/* JSON Formatter — Dark Mode Default, Light Mode Toggle */

/* ========================================
   THEME VARIABLES
   ======================================== */

:root {
    /* Dark theme (default) */
    --bg-primary: #1a1b26;
    --bg-secondary: #24283b;
    --bg-tertiary: #2f3348;
    --text-primary: #c0caf5;
    --text-secondary: #a9b1d6;
    --text-muted: #565f89;
    --accent: #7aa2f7;
    --accent-hover: #89b4fa;
    --accent-glow: rgba(122, 162, 247, 0.15);
    --success: #9ece6a;
    --error: #f7768e;
    --warning: #e0af68;
    --border: #3b4261;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', 'Cascadia Code', Consolas, monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    --radius: 8px;
    --radius-sm: 4px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.4);
    --transition-fast: 0.15s ease;
    --transition-med: 0.25s ease;

    /* Syntax highlighting */
    --syn-key: #7aa2f7;
    --syn-string: #9ece6a;
    --syn-number: #ff9e64;
    --syn-boolean: #bb9af7;
    --syn-null: #565f89;
    --syn-bracket: #a9b1d6;
    --syn-colon: #89ddff;

    /* Diff colors */
    --diff-added-bg: rgba(158, 206, 106, 0.12);
    --diff-added-border: rgba(158, 206, 106, 0.4);
    --diff-removed-bg: rgba(247, 118, 142, 0.12);
    --diff-removed-border: rgba(247, 118, 142, 0.4);
    --diff-changed-bg: rgba(224, 175, 104, 0.12);
    --diff-changed-border: rgba(224, 175, 104, 0.4);

    /* Search highlight */
    --search-highlight: rgba(224, 175, 104, 0.35);
    --search-highlight-border: rgba(224, 175, 104, 0.7);

    /* Drag overlay */
    --drag-overlay-bg: rgba(26, 27, 38, 0.92);
}

/* Light theme */
[data-theme="light"] {
    --bg-primary: #f5f5f7;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e8e8ec;
    --text-primary: #1e1e2e;
    --text-secondary: #4c4f69;
    --text-muted: #8c8fa1;
    --accent: #1e66f5;
    --accent-hover: #2c7af7;
    --accent-glow: rgba(30, 102, 245, 0.1);
    --success: #40a02b;
    --error: #d20f39;
    --warning: #df8e1d;
    --border: #ccd0da;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.12);

    --syn-key: #1e66f5;
    --syn-string: #40a02b;
    --syn-number: #fe640b;
    --syn-boolean: #8839ef;
    --syn-null: #8c8fa1;
    --syn-bracket: #4c4f69;
    --syn-colon: #04a5e5;

    --diff-added-bg: rgba(64, 160, 43, 0.1);
    --diff-added-border: rgba(64, 160, 43, 0.4);
    --diff-removed-bg: rgba(210, 15, 57, 0.1);
    --diff-removed-border: rgba(210, 15, 57, 0.4);
    --diff-changed-bg: rgba(223, 142, 29, 0.1);
    --diff-changed-border: rgba(223, 142, 29, 0.4);

    --search-highlight: rgba(223, 142, 29, 0.25);
    --search-highlight-border: rgba(223, 142, 29, 0.6);

    --drag-overlay-bg: rgba(245, 245, 247, 0.95);
}

/* ========================================
   RESET & BASE
   ======================================== */

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: background var(--transition-med), color var(--transition-med);
}

/* ========================================
   APP LAYOUT
   ======================================== */

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 1200px;
    margin: 0 auto;
}

/* ========================================
   HEADER
   ======================================== */

.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    border-bottom: 1px solid var(--border);
    flex: 0 0 auto;
    background: var(--bg-secondary);
    transition: background var(--transition-med), border-color var(--transition-med);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 6px;
}

.app-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    font-family: var(--font-mono);
    letter-spacing: -0.3px;
}

.privacy-badge {
    font-size: 0.65rem;
    padding: 2px 8px;
    background: rgba(158, 206, 106, 0.15);
    color: var(--success);
    border-radius: 12px;
    border: 1px solid rgba(158, 206, 106, 0.3);
    white-space: nowrap;
    font-weight: 500;
    letter-spacing: 0.2px;
}

[data-theme="light"] .privacy-badge {
    background: rgba(64, 160, 43, 0.1);
    border-color: rgba(64, 160, 43, 0.3);
}

.file-upload-btn {
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.78rem;
}

.indent-select {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 5px 8px;
    font-size: 0.78rem;
    font-family: var(--font-mono);
    cursor: pointer;
    transition: border-color var(--transition-fast), background var(--transition-med);
}

