/* Smart Split - Group Expense Tracker CSS */

:root {
    /* Color Palette */
    --primary: #4A90E2; /* A modern, friendly blue */
    --primary-dark: #357ABD;
    --secondary: #50E3C2; /* A vibrant, fresh green */
    --secondary-dark: #3CB3A2;
    --accent: #F8E71C; /* A bright, energetic yellow */
    --dark: #4A4A4A; /* A softer, more readable dark gray */
    --light: #F9F9F9; /* A clean, off-white background */
    --gray: #EAEAEA;
    --gray-dark: #9B9B9B;
    --success: #7ED321;
    --warning: #F5A623;
    --danger: #D0021B;
    
    /* Typography */
    --font-heading: 'Poppins', sans-serif;
    --font-title: 'Poppins', sans-serif; /* Using Poppins for a consistent, modern feel */
    --font-body: 'Inter', sans-serif;
    --font-accent: 'Inter', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    
    /* Shadows - Softer, more modern shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.1);
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-body);
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%); /* Subtle gradient background */
    color: var(--dark);
    line-height: 1.6;
    overflow-x: hidden;
}

.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-xl); /* Increased padding for more breathing room */
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    margin-bottom: var(--spacing-md);
    font-weight: 600; /* Slightly lighter for a modern look */
}

h1 {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--primary);
    text-shadow: none; /* Removed text shadow for a cleaner look */
    letter-spacing: 0.5px;
}

h2 {
    font-size: 1.6rem;
    color: var(--dark);
    border-bottom: 2px solid var(--primary); /* Using primary color for consistency */
    display: inline-block;
    padding-bottom: var(--spacing-xs);
}

h3 {
    font-size: 1.2rem;
    color: var(--dark);
    font-weight: 600;
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--gray-dark);
}

/* Navigation */
.main-nav {
    background-color: white;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: none; /* Removed border */
}

.logo {
    font-family: var(--font-title);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--primary);
    text-shadow: none;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-sm);
}

.nav-links a {
    color: var(--dark);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-links a:hover, .nav-links a.active {
    background-color: var(--primary);
    color: white;
    transform: translateY(0); /* Removed transform */
    box-shadow: none;
}

.nav-links i {
    font-size: 1rem;
}

/* Content Area */
.content {
    flex: 1;
    padding: var(--spacing-xl);
    background-color: rgba(255, 255, 255, 0.8); /* Semi-transparent white */
    backdrop-filter: blur(10px); /* Frosted glass effect */
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: none;
    position: relative;
    overflow: hidden;
}

/* Pages */
.page {
    display: none;
    /* animation: fadeIn 0.5s ease-in-out; */ /* Replaced with more specific animations */
}

.page.active {
    display: block;
}

.page-fade-in {
    animation: fadeIn 0.4s ease-out forwards;
}

.page-fade-out {
    animation: fadeOut 0.4s ease-in forwards;
}

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

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

.page-header {
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

/* Cards */
.balance-card {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    border: none;
    transform: rotate(0); /* Removed rotation */
}

.balance-amount {
    font-family: var(--font-heading);
    font-size: 2.8rem;
    font-weight: 700;
    color: white;
    text-shadow: none;
}

.expense-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.expense-card {
    background-color: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.expense-card:nth-child(odd) {
    transform: rotate(0);
    background-color: white;
    color: var(--dark);
}

.expense-card:nth-child(even) {
    transform: rotate(0);
    background-color: white;
    color: var(--dark);
}

.expense-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.expense-card h3 {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--dark);
}

.expense-card .amount {
    font-family: var(--font-heading);
    font-size: 1.6rem;
    font-weight: 600;
    margin: var(--spacing-sm) 0;
    color: var(--primary);
}

.expense-card .meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    margin-top: var(--spacing-sm);
    color: var(--gray-dark);
}

.expense-card .category {
    position: absolute;
    top: 10px;
    right: 10px;
    background-color: var(--secondary);
    color: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-weight: 500;
    font-size: 0.75rem;
    border: none;
}

/* People List */
.people-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.person-card {
    background-color: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    transition: all 0.3s ease;
}

.person-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.person-emoji {
    font-size: 2rem;
    background-color: var(--gray);
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    border: none;
}

