:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-light: #64748b;
    --border-color: #e2e8f0;
    
    --success: #10b981;
    --success-light: #d1fae5;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --danger: #ef4444;
    
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
}

.app-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
.app-header {
    margin-bottom: 24px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--card-bg);
    padding: 16px 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-area i {
    font-size: 28px;
    color: var(--primary-color);
}

.logo-area h1 {
    font-size: 1.25rem;
    font-weight: 700;
}

.month-selector {
    display: flex;
    align-items: center;
    gap: 8px;
}

.icon-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 20px;
    color: var(--text-light);
    padding: 4px;
    border-radius: 4px;
    transition: all 0.2s;
}

.icon-btn:hover {
    background-color: var(--border-color);
    color: var(--text-main);
}

.month-input {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: inherit;
    font-weight: 600;
    color: var(--text-main);
    background: var(--bg-color);
}

/* Dashboard Summary */
.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.summary-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: var(--shadow);
}

.icon-wrapper {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.card-estimated .icon-wrapper { background: var(--bg-color); color: var(--text-main); }
.card-paid .icon-wrapper { background: var(--success-light); color: var(--success); }
.card-remaining .icon-wrapper { background: var(--warning-light); color: var(--warning); }

.summary-info p {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: 4px;
}

.summary-info h2 {
    font-size: 1.5rem;
    font-weight: 700;
}

/* Actions Bar */
.actions-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.actions-bar h3 {
    font-size: 1.125rem;
    color: var(--text-light);
}

/* Buttons */
.btn-primary, .btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

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

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

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

.btn-secondary:hover {
    background-color: #e2e8f0;
}

/* Expense List */
.expense-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.expense-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 16px;
}

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

.expense-title {
    display: flex;
    align-items: center;
    gap: 8px;
}

.expense-title h4 {
    font-size: 1.125rem;
    font-weight: 600;
}

.badge {
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 99px;
    background: var(--bg-color);
    color: var(--text-light);
}

.badge.fixed { background: var(--bg-color); }
.badge.extra { background: var(--warning-light); color: var(--warning); }

.expense-amounts {
    text-align: right;
}

.amount-paid {
    font-weight: 700;
    font-size: 1.125rem;
}

.amount-estimated {
    font-size: 0.875rem;
    color: var(--text-light);
}

/* Progress Bar */
.progress-container {
    width: 100%;
    height: 8px;
    background-color: var(--bg-color);
    border-radius: 99px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

.progress-bar.complete {
    background-color: var(--success);
}

.progress-bar.overpaid {
    background-color: var(--danger);
}

.expense-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
}

.remaining-text {
    color: var(--text-light);
}

.remaining-text strong {
    color: var(--text-main);
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: var(--text-light);
    background: var(--card-bg);
    border-radius: var(--radius);
}
.empty-state i {
    font-size: 48px;
    margin-bottom: 16px;
    opacity: 0.5;
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
}

.modal-overlay.hidden {
    display: none;
}

.modal {
    background: var(--card-bg);
    border-radius: var(--radius);
    width: 100%;
    max-width: 450px;
    padding: 24px;
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.close-modal {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    color: var(--text-light);
}

.form-group {
    margin-bottom: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-main);
}

.form-group input[type="text"],
.form-group input[type="number"] {
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: inherit;
    font-size: 1rem;
}

.checkbox-group {
    flex-direction: row;
    align-items: flex-start;
    gap: 12px;
    background: var(--bg-color);
    padding: 12px;
    border-radius: 8px;
}

.checkbox-group input {
    margin-top: 4px;
}

.checkbox-group label {
    display: flex;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.checkbox-group label span {
    font-size: 0.75rem;
    color: var(--text-light);
    font-weight: 400;
}

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

.pay-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 16px;
    text-align: center;
}

.payment-info {
    background: var(--bg-color);
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    text-align: center;
}

.info-item {
    font-size: 1rem;
    color: var(--text-light);
}

.info-item strong {
    font-size: 1.25rem;
    display: block;
    margin-top: 4px;
}

.text-orange { color: var(--warning); }
.text-green { color: var(--success); }
/* --- LOGIN SCREEN --- */
.login-screen {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--bg);
}
.login-card {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    width: 100%;
    max-width: 400px;
}