:root {
    --bg-color: #f1f5f9;
    --primary-color: #4f46e5; /* Indigo/Blue */
    --accent-color: #fde047; /* Yellow */
    --danger-color: #f26868; /* Red */
    --success-color: #86efac; /* Green */
    --black: #000000;
    --white: #ffffff;
    --border-w: 3px;
    --shadow: 5px 5px 0px var(--black);
    --shadow-hover: 2px 2px 0px var(--black);
    --font-family: 'Space Grotesk', sans-serif;
    --border-radius: 4px;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--black);
    line-height: 1.6;
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

.hidden {
    display: none !important;
}

/* App Containers for Mobile First */
#auth-view, #app-view {
    width: 100%;
    max-width: 480px;
    background-color: var(--bg-color);
    min-height: 100vh;
    position: relative;
    padding-bottom: 80px; /* Space for FAB */
}

/* AUTH SECTION */
.auth-container {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 100vh;
}

.logo {
    font-size: 3rem;
    font-weight: 700;
    text-transform: uppercase;
    text-align: center;
    letter-spacing: -2px;
    margin-bottom: 0.2rem;
    color: var(--primary-color);
    text-shadow: 3px 3px 0px var(--black);
    -webkit-text-stroke: 1px var(--black);
}

.subtitle {
    text-align: center;
    font-weight: 600;
    margin-bottom: 2rem;
    border: var(--border-w) solid var(--black);
    background-color: var(--accent-color);
    padding: 0.5rem;
    box-shadow: var(--shadow);
}

.form-card {
    background-color: var(--white);
    border: var(--border-w) solid var(--black);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    margin-bottom: 1rem;
}

.form-card h2 {
    margin-bottom: 1rem;
    font-size: 1.5rem;
    border-bottom: var(--border-w) solid var(--black);
    padding-bottom: 0.5rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

input, select {
    width: 100%;
    padding: 0.8rem;
    font-family: var(--font-family);
    font-size: 1rem;
    font-weight: 600;
    border: var(--border-w) solid var(--black);
    background-color: #fff;
    outline: none;
    transition: all 0.2s;
}

input:focus, select:focus {
    background-color: #fdfdfd;
    box-shadow: 3px 3px 0px var(--primary-color);
}

.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    font-family: var(--font-family);
    font-size: 1rem;
    font-weight: 700;
    text-align: center;
    cursor: pointer;
    border: var(--border-w) solid var(--black);
    box-shadow: var(--shadow);
    transition: all 0.1s;
    background-color: var(--white);
    color: var(--black);
    text-transform: uppercase;
}

.btn:active {
    box-shadow: var(--shadow-hover);
    transform: translate(3px, 3px);
}

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

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

.btn-block {
    width: 100%;
    margin-top: 1rem;
}

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.8rem;
}

.switch-auth {
    margin-top: 1rem;
    text-align: center;
    font-weight: 600;
}

.switch-auth a {
    color: var(--primary-color);
    font-weight: 700;
    text-decoration: none;
}
.switch-auth a:hover {
    text-decoration: underline;
}

/* APP HEADER */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background-color: var(--primary-color);
    color: var(--white);
    border-bottom: var(--border-w) solid var(--black);
}
.app-header h2 {
    font-size: 1.2rem;
    -webkit-text-stroke: 1px var(--black);
    text-shadow: 2px 2px 0px var(--black);
}

.app-content {
    padding: 1rem;
}

/* SUMMARY CARDS */
.card {
    background-color: var(--white);
    border: var(--border-w) solid var(--black);
    box-shadow: var(--shadow);
    padding: 1rem;
    margin-bottom: 1rem;
}

.balance-card {
    background-color: var(--accent-color);
    text-align: center;
}
.balance-card h1 {
    font-size: 2rem;
    margin-top: 0.5rem;
}

.card-row {
    display: flex;
    gap: 1rem;
}

.card-row .card {
    flex: 1;
    margin-bottom: 0;
}

.income-card {
    background-color: var(--success-color);
}
.expense-card {
    background-color: var(--danger-color);
}

/* TRANSACTIONS SECTION */
.transactions-section {
    margin-top: 2rem;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    border-bottom: var(--border-w) solid var(--black);
    padding-bottom: 0.5rem;
}

.filter-group select {
    padding: 0.3rem;
    font-size: 0.9rem;
    box-shadow: none;
    border-width: 2px;
}

.transactions-list {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.tx-item {
    background-color: var(--white);
    border: var(--border-w) solid var(--black);
    padding: 0.8rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 3px 3px 0px var(--black);
    cursor: pointer;
    transition: all 0.1s;
}

.tx-item:active {
    box-shadow: 1px 1px 0px var(--black);
    transform: translate(2px, 2px);
}

.tx-left {
    display: flex;
    flex-direction: column;
}

.tx-category {
    font-weight: 700;
    font-size: 1.1rem;
}

.tx-date {
    font-size: 0.8rem;
    color: #444;
    font-weight: 600;
}
.tx-note {
    font-size: 0.85rem;
    color: #666;
    margin-top: 0.2rem;
}

.tx-right {
    font-weight: 700;
    font-size: 1.1rem;
}

.tx-income {
    color: #166534;
}

.tx-expense {
    color: #991b1b;
}

.empty-state {
    text-align: center;
    padding: 2rem;
    font-weight: 700;
    border: var(--border-w) dashed var(--black);
}

/* FAB */
.fab {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    width: 60px;
    height: 60px;
    border-radius: 0;
    background-color: var(--primary-color);
    color: var(--white);
    font-size: 2rem;
    font-weight: 700;
    border: var(--border-w) solid var(--black);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 10;
}
.fab:active {
    box-shadow: var(--shadow-hover);
    transform: translate(3px, 3px);
}

/* MODALS */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    padding: 1rem;
}

.modal-content {
    background-color: var(--white);
    border: var(--border-w) solid var(--black);
    width: 100%;
    max-width: 400px;
    box-shadow: 8px 8px 0px var(--primary-color);
    padding: 1.5rem;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    border-bottom: var(--border-w) solid var(--black);
    padding-bottom: 0.5rem;
}

.btn-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    font-weight: 900;
    cursor: pointer;
    font-family: var(--font-family);
}

.btn-group {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}
.btn-group .btn {
    flex: 1;
}

/* TOAST */
.toast {
    position: fixed;
    top: 1rem;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--accent-color);
    border: var(--border-w) solid var(--black);
    padding: 0.8rem 1.5rem;
    font-weight: 700;
    box-shadow: var(--shadow);
    z-index: 1000;
}