:root {
    --primary: #4361ee;
    --secondary: #3f37c9;
    --success: #4cc9f0;
    --danger: #f72585;
    --warning: #f8961e;
    --light: #f8f9fa;
    --dark: #212529;
    --gray: #6c757d;
    --bg-color: #f5f7fb;
    --card-bg: #ffffff;
    --text-color: #212529;
    --border-color: #dee2e6;
}

.dark-mode {
    --primary: #5a75f0;
    --secondary: #4d47d4;
    --success: #5fd4f8;
    --danger: #ff3b8f;
    --warning: #ffa94d;
    --light: #343a40;
    --dark: #f8f9fa;
    --gray: #adb5bd;
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-color: #f8f9fa;
    --border-color: #444444;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    transition: background-color 0.3s, color 0.3s;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Login Screen Styles */
#login-screen, #register-screen {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    position: relative;
    overflow: hidden;
}

/* Financial-themed animated grid and floating "coins" */
#login-screen::before, #register-screen::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 10% 120%, rgba(255,255,255,0.14) 0 6px, transparent 7px),
        radial-gradient(circle at 80% -10%, rgba(255,255,255,0.12) 0 8px, transparent 9px),
        linear-gradient(135deg, rgba(255,255,255,0.06), rgba(0,0,0,0.12)),
        repeating-linear-gradient(0deg, rgba(255,255,255,0.12) 0 1px, transparent 1px 36px),
        repeating-linear-gradient(90deg, rgba(255,255,255,0.12) 0 1px, transparent 1px 36px);
    background-size: 120px 120px, 160px 160px, 100% 100%, 100% 36px, 36px 100%;
    background-position: 0 0, 0 0, 0 0, 0 0, 0 0;
    animation: grid-pan 14s linear infinite;
    pointer-events: none;
}

#login-screen::after, #register-screen::after {
    content: "";
    position: absolute;
    left: 50%;
    top: 100%;
    width: 160vmax;
    height: 160vmax;
    transform: translateX(-50%);
    background:
        radial-gradient(circle 28px at 18% 92%, rgba(255,255,255,0.28) 40%, transparent 41%),
        radial-gradient(circle 22px at 48% 86%, rgba(255,255,255,0.24) 40%, transparent 41%),
        radial-gradient(circle 24px at 78% 90%, rgba(255,255,255,0.26) 40%, transparent 41%),
        radial-gradient(circle 16px at 32% 80%, rgba(255,255,255,0.20) 40%, transparent 41%),
        radial-gradient(circle 14px at 68% 82%, rgba(255,255,255,0.18) 40%, transparent 41%);
    animation: coins-float 18s linear infinite;
    pointer-events: none;
}

@keyframes grid-pan {
    0% { background-position: 0 0, 0 0, 0 0, 0 0, 0 0; }
    100% { background-position: 0 -240px, 0 -320px, 0 0, 0 -240px, -240px 0; }
}

@keyframes coins-float {
    0% { transform: translate(-50%, 0); opacity: 1; }
    50% { transform: translate(-50%, -9%); opacity: 1; }
    100% { transform: translate(-50%, -18%); opacity: 1; }
}

/* Increase density on small screens for better contrast */
@media (max-width: 480px) {
    #login-screen::before, #register-screen::before {
        background-size: 100px 100px, 140px 140px, 100% 100%, 100% 28px, 28px 100%;
    }
}

.login-container, .register-container {
    background: var(--card-bg);
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 400px;
    padding: 30px;
    animation: auth-pop 600ms cubic-bezier(.2,.7,.3,1) both;
    border: 1px solid rgba(255,255,255,0.12);
}

@keyframes auth-pop {
    from { opacity: 0; transform: translateY(16px) scale(.98); }
    to   { opacity: 1; transform: translateY(0) scale(1); }
}

.login-header, .register-header {
    text-align: center;
    margin-bottom: 30px;
    animation: fade-slide 600ms ease both;
}

.login-header h1, .register-header h1 {
    color: var(--primary);
    margin-bottom: 10px;
}

.login-header p, .register-header p {
    color: var(--gray);
}

.form-group {
    margin-bottom: 20px;
    animation: fade-slide 600ms ease both;
}

.login-container form .form-group:nth-child(1),
.register-container form .form-group:nth-child(1) { animation-delay: 60ms; }
.login-container form .form-group:nth-child(2),
.register-container form .form-group:nth-child(2) { animation-delay: 120ms; }
.login-container form .form-group:nth-child(3),
.register-container form .form-group:nth-child(3) { animation-delay: 180ms; }
.login-container form .form-group:nth-child(4),
.register-container form .form-group:nth-child(4) { animation-delay: 240ms; }
.login-container form .form-group:nth-child(5),
.register-container form .form-group:nth-child(5) { animation-delay: 300ms; }

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-color);
}

input {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background-color: var(--card-bg);
    color: var(--text-color);
    transition: border-color 200ms ease, background-color 200ms ease, color 200ms ease;
}

input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: none;
}

input:hover {
    background-color: rgba(255,255,255,0.85);
}

.password-container {
    position: relative;
}

/* Place the password visibility toggle below the input */
.toggle-password {
    position: static;
    right: auto;
    top: auto;
    transform: none;
    background: none;
    border: none;
    color: var(--gray);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 8px;
    width: auto;
}

