/* ====== Modern Sleek Dark Aesthetic (Fully Responsive) ====== */
:root {
    --bg: #0b0c10;
    --surface: #15171e;
    --surface-light: #1e2029;
    --border: #2a2d37;
    --fg: #e2e4e9;
    --muted: #858a97;
    --accent: #00c2cb;
    --accent-soft: rgba(0,194,203,0.08);
    --danger: #e0556a;
    --code-bg: #1a1d26;
    --code-fg: #c9d1d9;
    --font-sans: 'Inter', 'Segoe UI', system-ui, sans-serif;
    --font-serif: 'Merriweather', 'Georgia', serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --radius: 8px;
    --shadow: 0 4px 24px rgba(0,0,0,0.4);
    --transition: 0.2s ease;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    background: var(--bg);
    color: var(--fg);
    font-family: var(--font-sans);
    line-height: 1.75;
    font-size: 1.05rem;
    -webkit-font-smoothing: antialiased;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

/* Header */
.site-header {
    background: rgba(15,17,22,0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 0 1.8rem;
    position: sticky;
    top: 0;
    z-index: 100;
}
.header-inner {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}
.logo {
    color: var(--fg);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.logo-accent { color: var(--accent); font-weight: 800; }
.main-nav { display: flex; gap: 1.6rem; align-items: center; }
.main-nav a {
    color: var(--muted);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.6px;
    transition: color var(--transition);
    padding: 0.35rem 0;
    border-bottom: 2px solid transparent;
}
.main-nav a:hover { color: var(--fg); border-bottom-color: var(--accent); }

/* Layout */
.container {
    max-width: 860px;
    margin: 2.2rem auto 0;
    padding: 0 1.6rem 2.5rem;
    width: 100%;
}
.enterprise-content {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.8rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    position: relative;
    width: 100%;
}
.enterprise-content::before {
    content: attr(data-label);
    position: absolute;
    top: -15px;
    left: 24px;
    background: var(--bg);
    color: var(--accent);
    font-size: 0.7rem;
    letter-spacing: 1.8px;
    padding: 0 12px;
    font-weight: 700;
    text-transform: uppercase;
    white-space: nowrap;
}

/* Typography */
h1, h2, h3, h4 { font-family: var(--font-sans); color: #f0f1f5; }
h1 {
    font-size: 2.1rem;
    margin-bottom: 1.2rem;
    border-left: 4px solid var(--accent);
    padding-left: 1.2rem;
    letter-spacing: -0.3px;
}
h2 { font-size: 1.5rem; margin: 2.2rem 0 1rem; color: var(--accent); }
h3 { font-size: 1.2rem; margin: 1.6rem 0 0.7rem; color: #d0d4de; }
p { margin-bottom: 1.2rem; color: #c4c7d1; }
a { color: var(--accent); text-decoration: none; font-weight: 500; }
a:hover { text-decoration: underline; }
strong { color: #ecedf2; font-weight: 600; }
em { color: var(--accent); font-style: italic; }
code {
    background: var(--code-bg);
    color: var(--code-fg);
    padding: 0.2em 0.5em;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.9em;
}

/* Lists */
ul, ol { padding-left: 2rem; margin-bottom: 1.2rem; }
li { margin-bottom: 0.6rem; }

/* Toolbar */
.action-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--surface);
    border: 1px solid var(--border);
    padding: 0.9rem 1.4rem;
    border-radius: var(--radius);
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}
.tts-engine-widget { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.tts-btn {
    background: transparent;
    border: 1.5px solid var(--accent);
    color: var(--accent);
    padding: 0.55rem 1.4rem;
    border-radius: 8px;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition);
}
.tts-btn:hover { background: var(--accent); color: #0b0c10; }
.tts-btn.active-speaking {
    background: var(--danger);
    border-color: var(--danger);
    color: #fff;
    animation: softPulse 2s infinite;
}
@keyframes softPulse { 0%,100%{ box-shadow: 0 0 0 0 rgba(224,85,106,0.4); } 50%{ box-shadow: 0 0 0 8px rgba(224,85,106,0); } }
.voice-indicator { font-size: 0.82rem; color: var(--muted); min-width: 210px; font-family: var(--font-mono); }
.voice-selector {
    background: var(--surface-light);
    color: var(--fg);
    border: 1px solid var(--border);
    padding: 0.45rem 0.9rem;
    border-radius: 8px;
    font-family: var(--font-mono);
    font-size: 0.82rem;
    max-width: 230px;
    cursor: pointer;
}
.section-nav-links { display: flex; gap: 1rem; }
.nav-btn {
    color: var(--muted);
    text-decoration: none;
    padding: 0.5rem 1.1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface-light);
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 0.82rem;
    transition: all var(--transition);
}
.nav-btn:hover { border-color: var(--accent); color: var(--accent); background: var(--surface); }

/* Callouts */
.callout-block {
    border: 1px solid;
    padding: 1.6rem;
    margin: 2rem 0;
    border-radius: var(--radius);
    font-family: var(--font-sans);
}
.warning-callout { border-color: var(--danger); background: rgba(224,85,106,0.06); }
.summary-callout { border-color: var(--accent); background: rgba(0,194,203,0.06); }
.callout-label {
    font-weight: 700;
    font-size: 0.75rem;
    margin-bottom: 0.6rem;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 1.2px;
}

/* Code box */
.code-output-box {
    background: var(--code-bg);
    border: 1px solid var(--border);
    color: var(--code-fg);
    padding: 1rem 1.3rem;
    border-radius: var(--radius);
    font-family: var(--font-mono);
    margin: 1.2rem 0;
    font-size: 0.95rem;
    overflow-x: auto;
    white-space: pre-wrap;
    word-break: break-word;
}

/* SVG Diagram */
.svg-wrapper { margin: 2rem 0; }
.responsive-svg-render {
    width: 100%;
    max-width: 800px;
    height: auto;
    display: block;
    margin: 0 auto;
    border-radius: 6px;
}
.diagram-caption { text-align: center; font-size: 0.85rem; color: var(--muted); margin-top: 0.9rem; }

/* Floating TTS Controller */
.floating-tts-controller {
    position: fixed;
    bottom: 28px;
    right: 28px;
    background: var(--surface);
    border: 1px solid var(--accent);
    border-radius: 18px;
    padding: 0.9rem 1.6rem;
    display: flex;
    align-items: center;
    gap: 20px;
    box-shadow: 0 10px 36px rgba(0,0,0,0.7);
    z-index: 9999;
    opacity: 0;
    transform: translateY(20px);
    pointer-events: none;
    transition: opacity 0.3s, transform 0.3s;
}
.floating-tts-controller.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
.float-btn {
    background: transparent;
    border: none;
    color: var(--accent);
    font-size: 1.3rem;
    cursor: pointer;
    padding: 0.3rem 0.7rem;
    border-radius: 10px;
    transition: background var(--transition);
}
.float-btn:hover { background: var(--accent-soft); }
.float-btn.close-btn {
    color: var(--muted);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 50%;
    width: 32px;
    height: 32px;
    padding: 0;
    font-size: 1rem;
    position: absolute;
    top: -14px;
    right: -14px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.float-btn.close-btn:hover { background: var(--danger); border-color: var(--danger); color: #fff; }

/* Pagination & Footer */
.pagination-container-block {
    display: flex;
    justify-content: space-between;
    border-top: 1px solid var(--border);
    padding-top: 2rem;
    margin-top: 2rem;
}
.web-footer {
    text-align: center;
    margin-top: 3rem;
    padding: 1.5rem 0;
    color: var(--muted);
    font-size: 0.82rem;
    border-top: 1px solid var(--border);
}

/* Utility */
.horizontal-divider { height: 1px; background: var(--border); margin: 1rem 0; }
.book-only { display: none; }

/* ===== Universal Responsive & Mobile Fixes ===== */

/* Prevent horizontal overflow */
html, body {
    overflow-x: hidden;
}

/* Containers fill width */
.container,
.enterprise-content {
    width: 100% !important;
    max-width: 100% !important;
    box-sizing: border-box;
}

/* Images and media never overflow */
img, svg, video, iframe, object, embed {
    max-width: 100% !important;
    height: auto !important;
    display: block;
}

/* Tables scroll horizontally if too wide */
.table-responsive-wrapper,
.preview-box table,
.spec-matrix-table {
    display: block;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

/* Smaller screens */
@media (max-width: 768px) {
    .header-inner {
        flex-wrap: wrap;
        gap: 0.5rem;
        height: auto;
        padding: 0.5rem 0;
    }
    .site-header {
        padding: 0 0.8rem !important;
    }
    .main-nav {
        flex-wrap: wrap;
        gap: 0.8rem;
    }

    .container {
        padding-left: 0.8rem !important;
        padding-right: 0.8rem !important;
    }

    .enterprise-content {
        padding: 1.5rem 1rem !important;
        margin-bottom: 1.5rem !important;
    }
    .enterprise-content::before {
        left: 12px;
        font-size: 0.6rem;
        padding: 0 8px;
    }

    h1 {
        font-size: 1.5rem !important;
        padding-left: 0.8rem !important;
        border-left-width: 3px !important;
    }
    h2 { font-size: 1.25rem !important; }
    h3 { font-size: 1.1rem !important; }

    .action-toolbar,
    .pagination-container-block {
        flex-direction: column !important;
        align-items: flex-start !important;
        gap: 0.75rem !important;
    }

    button, .tts-btn, .nav-btn, .float-btn {
        min-height: 44px;
        font-size: 0.9rem !important;
        padding: 0.5rem 1rem !important;
    }

    .floating-tts-controller {
        bottom: 12px !important;
        right: 12px !important;
        padding: 0.5rem 0.8rem !important;
        border-radius: 12px !important;
        gap: 8px !important;
    }
    .float-btn {
        font-size: 1rem !important;
        padding: 0.2rem 0.4rem !important;
    }

    .preview-box {
        padding: 1rem !important;
        margin: 1rem 0 !important;
    }

    /* Code blocks: allow horizontal scroll on narrow screens */
    .code-output-box,
    .preview-box pre,
    pre {
        white-space: pre !important;
        overflow-x: auto !important;
        -webkit-overflow-scrolling: touch;
        word-wrap: normal !important;
        word-break: normal !important;
        max-width: 100% !important;
        padding: 0.8rem !important;
        border-radius: 4px;
    }
}