/* ===== GPT Banner ===== */
.gpt-banner {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: #0a0f1a;
    overflow: hidden;
    padding-top: 70px;
}

.gpt-banner-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 50% 0%, rgba(16, 163, 127, 0.2) 0%, transparent 60%),
        radial-gradient(ellipse 60% 50% at 80% 80%, rgba(0, 120, 212, 0.15) 0%, transparent 55%),
        radial-gradient(ellipse 50% 40% at 10% 70%, rgba(16, 163, 127, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.gpt-banner .container {
    position: relative;
    z-index: 1;
    display: flex;
    justify-content: center;
}

.banner-content {
    text-align: center;
    max-width: 780px;
    color: #fff;
}

.gpt-logo-wrap {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(16, 163, 127, 0.3);
    border-radius: 50px;
    padding: 6px 20px;
    margin-bottom: 28px;
    backdrop-filter: blur(8px);
}

.gpt-icon {
    font-size: 1.3rem;
    background: linear-gradient(135deg, #10a37f, #00d4aa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.gpt-brand {
    font-size: 1.1rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    letter-spacing: 0.05em;
}

.gpt-by {
    font-size: 0.8rem;
    color: rgba(16, 163, 127, 0.7);
    font-style: italic;
}

.gpt-banner h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    color: #fff;
}

.gpt-gradient-text {
    background: linear-gradient(90deg, #10a37f, #00d4aa, #0078d4, #10a37f);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% auto;
    animation: gptGradient 4s linear infinite;
}

@keyframes gptGradient {
    0% { background-position: 0% center; }
    100% { background-position: 200% center; }
}

.banner-desc {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.65);
    line-height: 1.8;
    margin-bottom: 36px;
}

.banner-btns {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 56px;
}

.gpt-btn-primary {
    display: inline-block;
    padding: 14px 32px;
    background: linear-gradient(135deg, #10a37f, #00d4aa);
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.gpt-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(16, 163, 127, 0.45);
}

.gpt-btn-secondary {
    display: inline-block;
    padding: 14px 32px;
    background: rgba(255, 255, 255, 0.08);
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    border: 1px solid rgba(16, 163, 127, 0.3);
    transition: all 0.3s ease;
}

.gpt-btn-secondary:hover {
    background: rgba(255, 255, 255, 0.14);
    border-color: rgba(16, 163, 127, 0.5);
}

.banner-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.stat-num {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(90deg, #10a37f, #00d4aa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.5);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: rgba(16, 163, 127, 0.25);
}

/* ===== 模型系列 ===== */
.section-models {
    padding: 80px 0;
    background: #f7faf9;
}

.models-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.model-card {
    background: #fff;
    border-radius: 16px;
    padding: 28px;
    border: 1px solid #e0ede9;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.model-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(16, 163, 127, 0.1);
}

.card-4o   { border-top: 3px solid #10a37f; }
.card-o1   { border-top: 3px solid #0078d4; }
.card-plus { border-top: 3px solid #00d4aa; }
.card-api  { border-top: 3px solid #005a9e; }

.model-header {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-bottom: 16px;
}

.model-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    background: linear-gradient(135deg, rgba(16, 163, 127, 0.1), rgba(0, 212, 170, 0.1));
    flex-shrink: 0;
    color: #10a37f;
}

.model-name {
    font-size: 1.15rem;
    font-weight: 700;
    color: #0a1a14;
    margin-bottom: 4px;
}

.model-tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 20px;
    font-size: 0.72rem;
    font-weight: 600;
}

.tag-flagship  { background: rgba(16, 163, 127, 0.12); color: #10a37f; }
.tag-reasoning { background: rgba(0, 120, 212, 0.12);  color: #0078d4; }
.tag-plus      { background: rgba(0, 212, 170, 0.15);  color: #008a6e; }
.tag-enterprise{ background: rgba(0, 90, 158, 0.12);   color: #005a9e; }

.model-desc {
    font-size: 0.9rem;
    color: #666;
    line-height: 1.6;
    margin-bottom: 20px;
}

