/* ===== CSS Variables ===== */
:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #22d3ee;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md:
        0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg:
        0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl:
        0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family:
        "Inter",
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        sans-serif;
    background: linear-gradient(
        135deg,
        var(--bg-secondary) 0%,
        var(--bg-tertiary) 100%
    );
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ===== Background Animation ===== */
.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}

.floating-shape {
    position: absolute;
    border-radius: 50%;
    background: linear-gradient(
        135deg,
        var(--primary-light),
        var(--secondary-color)
    );
    opacity: 0.1;
    animation: float 20s infinite ease-in-out;
}

.shape-1 {
    width: 300px;
    height: 300px;
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 200px;
    height: 200px;
    top: 60%;
    right: 10%;
    animation-delay: 5s;
}

.shape-3 {
    width: 150px;
    height: 150px;
    bottom: 20%;
    left: 60%;
    animation-delay: 10s;
}

@keyframes float {
    0%,
    100% {
        transform: translateY(0) rotate(0deg);
    }
    50% {
        transform: translateY(-30px) rotate(180deg);
    }
}

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

/* ===== Header ===== */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.logo i {
    font-size: 2rem;
}

.logo h1 {
    background: linear-gradient(
        135deg,
        var(--primary-color),
        var(--primary-dark)
    );
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.nav-btn {
    background: transparent;
    border: 2px solid transparent;
    padding: 0.75rem 1.25rem;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.95rem;
}

.nav-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    transform: translateY(-2px);
}

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

.nav-btn i {
    font-size: 1rem;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.username {
    font-weight: 600;
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.logout-btn {
    background: transparent;
    border: 1px solid var(--error-color);
    color: var(--error-color);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
}

.logout-btn:hover {
    background: var(--error-color);
    color: white;
}

/* ===== Main Content ===== */
.main {
    padding: 2rem 0;
    min-height: calc(100vh - 100px);
}

.view {
    animation: fadeIn 0.5s ease-out;
}

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

.view-header {
    text-align: center;
    margin-bottom: 2rem;
}

.view-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(
        135deg,
        var(--primary-color),
        var(--primary-dark)
    );
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.view-header p {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* ===== Notes Grid ===== */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.note-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: var(--transition);
    cursor: pointer;
    position: relative;
}

.note-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.note-header {
    padding: 1.25rem;
    background: linear-gradient(
        135deg,
        var(--bg-tertiary),
        var(--bg-secondary)
    );
    border-bottom: 1px solid var(--border-color);
}

.note-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.note-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.note-author {
    font-weight: 500;
    color: var(--primary-color);
}

.note-visibility {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.note-visibility i {
    font-size: 0.875rem;
}

.visibility-public {
    color: var(--success-color);
}

.visibility-private {
    color: var(--text-tertiary);
}

.note-content {
    padding: 1.25rem;
}

.note-text {
    color: var(--text-secondary);
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin-bottom: 1rem;
}

.note-actions {
    padding: 0 1.25rem 1.25rem;
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
}

/* ===== Buttons ===== */
.btn {
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(
        135deg,
        var(--primary-color),
        var(--primary-dark)
    );
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

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

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

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

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

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.75rem;
}

.btn-icon {
    width: 2rem;
    height: 2rem;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.full-width {
    width: 100%;
}

/* ===== Forms ===== */
.form-group {
    margin-bottom: 1.5rem;
}

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

input[type="text"],
input[type="password"],
textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--bg-primary);
    color: var(--text-primary);
}

input[type="text"]:focus,
input[type="password"]:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

textarea {
    resize: vertical;
    font-family: inherit;
    line-height: 1.6;
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    font-weight: 500;
    color: var(--text-primary);
}

input[type="checkbox"] {
    display: none;
}

.checkmark {
    width: 1.25rem;
    height: 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    position: relative;
    transition: var(--transition);
}

input[type="checkbox"]:checked + .checkmark {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

input[type="checkbox"]:checked + .checkmark::after {
    content: "\f00c";
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    color: white;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 0.75rem;
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    margin-top: 2rem;
}

