:root {
    --primary: #4F46E5;
    --primary-hover: #4338CA;
    --bg-color: #0F172A;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-main: #F8FAFC;
    --text-muted: #94A3B8;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
    background: var(--bg-color);
    background-image: radial-gradient(circle at top right, #312E81 0%, transparent 40%),
                      radial-gradient(circle at bottom left, #064E3B 0%, transparent 40%);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    width: 100%;
    max-width: 600px;
    padding: 3rem;
    background: var(--card-bg);
    border-radius: 24px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    margin-top: 0;
}

h1 span {
    color: #34D399;
}

header p {
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    line-height: 1.5;
}

.drop-zone {
    border: 2px dashed rgba(255, 255, 255, 0.2);
    border-radius: 16px;
    padding: 4rem 2rem;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.02);
}

.drop-zone.dragover {
    border-color: var(--primary);
    background: rgba(79, 70, 229, 0.1);
    transform: scale(1.02);
}

.drop-zone .icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.drop-zone p {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    margin-top: 0;
}

.drop-zone span {
    display: block;
    color: var(--text-muted);
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s, transform 0.1s;
}

button:hover {
    background: var(--primary-hover);
}

button:active {
    transform: scale(0.98);
}

.hidden {
    display: none !important;
}

/* Loading state */
.loading {
    padding: 3rem 0;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid rgba(255,255,255,0.1);
    border-top-color: #34D399;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1.5rem;
}

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

.success .icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.error {
    color: #F87171;
    padding: 2rem 0;
}

#error-reset-btn {
    background: #DC2626;
    margin-top: 1rem;
}
#error-reset-btn:hover {
    background: #B91C1C;
}