/* Modern Minimalistic Theme Variables */
:root {
    --primary: #2d3436;
    --secondary: #0984e3;
    --accent: #00b894;
    --background: #f5f6fa;
    --surface: #ffffff;
    --text: #2d3436;
    --text-light: #636e72;
    --border: #dfe6e9;
    --error: #d63031;
    --success: #00b894;
    --warning: #fdcb6e;
    --shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --radius-sm: 6px;
    --transition: all 0.3s ease;

    /* Typography */
    --font-primary: 'Space Grotesk', system-ui, -apple-system, sans-serif;
    --font-secondary: 'DM Sans', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Font Sizes */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;

    /* Line Heights */
    --leading-tight: 1.2;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;

    /* Letter Spacing */
    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
}

[data-theme="dark"] {
    --primary: #dfe6e9;
    --secondary: #74b9ff;
    --accent: #55efc4;
    --background: #2d3436;
    --surface: #353b48;
    --text: #dfe6e9;
    --text-light: #b2bec3;
    --border: #636e72;
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-secondary);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    color: var(--text);
    background: var(--background);
    transition: var(--transition);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
}

/* Header & Navigation */
header {
    background: var(--surface);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1rem;
}

.nav-content h1 {
    font-family: var(--font-primary);
    font-size: var(--text-2xl);
    font-weight: 600;
    color: var(--primary);
}

#theme-switch {
    background: transparent;
    border: 2px solid var(--border);
    color: var(--text);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

#theme-switch:hover {
    background: var(--border);
}

/* Main Content */
main {
    padding: 2rem 0;
}

/* Calculator Section */
.calculator-container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.calculator-section {
    background: var(--surface);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.calculator-content {
    max-width: 600px;
    margin: 0 auto;
}

/* Form Elements */
.input-group {
    margin-bottom: 1.5rem;
}

.input-group label {
    font-family: var(--font-primary);
    font-size: var(--text-sm);
    font-weight: 500;
    letter-spacing: var(--tracking-wide);
    text-transform: uppercase;
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.input-with-unit {
    display: flex;
    gap: 0.75rem;
}

input[type="number"],
select {
    font-family: var(--font-mono);
    font-size: var(--text-base);
    letter-spacing: 0.5px;
    padding: 0.75rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text);
    transition: var(--transition);
}

input[type="number"]:focus,
select:focus {
    border-color: var(--secondary);
    outline: none;
    box-shadow: 0 0 0 3px rgba(9, 132, 227, 0.1);
}

input[type="number"] {
    flex: 1;
}

select {
    width: 120px;
}

/* Buttons */
.button-group {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.primary-btn,
.secondary-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: var(--text-base);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.primary-btn {
    background: var(--secondary);
    color: white;
}

.primary-btn:hover {
    background: #0070c9;
    transform: translateY(-1px);
}

.secondary-btn {
    background: transparent;
    border: 2px solid var(--border);
    color: var(--text);
}

.secondary-btn:hover {
    background: var(--border);
    transform: translateY(-1px);
}

/* Results Section */
.results {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--background);
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
}

.results h3 {
    font-family: var(--font-primary);
    font-size: var(--text-xl);
    font-weight: 600;
    color: var(--text);
    margin-bottom: 1rem;
}

.results p {
    margin-bottom: 0.75rem;
    color: var(--text-light);
}

.results span {
    color: var(--text);
    font-weight: 500;
}

/* Reference Guide Styles */
.reference-section {
    background: var(--surface);
    padding: 2.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin: 2rem auto;
    max-width: 900px;
}

.reference-section h2 {
    font-family: var(--font-primary);
    font-size: var(--text-2xl);
    font-weight: 600;
    letter-spacing: var(--tracking-tight);
    color: var(--text);
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    text-align: center;
    position: relative;
    padding-bottom: 1rem;
}

.reference-section h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--secondary);
    border-radius: 2px;
}

/* Tabs Navigation */
.tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border);
    padding-bottom: 0.5rem;
}

.tab-btn {
    font-family: var(--font-primary);
    font-size: var(--text-sm);
    font-weight: 500;
    letter-spacing: var(--tracking-wide);
    text-transform: uppercase;
    background: transparent;
    border: none;
    color: var(--text-light);
    padding: 0.75rem 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    font-size: 1.1rem;
}

.tab-btn::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--secondary);
    transform: scaleX(0);
    transition: var(--transition);
}

