:root {
    --bg-deep: #050505;
    --bg-surface: #0d0d0d;
    --bg-card: #141414;
    --border: rgba(255, 255, 255, 0.08);
    --accent: #10b981;
    --accent-glow: rgba(16, 185, 129, 0.2);
    --text-main: #e2e8f0;
    --text-muted: #94a3b8;
    --sidebar-width: 260px;
    --font-sans: 'Inter', system-ui, sans-serif;
    --font-mono: 'Fira Code', monospace;
}

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

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

.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-surface);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 1.5rem 0;
}

.sidebar-header {
    padding: 0 1.5rem 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    color: var(--text-main);
}

.logo i {
    color: var(--accent);
}

.sidebar-nav {
    flex: 1;
    padding: 0 0.75rem;
}

.nav-item {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    margin-bottom: 0.25rem;
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-main);
}

.nav-item.active {
    background: var(--accent-glow);
    color: var(--accent);
}

.sidebar-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border);
}

.back-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.85rem;
    transition: color 0.2s;
}

.back-link:hover {
    color: var(--text-main);
}

/* Main Content */
.content {
    flex: 1;
    padding: 3rem;
    overflow-y: auto;
    background-image: radial-gradient(circle at 10% 20%, rgba(16, 185, 129, 0.05) 0%, transparent 40%);
}

.tool-section {
    display: none;
    max-width: 1000px;
    margin: 0 auto;
    animation: fadeIn 0.4s ease-out;
}

.tool-section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.section-header {
    margin-bottom: 2.5rem;
}

.section-header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    margin-bottom: 0.5rem;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Editors */
.editor-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    height: 60vh;
}

.editor-container.single-column {
    grid-template-columns: 1fr;
}

.editor-pane {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.editor-toolbar {
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.02);
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 700;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.actions {
    display: flex;
    gap: 0.5rem;
}

button {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    color: var(--text-main);
    padding: 0.4rem 0.8rem;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

button:hover {
    background: rgba(255, 255, 255, 0.1);
}

button.primary {
    background: var(--accent);
    color: var(--bg-deep);
    border: none;
}

button.primary:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

textarea {
    flex: 1;
    background: transparent;
    border: none;
    padding: 1.5rem;
    color: var(--text-main);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
    resize: none;
    outline: none;
}

/* Grid Tools */
.grid-tools {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
    gap: 1.5rem;
}

.tool-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2rem;
}

.tool-card.full-width {
    grid-column: 1 / -1;
}

.tool-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.tool-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

.main-input {
    width: 100%;
    background: var(--bg-surface);
    border: 1px solid var(--border);
    padding: 1rem;
    border-radius: 8px;
    color: #fff;
    font-size: 1rem;
    margin-bottom: 2rem;
    outline: none;
}

.hash-results {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.result-row label {
    display: block;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.copy-input {
    display: flex;
    gap: 0.5rem;
}

.copy-input input {
    flex: 1;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border);
    padding: 0.75rem;
    border-radius: 6px;
    color: var(--accent);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    outline: none;
}

.id-box {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: rgba(255, 255, 255, 0.03);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px dashed var(--border);
}

#uuid-result, #nanoid-result {
    flex: 1;
    font-family: var(--font-mono);
    color: var(--accent);
    font-weight: 600;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--accent);
    color: var(--bg-deep);
    padding: 1rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    transform: translateY(100px);
    transition: transform 0.3s cubic-bezier(0.18, 0.89, 0.32, 1.28);
    z-index: 10000;
}

.toast.show {
    transform: translateY(0);
}

@media (max-width: 768px) {
    .editor-container { grid-template-columns: 1fr; }
    .sidebar { display: none; }
}