* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--bg-color, #f8fafc);
    color: var(--text-color, #1e293b);
    line-height: 1.5;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    transition: background-color 0.2s, color 0.2s;
}

.container {
    width: 100%;
    max-width: 1150px;
    background: var(--card-bg, #ffffff);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.08);
    border: 1px solid var(--border-color, #cbd5e1);
    transition: background-color 0.2s, border-color 0.2s;
}

.header-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 25px;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-logo {
    position: relative;
    z-index: 10;
}

.header-logo a {
    text-decoration: none;
    color: inherit;
    display: inline-block;
    cursor: pointer;
}

.header-logo img {
    max-height: 85px;
    width: auto;
    display: block;
}

.logo-dark { display: none !important; }
[data-theme="dark"] .logo-light { display: none !important; }
[data-theme="dark"] .logo-dark { display: block !important; }

.theme-toggle-btn {
    background: var(--light-bg, #f1f5f9);
    border: 1px solid var(--border-color, #cbd5e1);
    color: var(--text-color, #1e293b);
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.theme-toggle-btn:hover {
    border-color: var(--accent, var(--primary));
}

.lang-select {
    padding: 8px 14px;
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 6px;
    background: var(--card-bg, #ffffff);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-color, #1e293b);
    cursor: pointer;
}

.lang-select:focus {
    outline: none;
    border-color: var(--accent, var(--primary));
}

.hero-section {
    text-align: center;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color, #cbd5e1);
    padding-bottom: 20px;
}

.hero-title {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-color, #1e293b);
    margin-bottom: 6px;
    letter-spacing: -0.01em;
}

.sub-text {
    font-size: 0.85rem;
    color: var(--subtext-color, #64748b);
}

.generator-box {
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 8px;
    padding: 20px 25px;
    margin-bottom: 30px;
    background: var(--light-bg, #f1f5f9);
}

.generator-title {
    font-size: 0.9rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--primary, #0284c7);
    margin-bottom: 15px;
}

[data-theme="dark"] .generator-title {
    color: var(--accent, var(--primary));
}

.generator-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    flex-wrap: wrap;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.control-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-color, #1e293b);
}

.number-input {
    width: 72px;
    padding: 7px 8px;
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    text-align: center;
    background: var(--input-bg, #ffffff);
    color: var(--text-color, #1e293b);
    transition: border-color 0.2s;
}

.number-input:focus {
    outline: none;
    border-color: var(--accent, var(--primary));
    box-shadow: 0 0 0 2px rgba(2, 132, 199, 0.15);
}

.switch { position: relative; display: inline-block; width: 44px; height: 24px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider { position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0; background-color: #cbd5e1; transition: .3s; border-radius: 24px; }
.slider:before { position: absolute; content: ""; height: 18px; width: 18px; left: 3px; bottom: 3px; background-color: white; transition: .3s; border-radius: 50%; }
input:checked + .slider { background-color: var(--accent, var(--primary)); }
input:checked + .slider:before { transform: translateX(20px); }

.segmented-control, .validity-control {
    display: flex;
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 6px;
    overflow: hidden;
    background: var(--card-bg, #ffffff);
}

.validity-control {
    width: 100%;
    margin-bottom: 25px;
}

.segment-btn {
    padding: 8px 16px;
    background: var(--card-bg, #ffffff);
    border: none;
    border-right: 1px solid var(--border-color, #cbd5e1);
    font-size: 0.75rem;
    font-weight: 700;
    cursor: pointer;
    color: var(--subtext-color, #64748b);
    transition: all 0.2s;
}

.validity-control .segment-btn { flex: 1; text-align: center; padding: 10px 5px; white-space: nowrap; }

.segment-btn:last-child { border-right: none; }
.segment-btn.active { background-color: var(--primary, #0284c7); color: white; }
[data-theme="dark"] .segment-btn.active { background-color: var(--accent, var(--primary)); color: white; }
.segment-btn:hover:not(.active) { background-color: var(--light-bg, #f1f5f9); }

.upload-dropzone {
    border: 2px dashed var(--border-color, #cbd5e1);
    border-radius: 8px;
    padding: 25px 20px;
    text-align: center;
    background: var(--light-bg, #f1f5f9);
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 15px;
}

.upload-dropzone:hover, .upload-dropzone.dragover {
    border-color: var(--accent, var(--primary));
    background: var(--card-bg, #ffffff);
}

.dropzone-text {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--subtext-color, #64748b);
    margin-top: 8px;
}

.dropzone-hint {
    font-size: 0.75rem;
    color: var(--subtext-color, #64748b);
    margin-top: 2px;
}

