:root {
    /* Modern Color Palette (Tailwind/Stripe inspired) */
    --primary: #6366f1; /* Indigo 500 */
    --primary-hover: #4f46e5; /* Indigo 600 */
    --primary-light: #e0e7ff; /* Indigo 100 */
    
    --secondary: #64748b; /* Slate 500 */
    --secondary-hover: #475569; /* Slate 600 */
    
    --success: #10b981; /* Emerald 500 */
    --success-hover: #059669; /* Emerald 600 */
    
    --danger: #ef4444; /* Red 500 */
    --danger-hover: #dc2626; /* Red 600 */
    --danger-light: #fef2f2; /* Red 50 */
    
    --background: #f8fafc; /* Slate 50 */
    --surface: #ffffff;
    
    --text-main: #0f172a; /* Slate 900 */
    --text-muted: #64748b; /* Slate 500 */
    --text-light: #94a3b8; /* Slate 400 */
    
    --border: #e2e8f0; /* Slate 200 */
    --border-focus: #6366f1;
    
    /* Spacing & Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-md: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Transitions */
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

@keyframes slideIn {
    from { transform: translateX(20px); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

.fade-in {
    animation: fadeIn 0.5s ease-out forwards;
}

/* Layout */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* Navbar */
.navbar {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    transition: var(--transition);
}

.nav-content {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: -0.025em;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-brand span {
    color: var(--primary);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-user {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-nav-logout {
    font-size: 0.875rem;
    color: var(--danger);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    background: var(--danger-light);
    transition: var(--transition);
}

.btn-nav-logout:hover {
    background: #fee2e2;
    transform: translateY(-1px);
}

/* Page Header */
.page-header {
    text-align: center;
    margin: 3rem 0 4rem;
    animation: fadeIn 0.6s ease-out;
}

.page-header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 1rem;
    letter-spacing: -0.03em;
    line-height: 1.2;
}

.page-header p {
    color: var(--text-muted);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Controls */
.control-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 2.5rem;
    justify-content: center;
    animation: fadeIn 0.8s ease-out;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 8px -1px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: white;
    border: 1px solid var(--border);
    color: var(--text-main);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    border-color: var(--text-muted);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-muted);
}

.btn-outline:hover {
    border-color: var(--danger);
    color: var(--danger);
    background: var(--danger-light);
}

.btn-danger {
    background: var(--danger-light);
    color: var(--danger);
    border: 1px solid transparent;
}

.btn-danger:hover {
    background: #fee2e2;
    border-color: #fecaca;
}

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.75rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
}

/* Forms */
.form-section {
    background: var(--surface);
    padding: 2.5rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
    border: 1px solid var(--border);
    transition: var(--transition);
    animation: fadeIn 0.8s ease-out;
}

.form-section:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.section-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    letter-spacing: -0.01em;
}

.form-grid-2 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

/* Password Toggle */
.password-wrapper {
    position: relative;
}

.password-toggle {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.password-toggle:hover {
    color: var(--primary);
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-main);
    margin-bottom: 0.5rem;
}

.form-input, .form-textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.95rem;
    color: var(--text-main);
    background: var(--background);
    transition: var(--transition);
}

.form-input::placeholder, .form-textarea::placeholder {
    color: var(--text-light);
}

.form-input:focus, .form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: white;
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
    line-height: 1.6;
}

/* Dynamic Entries */
.entry-item {
    background: #f8fafc;
    padding: 2rem;
    border-radius: var(--radius-lg);
    margin-bottom: 1.5rem;
    position: relative;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.entry-item:hover {
    border-color: var(--primary-light);
    background: white;
    box-shadow: var(--shadow-sm);
}

.button-container {
    display: flex;
    justify-content: flex-end;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px dashed var(--border);
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 1.5rem;
    right: 1.5rem;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.toast {
    background: white;
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    min-width: 300px;
    border-left: 4px solid var(--primary);
    animation: slideIn 0.3s ease-out;
    font-size: 0.9rem;
    font-weight: 500;
}

.toast-success { border-color: var(--success); }
.toast-error { border-color: var(--danger); }
.toast-warning { border-color: #f59e0b; }

/* Action Buttons */
.action-buttons {
    display: flex;
    flex-direction: row;
    gap: 1rem;
    margin: 3rem;
    align-items: center;
}

/* Login/Signup Cards */
.card {
    background: var(--surface);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 25px 30px -5px rgb(0 0 0 / 0.1);
}

/* Responsive */
@media (max-width: 768px) {
    .container { padding: 1rem; }
    .form-section { padding: 1.5rem; }
    .page-header h1 { font-size: 2rem; }
    .nav-content { flex-direction: column; gap: 1rem; }
    .form-grid-2, .form-grid-3 { grid-template-columns: 1fr; }
}