/* 1. Reset */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
html {
    scroll-behavior: smooth;
    overflow-x: hidden;
    scroll-padding-top: var(--nav-height);
}
body {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    width: 100%;
}

/* 2. Variables */
:root {
    --color-bg: #F4F3EE;
    --color-black: #171717;
    --color-gray: #D8D6CF;
    --color-gray-dark: #8F8C83;
    --color-red: #E6332A;
    --color-white: #FFFFFF;
    
    --font-primary: 'Helvetica Neue', 'Inter', sans-serif;
    
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;
    
    --grid-gap: 2rem;
    --nav-height: 60px;
    
    --transition-fast: 150ms ease;
    --transition-med: 250ms ease;
}

/* 3. Typography */
body {
    font-family: var(--font-primary);
    background-color: var(--color-bg);
    color: var(--color-black);
    line-height: 1.4;
    font-size: 16px;
}

h1, h2, h3, h4, .hero-title {
    font-weight: 800;
    letter-spacing: -0.02em;
    text-transform: uppercase;
}

.hero-title {
    font-size: clamp(4rem, 8vw, 8rem);
    line-height: 0.9;
    margin-bottom: var(--space-md);
}

.hero-subtitle {
    font-size: clamp(1.2rem, 2vw, 1.5rem);
    font-weight: 500;
    margin-bottom: var(--space-md);
    max-width: 600px;
    color: var(--color-black);
}

.section-label {
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-md);
    border-bottom: 2px solid var(--color-black);
    padding-bottom: var(--space-xs);
    display: inline-block;
}

/* 4. Layout */
.grid-container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 var(--space-md);
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: var(--grid-gap);
}

/* 5. Navigation */
.editorial-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--nav-height);
    padding: 0 var(--space-md);
    border-bottom: 1px solid var(--color-gray);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    position: sticky;
    top: 0;
    background-color: var(--color-bg);
    z-index: 100;
}

.nav-center {
    display: flex;
    gap: var(--space-md);
}

.nav-center a {
    color: var(--color-black);
    text-decoration: none;
    position: relative;
    padding-bottom: 4px;
}

.nav-center a:hover::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--color-red);
}

.nav-right {
    font-weight: 700;
    letter-spacing: 0.05em;
    color: var(--color-black);
    display: flex;
    align-items: center;
    white-space: nowrap;
}

.status-dot {
    color: var(--color-red);
    margin-left: 6px;
    font-size: 1.1em;
}

/* 6. Hero */
.hero-section {
    padding-top: var(--space-xl);
    padding-bottom: var(--space-xl);
    align-items: center;
    min-height: calc(100vh - var(--nav-height));
}

.hero-content {
    grid-column: 1 / 8;
}

.hero-meta {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}

.meta-item {
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--color-black);
}

/* 7. Geometric Artwork */
.hero-graphic {
    grid-column: 8 / 13;
    display: flex;
    justify-content: flex-end;
}

.bauhaus-svg {
    width: 100%;
    max-width: 500px;
    height: auto;
}

/* 8. Calculator Section */
.calculator-section {
    padding-top: var(--space-lg);
    padding-bottom: var(--space-xl);
    border-top: 1px solid var(--color-black);
}

.calc-setup {
    grid-column: 1 / 7;
    padding-right: var(--space-md);
}

.calc-result {
    grid-column: 7 / 13;
    border-left: 1px solid var(--color-gray);
    padding-left: var(--space-md);
}

/* 9. Forms */
.input-group {
    margin-bottom: var(--space-md);
}

.input-group label {
    display: block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-xs);
    color: var(--color-black);
}

.input-row {
    display: flex;
    align-items: baseline;
    border-bottom: 2px solid var(--color-black);
    padding-bottom: 8px;
    transition: border-color var(--transition-fast);
}

.input-row:focus-within {
    border-color: var(--color-red);
}

input[type="number"] {
    appearance: none;
    background: transparent;
    border: none;
    font-family: var(--font-primary);
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--color-black);
    width: 100%;
    outline: none;
    padding: 0;
}

/* Handle native number arrows */
input[type=number]::-webkit-inner-spin-button, 
input[type=number]::-webkit-outer-spin-button { 
    -webkit-appearance: none; 
    margin: 0; 
}
input[type=number] {
    -moz-appearance: textfield;
}

.input-suffix {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-gray-dark);
    margin-left: var(--space-xs);
}

/* Target Selector */
.target-selector {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
    flex-wrap: wrap;
}

.target-btn {
    background: transparent;
    border: none;
    font-family: var(--font-primary);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-gray-dark);
    cursor: pointer;
    padding-bottom: 4px;
    border-bottom: 3px solid transparent;
    transition: all var(--transition-fast);
}

.target-btn:hover {
    color: var(--color-black);
}

.target-btn.active {
    color: var(--color-black);
    border-bottom-color: var(--color-red);
}

