:root {
    --bg:          #0d0d14;
    --surface:     #16161f;
    --surface-2:   #1e1e2e;
    --border:      #2a2a3d;
    --accent:      #7c3aed;
    --accent-l:    #a855f7;
    --text:        #cdd6f4;
    --text-muted:  #6c7086;
    --danger:      #f38ba8;
    --success:     #a6e3a1;
    --warning:     #fab387;
    --r:           6px;
    --mono:        'JetBrains Mono', 'Fira Code', 'Cascadia Code', ui-monospace, monospace;
    --sans:        'Inter', system-ui, -apple-system, sans-serif;
}

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

body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--sans);
    height: 100vh;
    overflow: hidden;
}

/* -------------------------------------------------------------------------
   Shared
------------------------------------------------------------------------- */

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: .375rem;
    padding: .375rem .75rem;
    border-radius: var(--r);
    font-size: .8125rem;
    font-weight: 500;
    cursor: pointer;
    border: 1px solid transparent;
    transition: background .12s, color .12s, border-color .12s, opacity .12s;
    white-space: nowrap;
}
.btn:disabled { opacity: .4; cursor: not-allowed; }

.btn-ghost {
    background: transparent;
    color: var(--text-muted);
    border-color: var(--border);
}
.btn-ghost:hover:not(:disabled) { background: var(--surface-2); color: var(--text); }

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    width: 100%;
    justify-content: center;
    padding: .6875rem 1rem;
    font-size: .9375rem;
}
.btn-primary:hover:not(:disabled) { background: #6d28d9; border-color: #6d28d9; }

.btn-danger {
    background: transparent;
    color: var(--danger);
    border-color: rgba(243,139,168,.3);
}
.btn-danger:hover:not(:disabled) { background: rgba(243,139,168,.08); }

/* -------------------------------------------------------------------------
   Login page
------------------------------------------------------------------------- */

.login-wrap {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 1.5rem;
}

.login-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2.5rem;
    width: 100%;
    max-width: 400px;
}

.login-logo {
    display: flex;
    align-items: center;
    gap: .625rem;
    margin-bottom: 2rem;
}
.login-logo svg { color: var(--accent-l); flex-shrink: 0; }
.login-logo span { font-size: 1.25rem; font-weight: 700; letter-spacing: -.02em; }

.form-group { margin-bottom: 1.125rem; }

label {
    display: block;
    font-size: .75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: .07em;
    color: var(--text-muted);
    margin-bottom: .4rem;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: .625rem .875rem;
    color: var(--text);
    font-size: .9375rem;
    outline: none;
    transition: border-color .15s;
}
input:focus { border-color: var(--accent); }
input[type="password"] { font-family: var(--mono); letter-spacing: .1em; }

.error-msg {
    color: var(--danger);
    font-size: .8125rem;
    margin-top: .625rem;
    min-height: 1.25rem;
}

.login-hint {
    color: var(--text-muted);
    font-size: .75rem;
    margin-top: 1.25rem;
    text-align: center;
    line-height: 1.6;
}

/* -------------------------------------------------------------------------
   App layout  (CSS grid: sidebar | content, below topbar)
------------------------------------------------------------------------- */

.app-layout {
    display: grid;
    grid-template-columns: 260px 1fr;
    grid-template-rows: 52px 1fr;
    height: 100vh;
}

/* Top bar */
.topbar {
    grid-column: 1 / -1;
    display: flex;
    align-items: center;
    gap: .75rem;
    padding: 0 .75rem;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.topbar-brand {
    display: flex;
    align-items: center;
    gap: .5rem;
    font-size: .8125rem;
    font-weight: 600;
    color: var(--text-muted);
    white-space: nowrap;
    flex: 1;
}
.topbar-brand svg { color: var(--accent-l); }

.topbar-actions {
    display: flex;
    align-items: center;
    gap: .5rem;
    flex-shrink: 0;
}

#status-msg { font-size: .75rem; color: var(--text-muted); min-width: 4rem; text-align: right; }
#status-msg.success { color: var(--success); }
#status-msg.error   { color: var(--danger);  }

/* Sidebar */
.sidebar {
    background: var(--surface);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: .625rem .75rem;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}
.sidebar-header h2 {
    font-size: .6875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .1em;
    color: var(--text-muted);
}

#notes-list {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    padding: .375rem;
}

/* -------------------------------------------------------------------------
   Outline panel
------------------------------------------------------------------------- */

.outline-panel {
    flex-shrink: 0;
    max-height: 40%;
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--border);
    overflow: hidden;
}

.outline-panel-label {
    flex-shrink: 0;
    font-size: .625rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .1em;
    color: var(--text-muted);
    padding: .5rem .75rem .3rem;
}

.outline-list {
    overflow-y: auto;
    padding: 0 .375rem .5rem;
}

.outline-item {
    font-size: .75rem;
    color: var(--text-muted);
    padding: .2rem .5rem;
    border-radius: 4px;
    cursor: pointer;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: background .1s, color .1s;
}
.outline-item:hover { background: var(--surface-2); color: var(--text); }

