@import url("https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=JetBrains+Mono:wght@400;500;600&display=swap");

:root {
    --android-primary: #3ddc84;
    --android-primary-dark: #2eb872;
    --android-accent: #7f52ff;
    --android-dark: #061620;
    --android-card-border: #dce8e0;
    --android-text: #1a2e24;
    --android-muted: #5a6f63;
    --font-body: "DM Sans", system-ui, -apple-system, sans-serif;
    --font-code: "JetBrains Mono", "Fira Code", Consolas, monospace;
}

body {
    font-family: var(--font-body);
    color: var(--android-text);
    background: radial-gradient(circle at 12% 8%, #e8fff3 0, transparent 42%),
                radial-gradient(circle at 88% 2%, #ede8ff 0, transparent 38%),
                linear-gradient(180deg, #f8fffb 0%, #ffffff 40%, #f4f9f6 100%);
    line-height: 1.65;
}

.main-content {
    font-size: 1.02rem;
}

.main-content h2 {
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--android-dark);
}

.main-content code:not(.code-body) {
    font-family: var(--font-code);
    font-size: 0.88em;
    background: linear-gradient(135deg, #ecfdf3, #e8f4ff);
    color: #0d5c3a;
    padding: 0.15rem 0.45rem;
    border-radius: 6px;
    border: 1px solid rgba(61, 220, 132, 0.35);
}

/* Hero */
.hero-section {
    border: 1px solid rgba(61, 220, 132, 0.45);
    margin-bottom: 1.25rem;
    background: linear-gradient(135deg, #061620 0%, #0a3d2e 45%, #1a1040 85%, #061620 100%) !important;
    box-shadow: 0 14px 40px rgba(6, 22, 32, 0.35);
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 50%, rgba(61, 220, 132, 0.18) 0, transparent 55%),
                radial-gradient(circle at 80% 30%, rgba(127, 82, 255, 0.12) 0, transparent 50%);
    pointer-events: none;
}

.hero-section > * { position: relative; z-index: 1; }

.hero-section h1 {
    font-weight: 800;
    letter-spacing: -0.03em;
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

.android-pill {
    display: inline-block;
    padding: 0.4rem 0.85rem;
    border-radius: 999px;
    background: linear-gradient(135deg, rgba(61, 220, 132, 0.95), rgba(46, 184, 114, 0.95));
    color: #061620;
    font-weight: 700;
    font-size: 0.82rem;
    margin: 0.25rem;
    border: 1px solid rgba(255, 255, 255, 0.25);
    box-shadow: 0 2px 8px rgba(61, 220, 132, 0.35);
    transition: transform 0.2s, box-shadow 0.2s;
}

.android-pill:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 14px rgba(61, 220, 132, 0.45);
}

/* Topic sections */
.topic-section {
    border: 1px solid var(--android-card-border);
    border-left: 6px solid var(--android-primary);
    border-radius: 16px;
    margin-bottom: 1.35rem;
    padding: 1.5rem 1.45rem;
    background: #fff;
    box-shadow: 0 8px 28px rgba(15, 23, 42, 0.07);
    transition: box-shadow 0.25s, transform 0.25s;
}

.topic-section:hover {
    box-shadow: 0 12px 36px rgba(61, 220, 132, 0.12);
}

.section-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--android-primary), var(--android-primary-dark));
    color: var(--android-dark);
    font-weight: 800;
    font-size: 0.9rem;
    margin-right: 0.65rem;
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(61, 220, 132, 0.4);
}

.topic-section h2 {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
}

/* Callouts */
.definition-box {
    border-left: 5px solid var(--android-primary);
    background: linear-gradient(90deg, #ecfdf3 0%, #f8fffb 100%);
    border-radius: 0 12px 12px 0;
    box-shadow: inset 0 0 0 1px rgba(61, 220, 132, 0.15);
}

.tip-box {
    border-left: 5px solid var(--android-accent);
    background: linear-gradient(90deg, #f3f0ff 0%, #faf8ff 100%);
    border-radius: 0 12px 12px 0;
    padding: 1rem 1.15rem;
    margin: 1rem 0;
    box-shadow: inset 0 0 0 1px rgba(127, 82, 255, 0.12);
}

.tip-box .tip-title {
    font-weight: 700;
    color: #5b3fd4;
    margin-bottom: 0.35rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.note-box {
    border-left: 5px solid #f59e0b;
    background: linear-gradient(90deg, #fffbeb 0%, #fffef5 100%);
    border-radius: 0 12px 12px 0;
    padding: 0.85rem 1.1rem;
    margin-top: 1rem;
    font-size: 0.97rem;
}

