/* --- THEME VARIABLEN (MODERN) --- */
:root {
    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --card-bg: #ffffff;
    --text-main: #2d3748;
    --text-muted: #718096;
    --border-color: #e2e8f0;
    --primary-color: #3182ce;
    --primary-hover: #2b6cb0;
    --success-bg: #f0fff4;
    --success-border: #c6f6d5;
    --success-text: #22543d;
    --error-bg: #fff5f5;
    --error-border: #fed7d7;
    --error-text: #742a2a;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
}

/* System Dark-Mode */
@media (prefers-color-scheme: dark) {
    :root[data-theme="auto"] {
        --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
        --card-bg: #1e293b;
        --text-main: #f8fafc;
        --text-muted: #94a3b8;
        --border-color: #334155;
        --primary-color: #3b82f6;
        --primary-hover: #60a5fa;
        --success-bg: #064e3b;
        --success-border: #047857;
        --success-text: #a7f3d0;
        --error-bg: #7f1d1d;
        --error-border: #b91c1c;
        --error-text: #fca5a5;
        --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
    }
}

/* Explizites Dark Theme */
:root[data-theme="dark"] {
    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    --card-bg: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --primary-color: #3b82f6;
    --primary-hover: #60a5fa;
    --success-bg: #064e3b;
    --success-border: #047857;
    --success-text: #a7f3d0;
    --error-bg: #7f1d1d;
    --error-border: #b91c1c;
    --error-text: #fca5a5;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
}

/* Explizites Light Theme */
:root[data-theme="light"] {
    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --card-bg: #ffffff;
    --text-main: #2d3748;
    --text-muted: #718096;
    --border-color: #e2e8f0;
    --primary-color: #3182ce;
    --primary-hover: #2b6cb0;
    --success-bg: #f0fff4;
    --success-border: #c6f6d5;
    --success-text: #22543d;
    --error-bg: #fff5f5;
    --error-border: #fed7d7;
    --error-text: #742a2a;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
}

/* --- SEITEN-LAYOUT --- */
* {
    box-sizing: border-box;
}

body { 
    margin: 0; 
    padding: 2rem 1rem; 
    min-height: 100vh;
    background: var(--bg-gradient); 
    color: var(--text-main); 
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background 0.3s ease, color 0.3s ease;
}

.container {
    width: 100%;
    max-width: 620px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* --- HEADER & LOGO --- */
#logo {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 1rem;
}

#logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0;
    letter-spacing: -0.025em;
}

.logo-img {
    max-height: 40px;
    object-fit: contain;
}

/* --- CARD-STYLING --- */
.card { 
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.intro p {
    font-size: 1.05rem;
    margin-top: 0;
    line-height: 1.5;
}

.steps {
    background-color: var(--border-color);
    opacity: 0.85;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.step-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--primary-color);
    color: white;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: bold;
    margin-right: 4px;
}

h3 {
    font-size: 1.15rem;
    font-weight: 600;
    margin-top: 0;
}

/* --- FORMULARE --- */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.upload-controls {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

/* Style den Standard-File-Upload-Button um */
.file-input {
    flex-grow: 1;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--card-bg);
    color: var(--text-main);
}

/* --- BUTTONS --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.65rem 1.25rem;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-secondary {
    background-color: var(--border-color);
    color: var(--text-main);
    width: 100%;
}

.btn-secondary:hover {
    opacity: 0.9;
}

.btn-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.btn-link:hover {
    text-decoration: underline;
}

.center-text {
    text-align: center;
    margin-top: 1rem;
}

/* --- BANNERS & BOXES --- */
.banner-error {
    background-color: var(--error-bg);
    border: 1px solid var(--error-border);
    color: var(--error-text);
    padding: 0.75rem 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.success-box {
    background-color: var(--success-bg);
    border: 1px solid var(--success-border);
    color: var(--success-text);
    padding: 1.5rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
}

.success-header {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.link-box {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 0.75rem;
    border-radius: 8px;
    word-break: break-all;
    margin: 0.75rem 0;
}

.download-url {
    font-family: monospace;
    font-size: 0.95rem;
    color: var(--primary-color) !important;
    font-weight: bold;
}

.badge-expiry {
    font-size: 0.85rem;
    opacity: 0.9;
    font-weight: 600;
    margin-bottom: 1rem;
}

.info-text {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.rechts {
    text-align: right;
}

/* --- MODERNER CSS-SPINNER --- */
.spinner-wrapper {
    text-align: center;
    padding: 2rem 0;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* --- FOOTER & DROPDOWN --- */
.site-footer {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.75rem;
    padding: 0 1rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer-item {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.footer-separator {
    opacity: 0.5;
}

.footer-label {
    font-weight: 600;
}

.theme-dropdown {
    background-color: var(--card-bg);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    padding: 3px 6px;
    font-size: 0.8rem;
    border-radius: 6px;
    cursor: pointer;
    outline: none;
}

.allowed-extensions code {
    background-color: var(--card-bg);
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    font-size: 0.8rem;
}

/* Responsive Anpassungen für Mobilgeräte */
@media (max-width: 480px) {
    body {
        padding: 1rem 0.5rem;
    }
    .card {
        padding: 1.25rem;
    }
    .upload-controls {
        flex-direction: column;
        align-items: stretch;
    }
    .site-footer {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
    .footer-separator {
        display: none;
    }
}