.file-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--light-bg, #f1f5f9);
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 8px;
    margin-bottom: 15px;
}

.file-info {
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 0;
}

.file-name {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-color, #1e293b);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.btn-download-file {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background-color: var(--primary, #0284c7);
    color: #ffffff;
    border: none;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 700;
    text-decoration: none;
    cursor: pointer;
    transition: background-color 0.2s;
}

.btn-download-file:hover {
    background-color: var(--primary-hover, #0369a1);
}

.btn-generate-box {
    background-color: var(--card-bg, #ffffff);
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 6px;
    padding: 9px 18px;
    font-weight: 700;
    font-size: 0.8rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-color, #1e293b);
    transition: all 0.2s;
}

.btn-generate-box:hover {
    border-color: var(--accent, var(--primary));
    color: var(--accent, var(--primary));
}

.section-title {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-color, #1e293b);
    margin-bottom: 8px;
}

.textarea-wrapper {
    position: relative;
    margin-bottom: 12px;
}

textarea {
    width: 100%;
    min-height: 180px;
    padding: 15px;
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 8px;
    font-size: 0.95rem;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    resize: vertical;
    background: var(--input-bg, #ffffff);
    color: var(--text-color, #1e293b);
}

textarea:focus {
    outline: none;
    border-color: var(--accent, var(--primary));
    box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
}

.textarea-copy-btn {
    position: absolute;
    top: 12px;
    right: 12px;
    background: var(--primary, #0284c7);
    color: white;
    border: none;
    padding: 6px 14px;
    font-size: 0.75rem;
    font-weight: 700;
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.2s;
}

.textarea-copy-btn:hover { background: var(--primary-hover, #0369a1); }

.strength-meter-container {
    margin-bottom: 25px;
    display: none;
}

.strength-bar-bg {
    height: 6px;
    width: 100%;
    background: var(--border-color, #cbd5e1);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 4px;
}

.strength-bar-fill {
    height: 100%;
    width: 0%;
    transition: width 0.3s, background-color 0.3s;
}

.strength-text {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--subtext-color, #64748b);
}

.link-box {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    margin-top: 10px;
}

.link-box input[type="text"] {
    flex: 1;
    min-width: 0;
    padding: 12px 15px;
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 8px;
    font-size: 0.95rem;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    background: var(--input-bg, #ffffff);
    color: var(--text-color, #1e293b);
}

.link-box .textarea-copy-btn {
    position: static;
    flex-shrink: 0;
    padding: 12px 20px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.qr-wrapper {
    margin-top: 15px;
    padding: 20px;
    background: #ffffff;
    border: 1px solid var(--border-color, #cbd5e1);
    border-radius: 8px;
    display: inline-block;
    text-align: center;
}

.qr-wrapper #qrcode canvas, .qr-wrapper #qrcode img,
.qr-wrapper #secret-qrcode canvas, .qr-wrapper #secret-qrcode img {
    margin: 0 auto;
}

.btn-submit {
    display: block;
    width: 100%;
    padding: 14px;
    background-color: var(--primary, #0284c7);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    transition: all 0.2s;
    letter-spacing: 0.05em;
    margin-top: 15px;
}

.btn-submit:hover:not(:disabled) { background-color: var(--primary-hover, #0369a1); }

.btn-submit:disabled {
    background-color: #cbd5e1 !important;
    cursor: not-allowed;
    box-shadow: none !important;
    opacity: 0.7;
}

.shortcut-hint {
    text-align: center;
    font-size: 0.75rem;
    color: var(--subtext-color, #64748b);
    margin-top: 6px;
}

.hint-text {
    text-align: center;
    font-size: 0.8rem;
    color: var(--subtext-color, #64748b);
    font-style: italic;
    margin-top: 15px;
}

.alert {
    padding: 14px 18px;
    border-radius: 8px;
    margin-bottom: 25px;
    font-size: 0.9rem;
}

.alert-danger { background-color: #fee2e2; color: #991b1b; border: 1px solid #f87171; }
.alert-success { 
    background-color: var(--success-bg, #dcfce7); 
    color: var(--success-text, #166534); 
    border: 1px solid var(--success-border, #4ade80); 
}

.footer {
    text-align: center;
    margin-top: 35px;
    font-size: 0.8rem;
    color: var(--subtext-color, #64748b);
}

@media (max-width: 900px) {
    .container { padding: 20px; }
    .header-row { flex-direction: column; gap: 15px; text-align: center; }
    .generator-controls { flex-direction: column; align-items: stretch; }
    .segmented-control, .validity-control { flex-direction: column; }
    .link-box { flex-direction: column; }
    .link-box .textarea-copy-btn { width: 100%; justify-content: center; }
}