rem;
    -webkit-appearance: none;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-tertiary);
    outline: none;
}

.habit-slider input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-green);
    cursor: pointer;
    transition: var(--transition);
}

.habit-slider input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.slider-value {
    color: var(--accent-green);
    font-weight: 600;
    min-width: 40px;
    text-align: right;
}

/* Progress Page */
.progress-container h1 {
    color: var(--accent-green);
    margin-bottom: 1.5rem;
    font-size: 2rem;
}

.weekly-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-box {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid var(--bg-tertiary);
}

.stat-box h3 {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(45deg, var(--accent-green), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.chart-container {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
    border: 1px solid var(--bg-tertiary);
}

.weight-inputs {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.input-group {
    display: flex;
    flex-direction: column;
}

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

.input-group input,
.input-group select {
    padding: 0.75rem;
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--border-radius);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-family: 'Poppins', sans-serif;
}

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

/* Rewards Page */
.rewards-container h1 {
    color: var(--accent-green);
    margin-bottom: 1.5rem;
    font-size: 2rem;
}

.badges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 1rem;
}

.badge-item {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid var(--bg-tertiary);
    transition: var(--transition);
    opacity: 0.5;
}

.badge-item.unlocked {
    opacity: 1;
    border-color: var(--accent-green);
    transform: scale(1.05);
}

.badge-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    display: block;
}

.badge-name {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

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

/* Settings Page */
.settings-container h1 {
    color: var(--accent-green);
    margin-bottom: 1.5rem;
    font-size: 2rem;
}

.setting-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
    border-bottom: 1px solid var(--bg-tertiary);
}

.setting-item:last-child {
    border-bottom: none;
}

.btn-danger {
    background: var(--danger);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.btn-danger:hover {
    opacity: 0.8;
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--bg-tertiary);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
    border-color: var(--accent-green);
    color: var(--accent-green);
}

.data-info {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--bg-tertiary);
}

.data-info p {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.data-info span {
    color: var(--accent-green);
    font-weight: 600;
}

/* Switch Toggle */
.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--bg-tertiary);
    transition: var(--transition);
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: var(--text-primary);
    transition: var(--transition);
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--accent-green);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

/* Level Up Animation */
.level-up-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(10, 10, 10, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.level-up-animation.show {
    opacity: 1;
    pointer-events: all;
}

.level-up-content {
    text-align: center;
    background: var(--bg-secondary);
    padding: 3rem;
    border-radius: var(--border-radius);
    border: 2px solid var(--accent-green);
    transform: scale(0.8);
    transition: transform 0.3s ease;
}

.level-up-animation.show .level-up-content {
    transform: scale(1);
}

.level-up-content h2 {
    font-size: 3rem;
    color: var(--accent-green);
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.level-up-content p {
    font-size: 1.5rem;
    color: var(--accent-blue);
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeOut {
    from {
        opacity: 1;
    }
    to {
        opacity: 0;
    }
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

/* Apply animations to elements */
.card {
    animation: slideIn 0.5s ease-out;
}

.submit-habits-btn:active {
    animation: bounce 0.3s ease;
}

.habit-checkbox input[type="checkbox"]:checked + .checkmark {
    animation: pulse 0.3s ease;
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-primary);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader {
    width: 50px;
    height: 50px;
    border: 4px solid var(--bg-tertiary);
    border-top: 4px solid var(--accent-green);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-text {
    color: var(--accent-green);
    font-size: 24px;
    font-weight: 600;
    margin: 0;
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .nav-links {
        width: 100%;
        justify-content: center;
    }
    
    .main-content {
        padding: 1rem;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
    
    .habit-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .habit-checkbox {
        width: 100%;
    }
    
    .weekly-stats {
        grid-template-columns: 1fr;
    }
    
    .weight-inputs {
        grid-template-columns: 1fr;
    }
    
    .setting-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}

/* Watermark */
.watermark {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
    font-size: 14px;
    opacity: 0.5;
    transition: opacity 0.3s ease;
}

.watermark a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.3s ease;
}

.watermark a:hover {
    color: var(--accent-green);
    opacity: 1;
    text-decoration: underline;
}