.indent-select:focus {
    outline: none;
    border-color: var(--accent);
}

/* Theme Toggle */
.theme-toggle {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
    padding: 0;
    line-height: 1;
}

.theme-toggle:hover {
    background: var(--accent-glow);
    border-color: var(--accent);
    transform: scale(1.05);
}

.theme-toggle:active {
    transform: scale(0.95);
}

/* Shortcuts button */
.shortcuts-btn {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    width: 26px;
    height: 26px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ========================================
   TAB CONTENT
   ======================================== */

.tab-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
}

.tab-content.hidden {
    display: none !important;
}

/* Main Content (Format tab) */
.main-content {
    padding: 10px 16px;
    gap: 8px;
}

/* ========================================
   PANELS
   ======================================== */

.panel {
    display: flex;
    flex-direction: column;
    flex: 1;
    min-height: 0;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: background var(--transition-med), border-color var(--transition-med);
}

.panel:focus-within {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 6px 12px;
    border-bottom: 1px solid var(--border);
    background: var(--bg-tertiary);
    flex: 0 0 auto;
    transition: background var(--transition-med), border-color var(--transition-med);
}

.panel-label {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
}

.panel-actions {
    display: flex;
    gap: 2px;
    align-items: center;
}

/* ========================================
   BUTTONS
   ======================================== */

.btn-icon {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.78rem;
    transition: background var(--transition-fast), color var(--transition-fast), transform 0.1s;
}

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

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

.btn-primary {
    background: var(--accent);
    color: #fff;
    border: none;
    padding: 9px 22px;
    border-radius: var(--radius);
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--transition-fast), transform 0.1s, box-shadow var(--transition-fast);
    letter-spacing: 0.2px;
}

[data-theme="light"] .btn-primary {
    color: #fff;
}

.btn-primary:hover {
    background: var(--accent-hover);
    box-shadow: 0 2px 8px var(--accent-glow);
}

.btn-primary:active {
    transform: scale(0.97);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 9px 16px;
    border-radius: var(--radius);
    font-size: 0.88rem;
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition-fast), border-color var(--transition-fast);
}

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

.btn-sm {
    padding: 5px 10px;
    font-size: 0.78rem;
}

/* ========================================
   ACTION BAR
   ======================================== */

.action-bar {
    display: flex;
    gap: 8px;
    justify-content: center;
    align-items: center;
    padding: 4px 16px;
    flex: 0 0 auto;
}

.action-bar-vertical {
    flex-direction: column;
    padding: 4px 8px;
}

/* ========================================
   TEXTAREA & OUTPUT
   ======================================== */

.code-textarea {
    flex: 1;
    width: 100%;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: none;
    padding: 12px;
    font-family: var(--font-mono);
    font-size: 0.83rem;
    line-height: 1.6;
    resize: none;
    outline: none;
    tab-size: 4;
    transition: background var(--transition-med), color var(--transition-med);
}

.code-textarea::placeholder {
    color: var(--text-muted);
}

.code-textarea[readonly] {
    cursor: default;
}

.code-output {
    flex: 1;
    overflow: auto;
    padding: 12px;
    font-family: var(--font-mono);
    font-size: 0.83rem;
    line-height: 1.6;
    margin: 0;
    white-space: pre-wrap;
    word-wrap: break-word;
    transition: color var(--transition-med);
}

/* ========================================
   VALIDATION STATUS
   ======================================== */

.validation-status {
    padding: 7px 12px;
    font-size: 0.78rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 6px;
    animation: fadeIn 0.2s ease;
}

.validation-status.hidden {
    display: none;
}

.validation-status.valid {
    background: rgba(158, 206, 106, 0.1);
    color: var(--success);
    border-bottom: 1px solid rgba(158, 206, 106, 0.2);
}

.validation-status.invalid {
    background: rgba(247, 118, 142, 0.1);
    color: var(--error);
    border-bottom: 1px solid rgba(247, 118, 142, 0.2);
}

[data-theme="light"] .validation-status.valid {
    background: rgba(64, 160, 43, 0.08);
    border-bottom-color: rgba(64, 160, 43, 0.2);
}

[data-theme="light"] .validation-status.invalid {
    background: rgba(210, 15, 57, 0.08);
    border-bottom-color: rgba(210, 15, 57, 0.2);
}

/* Stats Inline */
.stats-inline {
    font-size: 0.68rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
    white-space: nowrap;
}