.model-features {
    list-style: none;
    margin-bottom: 24px;
    flex: 1;
}

.model-features li {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    font-size: 0.875rem;
    color: #444;
    padding: 5px 0;
    border-bottom: 1px solid #f0f7f5;
}

.model-features li:last-child { border-bottom: none; }

.check {
    color: #10a37f;
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 1px;
}

.model-btn {
    display: block;
    text-align: center;
    padding: 12px;
    background: linear-gradient(135deg, #10a37f, #00d4aa);
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-top: auto;
}

.model-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(16, 163, 127, 0.4);
}

/* ===== 核心优势 ===== */
.section-advantages {
    padding: 80px 0;
    background: #fff;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.adv-card {
    padding: 28px 24px;
    background: #f7faf9;
    border-radius: 14px;
    border: 1px solid #e0ede9;
    transition: all 0.3s ease;
}

.adv-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 28px rgba(16, 163, 127, 0.1);
    border-color: rgba(16, 163, 127, 0.3);
}

.adv-icon {
    font-size: 2rem;
    margin-bottom: 14px;
}

.adv-card h4 {
    font-size: 1.05rem;
    font-weight: 700;
    color: #0a1a14;
    margin-bottom: 10px;
}

.adv-card p {
    font-size: 0.875rem;
    color: #666;
    line-height: 1.65;
}

/* ===== 对比表格 ===== */
.section-compare {
    padding: 80px 0;
    background: #f7faf9;
}

.compare-table-wrap {
    margin-top: 40px;
    overflow-x: auto;
    border-radius: 14px;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.07);
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    font-size: 0.9rem;
}

.compare-table thead tr {
    background: linear-gradient(135deg, #0a1a14, #0d2e22);
    color: #fff;
}

.compare-table th {
    padding: 18px 20px;
    text-align: center;
    font-weight: 600;
    font-size: 0.95rem;
}

.compare-table th:first-child { text-align: left; }

.th-icon { margin-right: 6px; }

.compare-table td {
    padding: 14px 20px;
    text-align: center;
    border-bottom: 1px solid #f0f7f5;
    color: #444;
}

.compare-table td:first-child {
    text-align: left;
    font-weight: 600;
    color: #0a1a14;
}

.compare-table tbody tr:hover { background: #f7faf9; }
.compare-table tbody tr:last-child td { border-bottom: none; }

.highlight-cell {
    color: #10a37f !important;
    font-weight: 700 !important;
}

/* ===== 为什么选择我们 ===== */
.section-why {
    padding: 80px 0;
    background: #fff;
}

.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.why-card {
    padding: 28px 24px;
    background: #f7faf9;
    border-radius: 14px;
    border: 1px solid #e0ede9;
    transition: all 0.3s ease;
}

.why-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 28px rgba(16, 163, 127, 0.1);
    border-color: rgba(16, 163, 127, 0.3);
}

.why-icon {
    font-size: 2rem;
    margin-bottom: 14px;
}

.why-card h4 {
    font-size: 1.05rem;
    font-weight: 700;
    color: #0a1a14;
    margin-bottom: 10px;
}

.why-card p {
    font-size: 0.875rem;
    color: #666;
    line-height: 1.65;
}

/* ===== 开通流程 ===== */
.section-steps {
    padding: 80px 0;
    background: linear-gradient(135deg, #0a0f1a 0%, #0a1a14 100%);
}

.section-steps .title,
.section-steps .title-desc {
    color: #fff;
}

.section-steps .title-desc {
    color: rgba(255, 255, 255, 0.6);
}

.steps-wrap {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 0;
    margin-top: 50px;
    flex-wrap: wrap;
}

.step-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 200px;
    flex: 1;
    min-width: 160px;
}

.step-num {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, #10a37f, #00d4aa);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 16px;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}

.step-content p {
    font-size: 0.82rem;
    color: rgba(255, 255, 255, 0.55);
    line-height: 1.6;
}

.step-arrow {
    font-size: 1.8rem;
    color: rgba(16, 163, 127, 0.5);
    padding: 0 8px;
    margin-top: 18px;
    flex-shrink: 0;
}

