:root {
    /* Modern Color Palette */
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;

    /* Backgrounds */
    --bg-gradient-start: #f8fafc;
    --bg-gradient-end: #e0e7ff;
    --card-bg: #ffffff;
    --card-hover-bg: #fefefe;

    /* Text */
    --text-main: #0f172a;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;

    /* Borders & Shadows */
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Status Colors */
    --error-color: #ef4444;
    --success-color: #10b981;
    --warning-color: #f59e0b;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========== LOGIN PAGE ========== */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: var(--spacing-md);
    position: relative;
    overflow: hidden;
}

.login-container::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
    animation: float 20s ease-in-out infinite;
}

@keyframes float {

    0%,
    100% {
        transform: translate(0, 0) rotate(0deg);
    }

    33% {
        transform: translate(30px, -30px) rotate(120deg);
    }

    66% {
        transform: translate(-20px, 20px) rotate(240deg);
    }
}

.login-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    width: 100%;
    max-width: 420px;
    text-align: center;
    position: relative;
    z-index: 1;
    border: 1px solid rgba(255, 255, 255, 0.8);
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.logo-container {
    margin-bottom: var(--spacing-xl);
}

.logo {
    width: 80px;
    height: 80px;
    margin-bottom: var(--spacing-md);
    object-fit: contain;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05);
    }
}

.logo-container h1 {
    font-size: 1.75rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
}

.logo-container p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ========== BUTTONS ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    width: 100%;
    padding: 0.875rem var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.9375rem;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width var(--transition-slow), height var(--transition-slow);
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--card-bg);
    color: var(--text-main);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-gradient-start);
    border-color: var(--primary-color);
}

.btn-outline {
    background: transparent;
    color: var(--text-secondary);
    border: 2px solid var(--border-color);
}

.btn-outline:hover {
    background: var(--card-bg);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-danger {
    background: linear-gradient(135deg, var(--error-color) 0%, #dc2626 100%);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(239, 68, 68, 0.4);
}

/* ========== FORMS ========== */
.divider {
    display: flex;
    align-items: center;
    margin: var(--spacing-lg) 0;
    color: var(--text-muted);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

.divider::before,
.divider::after {
    content: "";
    flex: 1;
    border-top: 2px solid var(--border-color);
}

.divider span {
    padding: 0 var(--spacing-md);
}

.form-group {
    margin-bottom: var(--spacing-lg);
    text-align: left;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-main);
    margin-bottom: var(--spacing-xs);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    font-family: inherit;
    transition: all var(--transition-base);
    background: var(--card-bg);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
    transform: translateY(-1px);
}

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

.error-message {
    color: var(--error-color);
    font-size: 0.875rem;
    font-weight: 500;
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(239, 68, 68, 0.1);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--error-color);
    min-height: 1.25em;
    animation: shake 0.3s ease-in-out;
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-10px);
    }

    75% {
        transform: translateX(10px);
    }
}

/* ========== DASHBOARD ========== */
.dashboard-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    min-height: 100vh;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-lg);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(255, 255, 255, 0.8);
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.header-logo {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.user-email {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
}

/* ========== TOOLBAR ========== */
.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.sort-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.sort-controls label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.sort-controls select {
    padding: 0.5rem var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    background: var(--card-bg);
    cursor: pointer;
    transition: all var(--transition-base);
}

.sort-controls select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* ========== SEARCH BOX ========== */
.search-box {
    position: relative;
    flex: 1;
    max-width: 400px;
}

.search-box .search-icon {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1.25rem;
    pointer-events: none;
}

.search-box input {
    width: 100%;
    padding: 0.625rem 0.75rem 0.625rem 2.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    background: var(--card-bg);
    transition: all var(--transition-base);
}

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

.search-box input::placeholder {
    color: var(--text-muted);
}

/* ========== CATEGORY GROUPS ========== */
.category-group {
    margin-bottom: var(--spacing-2xl);
}

.category-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 3px solid var(--border-color);
}