/* Reset padding since the eye icon is below, not overlaid */
.password-container input {
    padding-right: 15px;
}

/* Slightly larger clickable area and spacing from the edge */
.toggle-password {
    padding: 6px;
}

.login-btn, .register-btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    width: 100%;
    margin-top: 10px;
    position: relative;
    overflow: hidden;
    transition: transform 140ms ease, background 200ms ease;
}

.login-btn:hover, .register-btn:hover {
    background: var(--secondary);
    transform: translateY(-1px);
}

.login-btn::before, .register-btn::before {
    content: "";
    position: absolute;
    left: -40%;
    top: 0;
    width: 40%;
    height: 100%;
    background: linear-gradient(120deg, rgba(255,255,255,0.0), rgba(255,255,255,0.25), rgba(255,255,255,0.0));
    transform: skewX(-20deg);
}

.login-btn:hover::before, .register-btn:hover::before {
    transition: left 500ms ease;
    left: 140%;
}

/* Loading and success states for auth buttons */
.login-btn.loading,
.register-btn.loading {
    pointer-events: none;
    opacity: 0.9;
}

.login-btn.loading::after,
.register-btn.loading::after {
    content: "";
    position: absolute;
    right: 16px;
    top: 50%;
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255,255,255,0.45);
    border-top-color: #fff;
    border-radius: 50%;
    transform: translateY(-50%);
    animation: spin 900ms linear infinite;
}

.login-btn.success,
.register-btn.success {
    background: #2fbf71;
}

@keyframes spin { to { transform: translateY(-50%) rotate(360deg); } }

.error-message {
    color: var(--danger);
    font-size: 0.9rem;
    margin-top: 5px;
    display: none;
}

.success-message {
    color: var(--success);
    font-size: 0.9rem;
    margin-top: 5px;
    display: none;
}

.demo-credentials {
    background: var(--light);
    border-radius: 8px;
    padding: 15px;
    margin-top: 20px;
    border-left: 4px solid var(--primary);
}

.demo-credentials h4 {
    margin-bottom: 10px;
    color: var(--primary);
}

.demo-account {
    display: flex;
    justify-content: space-between;
    margin-bottom: 5px;
    padding: 5px 0;
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    transition: background-color 180ms ease, transform 140ms ease;
}

.demo-account:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.demo-account:hover {
    background-color: rgba(67,97,238,0.06);
    transform: translateY(-1px);
}

@keyframes fade-slide {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.auth-switch {
    text-align: center;
    margin-top: 20px;
    color: var(--gray);
}

.auth-switch a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    cursor: pointer;
}

.auth-switch a:hover {
    text-decoration: underline;
}

/* App Screen Styles */
#app-screen {
    display: none;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 20px;
    background: var(--card-bg);
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.header-left h1 {
    font-size: 2rem;
    color: var(--primary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.5rem;
    cursor: pointer;
}

.logout-btn {
    background: var(--danger);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
}

.summary-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    text-align: center;
}

.card h3 {
    font-size: 1rem;
    color: var(--gray);
    margin-bottom: 10px;
}

.card .amount {
    font-size: 1.8rem;
    font-weight: bold;
}

.balance .amount {
    color: var(--primary);
}

.income .amount {
    color: var(--success);
}

.expenses .amount {
    color: var(--danger);
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 30px;
}

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

.form-section, .transactions-section, .charts-section {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.section-title {
    font-size: 1.5rem;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}

.radio-group {
    display: flex;
    gap: 15px;
    margin-top: 5px;
}

.radio-option {
    display: flex;
    align-items: center;
    gap: 5px;
}

button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background 0.3s;
    width: 100%;
}

button:hover {
    background: var(--secondary);
}

.transaction-list {
    max-height: 400px;
    overflow-y: auto;
}

.transaction-item {
    display: flex;
    justify-content: space-between;
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
    align-items: center;
}

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

.transaction-info {
    flex-grow: 1;
}

.transaction-title {
    font-weight: 500;
    margin-bottom: 5px;
}

.transaction-meta {
    font-size: 0.85rem;
    color: var(--gray);
}

.transaction-amount {
    font-weight: bold;
    font-size: 1.1rem;
}

.income-amount {
    color: var(--success);
}

.expense-amount {
    color: var(--danger);
}

.delete-btn {
    background: none;
    border: none;
    color: var(--danger);
    cursor: pointer;
    font-size: 1.2rem;
    width: auto;
    padding: 5px;
}

.charts-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

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

.chart-container {
    position: relative;
    height: 250px;
}

.no-data {
    text-align: center;
    color: var(--gray);
    padding: 20px;
}

.password-strength {
    margin-top: 5px;
    font-size: 0.8rem;
}

.strength-weak {
    color: var(--danger);
}

.strength-medium {
    color: var(--warning);
}

.strength-strong {
    color: var(--success);
}

/* Optional: Shake animation keyframes for login error */
@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation: none !important; transition: none !important; }
}