/* ===========================
   CSS Variables
   =========================== */
:root {
    /* Colors */
    --bg-primary: #000000;
    --bg-secondary: #1c1c1e;
    --bg-tertiary: #2c2c2e;
    --bg-elevated: #3a3a3c;

    --text-primary: #ffffff;
    --text-secondary: #8e8e93;
    --text-tertiary: #636366;

    --accent: #0a84ff;
    --accent-dim: rgba(10, 132, 255, 0.2);
    --danger: #ff453a;
    --danger-dim: rgba(255, 69, 58, 0.2);
    --success: #30d158;
    --warning: #ffd60a;

    --border-color: #38383a;
    --border-light: #2c2c2e;

    /* Typography */
    --font-mono: 'SF Mono', 'Menlo', 'Monaco', 'Courier New', monospace;
    --font-size-xs: 11px;
    --font-size-sm: 13px;
    --font-size-base: 15px;
    --font-size-lg: 17px;
    --font-size-xl: 20px;
    --font-size-2xl: 28px;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-2xl: 24px;

    /* Layout */
    --header-height: 60px;
    --nav-height: 80px;
    --max-width: 600px;
    --border-radius: 12px;
    --border-radius-sm: 8px;

    /* Safe areas */
    --safe-top: env(safe-area-inset-top, 0px);
    --safe-bottom: env(safe-area-inset-bottom, 0px);
    --safe-left: env(safe-area-inset-left, 0px);
    --safe-right: env(safe-area-inset-right, 0px);

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.2s ease;
    --transition-slow: 0.3s ease;
}

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

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-mono);
    font-size: var(--font-size-base);
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    min-height: 100vh;
    min-height: 100dvh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    -webkit-tap-highlight-color: transparent;
}

input, textarea, button {
    font-family: inherit;
    font-size: inherit;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    color: inherit;
}

a {
    color: var(--accent);
    text-decoration: none;
}

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

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* ===========================
   Header
   =========================== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    height: var(--header-height);
    padding-top: var(--safe-top);
    background: rgba(0, 0, 0, 0.72);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
}

.header-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    letter-spacing: -0.02em;
}

/* ===========================
   Views Container
   =========================== */
.views-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--spacing-lg);
    padding-bottom: calc(100px + var(--safe-bottom));
}

.view {
    display: none;
    animation: fadeIn var(--transition-normal);
}

.view.active {
    display: block;
}

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

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(100%);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===========================
   Bottom Navigation
   =========================== */
.bottom-nav {
    position: fixed;
    bottom: calc(20px + var(--safe-bottom));
    right: 20px;
    z-index: 1000;
    display: flex;
    gap: var(--spacing-xl);
    padding: var(--spacing-sm) var(--spacing-xl);
    background: rgba(28, 28, 30, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 32px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.nav-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    min-width: 44px;
    min-height: 44px;
    padding: var(--spacing-xs);
    background: transparent;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.nav-btn:active {
    transform: scale(0.95);
}

.nav-btn.active {
    color: var(--accent);
}

.nav-icon {
    width: 24px;
    height: 24px;
}

.nav-label {
    font-size: 10px;
    font-weight: 500;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    min-height: 44px;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-sm);
    font-weight: 500;
    border-radius: var(--border-radius);
    transition: all var(--transition-fast);
}

.btn:active {
    transform: scale(0.98);
}

.btn-primary {
    background: var(--accent);
    color: var(--text-primary);
}

.btn-primary:hover {
    background: #0077e6;
}

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

.btn-secondary:hover {
    background: var(--bg-elevated);
}

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

.btn-danger:hover {
    background: rgba(255, 69, 58, 0.3);
}

.btn-full {
    width: 100%;
}

/* ===========================
   Add/Edit View - Editor
   =========================== */
.editor-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.note-title-input {
    width: 100%;
    padding: var(--spacing-md);
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--border-color);
    outline: none;
    transition: border-color var(--transition-fast);
}

.note-title-input:focus {
    border-color: var(--accent);
}

.note-title-input::placeholder {
    color: var(--text-tertiary);
}

.tags-input-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
}

.tags-label {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.note-tags-input {
    flex: 1;
    padding: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    outline: none;
    transition: border-color var(--transition-fast);
}

.note-tags-input:focus {
    border-color: var(--accent);
}

.note-tags-input::placeholder {
    color: var(--text-tertiary);
}

.editor {
    min-height: 300px;
    padding: var(--spacing-md);
    font-size: var(--font-size-base);
    line-height: 1.7;
    color: var(--text-primary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    outline: none;
    overflow-y: auto;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.editor:focus {
    border-color: var(--accent);
}

.editor:empty::before {
    content: attr(data-placeholder);
    color: var(--text-tertiary);
    pointer-events: none;
}

/* Editor line styling */
.editor-line {
    min-height: 1.7em;
    padding: 2px 0;
}

.editor-line.focused {
    background: var(--bg-tertiary);
    border-radius: var(--border-radius-sm);
    margin: 0 calc(-1 * var(--spacing-sm));
    padding: 2px var(--spacing-sm);
}

/* Markdown rendered styles */
.editor .md-h1 {
    font-size: 1.75em;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0.5em 0 0.25em;
}

.editor .md-h2 {
    font-size: 1.5em;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0.5em 0 0.25em;
}

.editor .md-h3 {
    font-size: 1.25em;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0.5em 0 0.25em;
}

