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

:root {
    --bg: #f0f2f5;
    --card: #ffffff;
    --accent: #4f46e5;
    --accent-hover: #4338ca;
    --accent-light: #eef2ff;
    --text: #1e293b;
    --text-secondary: #64748b;
    --border: #e2e8f0;
    --radius: 16px;
    --shadow: 0 1px 3px rgba(0,0,0,.06), 0 8px 24px rgba(0,0,0,.06);
    --shadow-lg: 0 4px 12px rgba(0,0,0,.08), 0 20px 48px rgba(0,0,0,.08);
    --transition: .2s cubic-bezier(.4,0,.2,1);
}

html, body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100dvh;
    -webkit-font-smoothing: antialiased;
}

h1:focus { outline: none; }

/* ===== Language Switcher ===== */
.lang-bar {
    position: fixed;
    top: .75rem;
    right: 1rem;
    z-index: 100;
}

.lang-select {
    appearance: none;
    -webkit-appearance: none;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: .4rem 2rem .4rem .75rem;
    font-size: .8rem;
    font-weight: 500;
    color: var(--text);
    cursor: pointer;
    transition: border-color var(--transition), box-shadow var(--transition);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right .5rem center;
    box-shadow: 0 1px 2px rgba(0,0,0,.05);
}

.lang-select:hover,
.lang-select:focus {
    border-color: var(--accent);
    outline: none;
    box-shadow: 0 0 0 3px rgba(79,70,229,.1);
}

/* ===== Page Layout ===== */
.page {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100dvh;
    padding: 2rem 1rem;
}

/* ===== Card ===== */
.card {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 520px;
    padding: 2.5rem 2rem;
    text-align: center;
    animation: fadeUp .4s ease-out;
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ===== Header ===== */
.logo {
    display: inline-flex;
    align-items: center;
    gap: .5rem;
    margin-bottom: .25rem;
}

.logo svg { flex-shrink: 0; }

.card h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -.02em;
}

.subtitle {
    color: var(--text-secondary);
    font-size: .9rem;
    margin-bottom: 1.75rem;
}

.subtitle a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
}

.subtitle a:hover { text-decoration: underline; }

/* ===== Drop Zone ===== */
.drop-zone {
    position: relative;
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 2.5rem 1.5rem;
    cursor: pointer;
    transition: border-color var(--transition), background var(--transition);
    background: var(--bg);
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: var(--accent);
    background: var(--accent-light);
}

.drop-zone input[type="file"] {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
}

.drop-zone-content { pointer-events: none; }

.upload-icon {
    display: block;
    margin: 0 auto .75rem;
    color: var(--accent);
    opacity: .8;
    transition: opacity var(--transition), transform var(--transition);
}

.drop-zone:hover .upload-icon {
    opacity: 1;
    transform: translateY(-2px);
}

.drop-zone-content p {
    font-size: .95rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.drop-zone-content strong { color: var(--text); font-weight: 600; }

.hint {
    font-size: .8rem;
    color: #94a3b8;
    margin-top: .5rem;
}

.badges {
    display: flex;
    justify-content: center;
    gap: .5rem;
    margin-top: .75rem;
}

.badge {
    display: inline-block;
    padding: .2rem .6rem;
    border-radius: 6px;
    font-size: .75rem;
    font-weight: 600;
    letter-spacing: .02em;
}

.badge-docx { background: #dbeafe; color: #2563eb; }
.badge-xlsx { background: #dcfce7; color: #16a34a; }

/* ===== Selected File ===== */
.file-info {
    display: flex;
    align-items: center;
    gap: .75rem;
    text-align: left;
}

.file-icon-wrap {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.file-icon-wrap.docx { background: #dbeafe; }
.file-icon-wrap.xlsx { background: #dcfce7; }

.file-meta { min-width: 0; }

.file-name {
    font-weight: 600;
    font-size: .95rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 320px;
}

.file-size {
    color: var(--text-secondary);
    font-size: .8rem;
}

/* ===== Convert Button ===== */
.convert-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: .5rem;
    margin-top: 1.5rem;
    padding: .75rem 2rem;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--transition), box-shadow var(--transition), transform var(--transition);
    width: 100%;
    max-width: 280px;
}

.convert-btn:hover:not(:disabled) {
    background: var(--accent-hover);
    box-shadow: 0 4px 14px rgba(79,70,229,.35);
    transform: translateY(-1px);
}

.convert-btn:active:not(:disabled) { transform: translateY(0); }

.convert-btn:disabled {
    opacity: .45;
    cursor: not-allowed;
}

/* ===== Spinner ===== */
.spinner {
    width: 16px;
    height: 16px;
    border: 2.5px solid rgba(255,255,255,.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin .6s linear infinite;
}

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

/* ===== Alerts ===== */
.alert {
    margin-top: 1.25rem;
    padding: .75rem 1rem;
    border-radius: 10px;
    font-size: .875rem;
    text-align: left;
    display: flex;
    align-items: flex-start;
    gap: .5rem;
    animation: fadeUp .3s ease-out;
}

.alert-error {
    background: #fef2f2;
    color: #b91c1c;
    border: 1px solid #fecaca;
}

.alert-success {
    background: #f0fdf4;
    color: #15803d;
    border: 1px solid #bbf7d0;
}

/* ===== Intro Section ===== */
.intro {
    width: 100%;
    max-width: 520px;
    margin-top: 1.5rem;
    padding: 1.5rem 2rem;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    text-align: center;
    animation: fadeUp .5s ease-out;
}

.intro h2 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: .5rem;
    letter-spacing: -.01em;
}

.intro > p {
    color: var(--text-secondary);
    font-size: .875rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.intro-links {
    display: flex;
    justify-content: center;
    gap: .75rem;
    margin-bottom: 1rem;
}

.intro-links a {
    display: inline-flex;
    align-items: center;
    gap: .35rem;
    padding: .45rem 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: .8rem;
    font-weight: 500;
    color: var(--text);
    text-decoration: none;
    transition: border-color var(--transition), background var(--transition);
}

.intro-links a:hover {
    border-color: var(--accent);
    background: var(--accent-light);
    color: var(--accent);
}

/* ===== Donate Link ===== */
.donate-link {
    border-color: #e879a0 !important;
    color: #db2777 !important;
    background: #fdf2f8 !important;
}

.donate-link:hover {
    border-color: #db2777 !important;
    background: #fce7f3 !important;
    color: #be185d !important;
}

/* ===== Privacy Note ===== */
.privacy-note {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: .4rem;
    margin-bottom: .75rem;
    padding: .5rem .75rem;
    font-size: .78rem;
    color: var(--text-secondary);
    background: #f8fafc;
    border-radius: 8px;
}

.privacy-note svg {
    flex-shrink: 0;
    color: #16a34a;
}

.feedback {
    border-top: 1px solid var(--border);
    padding-top: .75rem;
}

.feedback p {
    font-size: .8rem;
    color: var(--text-secondary);
}

.feedback a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
}

.feedback a:hover { text-decoration: underline; }

/* ===== Blazor infra ===== */
.blazor-error-boundary {
    background: #b32121;
    padding: 1rem;
    color: white;
    border-radius: 8px;
}

.blazor-error-boundary::after { content: "An error has occurred."; }

#blazor-error-ui { display: none; }