/* === Reset & Base === */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

:root {
    --primary: #6366F1;
    --primary-light: #EEF2FF;
    --primary-hover: #4F46E5;
    --primary-glow: rgba(99, 102, 241, 0.15);
    --bg: #F9FAFB;
    --white: #FFFFFF;
    --gray-50: #F9FAFB;
    --gray-100: #F3F4F6;
    --gray-200: #E5E7EB;
    --gray-300: #D1D5DB;
    --gray-400: #9CA3AF;
    --gray-500: #6B7280;
    --gray-600: #4B5563;
    --gray-700: #374151;
    --gray-800: #1F2937;
    --gray-900: #111827;
    --red-500: #EF4444;
    --red-50: #FEF2F2;
    --green-500: #10B981;
    --green-50: #ECFDF5;
    --sidebar-width: 256px;
    --topbar-height: 60px;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.03);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.06), 0 2px 4px rgba(0,0,0,0.03);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.08), 0 4px 8px rgba(0,0,0,0.04);
    --transition: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--gray-700);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    letter-spacing: -0.01em;
}

/* === Auth Pages === */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg);
    position: relative;
    overflow: hidden;
}

.auth-page::before {
    content: '';
    position: absolute;
    top: -40%;
    right: -20%;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.auth-page::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 500px;
    height: 500px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.05) 0%, transparent 70%);
    pointer-events: none;
}

.auth-container {
    width: 100%;
    max-width: 400px;
    padding: 20px;
    position: relative;
    z-index: 1;
}

.auth-card {
    background: var(--white);
    border-radius: 20px;
    padding: 44px 36px;
    box-shadow: 0 0 0 1px rgba(0,0,0,0.03), var(--shadow-lg);
}

.auth-logo {
    text-align: center;
    margin-bottom: 36px;
}

.auth-logo h1 {
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-900);
    margin-top: 14px;
    letter-spacing: -0.03em;
}

.auth-subtitle {
    color: var(--gray-400);
    font-size: 13.5px;
    margin-top: 6px;
    font-weight: 400;
}

.auth-form .form-group {
    margin-bottom: 16px;
}

.auth-form input {
    width: 100%;
    padding: 11px 16px;
    border: 1.5px solid var(--gray-200);
    border-radius: var(--radius);
    font-size: 14px;
    color: var(--gray-800);
    background: var(--white);
    transition: var(--transition);
    outline: none;
    font-family: inherit;
}

.auth-form input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.alert {
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    font-size: 13px;
    margin-bottom: 16px;
    font-weight: 500;
}

.alert-error {
    background: var(--red-50);
    color: var(--red-500);
    border: 1px solid #FECACA;
}

.alert-success {
    background: var(--green-50);
    color: var(--green-500);
    border: 1px solid #A7F3D0;
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 7px;
    padding: 9px 18px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 13.5px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    font-family: inherit;
    letter-spacing: -0.01em;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 1px 2px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    background: var(--primary-hover);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
    transform: translateY(-1px);
}

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

.btn-ghost {
    background: transparent;
    color: var(--gray-500);
    border: 1.5px solid var(--gray-200);
}

.btn-ghost:hover {
    background: var(--gray-50);
    border-color: var(--gray-300);
    color: var(--gray-700);
}

.btn-danger {
    background: transparent;
    color: var(--red-500);
    border: 1.5px solid #FECACA;
}

.btn-danger:hover {
    background: var(--red-50);
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12.5px;
}

.btn-full {
    width: 100%;
}

/* === App Layout === */
.app-layout {
    display: flex;
    min-height: 100vh;
}

/* === Sidebar === */
.sidebar {
    width: var(--sidebar-width);
    background: var(--white);
    border-right: 1px solid var(--gray-100);
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 100;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 18px 20px;
    border-bottom: 1px solid var(--gray-100);
}

.sidebar-title {
    font-size: 17px;
    font-weight: 700;
    color: var(--gray-900);
    letter-spacing: -0.03em;
}

.sidebar-nav {
    flex: 1;
    padding: 10px;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 11px;
    padding: 9px 14px;
    border-radius: var(--radius-sm);
    color: var(--gray-500);
    text-decoration: none;
    font-size: 13.5px;
    font-weight: 500;
    transition: var(--transition);
}