/* ========================================
   SYNTAX HIGHLIGHTING
   ======================================== */

.syn-key { color: var(--syn-key); }
.syn-string { color: var(--syn-string); }
.syn-number { color: var(--syn-number); }
.syn-boolean { color: var(--syn-boolean); }
.syn-null { color: var(--syn-null); font-style: italic; }
.syn-bracket { color: var(--syn-bracket); }
.syn-colon { color: var(--syn-colon); }

/* ========================================
   TREE VIEWER
   ======================================== */

.tree-toolbar {
    display: flex;
    gap: 8px;
    align-items: center;
    padding: 8px 16px;
    flex: 0 0 auto;
    flex-wrap: wrap;
}

.tree-panel {
    margin: 0 16px 10px;
}

.tree-container {
    flex: 1;
    overflow: auto;
    padding: 12px;
    font-family: var(--font-mono);
    font-size: 0.83rem;
    line-height: 1.5;
}

.tree-placeholder {
    color: var(--text-muted);
    font-style: italic;
    text-align: center;
    padding: 40px 20px;
    font-family: var(--font-sans);
}

/* Search box */
.search-box {
    display: flex;
    align-items: center;
    gap: 6px;
    flex: 1;
    max-width: 320px;
    min-width: 150px;
}

.search-input {
    flex: 1;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 5px 10px;
    font-size: 0.78rem;
    font-family: var(--font-mono);
    outline: none;
    transition: border-color var(--transition-fast), background var(--transition-med);
}

.search-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

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

/* Tree nodes */
.tree-node {
    margin-left: 0;
}

.tree-node .tree-node {
    margin-left: 20px;
}

.tree-row {
    display: flex;
    align-items: flex-start;
    padding: 2px 4px;
    border-radius: 3px;
    cursor: pointer;
    gap: 4px;
    transition: background 0.1s;
}

.tree-row:hover {
    background: var(--bg-tertiary);
}

.tree-row.search-match {
    background: var(--search-highlight);
    outline: 1px solid var(--search-highlight-border);
}

.tree-row.path-selected {
    background: rgba(122, 162, 247, 0.2);
    outline: 1px solid rgba(122, 162, 247, 0.5);
}

[data-theme="light"] .tree-row.path-selected {
    background: rgba(30, 102, 245, 0.12);
    outline-color: rgba(30, 102, 245, 0.4);
}

.tree-toggle {
    width: 16px;
    height: 16px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-muted);
    font-size: 0.7rem;
    flex-shrink: 0;
    border: none;
    background: none;
    padding: 0;
    margin-top: 2px;
    transition: transform var(--transition-fast), color var(--transition-fast);
    user-select: none;
}

.tree-toggle:hover {
    color: var(--accent);
}

.tree-toggle.collapsed {
    transform: rotate(-90deg);
}

.tree-toggle.leaf {
    visibility: hidden;
}

.tree-key {
    color: var(--syn-key);
    margin-right: 2px;
    flex-shrink: 0;
}

.tree-separator {
    color: var(--syn-colon);
    margin-right: 6px;
    flex-shrink: 0;
}

.tree-value {
    word-break: break-all;
}

.tree-value.type-string { color: var(--syn-string); }
.tree-value.type-number { color: var(--syn-number); }
.tree-value.type-boolean { color: var(--syn-boolean); }
.tree-value.type-null { color: var(--syn-null); font-style: italic; }

.tree-bracket {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.tree-count {
    color: var(--text-muted);
    font-size: 0.68rem;
    margin-left: 6px;
}

.tree-children {
    overflow: hidden;
}

.tree-children.collapsed {
    display: none;
}

/* Path Finder Toast */
.path-toast {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    flex: 0 0 auto;
    animation: slideDown 0.2s ease;
}

.path-toast.hidden {
    display: none;
}

.path-toast-text {
    color: var(--accent);
    flex: 1;
    word-break: break-all;
    user-select: all;
}

/* ========================================
   DIFF VIEWER
   ======================================== */

.diff-panels {
    display: flex;
    gap: 10px;
    padding: 10px 16px 0;
    flex: 1;
    min-height: 0;
}

.diff-input-panel {
    flex: 1;
}

.diff-output-panel {
    margin: 0 16px 10px;
    flex: 1;
    min-height: 120px;
}

.diff-output {
    flex: 1;
    overflow: auto;
    padding: 12px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    line-height: 1.6;
}

.diff-item {
    padding: 6px 10px;
    margin: 3px 0;
    border-radius: var(--radius-sm);
    border-left: 3px solid;
    display: flex;
    align-items: flex-start;
    gap: 8px;
    animation: fadeIn 0.15s ease;
}

