.etcg-app-wrap {
    --bg: #f0f4fb;
    --card: #ffffff;
    --text: #0f172a;
    --muted: #475569;
    --line: #dbe3ef;
    --accent: #2563eb;
    --accent-2: #60a5fa;
    --accent-hover: #1d4ed8;
    --ok-bg: #ecfdf5;
    --ok-line: #a7f3d0;
    --ok-text: #065f46;
    --err-bg: #fef2f2;
    --err-line: #fecaca;
    --err-text: #991b1b;
    --shadow: 0 4px 24px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 12px 40px rgba(15, 23, 42, 0.12);
}

.etcg-app-wrap * {
    box-sizing: border-box;
}

.etcg-app-wrap {
    width: min(900px, calc(100% - 24px));
    margin: 24px auto 48px;
    font-family: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
    color: var(--text);
    line-height: 1.5;
}

.etcg-app-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 20px;
    padding: 24px 24px 20px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: var(--card);
    box-shadow: var(--shadow);
    transition: box-shadow 0.2s ease;
}

.etcg-app-header:hover {
    box-shadow: var(--shadow-lg);
}

.etcg-app-header h1 {
    margin: 10px 0 0;
    font-size: clamp(1.35rem, 4vw, 1.75rem);
    font-weight: 700;
    line-height: 1.3;
    letter-spacing: -0.02em;
    color: var(--text);
}

.etcg-app-header p {
    margin: 10px 0 0;
    color: var(--muted);
    font-size: 0.95rem;
    max-width: 52ch;
}

.etcg-badge {
    display: inline-flex;
    align-items: center;
    padding: 6px 14px;
    border-radius: 999px;
    background: linear-gradient(135deg, #dbeafe 0%, #e0e7ff 100%);
    border: 1px solid #bfdbfe;
    color: #1d4ed8;
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.etcg-nav-links {
    display: flex;
    gap: 8px;
    flex-shrink: 0;
}

.etcg-nav-link {
    text-decoration: none;
    color: var(--muted);
    border: 1px solid var(--line);
    background: #fff;
    border-radius: 12px;
    padding: 10px 16px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: color 0.2s, border-color 0.2s, background 0.2s, box-shadow 0.2s;
}

.etcg-nav-link:hover {
    color: var(--accent);
    border-color: #93c5fd;
    background: #f8fafc;
}

.etcg-nav-link.active {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
    color: #fff;
    border-color: transparent;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.etcg-nav-link.active:hover {
    background: linear-gradient(135deg, var(--accent-hover) 0%, var(--accent) 100%);
    box-shadow: 0 6px 18px rgba(37, 99, 235, 0.4);
}

.etcg-security-note {
    margin-top: 16px;
    display: flex;
    flex-wrap: wrap;
    gap: 12px 16px;
    align-items: center;
    border: 1px dashed #93c5fd;
    border-radius: 14px;
    padding: 14px 18px;
    color: #1e3a8a;
    background: linear-gradient(135deg, #eff6ff 0%, #f0f9ff 100%);
    font-size: 0.9rem;
}

.etcg-security-note strong {
    font-weight: 600;
}

.etcg-security-note span {
    color: #475569;
    font-size: 0.875rem;
}

.etcg-intro-panel {
    padding: 24px 24px 28px;
}

.etcg-intro-title {
    margin: 0 0 14px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.01em;
}

.etcg-intro-lead {
    margin: 0 0 16px;
    line-height: 1.65;
    color: var(--muted);
    font-size: 0.95rem;
}

.etcg-intro-who {
    margin: 0 0 20px;
    padding: 14px 16px;
    background: #f8fafc;
    border-radius: 12px;
    border-left: 4px solid var(--accent);
    line-height: 1.55;
    color: var(--text);
    font-size: 0.95rem;
}

.etcg-intro-subtitle {
    margin: 0 0 10px;
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
}

.etcg-intro-steps {
    margin: 0 0 18px;
    padding-left: 24px;
    line-height: 1.7;
    color: var(--muted);
    font-size: 0.95rem;
}

.etcg-intro-steps li {
    margin-bottom: 8px;
}

.etcg-intro-steps li:last-child {
    margin-bottom: 0;
}

.etcg-intro-tip {
    margin: 0 0 20px;
    padding: 12px 16px;
    background: #eff6ff;
    border-radius: 12px;
    font-size: 0.9rem;
    line-height: 1.55;
    color: #1e40af;
}

/* FAQ list (SEO section) */
.etcg-faq-list {
    margin: 0;
    padding: 0;
    list-style: none;
}

.etcg-faq-list dt {
    margin: 14px 0 4px;
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--text);
}

.etcg-faq-list dt:first-child {
    margin-top: 0;
}

.etcg-faq-list dd {
    margin: 0 0 0 0;
    padding: 8px 0 8px 14px;
    border-left: 3px solid var(--line);
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--muted);
}

.etcg-faq-list dd:last-child {
    padding-bottom: 0;
}

.etcg-panel {
    margin-top: 16px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: var(--card);
    box-shadow: var(--shadow);
    padding: 20px;
    transition: box-shadow 0.2s ease;
}

.etcg-panel:hover {
    box-shadow: var(--shadow-lg);
}

.etcg-form-grid {
    display: grid;
    gap: 12px;
}

.etcg-field-hint {
    display: block;
    margin: -4px 0 0;
    font-size: 13px;
    color: var(--muted);
}

.etcg-key-type-choose {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 14px 20px;
    margin-bottom: 4px;
}

