/* ===== CERT HERO ===== */
.cert-hero {
    position: relative;
    width: 100%;
    min-height: 400px;
    background: var(--slate-900);
    display: flex;
    align-items: center;
    padding: 56px 24px 72px;
    overflow: hidden;
}

.cert-hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 30% 40%, rgba(0, 104, 204, 0.15) 0%, transparent 70%);
    pointer-events: none;
}

.cert-hero-inner {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.cert-hero-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(4px);
    padding: 4px 18px;
    border-radius: 100px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.8px;
    text-transform: uppercase;
    color: rgba(255, 255, 255, 0.70);
    border: 1px solid rgba(255, 255, 255, 0.06);
    width: fit-content;
}

.cert-hero h1 {
    font-size: 48px;
    font-weight: 700;
    color: var(--white);
    letter-spacing: -0.02em;
    line-height: 1.08;
    max-width: 700px;
}

.cert-hero h1 .highlight {
    color: var(--blue-500);
}

.cert-hero p {
    font-size: 17px;
    color: rgba(255, 255, 255, 0.65);
    max-width: 600px;
    line-height: 1.7;
    margin-top: 2px;
}

.cert-hero-stats {
    display: flex;
    flex-wrap: wrap;
    gap: 24px 40px;
    margin-top: 12px;
}

.hero-stat {
    display: flex;
    flex-direction: column;
}

.hero-stat-number {
    font-size: 28px;
    font-weight: 700;
    color: var(--white);
    line-height: 1.1;
}

.hero-stat-label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: rgba(255, 255, 255, 0.50);
}

/* ===== CERT GRID ===== */
.cert-grid-section {
    padding: 72px 24px 80px;
    background: var(--white);
}

.cert-grid-inner {
    max-width: 1200px;
    margin: 0 auto;
}

.cert-grid-header {
    text-align: center;
    margin-bottom: 48px;
}

.cert-grid-header .cert-grid-tag {
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--red-600);
    margin-bottom: 6px;
}

.cert-grid-header h2 {
    font-size: 34px;
    font-weight: 700;
    color: var(--slate-900);
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 8px;
}

.cert-grid-header p {
    font-size: 15px;
    color: var(--slate-600);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* A4 比例：宽高比 1:1.414 */
.cert-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px 24px;
    margin-top: 8px;
}

.cert-card {
    aspect-ratio: 1 / 1.414; /* A4 */
    overflow: hidden;
    border-radius: 4px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    background: var(--white);
    cursor: default;
    position: relative;
}
.cert-download-btn {
    position: absolute;
    bottom: 12px;
    right: 12px;
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(4px);
    color: #ffffff;
    padding: 6px 12px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    text-decoration: none;
    opacity: 0;
    transform: translateY(6px);
    transition: all 0.3s ease;
    z-index: 3;
}

.cert-card:hover .cert-download-btn {
    opacity: 1;
    transform: translateY(0);
}

.cert-download-btn:hover {
    background: var(--blue-500, #0068cc);
    color: #ffffff;
}
.cert-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.08);
}

.cert-card img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    background: var(--white);
    padding: 4px;
}

.cert-grid-note {
    text-align: center;
    font-size: 13px;
    color: var(--slate-500);
    margin-top: 40px;
    border-top: 1px solid var(--slate-200);
    padding-top: 28px;
}

/* ===== SEO COLLAPSIBLE ===== */
.cert-seo-section {
    padding: 56px 24px 72px;
    background: var(--slate-50);
    border-top: 1px solid var(--slate-200);
}

.cert-seo-inner {
    max-width: 1200px;
    margin: 0 auto;
}

.cert-seo-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--slate-900);
    letter-spacing: -0.02em;
    margin-bottom: 24px;
}

.cert-seo-content {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.seo-paragraph {
    font-size: 15px;
    line-height: 1.7;
    color: var(--slate-700);
    padding: 12px 16px;
    background: var(--white);
    border-radius: 8px;
    border: 1px solid var(--slate-200);
}

.seo-paragraph.seo-hidden {
    display: none;
}

.seo-paragraph.seo-hidden.visible {
    display: block;
}

.seo-toggle-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin-top: 24px;
    padding: 10px 28px;
    background: var(--white);
    border: 1px solid var(--slate-300);
    border-radius: 30px;
    font-size: 14px;
    font-weight: 600;
    color: var(--slate-700);
    transition: all 0.25s ease;
    cursor: pointer;
}

.seo-toggle-btn:hover {
    background: var(--slate-100);
    border-color: var(--blue-500);
    color: var(--blue-500);
}

.seo-toggle-btn .toggle-icon {
    transition: transform 0.3s ease;
    font-size: 12px;
}

.seo-toggle-btn[aria-expanded="true"] .toggle-icon {
    transform: rotate(180deg);
}

.seo-toggle-btn[aria-expanded="true"] .toggle-label {
    content: 'Show Less';
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
    .cert-hero h1 {
        font-size: 38px;
    }
    .cert-hero p {
        font-size: 16px;
    }
    .cert-grid {
        gap: 24px 18px;
    }
}

@media (max-width: 820px) {
    .cert-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    .cert-hero h1 {
        font-size: 32px;
    }
    .cert-hero-stats {
        gap: 16px 28px;
    }
    .hero-stat-number {
        font-size: 24px;
    }
}

@media (max-width: 480px) {
    .cert-hero {
        min-height: 300px;
        padding: 36px 16px 48px;
    }
    .cert-hero h1 {
        font-size: 26px;
    }
    .cert-hero p {
        font-size: 14px;
    }
    .hero-stat-number {
        font-size: 20px;
    }
    .hero-stat-label {
        font-size: 9px;
    }
    .cert-grid-section {
        padding: 40px 16px 56px;
    }
    .cert-grid-header h2 {
        font-size: 26px;
    }
    .cert-grid {
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }
    .cert-card {
        aspect-ratio: 1 / 1.4;
    }
    .cert-seo-section {
        padding: 40px 16px 56px;
    }
    .cert-seo-title {
        font-size: 22px;
    }
    .seo-paragraph {
        font-size: 14px;
        padding: 10px 14px;
    }
    .seo-toggle-btn {
        padding: 8px 20px;
        font-size: 13px;
    }
}

@media (max-width: 360px) {
    .cert-grid {
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }
    .cert-hero h1 {
        font-size: 22px;
    }
}