/* ===== Modals ===== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    z-index: 1000;
    animation: fadeIn 0.3s ease-out;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

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

@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.close-btn {
    background: transparent;
    border: none;
    color: var(--text-tertiary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.close-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.note-form,
.login-form {
    padding: 1.5rem;
}

.login-modal {
    max-width: 400px;
}

.detail-modal {
    max-width: 700px;
}

/* ===== Loading & Empty States ===== */
.loading-spinner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 3rem;
    color: var(--text-secondary);
    font-size: 1.125rem;
}

.loading-spinner i {
    font-size: 2rem;
    color: var(--primary-color);
}

.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 4rem;
    color: var(--text-tertiary);
    margin-bottom: 1rem;
}

.empty-state h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.empty-state p {
    margin-bottom: 2rem;
    line-height: 1.6;
}

/* ===== Stats Container ===== */
.stats-container {
    padding: 2rem 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    max-width: 800px;
    margin: 0 auto;
}

.stat-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.stat-icon {
    width: 3rem;
    height: 3rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.stat-icon.public {
    color: var(--success-color);
}

.stat-icon.private {
    color: var(--warning-color);
}

.stat-info h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.stat-label {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    font-weight: 500;
}

/* ===== Note Detail ===== */
.note-detail {
    padding: 1.5rem;
}

.note-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.note-author,
.note-date,
.note-visibility {
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
}

.note-content-detail {
    line-height: 1.8;
    font-size: 1.125rem;
    color: var(--text-primary);
    white-space: pre-wrap;
    word-wrap: break-word;
    padding: 1.5rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    margin-bottom: 1.5rem;
}

/* ===== Toast Notifications ===== */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    min-width: 300px;
    max-width: 400px;
    z-index: 2000;
    transform: translateX(400px);
    transition: transform 0.3s ease-out;
}

.toast.show {
    transform: translateX(0);
}

.toast-content {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
}

.toast-icon {
    font-size: 1.25rem;
    width: 1.5rem;
    text-align: center;
}

.toast.success .toast-icon {
    color: var(--success-color);
}

.toast.error .toast-icon {
    color: var(--error-color);
}

.toast.warning .toast-icon {
    color: var(--warning-color);
}

.toast-message {
    flex: 1;
    font-weight: 500;
    color: var(--text-primary);
}

.toast-progress {
    height: 3px;
    background: var(--primary-color);
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    animation: progress 3s linear forwards;
}

@keyframes progress {
    from {
        width: 100%;
    }
    to {
        width: 0%;
    }
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }

    .nav {
        flex-wrap: wrap;
        justify-content: center;
    }

    .notes-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .modal-content {
        width: 95%;
        margin: 1rem;
    }

    .view-header h2 {
        font-size: 2rem;
    }

    .stats-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .toast {
        bottom: 1rem;
        right: 1rem;
        left: 1rem;
        min-width: auto;
        max-width: none;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .nav-btn {
        padding: 0.625rem 1rem;
        font-size: 0.875rem;
    }

    .nav-btn span {
        display: none;
    }

    .logo {
        font-size: 1.25rem;
    }

    .logo i {
        font-size: 1.5rem;
    }

    .view-header h2 {
        font-size: 1.75rem;
    }

    .form-actions {
        flex-direction: column;
    }

    .btn {
        justify-content: center;
    }
}

/* ===== Accessibility ===== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .floating-shape {
        display: none;
    }
}

/* ===== Focus States ===== */
.btn:focus,
.nav-btn:focus,
input:focus,
textarea:focus,
.close-btn:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* ===== Print Styles ===== */
@media print {
    .header,
    .nav,
    .modal,
    .toast,
    .bg-animation {
        display: none !important;
    }

    .main {
        padding: 0;
    }

    .note-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ccc;
    }
}