.tab-btn:hover {
    color: var(--secondary);
}

.tab-btn.active {
    color: var(--secondary);
}

.tab-btn.active::after {
    transform: scaleX(1);
}

/* Tab Content */
.tab-content {
    display: none;
    animation: fadeIn 0.4s ease;
}

.tab-content.active {
    display: block;
}

/* Reference Table */
.reference-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 1.5rem 0;
    background: var(--surface);
    border-radius: var(--radius-sm);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.reference-table caption {
    font-size: 1.2rem;
    color: var(--text);
    margin-bottom: 1rem;
    font-weight: 500;
}

.reference-table th,
.reference-table td {
    padding: 1.25rem;
    text-align: left;
    border-bottom: 2px solid var(--border);
}

.reference-table th {
    font-family: var(--font-primary);
    font-size: var(--text-sm);
    font-weight: 600;
    letter-spacing: var(--tracking-wide);
    text-transform: uppercase;
    background: var(--secondary);
    color: white;
    font-size: 0.9rem;
    letter-spacing: 0.5px;
}

.reference-table tr:last-child td {
    border-bottom: none;
}

.reference-table tr:hover td {
    background: color-mix(in srgb, var(--secondary) 5%, var(--surface));
}

/* Category Badges */
.category-badge {
    font-family: var(--font-primary);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.1em;
    display: inline-block;
    padding: 0.35rem 1rem;
    border-radius: 2rem;
    font-size: 0.85rem;
    color: white;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.air-rifle {
    background: linear-gradient(135deg, var(--success) 0%, color-mix(in srgb, var(--success) 80%, white) 100%);
}

.handgun {
    background: linear-gradient(135deg, var(--warning) 0%, color-mix(in srgb, var(--warning) 80%, white) 100%);
}

.rifle {
    background: linear-gradient(135deg, var(--error) 0%, color-mix(in srgb, var(--error) 80%, white) 100%);
}

/* Formula Styles */
.formula-container {
    background: var(--background);
    padding: 2rem;
    border-radius: var(--radius-sm);
    margin: 1.5rem 0;
    border: 2px solid var(--border);
}

.formula {
    font-family: var(--font-mono);
    font-size: var(--text-lg);
    letter-spacing: 0.5px;
    color: var(--secondary);
    text-align: center;
    padding: 1.5rem;
    margin: 1rem 0;
    background: var(--surface);
    border-radius: var(--radius-sm);
    border: 2px solid color-mix(in srgb, var(--secondary) 30%, transparent);
}

.formula-note {
    font-family: var(--font-secondary);
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
    margin-top: 1.5rem;
    padding: 1rem;
    background: color-mix(in srgb, var(--accent) 10%, transparent);
    border-left: 4px solid var(--accent);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    color: var(--text-light);
}

.formula-note strong {
    color: var(--text);
    font-weight: 600;
}

/* Tips List */
.tips-list {
    list-style: none;
    padding: 0;
    margin: 1.5rem 0;
}

.tips-list li {
    background: var(--surface);
    padding: 1.25rem;
    margin: 1rem 0;
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
    transition: var(--transition);
}

.tips-list li:hover {
    transform: translateX(5px);
    border-color: var(--secondary);
}

.tips-list li strong {
    font-family: var(--font-primary);
    font-size: var(--text-lg);
    font-weight: 500;
    letter-spacing: var(--tracking-tight);
    display: block;
    color: var(--secondary);
    margin-bottom: 0.5rem;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .reference-section {
        padding: 1.5rem;
    }

    .tabs {
        flex-wrap: wrap;
        justify-content: flex-start;
    }

    .tab-btn {
        padding: 0.5rem 1rem;
        font-size: var(--text-sm);
    }

    .reference-table th,
    .reference-table td {
        padding: 1rem;
    }

    .formula {
        font-size: var(--text-lg);
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    .reference-table {
        display: block;
        overflow-x: auto;
    }

    .category-badge {
        padding: 0.25rem 0.75rem;
        font-size: 0.8rem;
    }
}

/* Footer */
footer {
    background: var(--surface);
    color: var(--text);
    padding: 2rem 0;
    text-align: center;
    margin-top: 3rem;
    border-top: 2px solid var(--border);
}

/* Responsive Design */
@media (max-width: 768px) {
    .calculator-container {
        grid-template-columns: 1fr;
    }

    .button-group {
        flex-direction: column;
    }

    .input-with-unit {
        flex-direction: column;
    }

    select {
        width: 100%;
    }

    .tabs {
        flex-wrap: wrap;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(5px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-light);
}