.custom-target-row {
    display: flex;
    align-items: baseline;
    gap: var(--space-sm);
    border-bottom: 2px solid var(--color-black);
    width: max-content;
    max-width: 100%;
    padding-bottom: 4px;
    transition: border-color var(--transition-fast);
}

.custom-target-row:focus-within {
    border-color: var(--color-red);
}

.custom-target-row input {
    width: 3ch;
    font-size: 2rem;
}
.custom-target-row label {
    margin-bottom: 0;
}

/* Buttons */
.cta-button, .submit-button {
    display: inline-block;
    background-color: var(--color-black);
    color: var(--color-white);
    font-size: 1rem;
    font-weight: 700;
    text-transform: uppercase;
    text-decoration: none;
    padding: 1.25rem 2.5rem;
    border: 1px solid var(--color-black);
    cursor: pointer;
    transition: all var(--transition-med);
    letter-spacing: 0.02em;
}

.cta-button:hover, .submit-button:hover:not(:disabled) {
    background-color: var(--color-red);
    border-color: var(--color-red);
    padding-left: 2.75rem;
    padding-right: 2.25rem;
}

.submit-button {
    width: 100%;
    margin-top: var(--space-lg);
    font-size: 1.25rem;
    padding: 1.5rem;
}

.submit-button:disabled {
    background-color: var(--color-gray-dark);
    border-color: var(--color-gray-dark);
    cursor: not-allowed;
}

.text-button {
    background: transparent;
    border: none;
    font-family: var(--font-primary);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    cursor: pointer;
    margin-top: var(--space-md);
    text-transform: uppercase;
    transition: color var(--transition-fast);
}

.text-button:hover {
    color: var(--color-red);
}

/* Dynamic Modules */
.modules-container {
    margin: var(--space-lg) 0;
}

.modules-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: var(--space-md);
    border-bottom: 1px solid var(--color-gray);
    padding-bottom: var(--space-xs);
}

.modules-header label {
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}

.modules-status {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--color-red);
}

.module-row {
    display: flex;
    align-items: baseline;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
}

.module-label {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-gray-dark);
    width: 2.5ch;
}

.module-inputs-container {
    flex: 1;
    display: flex;
    gap: var(--space-md);
}

.module-input-wrapper {
    flex: 1;
    display: flex;
    align-items: baseline;
    border-bottom: 2px solid var(--color-black);
    padding-bottom: 4px;
    transition: border-color var(--transition-fast);
    position: relative;
}

.input-label-small {
    position: absolute;
    top: -12px;
    left: 0;
    font-size: 0.6rem;
    font-weight: 700;
    color: var(--color-gray-dark);
}

.module-input-wrapper:focus-within {
    border-color: var(--color-red);
}

.module-input-wrapper input {
    font-size: 2.5rem;
}

.module-input-wrapper .input-suffix {
    font-size: 1rem;
}

.remove-module-btn {
    background: transparent;
    border: none;
    font-size: 2rem;
    line-height: 1;
    cursor: pointer;
    color: var(--color-gray-dark);
    transition: color var(--transition-fast);
}
.remove-module-btn:hover {
    color: var(--color-red);
}

/* 10. Results */
.result-placeholder {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-gray-dark);
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding-top: var(--space-md);
}

.result-block {
    margin-bottom: var(--space-md);
}

.result-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-xs);
    color: var(--color-gray-dark);
}

.result-value {
    font-size: clamp(3rem, 5vw, 4.5rem);
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.02em;
    color: var(--color-black);
}

.result-split {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-gray-dark);
    margin-top: 4px;
    letter-spacing: 0.05em;
}

.convert-section {
    margin-top: var(--space-xs);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
}

.convert-btn {
    display: inline-block;
    background: transparent;
    border: 1px solid var(--color-black);
    color: var(--color-black);
    font-family: var(--font-primary);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    padding: 6px 14px;
    cursor: pointer;
    text-transform: uppercase;
    transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.convert-btn:hover {
    background-color: var(--color-black);
    color: var(--color-white);
}

.convert-btn.active {
    background-color: var(--color-black);
    color: var(--color-white);
}

.convert-btn:focus-visible {
    outline: 2px solid var(--color-red);
    outline-offset: 2px;
}

.converted-value {
    font-size: clamp(2rem, 3.5vw, 2.75rem);
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.02em;
    color: var(--color-black);
    margin-top: 4px;
}

.result-status {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.25rem;
    font-weight: 700;
    margin-top: var(--space-xl);
    padding-top: var(--space-md);
    border-top: 2px solid var(--color-black);
}

.status-dot-large {
    font-size: 1.2em;
}

.status-success {
    color: var(--color-black);
}
.status-success .status-dot-large {
    color: var(--color-black);
}