.diff-item.added {
    background: var(--diff-added-bg);
    border-left-color: var(--success);
}

.diff-item.removed {
    background: var(--diff-removed-bg);
    border-left-color: var(--error);
}

.diff-item.changed {
    background: var(--diff-changed-bg);
    border-left-color: var(--warning);
}

.diff-badge {
    font-size: 0.62rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 2px 6px;
    border-radius: 3px;
    flex-shrink: 0;
    margin-top: 1px;
}

.diff-item.added .diff-badge {
    background: rgba(158, 206, 106, 0.25);
    color: var(--success);
}

.diff-item.removed .diff-badge {
    background: rgba(247, 118, 142, 0.25);
    color: var(--error);
}

.diff-item.changed .diff-badge {
    background: rgba(224, 175, 104, 0.25);
    color: var(--warning);
}

.diff-path {
    color: var(--accent);
    font-weight: 500;
    word-break: break-all;
}

.diff-detail {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.diff-values {
    font-size: 0.76rem;
    color: var(--text-secondary);
}

.diff-values .old-val {
    color: var(--error);
    text-decoration: line-through;
    opacity: 0.8;
}

.diff-values .new-val {
    color: var(--success);
}

.diff-summary {
    display: flex;
    gap: 16px;
    padding: 8px 12px;
    background: var(--bg-tertiary);
    border-top: 1px solid var(--border);
    font-size: 0.73rem;
    font-family: var(--font-mono);
    flex: 0 0 auto;
}

.diff-summary-item {
    display: flex;
    align-items: center;
    gap: 4px;
}

.diff-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.diff-dot.added { background: var(--success); }
.diff-dot.removed { background: var(--error); }
.diff-dot.changed { background: var(--warning); }

/* ========================================
   CONVERT (JSON <-> CSV)
   ======================================== */

.convert-toolbar {
    display: flex;
    gap: 8px;
    align-items: center;
    padding: 8px 16px;
    flex: 0 0 auto;
}

.convert-direction {
    display: flex;
    gap: 0;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}

.convert-dir-btn {
    border: none;
    border-radius: 0;
    padding: 5px 14px;
    font-size: 0.78rem;
    border-right: 1px solid var(--border);
    transition: background var(--transition-fast), color var(--transition-fast);
}

.convert-dir-btn:last-child {
    border-right: none;
}

.convert-dir-btn.active {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.convert-panels {
    display: flex;
    flex: 1;
    min-height: 0;
    gap: 0;
    padding: 0 16px 10px;
}

.convert-input-panel,
.convert-output-panel {
    flex: 1;
}

/* ========================================
   HISTORY
   ======================================== */

.history-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 16px;
    flex: 0 0 auto;
}

.history-panel {
    margin: 0 16px 10px;
}

.history-list {
    flex: 1;
    overflow: auto;
    padding: 8px;
}

.history-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px 12px;
    margin-bottom: 5px;
    background: var(--bg-tertiary);
    border-radius: var(--radius);
    border: 1px solid transparent;
    cursor: pointer;
    transition: border-color var(--transition-fast), background var(--transition-fast), transform 0.1s;
}

.history-item:hover {
    border-color: var(--accent);
    background: var(--accent-glow);
    transform: translateX(2px);
}

.history-item-content {
    flex: 1;
    min-width: 0;
}

.history-item-preview {
    font-family: var(--font-mono);
    font-size: 0.76rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.4;
}

.history-item-meta {
    display: flex;
    gap: 12px;
    font-size: 0.65rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.history-item-actions {
    display: flex;
    gap: 2px;
    flex-shrink: 0;
}

.history-item-actions .btn-icon {
    font-size: 0.73rem;
    padding: 2px 6px;
    opacity: 0.6;
    transition: opacity var(--transition-fast);
}

.history-item:hover .history-item-actions .btn-icon {
    opacity: 1;
}

/* ========================================
   BOTTOM NAVIGATION
   ======================================== */

.bottom-nav {
    display: flex;
    border-top: 1px solid var(--border);
    background: var(--bg-secondary);
    flex: 0 0 auto;
    transition: background var(--transition-med), border-color var(--transition-med);
}

.nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1px;
    padding: 8px 0;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    transition: color var(--transition-fast);
    border-top: 2px solid transparent;
    position: relative;
}

.nav-item:hover {
    color: var(--text-secondary);
}

.nav-item.active {
    color: var(--accent);
    border-top-color: var(--accent);
}

.nav-icon {
    font-size: 1.1rem;
    line-height: 1;
}

.nav-label {
    font-size: 0.6rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

