:root {
    --primary: #2563eb;
    --secondary: #38bdf8;
    --text: #333333;
    --muted: #4a5568;
    --card: rgba(255, 255, 255, 0.92);
}

* {
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    color: var(--text);
    background: linear-gradient(135deg, #dbeafe 0%, #eff6ff 100%);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
}

a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.page-shell {
    width: min(1040px, 100%);
    margin: 0 auto;
}

.page-title {
    width: 100%;
    margin: 34px 0 12px;
    color: var(--text);
    font-size: 35px;
    line-height: 1.25;
    text-align: center;
}

.page-title::after {
    content: "";
    display: block;
    width: 60px;
    height: 3px;
    margin: 10px auto 0;
    border-radius: 2px;
    background: var(--primary);
}

.intro {
    margin: 0 0 34px;
    color: var(--muted);
    text-align: center;
}

.step {
    margin-bottom: 20px;
    padding: 25px;
    background: var(--card);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(0, 0, 0, 0.10);
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s ease;
}

.step:hover {
    transform: translateY(-3px);
}

.step h2 {
    margin: 0 0 12px;
    color: var(--text);
    font-size: 24px;
}

.step p {
    margin: 0 0 15px;
    color: var(--muted);
}

.step img,
.tutorial-image {
    width: 100%;
    max-width: 100%;
    height: auto;
    border: 1px solid rgba(0, 0, 0, 0.10);
    border-radius: 8px;
    padding: 5px;
    background: #ffffff;
    display: block;
}

.image-placeholder {
    padding: 34px 20px;
    color: #64748b;
    background: #ffffff;
    border: 1px dashed rgba(37, 99, 235, 0.35);
    border-radius: 8px;
    text-align: center;
}

.accelerator-page {
    width: min(1180px, 100%);
    margin: 0 auto;
}

.section-title {
    margin: 30px 0 24px;
    font-size: 28px;
    text-align: center;
}

.accelerator-grid,
.steam-downloads {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.accelerator-card,
.steam-card,
.download-container {
    position: relative;
    padding: 24px;
    background: rgba(255, 255, 255, 0.94);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: 14px;
    box-shadow: 0 10px 26px rgba(15, 23, 42, 0.09);
}

.recommend-tag {
    position: absolute;
    top: 12px;
    right: 12px;
    padding: 3px 10px;
    color: #ffffff;
    background: #ef4444;
    border-radius: 999px;
    font-size: 12px;
}

.card-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 14px;
}

.logo-wrap {
    width: 64px;
    height: 64px;
    border-radius: 14px;
    background: #eef2ff;
    overflow: hidden;
    display: grid;
    place-items: center;
    color: var(--primary);
    font-weight: 800;
}

.logo-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.time-badge {
    display: inline-flex;
    margin-top: 4px;
    padding: 3px 8px;
    color: #0369a1;
    background: #e0f2fe;
    border-radius: 999px;
    font-size: 13px;
}

.button-group {
    display: grid;
    gap: 9px;
    margin-top: 16px;
}

.button,
.os-btn {
    width: 100%;
    border: 0;
    border-radius: 8px;
    padding: 11px 14px;
    color: #ffffff;
    background: var(--primary);
    font: inherit;
    font-weight: 700;
    cursor: pointer;
    text-align: center;
}

.button.secondary {
    color: var(--primary);
    background: #dbeafe;
}

.steam-section {
    margin-top: 32px;
}

.tutorial-panel {
    margin-top: 24px;
    padding: 24px;
    background: rgba(255, 255, 255, 0.94);
    border-radius: 14px;
    box-shadow: 0 8px 20px rgba(15, 23, 42, 0.08);
}

.tutorial-panel pre {
    white-space: pre-wrap;
    color: var(--muted);
    font: inherit;
}

.tutorial-images {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 16px;
}

.download-page {
    min-height: 100vh;
    background: linear-gradient(135deg, #0f172a 0%, #1d4ed8 100%);
}

.download-container {
    width: min(760px, 100%);
    margin: 36px auto;
    text-align: center;
}

.steam-logo {
    width: 96px;
    height: 96px;
    object-fit: contain;
}

.os-selector {
    display: grid;
    gap: 14px;
    margin: 24px 0;
}

.os-btn {
    background: #1d4ed8;
}

.os-btn.active {
    background: #0f172a;
}

.download-steps {
    text-align: left;
}

.download-step {
    display: flex;
    gap: 14px;
    margin: 14px 0;
    padding: 16px;
    background: #f8fafc;
    border-radius: 10px;
}

.step-number {
    flex: 0 0 auto;
    width: 34px;
    height: 34px;
    color: #ffffff;
    background: #2563eb;
    border-radius: 50%;
    display: grid;
    place-items: center;
    font-weight: 800;
}

.warning {
    margin-top: 18px;
    padding: 16px;
    color: #7f1d1d;
    background: #fee2e2;
    border-radius: 10px;
    text-align: left;
}

.progress-modal {
    position: fixed;
    inset: 0;
    display: none;
    place-items: center;
    background: rgba(15, 23, 42, 0.65);
    z-index: 50;
}

.progress-modal.active {
    display: grid;
}

.progress-box {
    width: min(380px, calc(100% - 32px));
    padding: 24px;
    background: #ffffff;
    border-radius: 14px;
    text-align: center;
}

.progress-track {
    height: 12px;
    margin: 16px 0;
    background: #e5e7eb;
    border-radius: 999px;
    overflow: hidden;
}

.progress-bar {
    width: 0;
    height: 100%;
    background: var(--primary);
}

@media (max-width: 900px) {
    body {
        padding: 14px;
    }

    .page-title {
        font-size: 30px;
    }
}