/* Theory Section Styles */
.theory-section {
    background: var(--surface);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin: 2rem 0;
}

.theory-section h2 {
    font-family: var(--font-primary);
    font-size: var(--text-2xl);
    font-weight: 600;
    letter-spacing: var(--tracking-tight);
    color: var(--text);
    font-size: 1.75rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.theory-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.theory-card {
    background: var(--background);
    padding: 1.5rem;
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
    transition: var(--transition);
}

.theory-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.theory-card h3 {
    font-family: var(--font-primary);
    font-size: var(--text-xl);
    font-weight: 600;
    letter-spacing: var(--tracking-tight);
    color: var(--secondary);
    margin-bottom: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theory-card h4 {
    font-family: var(--font-secondary);
    font-size: var(--text-lg);
    font-weight: 500;
    color: var(--text);
    margin: 1rem 0 0.5rem;
}

.theory-content {
    font-family: var(--font-secondary);
    font-size: var(--text-base);
    color: var(--text-light);
}

.theory-content ul {
    list-style: none;
    padding-left: 0;
    margin: 1rem 0;
}

.theory-content li {
    margin: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.theory-content li::before {
    content: '•';
    color: var(--secondary);
    position: absolute;
    left: 0;
}

.theory-content strong {
    color: var(--text);
    font-weight: 600;
}

.formula-box {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius-sm);
    margin: 1rem 0;
    border: 2px solid var(--border);
}

.formula-text {
    font-family: var(--font-mono);
    font-size: var(--text-lg);
    color: var(--secondary);
    text-align: center;
    padding: 1rem;
    margin: 0.5rem 0;
    background: var(--background);
    border-radius: var(--radius-sm);
}

.info-note {
    background: color-mix(in srgb, var(--accent) 10%, transparent);
    padding: 1rem;
    border-radius: var(--radius-sm);
    margin: 1rem 0;
    border-left: 4px solid var(--accent);
}

/* Applications Grid */
.applications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.application {
    background: var(--surface);
    padding: 1.25rem;
    border-radius: var(--radius-sm);
    text-align: center;
    border: 2px solid var(--border);
    transition: var(--transition);
}

.application:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.application i {
    font-size: 1.5rem;
    color: var(--secondary);
    margin-bottom: 0.75rem;
}

.application h5 {
    font-family: var(--font-secondary);
    font-size: var(--text-lg);
    font-weight: 500;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.application p {
    font-family: var(--font-secondary);
    font-size: var(--text-base);
    color: var(--text-light);
}

/* About Section Styles */
.about-section {
    background: var(--surface);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin: 2rem 0;
}

.about-section h2 {
    font-family: var(--font-primary);
    font-size: var(--text-2xl);
    font-weight: 600;
    letter-spacing: var(--tracking-tight);
    color: var(--text);
    font-size: 1.75rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.about-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.about-card {
    background: var(--background);
    padding: 1.5rem;
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
    transition: var(--transition);
}

.about-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.about-card h3 {
    font-family: var(--font-primary);
    font-size: var(--text-xl);
    font-weight: 600;
    letter-spacing: var(--tracking-tight);
    color: var(--secondary);
    margin-bottom: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin: 0.75rem 0;
    color: var(--text-light);
}

.feature-list i {
    color: var(--accent);
}

.tech-stack {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.tech-item {
    background: var(--surface);
    padding: 1rem;
    border-radius: var(--radius-sm);
    text-align: center;
    border: 2px solid var(--border);
    transition: var(--transition);
}

.tech-item:hover {
    transform: translateY(-2px);
    background: var(--background);
}

.tech-item i {
    font-size: 1.5rem;
    color: var(--secondary);
    margin-bottom: 0.5rem;
}

.tech-item span {
    display: block;
    font-family: var(--font-secondary);
    font-size: var(--text-base);
    color: var(--text);
    font-weight: 500;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social-link {
    color: var(--text-light);
    font-size: 1.5rem;
    transition: var(--transition);
}

.social-link:hover {
    color: var(--secondary);
    transform: translateY(-2px);
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .theory-grid,
    .about-content {
        grid-template-columns: 1fr;
    }

    .applications-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    }

    .tech-stack {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Responsive Typography */
@media (max-width: 768px) {
    :root {
        --text-3xl: 1.5rem;
        --text-2xl: 1.25rem;
        --text-xl: 1.125rem;
        --text-lg: 1rem;
        --text-base: 0.9375rem;
    }
}