/* ========================================
   TOAST NOTIFICATION
   ======================================== */

.toast-container {
    position: fixed;
    bottom: 70px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    pointer-events: none;
}

.toast {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 8px 18px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
    animation: toastIn 0.3s ease, toastOut 0.3s ease 2s forwards;
    pointer-events: auto;
    white-space: nowrap;
}

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

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

/* ========================================
   DRAG & DROP OVERLAY
   ======================================== */

.drag-overlay {
    position: fixed;
    inset: 0;
    background: var(--drag-overlay-bg);
    z-index: 999;
    display: none;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 12px;
    backdrop-filter: blur(4px);
}

.drag-overlay.active {
    display: flex;
}

.drag-overlay-icon {
    font-size: 3rem;
    animation: bounce 0.6s ease infinite alternate;
}

.drag-overlay-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--accent);
}

.drag-overlay-sub {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ========================================
   KEYBOARD SHORTCUTS MODAL
   ======================================== */

.shortcuts-modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1001;
    display: none;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(2px);
    animation: fadeIn 0.15s ease;
}

.shortcuts-modal-overlay.active {
    display: flex;
}

.shortcuts-modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    max-width: 420px;
    width: 90%;
    box-shadow: var(--shadow-lg);
    animation: modalIn 0.2s ease;
}

.shortcuts-modal h2 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.shortcuts-modal .shortcut-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 6px 0;
    border-bottom: 1px solid var(--border);
}

.shortcuts-modal .shortcut-row:last-child {
    border-bottom: none;
}

.shortcut-label {
    font-size: 0.82rem;
    color: var(--text-secondary);
}

.shortcut-keys {
    display: flex;
    gap: 4px;
    align-items: center;
}

.shortcut-key {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 2px 7px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--text-primary);
    min-width: 24px;
    text-align: center;
}

.shortcuts-modal .close-btn {
    margin-top: 16px;
    width: 100%;
    padding: 8px;
    font-size: 0.82rem;
}

/* ========================================
   ANIMATIONS
   ======================================== */

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

@keyframes toastIn {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes toastOut {
    from { opacity: 1; transform: translateY(0); }
    to { opacity: 0; transform: translateY(-12px); }
}

@keyframes bounce {
    from { transform: translateY(0); }
    to { transform: translateY(-8px); }
}

@keyframes modalIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

/* ========================================
   SCROLLBAR
   ======================================== */

::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

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

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

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

/* ========================================
   RESPONSIVE
   ======================================== */

@media (min-width: 768px) {
    .main-content {
        display: grid;
        grid-template-columns: 1fr 1fr;
        grid-template-rows: auto 1fr;
        gap: 10px;
    }

    .action-bar {
        grid-column: 1 / -1;
        grid-row: 1;
    }

    .input-panel {
        grid-column: 1;
        grid-row: 2;
    }

    .output-panel {
        grid-column: 2;
        grid-row: 2;
    }

    .convert-panels {
        flex-direction: row;
    }
}

@media (max-width: 767px) {
    .convert-panels {
        flex-direction: column;
    }

    .app-title {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .app-header {
        padding: 8px 10px;
    }

    .app-title {
        font-size: 0.85rem;
    }

    .privacy-badge {
        font-size: 0.58rem;
        padding: 2px 6px;
    }

    .main-content {
        padding: 6px 10px;
    }

    .btn-primary {
        padding: 8px 16px;
        font-size: 0.82rem;
    }

    .btn-secondary {
        padding: 8px 12px;
        font-size: 0.82rem;
    }

    .diff-panels {
        flex-direction: column;
        padding: 6px 10px 0;
    }

    .diff-input-panel {
        max-height: 30vh;
    }

    .tree-toolbar {
        padding: 6px 10px;
    }

    .tree-panel {
        margin: 0 10px 6px;
    }

    .diff-output-panel {
        margin: 0 10px 6px;
    }

    .tree-node .tree-node {
        margin-left: 14px;
    }

    .search-box {
        max-width: 100%;
        order: 10;
        flex-basis: 100%;
    }

    .convert-toolbar {
        padding: 6px 10px;
    }

    .convert-panels {
        padding: 0 10px 6px;
    }

    .history-toolbar {
        padding: 6px 10px;
    }

    .history-panel {
        margin: 0 10px 6px;
    }

    .nav-label {
        font-size: 0.52rem;
    }

    .nav-icon {
        font-size: 1rem;
    }

    .shortcuts-modal {
        padding: 16px;
    }

    .theme-toggle {
        width: 28px;
        height: 28px;
        font-size: 0.9rem;
    }
}