.outline-h1 { padding-left: .5rem;  font-weight: 600; color: var(--text); }
.outline-h2 { padding-left: .5rem; }
.outline-h3 { padding-left: 1.25rem; }
.outline-h4 { padding-left: 2rem; }
.outline-h5 { padding-left: 2.75rem; }
.outline-h6 { padding-left: 3.5rem; }

.note-item {
    padding: .5rem .625rem;
    border-radius: var(--r);
    cursor: pointer;
    border: 1px solid transparent;
    margin-bottom: 2px;
    transition: background .1s;
    outline: none;
}
.note-item:hover  { background: var(--surface-2); }
.note-item:focus  { border-color: var(--accent); }
.note-item.active {
    background: rgba(124,58,237,.12);
    border-color: rgba(124,58,237,.35);
}
.note-item-row {
    display: flex;
    align-items: center;
    gap: .25rem;
    margin-bottom: .2rem;
    min-width: 0;
}
.note-item-title-text {
    font-size: .8125rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
    min-width: 0;
}
.note-item-title-input {
    flex: 1;
    min-width: 0;
    background: transparent;
    border: none;
    border-bottom: 1px solid transparent;
    outline: none;
    color: var(--text);
    font-size: .8125rem;
    font-weight: 500;
    font-family: var(--sans);
    padding: 0;
    transition: border-color .15s;
}
.note-item-title-input:focus { border-bottom-color: var(--accent); }
.note-item-date { font-size: .6875rem; color: var(--text-muted); }
.empty-notes {
    padding: 2rem 1rem;
    text-align: center;
    color: var(--text-muted);
    font-size: .8125rem;
    line-height: 1.7;
}

/* Editor area */
.editor-area {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.editor-panes {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.editor-pane,
.preview-pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}
.editor-pane { border-right: 1px solid var(--border); }

.editor-panes.editor-hidden .editor-pane { display: none; }
.editor-panes.editor-hidden .preview-pane { flex: 1; }

.pane-label {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: .3125rem .5rem .3125rem 1rem;
    font-size: .6875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .1em;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border);
    background: var(--surface);
}

.btn-xs {
    padding: .125rem .5rem;
    font-size: .6875rem;
}

#editor {
    flex: 1;
    resize: none;
    background: var(--bg);
    border: none;
    color: var(--text);
    font-family: var(--mono);
    font-size: .9rem;
    line-height: 1.75;
    padding: 1.25rem 1.5rem;
    outline: none;
    tab-size: 4;
}
#editor::placeholder { color: var(--text-muted); }
#editor.drag-over { outline: 2px dashed var(--accent); outline-offset: -4px; }

.preview-content {
    flex: 1;
    overflow-y: auto;
    padding: 1.25rem 1.5rem;
    background: var(--bg);
}

/* -------------------------------------------------------------------------
   Markdown preview typography
------------------------------------------------------------------------- */

.preview-content h1,
.preview-content h2,
.preview-content h3,
.preview-content h4,
.preview-content h5,
.preview-content h6 {
    color: var(--text);
    line-height: 1.3;
    margin: 1.5rem 0 .625rem;
}
.preview-content h1 { font-size: 1.625rem; }
.preview-content h2 { font-size: 1.3rem; border-bottom: 1px solid var(--border); padding-bottom: .3rem; }
.preview-content h3 { font-size: 1.1rem; }

.preview-content p { margin: 0 0 .875rem; line-height: 1.75; }

.preview-content a { color: var(--accent-l); text-decoration: none; }
.preview-content a:hover { text-decoration: underline; }

.preview-content code {
    font-family: var(--mono);
    background: var(--surface-2);
    padding: .1em .35em;
    border-radius: 3px;
    font-size: .85em;
    color: var(--accent-l);
}

.preview-content pre {
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: .875rem 1rem;
    overflow-x: auto;
    margin: 0 0 .875rem;
}
.preview-content pre code {
    background: none;
    padding: 0;
    color: var(--text);
    font-size: .875rem;
}

.preview-content ul,
.preview-content ol { padding-left: 1.5rem; margin: 0 0 .875rem; }
.preview-content li { margin-bottom: .25rem; line-height: 1.75; }

.preview-content blockquote {
    border-left: 3px solid var(--accent);
    padding: .25rem 1rem;
    margin: 0 0 .875rem;
    color: var(--text-muted);
}

.preview-content hr { border: none; border-top: 1px solid var(--border); margin: 1.5rem 0; }

.preview-content img {
    max-width: 100%;
    border-radius: var(--r);
    display: block;
    margin: .5rem 0;
}

.preview-content table { width: 100%; border-collapse: collapse; margin: 0 0 .875rem; font-size: .9rem; }
.preview-content th,
.preview-content td { border: 1px solid var(--border); padding: .4rem .75rem; text-align: left; }
.preview-content th { background: var(--surface-2); font-weight: 600; }

/* -------------------------------------------------------------------------
   Misc
------------------------------------------------------------------------- */