.etcg-key-type-label {
    font-weight: 700;
    color: var(--text);
}

.etcg-radio-label {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    font-weight: 500;
    color: var(--muted);
}

.etcg-radio-label input[type="radio"] {
    margin: 0;
    cursor: pointer;
}

.etcg-key-input-wrap.etcg-is-hidden {
    display: none;
}

.etcg-field {
    display: grid;
    gap: 6px;
}

.etcg-field > span {
    font-weight: 700;
}

.etcg-app-wrap input[type="text"],
.etcg-app-wrap input[type="password"],
.etcg-app-wrap select,
.etcg-app-wrap textarea {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: #f8fafc;
    color: var(--text);
    font-size: 15px;
    padding: 12px 14px;
    transition: border-color 0.2s, box-shadow 0.2s, background 0.2s;
}

.etcg-app-wrap input:hover,
.etcg-app-wrap select:hover,
.etcg-app-wrap textarea:hover {
    background: #fff;
}

.etcg-app-wrap textarea {
    min-height: 180px;
    resize: vertical;
    line-height: 1.5;
}

.etcg-field small {
    font-size: 0.85rem;
    color: var(--muted);
    margin-top: 2px;
}

.etcg-app-wrap input:focus,
.etcg-app-wrap select:focus,
.etcg-app-wrap textarea:focus {
    outline: none;
    border-color: #93c5fd;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.16);
    background: #fff;
}

.etcg-app-wrap input.etcg-input-error:focus,
.etcg-app-wrap textarea.etcg-input-error:focus {
    border-color: #f87171;
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.2);
}

.etcg-grid-2 {
    display: grid;
    gap: 12px;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}

.etcg-pin-wrap {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 8px;
}

.etcg-eye-btn {
    border: 1px solid var(--line);
    background: #fff;
    border-radius: 10px;
    padding: 8px 14px;
    cursor: pointer;
    font-size: 1rem;
    transition: border-color 0.2s, background 0.2s;
}

.etcg-eye-btn:hover {
    background: #f8fafc;
    border-color: #93c5fd;
}

.etcg-checks {
    display: grid;
    gap: 10px;
    color: #334155;
    font-size: 0.9rem;
}

.etcg-checks label {
    display: flex;
    gap: 10px;
    align-items: center;
    cursor: pointer;
}

.etcg-checks input[type="checkbox"] {
    width: auto;
    margin: 0;
    cursor: pointer;
    accent-color: var(--accent);
}

.etcg-btn {
    border: 1px solid transparent;
    border-radius: 12px;
    padding: 12px 18px;
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s, border-color 0.2s;
}

.etcg-btn:hover {
    transform: translateY(-1px);
}

.etcg-btn:active {
    transform: translateY(0);
}

.etcg-btn-primary {
    color: #fff;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.etcg-btn-primary:hover {
    background: linear-gradient(135deg, var(--accent-hover) 0%, var(--accent) 100%);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.etcg-btn-ghost {
    background: #fff;
    border-color: var(--line);
    color: var(--text);
}

.etcg-btn-ghost:hover {
    border-color: #93c5fd;
    background: #f8fafc;
}

.etcg-status {
    margin-top: 14px;
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 10px 12px;
    font-weight: 600;
}

.etcg-is-hidden {
    display: none !important;
}

.etcg-status-success {
    background: var(--ok-bg);
    border-color: var(--ok-line);
    color: var(--ok-text);
}

.etcg-status-error {
    background: var(--err-bg);
    border-color: var(--err-line);
    color: var(--err-text);
}

.etcg-result-panel h2 {
    margin: 0 0 14px;
    font-size: 1.2rem;
    font-weight: 700;
}

.etcg-result-panel p {
    margin: 0 0 6px;
    font-size: 0.9rem;
    color: var(--muted);
}

.etcg-result-panel .etcg-link-row {
    margin-bottom: 14px;
}

.etcg-result-panel .etcg-link-row:last-of-type {
    margin-bottom: 10px;
}

.etcg-result-panel small {
    display: block;
    margin-top: 8px;
    font-size: 0.85rem;
    color: var(--muted);
}

.etcg-emoji-key {
    font-size: 26px;
    letter-spacing: 2px;
}

.etcg-link-row {
    display: grid;
    gap: 8px;
    grid-template-columns: 1fr auto;
    align-items: center;
}

.etcg-link-row input {
    font-size: 0.9rem;
    padding: 10px 12px;
}

.etcg-result-text {
    margin: 0;
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: inherit;
    background: #f8fafc;
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 14px;
    font-size: 0.95rem;
    line-height: 1.5;
}

.etcg-app-wrap small {
    color: #64748b;
}

@media (max-width: 640px) {
    .etcg-app-wrap {
        margin: 16px auto 32px;
        width: calc(100% - 16px);
    }

    .etcg-app-header {
        flex-direction: column;
        padding: 20px 18px;
        border-radius: 16px;
    }

    .etcg-app-header h1 {
        font-size: 1.25rem;
    }

    .etcg-nav-links {
        width: 100%;
        margin-top: 4px;
    }

    .etcg-nav-link {
        flex: 1;
        text-align: center;
    }

    .etcg-security-note {
        flex-direction: column;
        align-items: flex-start;
        padding: 12px 14px;
        gap: 8px;
    }

    .etcg-panel {
        padding: 16px;
        border-radius: 14px;
    }

    .etcg-link-row {
        grid-template-columns: 1fr;
    }

    .etcg-link-row .etcg-btn {
        width: 100%;
    }
}