:root {
    --accent: #00E5FF;
    --accent-glow: rgba(0, 229, 255, 0.2);
    --accent-hover: #00b8cc;
    --danger: #ef4444;
    --success: #10b981;
    
    /* Fluid Typography Variables */
    --text-xs: clamp(0.7rem, 0.2vw + 0.7rem, 0.8rem);
    --text-sm: clamp(0.8rem, 0.3vw + 0.8rem, 0.95rem);
    --text-md: clamp(0.95rem, 0.5vw + 0.9rem, 1.1rem);
    --text-lg: clamp(1.1rem, 0.8vw + 1.1rem, 1.4rem);
    --text-xl: clamp(1.4rem, 1.5vw + 1.2rem, 2rem);
    --text-xxl: clamp(2rem, 3vw + 1.5rem, 3.5rem);
}

[data-theme="dark"] {
    --bg-main: #0a0a0c;
    --bg-secondary: #13141a;
    --bg-panel: rgba(255, 255, 255, 0.03);
    --border-color: rgba(255, 255, 255, 0.08);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --input-bg: rgba(0, 0, 0, 0.3);
}

[data-theme="light"] {
    --bg-main: #f0f4f8; 
    --bg-secondary: rgba(255, 255, 255, 0.85); 
    --bg-panel: rgba(255, 255, 255, 0.65); 
    --border-color: rgba(0, 0, 0, 0.08);
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --input-bg: rgba(255, 255, 255, 0.9);
    --accent: #0ea5e9; 
    --accent-hover: #0284c7;
    --accent-glow: rgba(14, 165, 233, 0.15);
}

body[data-theme="light"] {
    background: linear-gradient(135deg, #e0e7ff 0%, #f1f5f9 50%, #e0f2fe 100%);
    background-attachment: fixed;
}

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

.hidden {
    display: none !important;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
    font-size: var(--text-md);
}

/* Mobile-First Dashboard Layout */
.dashboard-layout {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Base Top Panel / Sidebar (Mobile First) */
.sidebar {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    width: 100%;
}

.sidebar-header {
    padding: 1.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.logo-icon {
    flex-shrink: 0;
    filter: drop-shadow(0 4px 8px var(--accent-glow));
}

.logo-text {
    text-align: left;
}

.logo h1 {
    font-size: var(--text-xl);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.5px;
}

.logo .logo-subtitle {
    font-size: var(--text-xs);
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 700;
}

/* Navigation Tabs */
.sidebar-nav {
    display: flex;
    padding: 1rem;
    gap: 0.5rem;
    overflow: visible;
    border-bottom: 1px solid var(--border-color);
}

.nav-item {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.75rem 1rem;
    font-size: var(--text-sm);
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
    flex: 1;
    text-align: center;
}

.nav-item:hover {
    background-color: var(--bg-panel);
    color: var(--text-primary);
}

.nav-item.active {
    background-color: var(--accent-glow);
    color: var(--accent);
    box-shadow: 0 2px 0 var(--accent) inset;
}

/* Sidebar Info Sections */
.sidebar-section {
    padding: 1.5rem 1rem;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-section:not(.hidden) {
    animation: fadeIn 0.3s ease;
}

.sidebar-section h3 {
    font-size: var(--text-xs);
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 1px;
    margin-bottom: 1rem;
    font-weight: 700;
}

/* Forms */
.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.input-row {
    display: flex;
    gap: 0.5rem;
}

.half {
    flex: 1;
}

.form-group label {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    font-weight: 600;
}

input, select {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: clamp(0.6rem, 1vh, 1rem) clamp(0.75rem, 1vw, 1.25rem);
    border-radius: 6px;
    font-family: inherit;
    font-size: var(--text-md);
    outline: none;
    transition: all 0.2s ease;
    width: 100%;
}

input:focus, select:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

select option {
    background-color: var(--bg-main);
    color: var(--text-primary);
}

input.readonly-input {
    background-color: var(--bg-main);
    color: var(--accent);
    font-weight: 700;
    cursor: not-allowed;
    border-color: transparent;
}

/* Toggles */
.toggle-group {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
    font-size: var(--text-sm);
    font-weight: 500;
}

.switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
    flex-shrink: 0;
}

.switch input { 
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--border-color);
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 4px;
    bottom: 4px;
    background-color: #fff;
    transition: .4s;
    border: 1px solid rgba(0,0,0,0.1);
}

input:checked + .slider { background-color: var(--accent); }
input:checked + .slider:before { transform: translateX(20px); }
.slider.round { border-radius: 24px; }
.slider.round:before { border-radius: 50%; }

/* Buttons */
.sidebar-footer {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.action-btn {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.85rem;
    border-radius: 8px;
    cursor: pointer;
    font-family: inherit;
    font-weight: 600;
    font-size: var(--text-md);
    transition: all 0.2s;
    width: 100%;
}

.action-btn:hover { background: var(--input-bg); }

.primary-btn {
    background: var(--accent);
    color: #000;
    border: none;
    box-shadow: 0 4px 12px var(--accent-glow);
}

.primary-btn:hover { background: var(--accent-hover); transform: translateY(-2px); }

/* Main Content Area */
.content-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-image: radial-gradient(circle at 10% 20%, rgba(0, 229, 255, 0.02) 0%, transparent 40%);
}

.view-section {
    display: none;
    padding: clamp(1rem, 2vw, 3rem);
    width: 100%;
    animation: fadeIn 0.4s ease;
}

.view-section.active { display: block; }

/* Panels */
.panel {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.panel-header {
    padding: clamp(1rem, 1.5vw, 2rem);
    border-bottom: 1px solid var(--border-color);
}

.panel-header h2 {
    font-size: var(--text-lg);
    font-weight: 700;
    letter-spacing: -0.5px;
}

/* --- DASHBOARD INFOGRAPHICS --- */
.dashboard-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: clamp(1rem, 2vw, 1.5rem);
    width: 100%;
}

.dash-widget {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: clamp(1.25rem, 2vw, 2rem);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.04), 0 2px 8px rgba(0, 0, 0, 0.02); 
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
    display: flex;
    flex-direction: column;
}

[data-theme="light"] .dash-widget {
    box-shadow: 0 8px 32px rgba(14, 165, 233, 0.08), 0 4px 12px rgba(0, 0, 0, 0.04);
}

.dash-widget:hover {
    box-shadow: 0 12px 48px var(--accent-glow);
}

.widget-title {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
}

.total-cost-container {
    text-align: center;
    padding: 1rem 0;
    display: flex;
    align-items: center;
    justify-content: center;
    flex: 1;
}

.overview-widget {
    background: linear-gradient(135deg, rgba(0, 229, 255, 0.08), transparent);
    border-color: rgba(0, 229, 255, 0.2);
}

.overview-widget .total-value {
    font-size: var(--text-xxl);
    font-weight: 800;
    background: -webkit-linear-gradient(45deg, var(--accent), #fff);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 40px var(--accent-glow);
    line-height: 1.2;
    letter-spacing: -1px;
}

[data-theme="light"] .overview-widget .total-value {
    background: -webkit-linear-gradient(45deg, var(--accent), #0284c7);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.chart-container {
    position: relative;
    height: 300px;
    width: 100%;
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.cards-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.25rem;
}

.info-card {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
    transition: all 0.2s;
}

.info-card:hover {
    border-color: rgba(255, 255, 255, 0.15);
    background: var(--bg-secondary);
}

.info-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 4px; height: 100%;
    background: var(--accent);
    opacity: 0.8;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.card-title {
    font-weight: 800;
    font-size: var(--text-lg);
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.card-unit {
    font-size: var(--text-xs);
    background: var(--accent-glow);
    color: var(--accent);
    padding: 0.25rem 0.6rem;
    border-radius: 6px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.card-body {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.card-metric {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: var(--text-sm);
    color: var(--text-secondary);
    background: rgba(0,0,0,0.1);
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
}

.card-metric strong {
    color: var(--text-primary);
    font-weight: 700;
    font-size: var(--text-md);
}

.card-total {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px dashed var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 0.5rem;
}

.card-total span {
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    white-space: nowrap;
}

.card-total strong {
    font-size: clamp(1.2rem, 1.2vw + 1.1rem, 1.6rem);
    font-weight: 800;
    color: var(--accent);
    white-space: nowrap;
    text-align: right;
}

