/* ============================================================
   Mermaid Viewer Pro — Styles
   Open-source Mermaid diagram viewer, editor & exporter
   ============================================================ */

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #1c2333;
    --bg-card: #1e2535;
    --bg-editor: #0d1117;
    --border: #30363d;
    --border-active: #FF9900;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --text-muted: #6e7681;
    --accent: #FF9900;
    --accent-hover: #FFB84D;
    --accent-purple: #7B1FA2;
    --danger: #f85149;
    --success: #3fb950;
    --navy: #1a1a2e;
    --navy-light: #16213e;
    --diagram-bg: #141a26;
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

/* ============================================================
   TOP BAR
   ============================================================ */
.top-bar {
    background: var(--navy);
    padding: 12px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    z-index: 100;
    min-height: 56px;
    flex-shrink: 0;
}
.top-bar-left { display: flex; align-items: center; gap: 16px; }
.top-bar-left .logo {
    width: 32px; height: 32px;
    background: var(--accent);
    border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
    font-size: 18px; font-weight: 700; color: var(--navy);
}
.top-bar-title h1 { font-size: 16px; font-weight: 600; color: var(--text-primary); }
.top-bar-title .subtitle { font-size: 11px; color: var(--text-secondary); margin-top: 1px; }
.top-bar-right { display: flex; gap: 8px; align-items: center; }

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
    padding: 7px 14px; border-radius: 6px; border: 1px solid var(--border);
    background: var(--bg-secondary); color: var(--text-primary);
    font-size: 12px; cursor: pointer; transition: all 0.15s;
    display: flex; align-items: center; gap: 6px; white-space: nowrap;
    font-family: inherit;
}
.btn:hover { border-color: var(--text-secondary); background: var(--bg-tertiary); }
.btn-accent {
    background: var(--accent); border-color: var(--accent);
    color: var(--navy); font-weight: 600;
}
.btn-accent:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn-purple {
    background: var(--accent-purple); border-color: var(--accent-purple); color: white;
}
.btn-purple:hover { background: #9C27B0; border-color: #9C27B0; }
.btn-sm { padding: 5px 10px; font-size: 11px; }

select.btn {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%238b949e'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    padding-right: 28px;
}
select.btn option { background: var(--bg-secondary); color: var(--text-primary); }

.separator { width: 1px; height: 24px; background: var(--border); margin: 0 4px; }

/* ============================================================
   TAB BAR
   ============================================================ */
.tab-bar {
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    padding: 0 16px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    gap: 2px;
}
.view-tab {
    padding: 10px 16px; font-size: 13px; color: var(--text-secondary);
    cursor: pointer; border-bottom: 2px solid transparent;
    transition: all 0.15s; display: flex; align-items: center; gap: 6px;
    user-select: none;
}
.view-tab:hover { color: var(--text-primary); background: rgba(255,255,255,0.03); }
.view-tab.active { color: var(--accent); border-bottom-color: var(--accent); }
.tab-spacer { flex: 1; }

/* ============================================================
   VIEW CONTROLS & TOOLTIPS
   ============================================================ */
.view-controls { display: flex; gap: 2px; align-items: center; padding: 6px 0; }
.view-btn {
    padding: 5px 8px; border-radius: 4px; border: 1px solid var(--border);
    background: transparent; color: var(--text-secondary); cursor: pointer;
    font-size: 14px; transition: all 0.15s; line-height: 1;
    position: relative;
}
.view-btn:hover { background: var(--bg-tertiary); color: var(--text-primary); }
.view-btn.active { background: var(--accent); color: var(--navy); border-color: var(--accent); }

.view-btn::after {
    content: attr(data-tooltip);
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%) scale(0.9);
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 5px 10px;
    border-radius: 6px;
    font-size: 11px;
    white-space: nowrap;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.15s, transform 0.15s;
    z-index: 200;
    box-shadow: 0 4px 12px rgba(0,0,0,0.4);
}
.view-btn:hover::after {
    opacity: 1;
    transform: translateX(-50%) scale(1);
}

/* ============================================================
   MAIN CONTENT
   ============================================================ */
.main-content {
    flex: 1;
    overflow: hidden;
    position: relative;
}

/* ============================================================
   UPLOAD SCREEN
   ============================================================ */
.upload-screen {
    position: absolute; inset: 0;
    display: flex; align-items: center; justify-content: center;
    background: var(--bg-primary);
    z-index: 50;
}
.upload-screen.hidden { display: none; }
.upload-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 48px 64px;
    text-align: center;
    max-width: 520px;
    width: 90%;
}
.upload-icon {
    width: 80px; height: 80px; margin: 0 auto 24px;
    background: rgba(255,153,0,0.1);
    border-radius: 20px;
    display: flex; align-items: center; justify-content: center;
    font-size: 36px;
}
.upload-card h2 { font-size: 22px; font-weight: 600; margin-bottom: 8px; }
.upload-card p { font-size: 14px; color: var(--text-secondary); margin-bottom: 32px; line-height: 1.6; }
.upload-card .formats {
    font-size: 11px; color: var(--text-muted); margin-top: 16px;
    letter-spacing: 0.3px;
}

.upload-drop-zone {
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 32px;
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 8px;
}
.upload-drop-zone:hover, .upload-drop-zone.dragover {
    border-color: var(--accent);
    background: rgba(255,153,0,0.05);
}
.upload-drop-zone .drop-text { font-size: 14px; color: var(--text-secondary); }
.upload-drop-zone .drop-text strong { color: var(--accent); }

/* ============================================================
   WORKSPACE & LAYOUTS
   ============================================================ */
.workspace { position: absolute; inset: 0; display: flex; }
.workspace.hidden { display: none; }

.workspace.layout-diagram .panel-code { display: none; }
.workspace.layout-diagram .panel-diagram { flex: 1; }

.workspace.layout-code .panel-diagram { display: none; }
.workspace.layout-code .panel-code { flex: 1; }

.workspace.layout-split-h { flex-direction: row; }
.workspace.layout-split-h .panel-code { flex: 1; border-right: 2px solid var(--border); }
.workspace.layout-split-h .panel-diagram { flex: 1; }

.workspace.layout-split-v { flex-direction: column; }
.workspace.layout-split-v .panel-code { flex: 1; border-bottom: 2px solid var(--border); }
.workspace.layout-split-v .panel-diagram { flex: 1; }

.panel-code, .panel-diagram {
    display: flex; flex-direction: column;
    overflow: hidden; position: relative;
}

/* ============================================================
   CODE EDITOR
   ============================================================ */
.code-editor {
    flex: 1; width: 100%;
    background: var(--bg-editor);
    color: #c9d1d9;
    border: none; outline: none; resize: none;
    padding: 16px 20px;
    font-family: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', 'Consolas', monospace;
    font-size: 13px;
    line-height: 1.6;
    tab-size: 4;
    overflow: auto;
}
.code-editor::selection { background: rgba(255,153,0,0.25); }

/* ============================================================
   DIAGRAM VIEWPORT
   ============================================================ */
.diagram-viewport {
    flex: 1;
    overflow: auto;
    background: var(--diagram-bg);
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 24px;
}
.diagram-render {
    display: inline-block;
    min-width: fit-content;
}
.diagram-render .mermaid {
    display: inline-block;
}
.diagram-render svg {
    max-width: none !important;
    display: block;
}

/* ============================================================
   ERROR BANNER
   ============================================================ */
.error-banner {
    position: absolute; top: 0; left: 0; right: 0;
    background: rgba(248,81,73,0.12);
    border-bottom: 1px solid var(--danger);
    color: var(--danger);
    padding: 10px 16px;
    font-size: 12px;
    font-family: monospace;
    z-index: 10;
    display: none;
    max-height: 80px;
    overflow: auto;
}
.error-banner.visible { display: block; }

/* ============================================================
   RENDER LOADING INDICATOR
   ============================================================ */
.render-loading {
    position: absolute; top: 12px; right: 12px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 6px 14px;
    font-size: 11px;
    color: var(--accent);
    display: none;
    align-items: center;
    gap: 8px;
    z-index: 10;
}
.render-loading.visible { display: flex; }
.render-loading .mini-spinner {
    width: 12px; height: 12px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.3; } }

/* ============================================================
   TOAST NOTIFICATIONS
   ============================================================ */
.toast {
    position: fixed; bottom: 20px; right: 20px;
    background: var(--bg-card); border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 10px 20px; border-radius: 8px;
    font-size: 13px; z-index: 9999;
    opacity: 0; transform: translateY(10px);
    transition: all 0.25s;
    box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}
.toast.show { opacity: 1; transform: translateY(0); }
.toast.success { border-color: var(--success); }
.toast.error { border-color: var(--danger); }

/* ============================================================
   STATUS BAR
   ============================================================ */
.status-bar {
    background: var(--navy);
    border-top: 1px solid var(--border);
    padding: 4px 16px;
    display: flex;
    justify-content: space-between;
    font-size: 11px;
    color: var(--text-muted);
    flex-shrink: 0;
}
.status-bar .status-left, .status-bar .status-right {
    display: flex; gap: 16px; align-items: center;
}
.status-indicator {
    display: inline-block; width: 7px; height: 7px;
    border-radius: 50%; margin-right: 4px;
}
.status-indicator.ok { background: var(--success); }
.status-indicator.err { background: var(--danger); }
.status-indicator.loading { background: var(--accent); animation: pulse 1s ease-in-out infinite; }