.nav-item:hover {
    background: var(--gray-50);
    color: var(--gray-700);
}

.nav-item.active {
    background: var(--primary-light);
    color: var(--primary);
}

.nav-item.active svg {
    stroke: var(--primary);
}

.sidebar-footer {
    padding: 10px;
    border-top: 1px solid var(--gray-100);
}

.nav-logout:hover {
    background: var(--red-50);
    color: var(--red-500);
}

.nav-logout:hover svg {
    stroke: var(--red-500);
}

/* === Mobile Hamburger === */
.mobile-menu-btn {
    display: none;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    cursor: pointer;
    color: var(--gray-600);
    margin-right: 10px;
    flex-shrink: 0;
    transition: var(--transition);
}

.mobile-menu-btn:hover {
    background: var(--gray-100);
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(17, 24, 39, 0.4);
    backdrop-filter: blur(4px);
    z-index: 99;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.sidebar-overlay.active {
    opacity: 1;
}

/* === Sidebar close button (mobile) === */
.sidebar-close-btn {
    display: none;
    width: 32px;
    height: 32px;
    align-items: center;
    justify-content: center;
    border: none;
    background: var(--gray-100);
    border-radius: var(--radius-sm);
    cursor: pointer;
    color: var(--gray-500);
    margin-left: auto;
    transition: var(--transition);
}

.sidebar-close-btn:hover {
    background: var(--gray-200);
    color: var(--gray-700);
}

/* === Main Content === */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* === Topbar === */
.topbar {
    height: var(--topbar-height);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--gray-100);
    display: flex;
    align-items: center;
    padding: 0 24px;
    position: sticky;
    top: 0;
    z-index: 50;
}

.search-box {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--gray-50);
    border-radius: var(--radius);
    padding: 0 14px;
    flex: 1;
    max-width: 480px;
    transition: var(--transition);
    border: 1.5px solid var(--gray-100);
}

.search-box:focus-within {
    background: var(--white);
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.search-box input {
    flex: 1;
    border: none;
    background: transparent;
    padding: 9px 0;
    font-size: 13.5px;
    color: var(--gray-700);
    outline: none;
    font-family: inherit;
}

.search-box input::placeholder {
    color: var(--gray-400);
}

/* === Content Area === */
.content-area {
    padding: 24px;
    flex: 1;
}

.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}

.page-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-900);
    letter-spacing: -0.03em;
}

/* === Category Filter Tabs === */
.category-tabs {
    display: flex;
    gap: 6px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.cat-tab {
    padding: 5px 14px;
    border-radius: 20px;
    font-size: 12.5px;
    font-weight: 500;
    border: 1.5px solid var(--gray-200);
    background: var(--white);
    color: var(--gray-500);
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.cat-tab:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
}

.cat-tab.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.25);
}

/* === Bookmark Cards === */
.bookmark-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 14px;
}

.bookmark-card {
    background: var(--white);
    border: 1px solid var(--gray-100);
    border-radius: var(--radius);
    padding: 16px;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.bookmark-card:hover {
    border-color: rgba(99, 102, 241, 0.3);
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.08), 0 0 0 1px rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
}

.bookmark-card-header {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.bookmark-favicon {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: var(--gray-50);
    border: 1px solid var(--gray-100);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    overflow: hidden;
}

.bookmark-favicon img {
    width: 20px;
    height: 20px;
}

.bookmark-info {
    flex: 1;
    min-width: 0;
}

.bookmark-title {
    font-size: 13.5px;
    font-weight: 600;
    color: var(--gray-800);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    letter-spacing: -0.01em;
}

.bookmark-url {
    font-size: 12px;
    color: var(--gray-400);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    text-decoration: none;
    display: block;
    margin-top: 1px;
}

.bookmark-url:hover {
    color: var(--primary);
}

.bookmark-desc {
    font-size: 12.5px;
    color: var(--gray-500);
    line-height: 1.55;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.bookmark-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: auto;
    padding-top: 10px;
    border-top: 1px solid var(--gray-50);
}

.bookmark-category {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 20px;
    font-size: 11.5px;
    font-weight: 600;
    letter-spacing: 0.01em;
}

