:root {
    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --primary: #38bdf8;
    --primary-hover: #0ea5e9;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
}

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

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg-gradient);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
}

.container {
    max-width: 800px;
    width: 100%;
}

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

h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
}

.highlight {
    color: var(--primary);
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
    line-height: 1.6;
}

.upload-card, .result-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 2.5rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    margin-bottom: 2rem;
    transition: all 0.3s ease;
}

.file-drop-area {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 3rem 2rem;
    border: 2px dashed var(--card-border);
    border-radius: 12px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 2rem;
    background: rgba(0,0,0,0.2);
}

.file-drop-area:hover, .file-drop-area.dragover {
    border-color: var(--primary);
    background: rgba(56, 189, 248, 0.05);
}

.file-msg {
    color: var(--text-muted);
    font-size: 1.1rem;
    pointer-events: none;
}

#file-input {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 100%;
    cursor: pointer;
    opacity: 0;
}

button {
    width: 100%;
    padding: 1rem;
    border: none;
    border-radius: 8px;
    background: var(--primary);
    color: #fff;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
}

button:hover:not(:disabled) {
    background: var(--primary-hover);
}

button:disabled {
    background: #475569;
    cursor: not-allowed;
    color: #94a3b8;
}

.spinner {
    display: none;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

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

.hidden {
    display: none;
}

.result-card h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary);
}

pre {
    background: rgba(0,0,0,0.3);
    padding: 1.5rem;
    border-radius: 8px;
    font-family: monospace;
    white-space: pre-wrap;
    color: #e2e8f0;
    line-height: 1.5;
}