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

:root {
    --bg: #F8FAFC;
    --bg-card: #FFFFFF;
    --primary: #4F46E5;
    --primary-hover: #4338CA;
    --primary-light: #EEF2FF;
    --text: #1E293B;
    --text-secondary: #64748B;
    --border: #E2E8F0;
    --shadow: 0 1px 3px rgba(0,0,0,.08);
    --radius: 8px;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", sans-serif;
}

[data-theme="dark"] {
    --bg: #0F172A;
    --bg-card: #1E293B;
    --primary: #818CF8;
    --primary-hover: #6366F1;
    --primary-light: #1E1B4B;
    --text: #F1F5F9;
    --text-secondary: #94A3B8;
    --border: #334155;
    --shadow: 0 1px 3px rgba(0,0,0,.3);
}

html { font-size: 16px; }
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background .25s, color .25s;
}

/* ========== Header ========== */
header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 0 1.5rem;
    transition: background .25s, border-color .25s;
}
.header-inner {
    max-width: 960px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}
.logo {
    display: flex;
    align-items: center;
    gap: .5rem;
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--primary);
}
.header-actions {
    display: flex;
    align-items: center;
    gap: .5rem;
}
.header-actions button {
    background: var(--primary-light);
    color: var(--primary);
    border: none;
    padding: .375rem .75rem;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: .875rem;
    font-weight: 600;
    transition: opacity .15s;
    display: flex;
    align-items: center;
    gap: .25rem;
}
.header-actions button:hover { opacity: .85; }

/* ========== Nav ========== */
nav {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 0 1.5rem;
    transition: background .25s, border-color .25s;
}
.nav-inner {
    max-width: 960px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: .75rem;
    height: 44px;
}
.nav-menu-btn {
    background: none;
    border: none;
    color: var(--text);
    cursor: pointer;
    padding: .25rem;
    border-radius: var(--radius);
    transition: background .15s;
    display: flex;
    align-items: center;
}
.nav-menu-btn:hover {
    background: var(--primary-light);
}
.nav-tool-name {
    font-size: .9375rem;
    font-weight: 700;
    color: var(--text);
}

/* ========== Sidebar ========== */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.4);
    z-index: 90;
    transition: opacity .25s;
}
.sidebar-overlay.open { display: block; }

.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 280px;
    background: var(--bg-card);
    border-right: 1px solid var(--border);
    z-index: 100;
    transform: translateX(-100%);
    transition: transform .25s ease;
    display: flex;
    flex-direction: column;
    box-shadow: 2px 0 8px rgba(0,0,0,.1);
}
.sidebar.open {
    transform: translateX(0);
}
.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    font-weight: 700;
    font-size: 1rem;
    color: var(--primary);
}
.sidebar-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0 .25rem;
    line-height: 1;
    transition: color .15s;
}
.sidebar-close:hover { color: var(--text); }
.sidebar-body {
    flex: 1;
    overflow-y: auto;
    padding: .5rem 0;
}
.sidebar-group-title {
    padding: .75rem 1.25rem .375rem;
    font-size: .75rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: .05em;
}
.sidebar-item {
    display: block;
    width: 100%;
    background: none;
    border: none;
    padding: .625rem 1.25rem;
    font-size: .875rem;
    font-weight: 500;
    color: var(--text);
    cursor: pointer;
    text-align: left;
    transition: background .15s, color .15s;
}
.sidebar-item:hover {
    background: var(--primary-light);
    color: var(--primary);
}
.sidebar-item.active {
    background: var(--primary);
    color: #FFF;
    font-weight: 600;
}

/* ========== Main ========== */
main {
    max-width: 960px;
    width: 100%;
    margin: 1.5rem auto;
    padding: 0 1.5rem;
    flex: 1;
}

.tool-panel { display: none; }
.tool-panel.active { display: block; }

.tool-header {
    margin-bottom: 1.5rem;
}
.tool-header h2 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: .25rem;
}
.tool-header p {
    color: var(--text-secondary);
    font-size: .875rem;
}