.person-info {
    flex: 1;
}

.person-info h3 {
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
}

.person-balance {
    font-weight: 500;
    font-size: 0.9rem;
}

.person-balance.positive {
    color: var(--success);
}

.person-balance.negative {
    color: var(--danger);
}

.person-actions {
    display: flex;
    gap: var(--spacing-xs);
}

.person-actions button {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    color: var(--gray-dark);
    transition: all 0.2s ease;
    padding: var(--spacing-xs);
}

.person-actions button:hover {
    color: var(--primary);
    transform: scale(1.1);
}

/* Expenses List */
.expenses-list {
    margin-top: var(--spacing-lg);
}

.expense-item {
    background-color: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    transition: all 0.3s ease;
}

.expense-item:hover {
    transform: translateX(0);
    box-shadow: var(--shadow-md);
}

.expense-icon {
    font-size: 1.2rem;
    background-color: var(--secondary);
    color: white;
    width: 45px;
    height: 45px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    border: none;
}

.expense-details {
    flex: 1;
}

.expense-details h3 {
    margin-bottom: 0;
    font-weight: 600;
}

.expense-details p {
    margin-bottom: 0;
    font-size: 0.85rem;
    color: var(--gray-dark);
}

.expense-amount {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary);
}

.expense-actions {
    display: flex;
    gap: var(--spacing-xs);
}

.expense-actions button {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    color: var(--gray-dark);
    transition: all 0.2s ease;
    padding: var(--spacing-xs);
}

.expense-actions button:hover {
    color: var(--primary);
    transform: scale(1.1);
}

/* Summary Page */
.summary-chart-container {
    height: 300px;
    margin-bottom: var(--spacing-xl);
}

.settlement-summary {
    margin-top: var(--spacing-xl);
}

.settlement-item {
    background-color: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray);
    margin-bottom: var(--spacing-md);
    position: relative;
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    transition: all 0.3s ease;
}

.settlement-item:nth-child(odd) {
    background-color: white;
    color: var(--dark);
    transform: rotate(0);
}

.settlement-item:nth-child(even) {
    background-color: white;
    color: var(--dark);
    transform: rotate(0);
}

.settlement-item:hover {
    box-shadow: var(--shadow-md);
}

.settlement-item:before {
    display: none; /* Removed pseudo-element */
}

.settlement-amount {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 600;
    margin-left: auto;
    color: var(--primary);
}

/* Settings Page */
.settings-options {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.setting-card {
    background-color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray);
}

.setting-card h3 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.setting-card p {
    color: var(--gray-dark);
    margin-bottom: var(--spacing-md);
}

.setting-actions {
    display: flex;
    gap: var(--spacing-sm);
}

/* Buttons */
.action-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    border: none;
    box-shadow: var(--shadow-sm);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

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

.btn-secondary {
    background-color: var(--secondary);
    color: white;
}

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

.btn i {
    font-size: 1rem;
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.4); /* Slightly lighter backdrop */
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background-color: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: none;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: modalFadeIn 0.3s ease-out;
}

@keyframes modalFadeIn {
    from { transform: scale(0.95); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.modal-header {
    background-color: var(--primary);
    color: white;
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top-left-radius: var(--radius-lg);
    border-top-right-radius: var(--radius-lg);
}

.modal-header h2 {
    margin-bottom: 0;
    color: white;
    border-bottom: none;
    font-size: 1.4rem;
}

.close-modal {
    font-size: 1.5rem;
    cursor: pointer;
    color: white;
    line-height: 1;
    transition: transform 0.2s ease;
}

.close-modal:hover {
    transform: rotate(90deg) scale(1.1);
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
}

.modal-body {
    padding: var(--spacing-lg);
}

/* Forms */
.form-group {
    margin-bottom: var(--spacing-md);
}

label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--dark);
}

input, select, textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--gray);
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 1rem;
    transition: all 0.3s ease;
    background-color: white;
}

input:focus, select:focus, textarea:focus {
    border-color: var(--primary);
    outline: none;
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
}

.input-with-icon {
    position: relative;
}

.input-with-icon i {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray-dark);
}