/* TOC */
.toc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 0.65rem;
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-grid li a {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    padding: 0.65rem 0.85rem;
    border-radius: 10px;
    text-decoration: none;
    color: var(--android-text);
    font-weight: 500;
    background: linear-gradient(135deg, #f8fffb, #ffffff);
    border: 1px solid var(--android-card-border);
    transition: all 0.2s;
}

.toc-grid li a:hover {
    background: linear-gradient(135deg, #ecfdf3, #e8fff3);
    border-color: var(--android-primary);
    color: #0d5c3a;
    transform: translateX(4px);
}

.toc-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 1.6rem;
    height: 1.6rem;
    border-radius: 8px;
    background: var(--android-primary);
    color: var(--android-dark);
    font-weight: 800;
    font-size: 0.78rem;
}

/* Feature cards */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.feature-card {
    border-radius: 14px;
    padding: 1.15rem 1.2rem;
    border: 1px solid var(--android-card-border);
    background: #fff;
    transition: transform 0.2s, box-shadow 0.2s;
    height: 100%;
}

.feature-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 24px rgba(61, 220, 132, 0.15);
}

.feature-card .fc-icon {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    color: #fff;
}

.fc-green { background: linear-gradient(135deg, #3ddc84, #2eb872); }
.fc-purple { background: linear-gradient(135deg, #7f52ff, #6b3fd4); }
.fc-blue { background: linear-gradient(135deg, #3b82f6, #2563eb); }
.fc-orange { background: linear-gradient(135deg, #f97316, #ea580c); }
.fc-teal { background: linear-gradient(135deg, #14b8a6, #0d9488); }
.fc-pink { background: linear-gradient(135deg, #ec4899, #db2777); }
.fc-indigo { background: linear-gradient(135deg, #6366f1, #4f46e5); }
.fc-amber { background: linear-gradient(135deg, #f59e0b, #d97706); }
.fc-red { background: linear-gradient(135deg, #ef4444, #dc2626); }

.feature-card h5 {
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: 0.4rem;
    color: var(--android-dark);
}

.feature-card p {
    font-size: 0.92rem;
    color: var(--android-muted);
    margin: 0;
    line-height: 1.55;
}

/* Architecture */
.arch-card {
    border: 1px solid #c8f0dc;
    border-radius: 14px;
    padding: 1.15rem 1.2rem;
    background: linear-gradient(165deg, #ffffff 0%, #f0fff8 100%);
    height: 100%;
    transition: transform 0.2s, box-shadow 0.2s;
}

.arch-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(61, 220, 132, 0.12);
}

.arch-card h5 {
    font-weight: 700;
    color: #0d5c3a;
    display: flex;
    align-items: center;
    gap: 0.45rem;
}

.arch-card h5 .layer-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.75rem;
    height: 1.75rem;
    border-radius: 8px;
    background: var(--android-primary);
    color: var(--android-dark);
    font-size: 0.8rem;
    font-weight: 800;
}

.arch-stack {
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
    margin: 1.25rem 0;
}

.arch-layer {
    padding: 0.85rem 1.1rem;
    border-radius: 12px;
    text-align: center;
    font-weight: 600;
    font-size: 0.92rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: transform 0.2s;
}

.arch-layer:hover { transform: scale(1.01); }
.arch-layer-5 { background: linear-gradient(90deg, #3ddc84, #7ef0b0); color: #061620; }
.arch-layer-4 { background: linear-gradient(90deg, #34c978, #6ee7a8); color: #061620; }
.arch-layer-3 { background: linear-gradient(90deg, #2eb872, #5fd99a); color: #061620; }
.arch-layer-2 { background: linear-gradient(90deg, #259e60, #52c98a); color: #fff; }
.arch-layer-1 { background: linear-gradient(90deg, #1a7a4a, #45b87a); color: #fff; }

/* Tables */
.android-table {
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--android-card-border);
    box-shadow: 0 4px 16px rgba(15, 23, 42, 0.06);
}

.android-table thead th {
    background: linear-gradient(135deg, #061620, #0a3d2e) !important;
    color: #3ddc84 !important;
    font-weight: 700;
    font-size: 0.88rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    border: none !important;
    padding: 0.85rem 1rem;
    white-space: nowrap;
}

.android-table tbody tr {
    transition: background 0.15s;
}

.android-table tbody tr:hover {
    background: #f0fff8 !important;
}

.android-table tbody td {
    padding: 0.75rem 1rem;
    vertical-align: middle;
    border-color: #e8f0eb !important;
}

.api-badge {
    display: inline-block;
    padding: 0.2rem 0.55rem;
    border-radius: 6px;
    background: linear-gradient(135deg, #ede8ff, #f3f0ff);
    color: #5b3fd4;
    font-family: var(--font-code);
    font-size: 0.82rem;
    font-weight: 600;
    border: 1px solid rgba(127, 82, 255, 0.25);
}

.version-name {
    font-weight: 600;
    color: #0d5c3a;
}

/* App type cards */
.app-type-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 0.85rem;
    margin: 1rem 0;
}