/* Concrete Calculator Layout */
.concrete-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: clamp(1rem, 2vw, 2rem);
}

.mt-4 { margin-top: 2rem; }

.metric-card {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    padding: clamp(1rem, 1.5vw, 1.5rem);
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.metric-card span { color: var(--text-secondary); font-weight: 600; font-size: var(--text-sm); }
.metric-card strong { font-size: var(--text-lg); font-weight: 800; color: var(--accent); }

.materials-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.mat-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: clamp(1rem, 1.5vw, 1.5rem);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-main);
}

.mat-details h4 {
    font-weight: 800;
    font-size: var(--text-lg);
    margin-bottom: 0.25rem;
}

.mat-details span {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    font-weight: 500;
}

.mat-final {
    font-size: var(--text-xl);
    font-weight: 800;
}
.mat-final.highlight { color: var(--accent); }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Desktop Dashboard Enhancements */
@media (min-width: 1000px) {
    .dashboard-layout {
        flex-direction: row;
        height: 100vh;
        overflow: hidden;
    }

    .sidebar {
        flex: 0 0 min-content;
        height: 100vh;
        overflow-y: auto;
        border-bottom: none;
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
    }
    
    .left-sidebar {
        min-width: 250px;
        max-width: 280px;
        border-right: 1px solid var(--border-color);
    }

    .config-sidebar {
        min-width: 320px;
        max-width: 380px;
        border-left: 1px solid var(--border-color);
        background-color: var(--bg-panel); /* slightly more transparent context for right side */
    }

    .sidebar-header { justify-content: flex-start; }
    .logo-text { text-align: left; }
    
    .sidebar-nav {
        flex-direction: column;
        border-right: none;
        border-bottom: none;
        overflow: visible;
    }

    .nav-item {
        text-align: left;
        border-left: 3px solid transparent;
        border-radius: 0 8px 8px 0;
        margin-right: 1rem;
    }
    .nav-item.active {
        box-shadow: none;
        border-left-color: var(--accent);
    }

    .sidebar-footer { margin-top: auto; }

    .content-area {
        height: 100vh;
        overflow-y: auto;
    }

    /* Dashboard Desktop layout */
    .dashboard-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .overview-widget {
        grid-column: 1 / -1;
    }
    .materials-widget {
        grid-column: 1 / -1;
    }
    .cards-grid {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    }

    .concrete-grid {
        grid-template-columns: 1fr;
        max-width: 800px;
        margin: 0 auto;
        align-items: flex-start;
    }
}

/* Legal & Compliance Footer */
.legal-footer {
    padding: 1rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
}
.legal-links { display: flex; justify-content: center; align-items: center; gap: 0.5rem; margin-bottom: 0.5rem; }
.legal-links a { color: var(--text-secondary); text-decoration: none; font-size: var(--text-xs); font-weight: 600; transition: color 0.2s; }
.legal-links a:hover { color: var(--accent); }
.separator { color: var(--border-color); font-size: var(--text-xs); }
.copyright { color: rgba(148, 163, 184, 0.5); font-size: clamp(0.6rem, 1vw, 0.7rem); }

/* Cookie Banner */
.cookie-banner { position: fixed; bottom: 20px; left: 20px; right: 20px; background: var(--bg-panel); border: 1px solid var(--border-color); box-shadow: 0 10px 40px rgba(0,0,0,0.3); padding: 1rem 1.5rem; border-radius: 12px; z-index: 9999; backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); transition: transform 0.3s ease, opacity 0.3s ease; }
.cookie-content { display: flex; flex-direction: column; gap: 1rem; align-items: center; text-align: center; }
.cookie-content p { font-size: var(--text-sm); color: var(--text-primary); margin: 0; line-height: 1.4; }
.cookie-content a { color: var(--accent); text-decoration: underline; }
.btn-small { padding: 0.5rem 1.5rem !important; width: auto !important; }

@media (min-width: 768px) {
    .cookie-banner { left: unset; right: 30px; bottom: 30px; max-width: 450px; }
    .cookie-content { flex-direction: row; text-align: left; }
}