.input-with-icon input {
    padding-left: 2.8rem;
}

.checkbox-group {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xs);
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background-color: var(--light);
    border: 1px solid var(--gray);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s ease;
}

.checkbox-item:hover {
    background-color: var(--gray);
    border-color: var(--gray-dark);
    transform: translateY(-2px);
}

.checkbox-item input {
    width: auto;
    margin-right: var(--spacing-xs);
}

/* Emoji Picker */
.emoji-picker {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xs);
}

.emoji-picker span {
    font-size: 1.5rem;
    cursor: pointer;
    background-color: var(--gray);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.emoji-picker span:hover {
    background-color: var(--accent);
}

.emoji-picker span.selected {
    background-color: var(--accent);
    transform: scale(1.1);
    border-color: var(--primary);
}

/* Empty States */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--gray-dark);
    background-color: rgba(255, 255, 255, 0.5);
    border-radius: var(--radius-md);
}

.empty-state i {
    margin-bottom: var(--spacing-md);
    color: var(--gray-dark);
    font-size: 2.5rem;
}

/* Hamburger Menu */
.nav-toggle {
    display: none;
    background: transparent;
    border: 0;
    cursor: pointer;
    padding: 5px;
}

.hamburger {
    display: block;
    position: relative;
    width: 25px;
    height: 3px;
    background: var(--dark);
    transition: all 0.2s ease-in-out;
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    height: 3px;
    background: var(--dark);
    right: 0;
    left: 0;
    transition: all 0.2s ease-in-out;
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    bottom: -8px;
}

.main-nav.nav-open .hamburger {
    background: transparent;
}

.main-nav.nav-open .hamburger::before {
    transform: rotate(45deg);
    top: 0;
}

.main-nav.nav-open .hamburger::after {
    transform: rotate(-45deg);
    top: 0;
}


/* Responsive Styles */
@media (max-width: 768px) {
    .app-container {
        padding: var(--spacing-md);
    }
    
    .main-nav {
        position: relative;
    }

    .user-info {
        display: none; /* Hide user info on mobile nav bar to save space */
    }
    
    .nav-toggle {
        display: block;
        position: absolute;
        top: 25px;
        right: var(--spacing-lg);
        z-index: 1001;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        background: rgba(255, 255, 255, 0.95);
        backdrop-filter: blur(10px);
        top: 0;
        left: 0;
        right: 0;
        padding: var(--spacing-xxl) var(--spacing-lg) var(--spacing-lg);
        box-shadow: var(--shadow-lg);
        border-radius: var(--radius-lg);
        animation: fadeInDown 0.3s ease-out;
        z-index: 1000;
    }

    .main-nav.nav-open .nav-links {
        display: flex;
    }

    @keyframes fadeInDown {
        from { opacity: 0; transform: translateY(-15px); }
        to { opacity: 1; transform: translateY(0); }
    }

    .nav-links a {
        width: 100%;
        justify-content: center;
        padding: var(--spacing-md);
        font-size: 1.1rem;
    }
    
    .content {
        padding: var(--spacing-lg);
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .settings-options, .people-list, .expense-cards {
        grid-template-columns: 1fr;
    }

    .balance-amount {
        font-size: 2.4rem;
    }

    h1 {
        font-size: 1.8rem;
    }
}

/* Animations */
.bounce-in {
    animation: fadeIn 0.5s;
}

.slide-in {
    animation: fadeIn 0.5s;
}

/* Confetti Animation */
.confetti-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
}

.confetti {
    position: absolute;
    width: 10px;
    height: 10px;
    background-color: var(--primary);
    opacity: 0.8;
    animation: confetti-fall 3s linear infinite;
}

.confetti:nth-child(2n) {
    background-color: var(--secondary);
}

.confetti:nth-child(3n) {
    background-color: var(--accent);
}

.confetti:nth-child(4n) {
    background-color: var(--success);
}

@keyframes confetti-fall {
    0% { transform: translateY(-100px) rotate(0deg); }
    100% { transform: translateY(100vh) rotate(360deg); }
}

/* Offline Badge */
.offline-badge {
    background-color: var(--gray-dark);
    color: white;
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 12px;
    margin-left: var(--spacing-sm);
    font-weight: 600;
    vertical-align: middle;
    display: inline-block;
}