.app-type-card {
    border-radius: 12px;
    padding: 1rem;
    text-align: center;
    border: 2px solid transparent;
    transition: all 0.2s;
}

.app-type-card.native { background: linear-gradient(135deg, #ecfdf3, #d1fae5); border-color: #3ddc84; }
.app-type-card.hybrid { background: linear-gradient(135deg, #eff6ff, #dbeafe); border-color: #3b82f6; }
.app-type-card.pwa { background: linear-gradient(135deg, #f3f0ff, #ede9fe); border-color: #7f52ff; }
.app-type-card.system { background: linear-gradient(135deg, #fff7ed, #ffedd5); border-color: #f97316; }

.app-type-card i {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
    display: block;
}

.app-type-card h6 {
    font-weight: 700;
    margin-bottom: 0.35rem;
}

.app-type-card p {
    font-size: 0.85rem;
    color: var(--android-muted);
    margin: 0;
}

/* Component pills */
.component-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.85rem;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.88rem;
    margin: 0.25rem;
}

.cp-activity { background: #ecfdf3; color: #0d5c3a; border: 1px solid #3ddc84; }
.cp-service { background: #eff6ff; color: #1d4ed8; border: 1px solid #3b82f6; }
.cp-receiver { background: #f3f0ff; color: #5b3fd4; border: 1px solid #7f52ff; }
.cp-provider { background: #fff7ed; color: #c2410c; border: 1px solid #f97316; }

/* SDK concept cards */
.sdk-concept-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 0.85rem;
    margin: 1rem 0;
}

.sdk-concept-card {
    text-align: center;
    padding: 1.1rem 0.85rem;
    border-radius: 14px;
    border: 1px solid var(--android-card-border);
    background: linear-gradient(180deg, #fff, #f8fffb);
    transition: transform 0.2s;
}

.sdk-concept-card:hover { transform: translateY(-3px); }

.sdk-concept-card .sdk-label {
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--android-muted);
    font-weight: 600;
}

.sdk-concept-card .sdk-value {
    font-weight: 700;
    font-size: 1rem;
    color: var(--android-dark);
    margin-top: 0.25rem;
}

/* Step cards (next steps) */
.steps-grid {
    display: grid;
    gap: 0.75rem;
    counter-reset: step-counter;
}

.step-card {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem 1.15rem;
    border-radius: 12px;
    background: linear-gradient(90deg, #f8fffb, #ffffff);
    border: 1px solid var(--android-card-border);
    transition: all 0.2s;
}

.step-card:hover {
    border-color: var(--android-primary);
    box-shadow: 0 6px 18px rgba(61, 220, 132, 0.12);
}

.step-num {
    flex-shrink: 0;
    width: 2.25rem;
    height: 2.25rem;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--android-primary), var(--android-primary-dark));
    color: var(--android-dark);
    font-weight: 800;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.95rem;
    box-shadow: 0 3px 10px rgba(61, 220, 132, 0.35);
}

.step-card p {
    margin: 0;
    padding-top: 0.35rem;
    font-weight: 500;
}

.sub-heading {
    font-size: 1.12rem;
    font-weight: 700;
    margin-top: 1.35rem;
    margin-bottom: 0.85rem;
    color: var(--android-dark);
    display: flex;
    align-items: center;
    gap: 0.45rem;
}

.sub-heading::before {
    content: "";
    width: 4px;
    height: 1.1rem;
    border-radius: 2px;
    background: linear-gradient(180deg, var(--android-primary), var(--android-accent));
}

/* Navigation */
.page-wrapper > .main-content { margin-left: 0 !important; }

.navigation-buttons {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin: 1rem 0;
}

.nav-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.6rem 1.15rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 700;
    border: 1px solid transparent;
    transition: transform 0.2s, box-shadow 0.2s;
}

.nav-btn:hover {
    transform: translateY(-2px);
    color: inherit;
}

.nav-btn-prev {
    background: linear-gradient(135deg, #64748b, #475569);
    color: #fff;
    box-shadow: 0 4px 12px rgba(100, 116, 139, 0.35);
}

.nav-btn-next {
    background: linear-gradient(135deg, #3ddc84, #2eb872);
    color: #061620;
    box-shadow: 0 4px 12px rgba(61, 220, 132, 0.4);
}

/* Code blocks — layout (colors in android-code-highlight.css) */
.code-example {
    border-left: 4px solid var(--android-primary);
    border-radius: 12px;
    padding: 1rem 1.15rem;
    margin-bottom: 1rem;
    overflow-x: auto;
    white-space: pre-wrap;
}

.code-example .code-label {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    color: #3ddc84;
    font-family: var(--font-code);
    font-weight: 700;
    margin-bottom: 0.75rem;
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}