:root {
    --bg-dark: #0f111a;
    --glass-bg: rgba(20, 24, 40, 0.6);
    --glass-border: rgba(255, 255, 255, 0.08);
    --text-primary: #f0f2f8;
    --text-secondary: #9ba1b8;
    --primary-color: #7b42f6;
    --primary-hover: #9361ff;
    --accent-color: #00d2ff;
    --error-color: #ff4a4a;
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-body);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

.glass-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    background: radial-gradient(circle at 15% 50%, rgba(123, 66, 246, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 85% 30%, rgba(0, 210, 255, 0.1) 0%, transparent 50%);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

.gradient-text {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-color), var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
}

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

.app-layout {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 2rem;
    align-items: start;
}

.sidebar nav {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 500;
    text-align: left;
    padding: 1rem 1.5rem;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

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

.nav-btn.active {
    color: var(--text-primary);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.nav-btn.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    height: 60%;
    width: 4px;
    background: var(--primary-color);
    border-radius: 0 4px 4px 0;
}

.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 2.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.tool-section {
    animation: fadeIn 0.4s ease forwards;
}

.tool-section.hidden {
    display: none;
}

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

.tool-section h2 {
    font-family: var(--font-heading);
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.tool-section p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.input-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

textarea {
    width: 100%;
    min-height: 150px;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 1rem;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1rem;
    resize: vertical;
    transition: all 0.3s ease;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(123, 66, 246, 0.2);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #5f2deb);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 12px;
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    width: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(123, 66, 246, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-family: var(--font-body);
    cursor: pointer;
    transition: all 0.2s;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
}

.result-container {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--glass-border);
    animation: fadeIn 0.5s ease;
}

.result-container.hidden {
    display: none;
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.markdown-body {
    background: rgba(0, 0, 0, 0.15);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid var(--glass-border);
    line-height: 1.6;
}

.markdown-body h1, .markdown-body h2, .markdown-body h3 {
    margin-bottom: 1rem;
    margin-top: 1.5rem;
    font-family: var(--font-heading);
}

.markdown-body h1:first-child, .markdown-body h2:first-child {
    margin-top: 0;
}

.markdown-body p, .markdown-body ul, .markdown-body ol {
    margin-bottom: 1rem;
}

.markdown-body ul, .markdown-body ol {
    padding-left: 2rem;
}

.markdown-body strong {
    color: var(--accent-color);
}

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

/* Spinner */
.spinner {
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
    display: inline-block;
}

.spinner.hidden {
    display: none;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@media (max-width: 768px) {
    .app-layout {
        grid-template-columns: 1fr;
    }
    
    .sidebar nav {
        flex-direction: row;
        overflow-x: auto;
        padding-bottom: 1rem;
    }
    
    .nav-btn {
        flex: 0 0 auto;
        padding: 0.8rem 1rem;
    }
    
    .nav-btn.active::before {
        height: 4px;
        width: 60%;
        top: auto;
        bottom: 0;
        left: 50%;
        transform: translateX(-50%);
        border-radius: 4px 4px 0 0;
    }
}