/* ===== 使用场景 ===== */
.section-usecases {
    padding: 80px 0;
    background: #f7faf9;
}

.usecase-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.usecase-card {
    padding: 28px 24px;
    background: #fff;
    border-radius: 14px;
    border: 1px solid #e0ede9;
    transition: all 0.3s ease;
}

.usecase-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.08);
    border-color: rgba(16, 163, 127, 0.3);
}

.usecase-icon {
    font-size: 2rem;
    margin-bottom: 14px;
}

.usecase-card h4 {
    font-size: 1.05rem;
    font-weight: 700;
    color: #0a1a14;
    margin-bottom: 10px;
}

.usecase-card p {
    font-size: 0.875rem;
    color: #666;
    line-height: 1.65;
}

/* ===== CTA ===== */
.section-cta {
    padding: 80px 0;
    background: #fff;
}

.cta-box {
    background: linear-gradient(135deg, #0a0f1a 0%, #0a1a14 50%, #0d2e22 100%);
    border-radius: 24px;
    padding: 60px 40px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-box::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 70% 60% at 50% 0%, rgba(16, 163, 127, 0.2) 0%, transparent 60%),
        radial-gradient(ellipse 50% 40% at 80% 100%, rgba(0, 212, 170, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.cta-gpt-icon {
    font-size: 3rem;
    background: linear-gradient(135deg, #10a37f, #00d4aa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 20px;
    display: block;
}

.cta-box h2 {
    font-size: clamp(1.6rem, 3vw, 2.4rem);
    font-weight: 700;
    color: #fff;
    margin-bottom: 16px;
    position: relative;
}

.cta-box p {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.6);
    line-height: 1.8;
    margin-bottom: 36px;
    position: relative;
}

.cta-btns {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    position: relative;
}

.cta-btn-primary {
    display: inline-block;
    padding: 14px 36px;
    background: linear-gradient(135deg, #10a37f, #00d4aa);
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.cta-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(16, 163, 127, 0.5);
}

.cta-btn-secondary {
    display: inline-block;
    padding: 14px 36px;
    background: rgba(255, 255, 255, 0.08);
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    border: 1px solid rgba(16, 163, 127, 0.3);
    transition: all 0.3s ease;
}

.cta-btn-secondary:hover {
    background: rgba(255, 255, 255, 0.14);
}

/* ===== 底部服务保障 ===== */
.section-service {
    display: flex;
    background: linear-gradient(135deg, #0a1a14, #0a0f1a);
}

.section-service .box {
    flex: 1;
    border-right: 1px solid rgba(16, 163, 127, 0.15);
    transition: background 0.3s ease;
}

.section-service .box:last-child { border-right: none; }

.section-service .box:hover {
    background: rgba(16, 163, 127, 0.1);
}

.section-service .box a {
    display: block;
    padding: 36px 24px;
    text-align: center;
    text-decoration: none;
}

.section-service .box h3 {
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}

.section-service .box p {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.5;
}

/* ===== 通用标题 ===== */
.title {
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 700;
    color: #0a1a14;
    text-align: center;
    margin-bottom: 12px;
}

.title-desc {
    font-size: 1rem;
    color: #888;
    text-align: center;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .gpt-banner {
        padding-top: 60px;
        min-height: auto;
        padding-bottom: 60px;
    }

    .banner-stats { gap: 20px; }
    .stat-divider { display: none; }

    .steps-wrap {
        flex-direction: column;
        align-items: center;
        gap: 24px;
    }

    .step-arrow {
        transform: rotate(90deg);
        margin: 0;
    }

    .step-item { max-width: 100%; }

    .section-service {
        flex-direction: column;
    }

    .section-service .box {
        border-right: none;
        border-bottom: 1px solid rgba(16, 163, 127, 0.15);
    }

    .section-service .box:last-child { border-bottom: none; }

    .compare-table th,
    .compare-table td {
        padding: 12px 10px;
        font-size: 0.8rem;
    }

    .cta-box { padding: 40px 20px; }

    .models-grid,
    .advantages-grid,
    .why-grid,
    .usecase-grid {
        grid-template-columns: 1fr;
    }
}