.editor .md-bold {
    font-weight: 700;
}

.editor .md-italic {
    font-style: italic;
}

.editor .md-code {
    font-family: var(--font-mono);
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.9em;
}

.editor .md-link {
    color: var(--accent);
    text-decoration: underline;
}

.editor .md-list-item::before {
    content: "• ";
    color: var(--accent);
}

.editor .md-blockquote {
    border-left: 3px solid var(--accent);
    padding-left: var(--spacing-md);
    color: var(--text-secondary);
    font-style: italic;
}

.editor-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.editor-actions .btn {
    flex: 1;
}

/* ===========================
   Notes List View
   =========================== */
.search-container {
    position: relative;
    margin-bottom: var(--spacing-md);
}

.search-input {
    width: 100%;
    padding: var(--spacing-md);
    padding-right: 40px;
    font-size: var(--font-size-base);
    color: var(--text-primary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    outline: none;
    transition: border-color var(--transition-fast);
}

.search-input:focus {
    border-color: var(--accent);
}

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

.btn-clear-search {
    position: absolute;
    right: var(--spacing-sm);
    top: 50%;
    transform: translateY(-50%);
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    border-radius: 50%;
    transition: all var(--transition-fast);
}

.btn-clear-search:hover {
    color: var(--text-primary);
    background: var(--bg-elevated);
}

.filter-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.filter-tags {
    display: flex;
    gap: var(--spacing-sm);
    overflow-x: auto;
    padding: var(--spacing-xs) 0;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.filter-tags::-webkit-scrollbar {
    display: none;
}

.filter-chip {
    flex-shrink: 0;
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-xs);
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    transition: all var(--transition-fast);
}

.filter-chip:hover {
    background: var(--bg-tertiary);
}

.filter-chip.active {
    color: var(--accent);
    background: var(--accent-dim);
    border-color: var(--accent);
}

.sort-controls {
    flex-shrink: 0;
}

.btn-sort {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.btn-sort:hover {
    background: var(--bg-tertiary);
}

.sort-arrow {
    transition: transform var(--transition-fast);
}

.btn-sort.asc .sort-arrow {
    transform: rotate(180deg);
}

.notes-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.note-card {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.note-card:hover {
    background: var(--bg-tertiary);
    border-color: var(--border-light);
}

.note-card:active {
    transform: scale(0.99);
}

.note-card-title {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.note-card-preview {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.note-card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-sm);
}

.note-card-tags {
    display: flex;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
    overflow: hidden;
}

.note-tag {
    padding: 2px var(--spacing-sm);
    font-size: var(--font-size-xs);
    color: var(--accent);
    background: var(--accent-dim);
    border-radius: 10px;
}

.note-card-date {
    flex-shrink: 0;
    font-size: var(--font-size-xs);
    color: var(--text-tertiary);
}

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl);
    text-align: center;
    color: var(--text-secondary);
}

.empty-hint {
    font-size: var(--font-size-sm);
    color: var(--text-tertiary);
    margin-top: var(--spacing-sm);
}

/* ===========================
   Settings View
   =========================== */
.settings-group {
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
}

.settings-title {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-md);
}

.settings-description {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.5;
}

.settings-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-light);
}

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

.settings-label {
    font-size: var(--font-size-sm);
    color: var(--text-primary);
}

.settings-value {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.settings-field {
    margin-bottom: var(--spacing-md);
}

.settings-field label {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.settings-input {
    width: 100%;
    padding: var(--spacing-md);
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    outline: none;
    transition: border-color var(--transition-fast);
}

.settings-input:focus {
    border-color: var(--accent);
}

.settings-input::placeholder {
    color: var(--text-tertiary);
}

.sync-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.sync-buttons .btn {
    flex: 1;
}

.settings-group .btn {
    margin-top: var(--spacing-sm);
}

/* ===========================
   Toast Notifications
   =========================== */
.toast-container {
    position: fixed;
    top: calc(var(--header-height) + var(--safe-top) + var(--spacing-md));
    left: 50%;
    transform: translateX(-50%);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-width: calc(var(--max-width) - var(--spacing-lg) * 2);
    width: 100%;
    padding: 0 var(--spacing-lg);
    pointer-events: none;
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-elevated);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
    animation: slideDown var(--transition-normal);
    pointer-events: auto;
}

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

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

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

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

.toast-close {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    cursor: pointer;
    transition: color var(--transition-fast);
}

.toast-close:hover {
    color: var(--text-primary);
}

/* ===========================
   Modal
   =========================== */
.modal {
    position: fixed;
    inset: 0;
    z-index: 3000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    width: 100%;
    max-width: 320px;
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    animation: slideUp var(--transition-slow);
}

.modal-message {
    font-size: var(--font-size-base);
    color: var(--text-primary);
    text-align: center;
    margin-bottom: var(--spacing-xl);
    line-height: 1.5;
}

.modal-actions {
    display: flex;
    gap: var(--spacing-md);
}

.modal-actions .btn {
    flex: 1;
}

/* ===========================
   Responsive
   =========================== */
@media (min-width: 768px) {
    .views-container {
        padding: var(--spacing-xl);
    }

    .editor {
        min-height: 400px;
    }
}

/* ===========================
   Selection & Focus
   =========================== */
::selection {
    background: var(--accent);
    color: var(--text-primary);
}

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Remove default focus for touch devices */
@media (hover: none) {
    :focus-visible {
        outline: none;
    }
}

/* ===========================
   Scrollbar
   =========================== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--bg-elevated);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}