.tool-body {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: .75rem;
    transition: background .25s, border-color .25s;
}

label {
    font-size: .8125rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: .03em;
}

textarea, input[type="text"], input[type="datetime-local"], select {
    width: 100%;
    padding: .625rem .75rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg);
    color: var(--text);
    font-family: var(--font);
    font-size: .875rem;
    resize: vertical;
    transition: border-color .15s, background .25s;
}
textarea:focus, input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
}
input[readonly] {
    background: var(--primary-light);
    cursor: default;
}

/* ========== Buttons ========== */
.btn-primary {
    background: var(--primary);
    color: #FFF;
    border: none;
    padding: .5rem 1.25rem;
    border-radius: var(--radius);
    font-size: .875rem;
    font-weight: 600;
    cursor: pointer;
    transition: background .15s;
    align-self: flex-start;
}
.btn-primary:hover { background: var(--primary-hover); }

.btn-secondary {
    background: var(--primary-light);
    color: var(--primary);
    border: 1px solid var(--border);
    padding: .5rem 1.25rem;
    border-radius: var(--radius);
    font-size: .875rem;
    font-weight: 600;
    cursor: pointer;
    transition: background .15s;
}
.btn-secondary:hover { opacity: .85; }

.btn-copy {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: .5rem .75rem;
    border-radius: var(--radius);
    font-size: .8125rem;
    cursor: pointer;
    white-space: nowrap;
    transition: border-color .15s, color .15s;
}
.btn-copy:hover {
    border-color: var(--primary);
    color: var(--primary);
}
.btn-copy.copied {
    color: #16A34A;
    border-color: #16A34A;
}

.btn-group {
    display: flex;
    gap: .5rem;
}

.output-row {
    display: flex;
    gap: .5rem;
    align-items: center;
}
.output-row input { flex: 1; min-width: 0; }

/* ========== Timestamp ========== */
.ts-current {
    background: var(--primary-light);
    padding: .75rem 1rem;
    border-radius: var(--radius);
    font-size: .875rem;
}
.ts-current code {
    font-weight: 700;
    color: var(--primary);
}
.ts-section {
    display: flex;
    flex-direction: column;
    gap: .75rem;
    padding-top: .75rem;
    border-top: 1px solid var(--border);
}
.ts-section h3 {
    font-size: .9375rem;
    font-weight: 600;
}

/* ========== UUID ========== */
.uuid-options {
    display: flex;
    align-items: center;
    gap: .5rem;
}
.uuid-options select { width: auto; }

/* ========== Footer ========== */
footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--text-secondary);
    font-size: .8125rem;
    border-top: 1px solid var(--border);
}

/* ========== K-line ========== */
.kline-input-row {
    display: flex;
    gap: .75rem;
    align-items: flex-end;
}
.kline-code {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: .25rem;
}
.kline-code input { max-width: 280px; }
.kline-periods {
    display: flex;
    gap: .375rem;
}
.period-btn {
    background: var(--primary-light);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    padding: .375rem .875rem;
    border-radius: var(--radius);
    font-size: .8125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all .15s;
}
.period-btn:hover { border-color: var(--primary); color: var(--primary); }
.period-btn.active {
    background: var(--primary);
    color: #FFF;
    border-color: var(--primary);
}
.kline-chart {
    width: 100%;
    height: 480px;
    margin-top: .5rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