.bookmark-date {
    font-size: 11.5px;
    color: var(--gray-400);
}

.bookmark-actions {
    display: flex;
    gap: 2px;
    opacity: 0;
    transition: var(--transition);
}

.bookmark-card:hover .bookmark-actions {
    opacity: 1;
}

.action-btn {
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    cursor: pointer;
    color: var(--gray-400);
    transition: var(--transition);
}

.action-btn:hover {
    background: var(--gray-100);
    color: var(--gray-600);
}

.action-btn.delete:hover {
    background: var(--red-50);
    color: var(--red-500);
}

/* === Notes === */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 14px;
}

.note-card {
    background: var(--white);
    border: 1px solid var(--gray-100);
    border-radius: var(--radius);
    padding: 16px;
    transition: var(--transition);
}

.note-card:hover {
    border-color: rgba(99, 102, 241, 0.3);
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.08);
}

.note-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 6px;
    letter-spacing: -0.01em;
}

.note-content {
    font-size: 12.5px;
    color: var(--gray-500);
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 4;
    -webkit-box-orient: vertical;
    overflow: hidden;
    white-space: pre-wrap;
}

.note-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px solid var(--gray-50);
}

/* === Categories Page === */
.category-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-width: 520px;
}

.category-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 13px 16px;
    background: var(--white);
    border: 1px solid var(--gray-100);
    border-radius: var(--radius);
    transition: var(--transition);
}

.category-item:hover {
    border-color: rgba(99, 102, 241, 0.3);
    box-shadow: var(--shadow-sm);
}

.category-name {
    font-size: 13.5px;
    font-weight: 600;
    color: var(--gray-700);
}

.category-count {
    font-size: 12px;
    color: var(--gray-400);
    background: var(--gray-50);
    padding: 3px 10px;
    border-radius: 20px;
    font-weight: 500;
}

/* === Modal === */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(17, 24, 39, 0.5);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
    opacity: 0;
    visibility: hidden;
    transition: 0.2s ease;
    padding: 20px;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--white);
    border-radius: 16px;
    padding: 28px;
    width: 100%;
    max-width: 460px;
    box-shadow: 0 24px 48px rgba(0,0,0,0.12), 0 0 0 1px rgba(0,0,0,0.03);
    transform: scale(0.96) translateY(8px);
    transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.modal-overlay.active .modal {
    transform: scale(1) translateY(0);
}

.modal-title {
    font-size: 17px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 20px;
    letter-spacing: -0.03em;
}

.modal .form-group {
    margin-bottom: 14px;
}

.modal .form-group label {
    display: block;
    font-size: 12.5px;
    font-weight: 600;
    color: var(--gray-500);
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.modal input,
.modal select,
.modal textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1.5px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-size: 13.5px;
    color: var(--gray-700);
    background: var(--white);
    outline: none;
    transition: var(--transition);
    font-family: inherit;
}

.modal input:focus,
.modal select:focus,
.modal textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.modal textarea {
    resize: vertical;
    min-height: 80px;
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 22px;
}

/* === Empty State === */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    color: var(--gray-400);
}

.empty-state svg {
    margin-bottom: 16px;
    opacity: 0.4;
}

.empty-state p {
    font-size: 14px;
    margin-bottom: 16px;
    font-weight: 500;
}

/* === Toast === */
.toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    padding: 11px 20px;
    background: var(--gray-900);
    color: white;
    border-radius: var(--radius);
    font-size: 13.5px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    transform: translateY(100px);
    opacity: 0;
    transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 300;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

/* === Responsive === */
@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
    }

    .sidebar-close-btn {
        display: flex;
    }

    .sidebar {
        transform: translateX(-100%);
        box-shadow: none;
    }

    .sidebar.open {
        transform: translateX(0);
        box-shadow: 16px 0 48px rgba(0,0,0,0.1);
    }

    .sidebar-overlay.active {
        display: block;
    }

    .main-content {
        margin-left: 0;
    }

    .topbar {
        padding: 0 16px;
    }

    .content-area {
        padding: 16px;
    }

    .bookmark-grid {
        grid-template-columns: 1fr;
    }

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

    .page-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .bookmark-actions {
        opacity: 1;
    }

    .modal {
        margin: 16px;
    }

    .category-list {
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    .search-box {
        max-width: 100%;
    }
}