:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a24;
    --bg-card: #16161f;
    --accent-blue: #3b82f6;
    --accent-cyan: #06b6d4;
    --accent-green: #10b981;
    --accent-yellow: #f59e0b;
    --accent-red: #ef4444;
    --accent-purple: #8b5cf6;
    --accent-orange: #f97316;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #2a2a3a;
    --border-highlight: #3b3b4f;
    --shadow-glow: rgba(59, 130, 246, 0.15);
    --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

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

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: 
        linear-gradient(rgba(59, 130, 246, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(59, 130, 246, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    z-index: -1;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.header-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 1rem;
}

header a {
    color: var(--accent-cyan);
    text-decoration: none;
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    display: inline-block;
    transition: all 0.3s ease;
    background: var(--bg-tertiary);
}

header a:hover {
    background: var(--bg-secondary);
    border-color: var(--accent-blue);
    box-shadow: 0 0 20px var(--shadow-glow);
}

.upload-section,
.results-section,
.examples-section {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 2rem;
    border-radius: 16px;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

h2 {
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.upload-methods {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.upload-method {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.file-upload-label {
    display: inline-block;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
    color: white;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    text-align: center;
    border: none;
    box-shadow: 0 4px 20px var(--shadow-glow);
}

.file-upload-label:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px var(--shadow-glow);
}

#file-upload {
    display: none;
}

label[for="yaml-input"] {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    margin: 0.5rem 0;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    resize: vertical;
    transition: all 0.3s ease;
}

textarea:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 20px var(--shadow-glow);
}

textarea::placeholder {
    color: var(--text-muted);
}

button {
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
    font-family: var(--font-sans);
    box-shadow: 0 4px 20px var(--shadow-glow);
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px var(--shadow-glow);
}

button:active {
    transform: translateY(0);
}

.example-btn {
    margin: 0.5rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    box-shadow: none;
}

.example-btn:hover {
    background: var(--bg-secondary);
    border-color: var(--accent-blue);
    box-shadow: 0 0 20px var(--shadow-glow);
}

.action-btn-small {
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 500;
    transition: all 0.2s ease;
    font-family: var(--font-sans);
}

.action-btn-small:hover {
    background: var(--bg-secondary);
    border-color: var(--accent-blue);
}

.filter-select {
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: 6px;
    font-size: 0.85rem;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.2s ease;
}

.filter-select:hover {
    border-color: var(--accent-blue);
}

.filter-select:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 10px var(--shadow-glow);
}

button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

button:disabled:hover {
    box-shadow: 0 4px 20px var(--shadow-glow);
}

.loading {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--text-muted);
    border-top-color: var(--accent-blue);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    margin-right: 0.5rem;
}

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

.hidden {
    display: none;
}

.results-section.visible {
    display: block;
    animation: fadeIn 0.4s ease;
}

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

.summary {
    padding: 1.5rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    border: 1px solid var(--border-color);
}

.summary.valid {
    background: rgba(16, 185, 129, 0.1);
    border-left: 4px solid var(--accent-green);
    color: var(--accent-green);
}

.summary.invalid {
    background: rgba(239, 68, 68, 0.1);
    border-left: 4px solid var(--accent-red);
    color: var(--accent-red);
}

.no-issues {
    padding: 2rem;
    text-align: center;
    font-size: 1.2em;
    color: var(--accent-green);
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    border-radius: 12px;
    font-weight: 600;
}

.issues-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.issue {
    padding: 1.25rem;
    border-radius: 12px;
    border-left: 4px solid;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

.issue:hover {
    background: var(--bg-secondary);
    border-color: var(--border-highlight);
}

.issue.error {
    border-left-color: var(--accent-red);
    background: rgba(239, 68, 68, 0.1);
}

.issue.warning {
    border-left-color: var(--accent-yellow);
    background: rgba(245, 158, 11, 0.1);
}

.issue.info {
    border-left-color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.1);
}

.severity-icon {
    font-size: 1.5em;
    flex-shrink: 0;
}

.issue-content {
    flex-grow: 1;
}

.issue-message {
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.issue-path {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-secondary);
    word-break: break-all;
}

footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.85rem;
    border-top: 1px solid var(--border-color);
    margin-top: 3rem;
}

footer p {
    margin-bottom: 1rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 1rem;
}

footer a {
    color: var(--accent-cyan);
    text-decoration: none;
    transition: all 0.2s ease;
}

footer a:hover {
    text-decoration: underline;
    color: var(--accent-blue);
}

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    header h1 {
        font-size: 1.75rem;
    }

    header .header-links {
        flex-direction: column;
        gap: 0.5rem;
    }

    header .header-links a {
        width: 100%;
    }

    .upload-section,
    .results-section,
    .examples-section {
        padding: 1.5rem;
    }

    .example-btn {
        width: 100%;
        margin: 0.5rem 0;
    }

    .action-btn-small {
        font-size: 0.75rem;
        padding: 0.4rem 0.75rem;
    }

    .filter-select {
        font-size: 0.75rem;
        padding: 0.4rem 0.75rem;
    }
}

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-highlight);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}