/* ========== Markdown Editor ========== */
.md-editor-body {
    padding: 1rem;
}
.md-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: .25rem;
    padding-bottom: .75rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: .75rem;
}
.md-btn {
    background: var(--primary-light);
    color: var(--text);
    border: 1px solid var(--border);
    padding: .375rem .625rem;
    border-radius: var(--radius);
    font-size: .8125rem;
    font-weight: 600;
    cursor: pointer;
    line-height: 1.2;
    transition: border-color .15s, color .15s;
}
.md-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}
.md-split {
    display: flex;
    gap: 1rem;
    height: 500px;
}
.md-pane {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: .5rem;
}
.md-pane-editor textarea {
    flex: 1;
    resize: none;
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
    font-size: .8125rem;
    line-height: 1.5;
    tab-size: 4;
}
.md-preview-content {
    flex: 1;
    padding: 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg);
    overflow-y: auto;
    line-height: 1.7;
    word-wrap: break-word;
}
.md-fullpreview-section {
    display: flex;
    flex-direction: column;
    gap: .5rem;
    margin-top: .75rem;
}
.md-fullpreview-content {
    max-height: 600px;
    padding: 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg);
    overflow-y: auto;
    line-height: 1.7;
    word-wrap: break-word;
}
:is(.md-preview-content,.md-fullpreview-content) h1,
:is(.md-preview-content,.md-fullpreview-content) h2,
:is(.md-preview-content,.md-fullpreview-content) h3,
:is(.md-preview-content,.md-fullpreview-content) h4,
:is(.md-preview-content,.md-fullpreview-content) h5,
:is(.md-preview-content,.md-fullpreview-content) h6 { margin-top:1rem; margin-bottom:.5rem; font-weight:700; line-height:1.3; }
:is(.md-preview-content,.md-fullpreview-content) h1 { font-size:1.5rem; border-bottom:1px solid var(--border); padding-bottom:.3rem; }
:is(.md-preview-content,.md-fullpreview-content) h2 { font-size:1.25rem; border-bottom:1px solid var(--border); padding-bottom:.25rem; }
:is(.md-preview-content,.md-fullpreview-content) h3 { font-size:1.1rem; }
:is(.md-preview-content,.md-fullpreview-content) p { margin-bottom:.75rem; }
:is(.md-preview-content,.md-fullpreview-content) ul,
:is(.md-preview-content,.md-fullpreview-content) ol { margin-bottom:.75rem; padding-left:1.5rem; }
:is(.md-preview-content,.md-fullpreview-content) blockquote { margin:.75rem 0; padding:.5rem 1rem; border-left:4px solid var(--primary); background:var(--primary-light); border-radius:0 var(--radius) var(--radius) 0; color:var(--text-secondary); }
:is(.md-preview-content,.md-fullpreview-content) code { background:var(--primary-light); padding:.125rem .375rem; border-radius:3px; font-size:.85em; font-family:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace; }
:is(.md-preview-content,.md-fullpreview-content) pre { margin-bottom:.75rem; padding:1rem; background:var(--primary-light); border-radius:var(--radius); overflow-x:auto; }
:is(.md-preview-content,.md-fullpreview-content) pre code { background:none; padding:0; font-size:.8125rem; }
:is(.md-preview-content,.md-fullpreview-content) table { width:100%; border-collapse:collapse; margin-bottom:.75rem; }
:is(.md-preview-content,.md-fullpreview-content) th,
:is(.md-preview-content,.md-fullpreview-content) td { border:1px solid var(--border); padding:.5rem .75rem; text-align:left; }
:is(.md-preview-content,.md-fullpreview-content) th { background:var(--primary-light); font-weight:600; }
:is(.md-preview-content,.md-fullpreview-content) img { max-width:100%; border-radius:var(--radius); }
:is(.md-preview-content,.md-fullpreview-content) a { color:var(--primary); text-decoration:underline; }
:is(.md-preview-content,.md-fullpreview-content) hr { border:none; border-top:1px solid var(--border); margin:1rem 0; }

/* ========== Responsive ========== */
@media (max-width: 640px) {
    .header-inner { height: 48px; }
    .sidebar { width: 260px; }
    .tool-body { padding: 1rem; }
    .output-row { flex-direction: column; }
    .output-row .btn-copy { align-self: flex-end; }
    .kline-input-row { flex-direction: column; }
    .kline-code input { max-width: 100%; }
    .kline-chart { height: 360px; }
    .md-split { flex-direction: column; height: 300px; }
    .md-fullpreview-content { max-height: 400px; }
}