/* ============================================================
   UPLOAD — URL INPUT SECTION
   ============================================================ */
.upload-divider {
    display: flex; align-items: center; gap: 12px;
    margin: 20px 0; color: var(--text-muted); font-size: 12px;
}
.upload-divider::before, .upload-divider::after {
    content: ''; flex: 1; height: 1px; background: var(--border);
}

.upload-url-row {
    display: flex; gap: 8px;
}
.upload-url-input {
    flex: 1; padding: 10px 14px;
    background: var(--bg-editor); color: var(--text-primary);
    border: 1px solid var(--border); border-radius: 8px;
    font-size: 13px; font-family: inherit; outline: none;
    transition: border-color 0.15s;
}
.upload-url-input:focus { border-color: var(--accent); }
.upload-url-input::placeholder { color: var(--text-muted); }

/* ============================================================
   DIAGRAM TABS (multi-tab bar)
   ============================================================ */
.diagram-tabs-bar {
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    padding: 0 8px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    min-height: 34px;
    gap: 1px;
    overflow-x: auto;
}
.diagram-tabs-bar::-webkit-scrollbar { height: 2px; }
.diagram-tabs-bar::-webkit-scrollbar-thumb { background: var(--border); }

#diagram-tabs {
    display: flex; align-items: center; gap: 1px;
    overflow-x: auto; flex: 1;
}

.diagram-tab {
    display: flex; align-items: center; gap: 4px;
    padding: 6px 12px; font-size: 11px;
    color: var(--text-secondary); cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.12s; white-space: nowrap;
    max-width: 180px; flex-shrink: 0;
}
.diagram-tab:hover { color: var(--text-primary); background: rgba(255,255,255,0.03); }
.diagram-tab.active { color: var(--accent); border-bottom-color: var(--accent); background: rgba(255,153,0,0.05); }

.diagram-tab-label {
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.diagram-tab-close {
    font-size: 14px; line-height: 1; opacity: 0.4;
    padding: 0 2px; border-radius: 3px; cursor: pointer;
    transition: all 0.1s;
}
.diagram-tab-close:hover { opacity: 1; background: rgba(248,81,73,0.2); color: var(--danger); }

.diagram-tabs-spacer { flex: 1; }

/* ============================================================
   ADD DIAGRAM DROPDOWN
   ============================================================ */
.add-diagram-wrapper { position: relative; }

.add-diagram-menu {
    position: absolute; top: calc(100% + 4px); right: 0;
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: 8px; padding: 4px; min-width: 180px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.5);
    z-index: 300; display: none;
}
.add-diagram-menu.visible { display: block; }

.add-menu-item {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 12px; font-size: 12px;
    color: var(--text-primary); cursor: pointer;
    border-radius: 6px; transition: background 0.1s;
    border: none; background: none; width: 100%;
    font-family: inherit; text-align: left;
}
.add-menu-item:hover { background: rgba(255,255,255,0.06); }
.add-menu-item .menu-icon { font-size: 14px; width: 20px; text-align: center; }

/* ============================================================
   MODALS (Error + URL)
   ============================================================ */
.modal-overlay {
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.6);
    display: none; align-items: center; justify-content: center;
    z-index: 500;
    backdrop-filter: blur(4px);
}
.modal-overlay.visible { display: flex; }

.modal {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 28px 32px;
    max-width: 480px; width: 90%;
    box-shadow: 0 16px 48px rgba(0,0,0,0.5);
}
.modal h3 {
    font-size: 16px; font-weight: 600; margin-bottom: 12px;
    display: flex; align-items: center; gap: 8px;
}
.modal p, .modal .modal-body {
    font-size: 13px; color: var(--text-secondary);
    line-height: 1.6; white-space: pre-wrap; margin-bottom: 20px;
}
.modal-actions {
    display: flex; justify-content: flex-end; gap: 8px;
}

/* Error modal specific */
.modal h3 .modal-icon-error { color: var(--danger); font-size: 20px; }
.modal h3 .modal-icon-url { color: var(--accent); font-size: 20px; }

/* URL modal input */
.modal .url-input-row {
    display: flex; gap: 8px; margin-bottom: 20px;
}
.modal .url-field {
    flex: 1; padding: 10px 14px;
    background: var(--bg-editor); color: var(--text-primary);
    border: 1px solid var(--border); border-radius: 8px;
    font-size: 13px; font-family: inherit; outline: none;
}
.modal .url-field:focus { border-color: var(--accent); }
.modal .url-field::placeholder { color: var(--text-muted); }
.modal .url-hint {
    font-size: 11px; color: var(--text-muted); margin-top: -12px; margin-bottom: 16px;
}

/* ============================================================
   UTILITIES
   ============================================================ */
#file-input, #add-file-input { display: none; }