.category-header h3 {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--spacing-md);
    animation: fadeIn var(--transition-base);
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    animation: slideUp 0.3s ease-out;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xl);
    border-bottom: 2px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.icon-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    color: var(--text-secondary);
}

.icon-btn:hover {
    background: var(--bg-gradient-start);
    color: var(--primary-color);
}

.modal form {
    padding: var(--spacing-xl);
}

.modal-actions {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-xl);
    border-top: 2px solid var(--border-color);
    background: var(--bg-gradient-start);
}

.spacer {
    flex: 1;
}

/* ========== UTILITY CLASSES ========== */
.hidden {
    display: none !important;
}

.text-btn {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    font-weight: 600;
    padding: var(--spacing-xs);
    transition: all var(--transition-base);
}

.text-btn:hover {
    text-decoration: underline;
}

.text-danger {
    color: var(--error-color);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
    .notes-grid {
        grid-template-columns: 1fr;
    }

    .toolbar {
        flex-direction: column;
        align-items: stretch;
    }

    header {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .header-right {
        flex-direction: column;
    }
}

.search-box input::placeholder {
    color: var(--text-muted);
}

/* ========== CATEGORY GROUPS ========== */
.category-group {
    margin-bottom: var(--spacing-lg);
}

.category-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    padding-bottom: var(--spacing-xs);
    border-bottom: 3px solid var(--border-color);
}

.category-header h3 {
    font-size: 1rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.category-count {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 1.5rem;
    height: 1.5rem;
    padding: 0 0.375rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border-radius: var(--radius-xl);
    font-size: 0.75rem;
    font-weight: 700;
}

/* ========== NOTES GRID ========== */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: var(--spacing-xs);
    margin-bottom: 0;
}

.note-card {
    background: var(--card-bg);
    padding: 0.75rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.note-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.note-card:hover::before {
    transform: scaleX(1);
}

.note-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.note-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.375rem;
}

.note-category {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border-radius: var(--radius-xl);
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.attachment-icon {
    color: var(--accent-color);
    font-size: 1.1rem;
}

.note-title {
    font-size: 0.875rem;
    font-weight: 700;
    gap: var(--spacing-sm);
}

.note-list-item {
    background: var(--card-bg);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    transition: all var(--transition-base);
    border-left: 4px solid transparent;
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.note-list-item:hover {
    box-shadow: var(--shadow-md);
    border-left-color: var(--primary-color);
    transform: translateX(4px);
}

.note-list-item .note-category {
    flex-shrink: 0;
}

.note-list-item .note-title {
    flex: 1;
    font-size: 1rem;
    margin: 0;
}

.note-list-item .attachment-icon {
    flex-shrink: 0;
}

.empty-state,
.loading-spinner,
.error-message {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--text-muted);
    font-size: 1rem;
}

/* ========== MODAL ========== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--spacing-md);
    animation: fadeIn var(--transition-base);
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    animation: slideUp 0.3s ease-out;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xl);
    border-bottom: 2px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.icon-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    color: var(--text-secondary);
}

.icon-btn:hover {
    background: var(--bg-gradient-start);
    color: var(--primary-color);
}

.modal form {
    padding: var(--spacing-xl);
}

.modal-actions {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-xl);
    border-top: 2px solid var(--border-color);
    background: var(--bg-gradient-start);
}

.spacer {
    flex: 1;
}

/* ========== UTILITY CLASSES ========== */
.hidden {
    display: none !important;
}

.text-btn {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    font-weight: 600;
    padding: var(--spacing-xs);
    transition: all var(--transition-base);
}

.text-btn:hover {
    text-decoration: underline;
}

.text-danger {
    color: var(--error-color);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
    .notes-grid {
        grid-template-columns: 1fr;
    }

    .toolbar {
        flex-direction: column;
        align-items: stretch;
    }

    header {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .header-right {
        flex-direction: column;
    }
}

/* ========== COMPACT NEW NOTE BUTTON ========== */
#new-note-btn {
    width: auto;
    padding: 0.5rem 0.875rem;
    font-size: 0.8125rem;
}

#new-note-btn .material-icons-round {
    font-size: 1.125rem;
}