.btn.unsaved::after { content: " •"; color: var(--warning); }

/* -------------------------------------------------------------------------
   Note banner
------------------------------------------------------------------------- */

.note-banner {
    flex-shrink: 0;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
}

.note-banner.banner-active {
    height: 160px;
    background: var(--surface-2);
}

.banner-btn-row {
    position: absolute;
    top: .625rem;
    right: .75rem;
    display: none;
    gap: .375rem;
    opacity: 0;
    transition: opacity .15s;
}
.note-banner.banner-active .banner-btn-row { display: flex; }
.note-banner:hover .banner-btn-row { opacity: 1; }

.banner-btn-row .btn {
    background: rgba(0,0,0,.45);
    color: #fff;
    border-color: rgba(255,255,255,.18);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}
.banner-btn-row .btn:hover {
    background: rgba(0,0,0,.65);
    color: #fff;
    border-color: rgba(255,255,255,.3);
}

/* -------------------------------------------------------------------------
   Cover picker
------------------------------------------------------------------------- */

.cover-picker {
    position: fixed;
    z-index: 1000;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: .875rem;
    width: 320px;
    box-shadow: 0 8px 24px rgba(0,0,0,.5);
}

.cover-picker-section-label {
    font-size: .625rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .1em;
    color: var(--text-muted);
    margin-bottom: .5rem;
}

.cover-picker-colors {
    display: flex;
    flex-wrap: wrap;
    gap: .4rem;
}

.cover-color-swatch {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform .1s, border-color .1s;
    flex-shrink: 0;
}
.cover-color-swatch:hover {
    transform: scale(1.2);
    border-color: var(--text);
}

.cover-picker-images {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: .375rem;
}

.cover-image-thumb {
    aspect-ratio: 2 / 1;
    border-radius: 4px;
    cursor: pointer;
    background-size: cover;
    background-position: center;
    border: 2px solid transparent;
    transition: border-color .1s, transform .1s;
}
.cover-image-thumb:hover {
    border-color: var(--accent-l);
    transform: scale(1.04);
}

/* -------------------------------------------------------------------------
   Note header (icon + title, above editor panes)
------------------------------------------------------------------------- */

.note-header {
    display: flex;
    align-items: center;
    gap: .75rem;
    padding: 1rem 1.5rem;
    flex-shrink: 0;
    background: rgba(13, 13, 20, 0.6);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-top: 1px solid rgba(255,255,255,.06);
}

.note-icon-display {
    font-size: 2rem;
    line-height: 1;
    background: none;
    border: 1px solid transparent;
    border-radius: var(--r);
    cursor: pointer;
    padding: .25rem .3rem;
    transition: background .12s, border-color .12s;
    flex-shrink: 0;
    opacity: .45;
}
.note-icon-display:hover {
    background: var(--surface-2);
    border-color: var(--border);
    opacity: 1;
}
.note-icon-display.icon-btn-set {
    opacity: 1;
}

.note-title-input {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text);
    font-family: var(--sans);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -.025em;
    outline: none;
    min-width: 0;
}
.note-title-input::placeholder { color: var(--text-muted); font-weight: 400; }

.note-title-display {
    flex: 1;
    color: var(--text);
    font-family: var(--sans);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -.025em;
    min-width: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* -------------------------------------------------------------------------
   Icon picker popup
------------------------------------------------------------------------- */

.icon-picker {
    position: fixed;
    z-index: 1000;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: .75rem;
    width: 260px;
    box-shadow: 0 8px 24px rgba(0,0,0,.5);
}

.icon-picker-label {
    font-size: .625rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .1em;
    color: var(--text-muted);
    margin-bottom: .5rem;
}

.emoji-grid {
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    gap: 2px;
    margin-bottom: .5rem;
}

.emoji-item {
    background: none;
    border: 1px solid transparent;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1.15rem;
    line-height: 1;
    padding: .25rem;
    text-align: center;
    transition: background .08s, border-color .08s;
}
.emoji-item:hover {
    background: var(--surface-2);
    border-color: var(--border);
}

.icon-picker-clear {
    width: 100%;
    justify-content: center;
    color: var(--text-muted);
}

/* -------------------------------------------------------------------------
   Note list icon
------------------------------------------------------------------------- */

.note-item-icon {
    font-size: .9rem;
    line-height: 1;
    flex-shrink: 0;
}

/* -------------------------------------------------------------------------
   Mermaid diagrams
------------------------------------------------------------------------- */

.mermaid-diagram {
    display: flex;
    justify-content: center;
    margin: 0 0 .875rem;
    padding: .875rem;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: var(--r);
    overflow-x: auto;
}

.mermaid-diagram svg {
    max-width: 100%;
    height: auto;
}

.preview-content pre.mermaid-error {
    border-color: var(--danger);
}

::-webkit-scrollbar          { width: 5px; height: 5px; }
::-webkit-scrollbar-track    { background: transparent; }
::-webkit-scrollbar-thumb    { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }