/* style.css - "Precision & Reliability - Technical Focus" Design */

/* --- CSS Variables --- */
:root {
    --color-text-drt: #1D1D1D; /* Very Dark Grey / Near Black */
    --color-background-drt: #FFFFFF; /* White */
    --color-background-section-drt: #F8F8F8; /* Very Light Grey for sections */
    --color-primary-accent-drt: #002366; /* Deep Navy Blue */
    --color-secondary-accent-drt: #0052CC; /* Clear, Actionable Medium Blue */
    --color-secondary-accent-hover-drt: #003DAA; /* Darker Medium Blue */
    --color-border-drt: #D0D0D0; /* Medium Grey for borders */
    
    /* System font stack for maximum performance */
    --font-family-drt: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    
    --container-max-width-drt: 1050px; 
    --spacing-base-drt: 1rem; 
    --border-radius-drt: 2px; /* Sharp, precise corners */
}

/* --- Global Resets & Base --- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; line-height: 1.6; }
body {
    font-family: var(--font-family-drt);
    color: var(--color-text-drt);
    background-color: var(--color-background-drt);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.main-content-drt { flex-grow: 1; }

.container-drt {
    width: 90%;
    max-width: var(--container-max-width-drt);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--spacing-base-drt);
    padding-right: var(--spacing-base-drt);
}

/* Accessibility: Skip Link */
.skip-link-drt { 
    position: absolute; 
    transform: translateY(-250%); 
    left: 0.5rem; 
    background: var(--color-secondary-accent-drt); 
    color: var(--color-background-drt); 
    padding: 0.5em 1em; 
    z-index: 10001; 
    text-decoration: none; 
    transition: transform 0.25s ease-out; 
    font-weight: 600;
    border-radius: 0 0 var(--border-radius-drt) var(--border-radius-drt);
}
.skip-link-drt:focus { transform: translateY(0.5rem); }

/* Accessibility: Focus Styles */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
    outline: 2px solid var(--color-secondary-accent-drt);
    outline-offset: 2px;
}

/* --- Typography --- */
h1, h2, h3 {
    font-family: var(--font-family-drt); 
    font-weight: 700; 
    line-height: 1.2;
    color: var(--color-primary-accent-drt); /* Deep Navy Blue for headings */
    margin-bottom: calc(var(--spacing-base-drt) * 1.3);
}
.logo-text-drt { /* Class for logo */
    font-family: var(--font-family-drt);
    font-weight: 700;
    color: var(--color-primary-accent-drt);
}
h1 { font-size: clamp(1.9rem, 5.5vw, 2.5rem); letter-spacing: -0.3px; }
h2 { font-size: clamp(1.6rem, 4.5vw, 2.1rem); text-align: center; margin-bottom: calc(var(--spacing-base-drt) * 2.2); border-bottom: 1px solid var(--color-border-drt); padding-bottom: var(--spacing-base-drt); }
h3 { font-size: clamp(1.15rem, 3.2vw, 1.35rem); color: var(--color-primary-accent-drt); font-weight: 600; margin-bottom: calc(var(--spacing-base-drt) * 0.7); }

/* --- Header --- */
.site-header-drt { 
    background-color: var(--color-background-drt);
    padding: calc(var(--spacing-base-drt) * 0.9) 0;
    border-bottom: 2px solid var(--color-primary-accent-drt); /* Stronger border */
}
.header-grid-drt { display: flex; justify-content: space-between; align-items: center; } 
.logo-text-drt { font-size: clamp(1.4rem, 4vw, 1.65rem); text-decoration: none; }
.header-phone-drt { font-size: clamp(0.95rem, 2.8vw, 1.1rem); font-weight: 700; color: var(--color-secondary-accent-drt); text-decoration: none; }
.header-phone-drt:hover { color: var(--color-secondary-accent-hover-drt); }

/* --- Hero Section --- */
.hero-drt { 
    background-color: var(--color-primary-accent-drt); /* Deep Navy Blue background */
    color: var(--color-background-drt); /* White text */
    padding: calc(var(--spacing-base-drt) * 3.5) 0; 
    text-align: center;
}
.hero-drt h1 { color: var(--color-background-drt); }
.hero-subtitle-drt { font-size: clamp(1.1rem, 3vw, 1.2rem); margin-bottom: calc(var(--spacing-base-drt) * 2); max-width: 700px; margin-left: auto; margin-right: auto; opacity: 0.95; line-height: 1.6;}
.hero-problem-drt { font-size: 1.05rem; margin-bottom: calc(var(--spacing-base-drt)*0.5); font-style: italic; opacity: 0.9;}
.hero-actions-drt { margin-top: calc(var(--spacing-base-drt) * 1.8); } 

/* --- Buttons --- */
.button-drt { 
    display: inline-block;
    padding: calc(var(--spacing-base-drt) * 0.8) calc(var(--spacing-base-drt) * 1.8); 
    text-decoration: none;
    border-radius: var(--border-radius-drt);
    font-weight: 600; 
    font-family: var(--font-family-drt);
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.15s ease-out, border-color 0.2s ease;
    cursor: pointer;
    border: 1.5px solid transparent;
    font-size: clamp(0.95rem, 2.5vw, 1rem);
    text-align: center;
    letter-spacing: 0.2px;
}
.button-accent-drt { 
    background-color: var(--color-secondary-accent-drt); /* Medium Blue */
    color: var(--color-background-drt); /* White text */
    border-color: var(--color-secondary-accent-drt);
}
.button-accent-drt:hover, .button-accent-drt:focus {
    background-color: var(--color-secondary-accent-hover-drt); /* Darker Blue */
    border-color: var(--color-secondary-accent-hover-drt);
    transform: translateY(-1px);
}
.button-secondary-drt { 
    background-color: transparent;
    color: var(--color-secondary-accent-drt); /* Medium Blue text */
    border-color: var(--color-secondary-accent-drt); /* Medium Blue border */
}
.button-secondary-drt:hover, .button-secondary-drt:focus {
    background-color: var(--color-secondary-accent-drt);
    color: var(--color-background-drt);
}
.button-large-drt {
    font-size: clamp(1.05rem, 3vw, 1.15rem);
    padding: calc(var(--spacing-base-drt) * 0.95) calc(var(--spacing-base-drt) * 2.2);
}

/* --- Services Section --- */
.services-drt { padding: calc(var(--spacing-base-drt) * 3) 0; background-color: var(--color-background-section-drt); } 
.services-layout-drt { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: calc(var(--spacing-base-drt) * 1.5); } 
.service-block-drt { 
    background-color: var(--color-background-drt); 
    padding: calc(var(--spacing-base-drt) * 1.5);
    border: 1px solid var(--color-border-drt);
    border-radius: var(--border-radius-drt);
    box-shadow: 0 2px 4px rgba(0,0,0,0.03);
}
.service-block-title-drt { font-weight: 600; } 
.service-block-drt p { font-size: clamp(0.9rem, 2.5vw, 0.95rem); line-height: 1.65; }

/* --- Why Choose Us Section --- */
.why-choose-us-drt { padding: calc(var(--spacing-base-drt) * 3) 0; background-color: var(--color-background-drt); } 
.why-choose-us-drt h2 { color: var(--color-primary-accent-drt); border-bottom: none; padding-bottom: 0;}
.benefits-grid-drt { 
    list-style: none; padding: 0; 
    display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: calc(var(--spacing-base-drt) * 1.2); 
    margin-bottom: calc(var(--spacing-base-drt) * 2.2);
}
.benefits-grid-drt li {
    font-size: clamp(0.95rem, 2.8vw, 1rem); 
    color: var(--color-text-drt); 
    padding: calc(var(--spacing-base-drt) * 0.8);
    background-color: var(--color-background-section-drt);
    border-radius: var(--border-radius-drt);
    border-left: 3px solid var(--color-secondary-accent-drt); /* Blue accent */
}
.why-cta-drt { text-align: center; } 

/* --- Final CTA Section --- */
.cta-final-drt { padding: calc(var(--spacing-base-drt) * 3.5) 0; background-color: var(--color-primary-accent-drt); color: var(--color-background-drt); text-align: center; } 
.cta-final-drt h2 { color: var(--color-background-drt); }
.cta-final-content-drt p { font-size: 1.15rem; margin-bottom: calc(var(--spacing-base-drt) * 1.5); max-width: 650px; margin-left: auto; margin-right: auto; opacity: 0.95; } 

/* --- Footer --- */
.site-footer-drt { 
    background-color: var(--color-text-drt); /* Near Black footer */
    color: var(--color-background-drt);
    text-align: center;
    padding: calc(var(--spacing-base-drt) * 1.8) 0;
    margin-top: auto; 
    font-size: clamp(0.85rem, 2.2vw, 0.9rem);
}
.site-footer-drt p { margin-bottom: calc(var(--spacing-base-drt) * 0.4); opacity: 0.9;}
.footer-link-drt { 
    color: var(--color-secondary-accent-drt); /* Blue link */
    text-decoration: none; 
    font-weight: 500; 
}
.footer-link-drt:hover { text-decoration: underline; }
.footer-nav-drt { margin-top: calc(var(--spacing-base-drt) * 0.5); } 
.footer-subtle-link-drt { 
    font-size: 0.6rem; 
    color: #383838;     /* Very dark grey, extremely low contrast against #1D1D1D footer bg */
    text-decoration: none;
    opacity: 0.3;      
    display: inline-block;
    padding: 1px 0;
    transition: opacity 0.2s ease;
    letter-spacing: 0.1px;
}
.footer-subtle-link-drt:hover {
    opacity: 0.4;      
    text-decoration: none; 
}
.footer-subtle-link-drt:focus-visible { 
    opacity: 1 !important;        
    text-decoration: underline !important; 
    color: var(--color-secondary-accent-drt) !important; 
    background-color: var(--color-text-drt) !important; 
    outline: 1px dashed var(--color-secondary-accent-drt) !important; 
    outline-offset: 1px !important;
    font-size: 0.7rem !important; 
    padding: 2px 3px !important;
    z-index: 1; 
}


/* --- Sticky CTA for Mobile --- */
.sticky-cta-drt-mobile { 
    display: none; position: fixed; bottom: 0; left: 0; width: 100%;
    background-color: var(--color-secondary-accent-drt); color: var(--color-background-drt); text-align: center;
    padding: calc(var(--spacing-base-drt) * 0.9) 0; font-size: clamp(1rem, 3vw, 1.1rem); font-weight: 700;
    text-decoration: none; z-index: 1000; box-shadow: 0 -2px 5px rgba(0,0,0,0.1);
}

/* --- Responsive Design Adjustments --- */
@media (max-width: 767px) {
    .header-grid-drt { flex-direction: column; text-align: center;}
    .logo-text-drt { margin-bottom: calc(var(--spacing-base-drt) * 0.5); }
    .sticky-cta-drt-mobile { display: block; }
    body { padding-bottom: 55px; } 
    h1 { font-size: clamp(1.7rem, 5vw, 2.1rem); }
    h2 { font-size: clamp(1.5rem, 4vw, 1.8rem); }
}

/* No image styles needed as HTML is image-free */
.feature-visual-sid, .feature-icon-hm, .feature-image-elg, .feature-visual-elg, .feature-image-display-vs, .feature-visual-tpc, .feature-image-srd, .feature-img-tpc { display: none !important; }