.status-fail {
    color: var(--color-red);
}
.status-fail .status-dot-large {
    color: var(--color-red);
}

/* 11. Sections / Information */
.info-section {
    padding-top: var(--space-lg);
    padding-bottom: var(--space-xl);
    border-top: 1px solid var(--color-black);
}

.info-column {
    grid-column: span 6;
}

.text-info-col {
    padding-left: var(--space-md);
    border-left: 1px solid var(--color-gray);
}

.math-explanation {
    font-family: monospace;
    font-size: 1rem;
    background-color: var(--color-white);
    padding: var(--space-md);
    border: 1px solid var(--color-black);
    overflow-x: auto;
}

.math-row {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.math-label {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--color-gray-dark);
    font-family: var(--font-primary);
    letter-spacing: 0.05em;
}

.math-formula {
    font-weight: 600;
    font-size: 1.1rem;
}

.math-operator {
    margin: var(--space-sm) 0;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-red);
}

.info-item {
    margin-bottom: var(--space-lg);
}

.info-number {
    font-size: 2.5rem;
    margin-bottom: var(--space-xs);
    line-height: 1;
}

.info-item p {
    font-size: 1.15rem;
    max-width: 400px;
    color: var(--color-black);
}

/* 12. Footer */
.app-footer {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: var(--space-md);
    border-top: 1px solid var(--color-black);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.footer-tagline {
    font-weight: 500;
    color: var(--color-gray-dark);
    margin-top: 4px;
}

.centagon-credits {
    text-align: center;
}

.centagon-credits strong {
    font-weight: 800;
    color: var(--color-red);
}

.social-links {
    display: flex;
    gap: var(--space-md);
    text-align: right;
}

.social-links a {
    color: var(--color-black);
    text-decoration: none;
    border-bottom: 2px solid transparent;
    padding-bottom: 2px;
    transition: border-color var(--transition-fast), color var(--transition-fast);
}

.social-links a:hover {
    border-color: var(--color-red);
    color: var(--color-red);
}

/* Utilities */
.hidden { display: none !important; }
.mt-large { margin-top: var(--space-lg); }

/* 13. Responsive */
@media (max-width: 1024px) {
    .grid-container {
        grid-template-columns: repeat(8, 1fr);
    }
    .hero-content {
        grid-column: 1 / 5;
    }
    .hero-graphic {
        grid-column: 5 / 9;
    }
    .calc-setup {
        grid-column: 1 / 5;
    }
    .calc-result {
        grid-column: 5 / 9;
    }
    .info-column {
        grid-column: span 8;
        margin-bottom: var(--space-lg);
    }
    .text-info-col {
        padding-left: 0;
        border-left: none;
    }
}

@media (max-width: 768px) {
    .grid-container {
        grid-template-columns: repeat(4, 1fr);
    }
    .hero-section {
        min-height: auto;
        padding-top: var(--space-lg);
        padding-bottom: var(--space-lg);
    }
    .hero-content, .calc-setup, .calc-result {
        grid-column: 1 / -1;
    }
    .hero-graphic {
        display: none !important;
    }
    .calc-result {
        border-left: none;
        padding-left: 0;
        margin-top: var(--space-xl);
        border-top: 1px solid var(--color-gray);
        padding-top: var(--space-md);
    }
    .hero-title {
        font-size: 3.5rem;
    }
    .app-footer {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-md);
    }
    .centagon-credits {
        text-align: left;
    }
    .social-links {
        justify-content: flex-start;
        text-align: left;
        flex-wrap: wrap;
    }
    .target-selector {
        gap: var(--space-sm);
    }
    .module-inputs-container {
        flex-direction: column;
        gap: var(--space-md);
    }
    .module-row {
        align-items: flex-start;
    }
}

@media (max-width: 640px) {
    .nav-right {
        display: none; /* Hide tagline on smaller screens so logo and nav links stay prominent */
    }
}

@media (max-width: 480px) {
    .nav-center {
        gap: var(--space-sm);
    }
    .hero-title {
        font-size: 2.8rem;
    }
    .hero-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-xs);
    }
    .module-label {
        font-size: 1.5rem;
    }
    .module-input-wrapper input {
        font-size: 2rem;
    }
    .remove-module-btn {
        font-size: 1.5rem;
    }
    .input-row input {
        font-size: 2.5rem;
    }
    .target-btn {
        font-size: 1.25rem;
    }
    .custom-target-row input {
        font-size: 1.5rem;
    }
    .custom-target-row {
        margin-top: var(--space-sm);
    }
    .result-value {
        font-size: 2.5rem;
    }
    .cta-button, .submit-button {
        padding: 1rem 1.5rem;
    }
}

/* 14. Accessibility & Errors */
.error-banner {
    margin-top: var(--space-md);
    padding: var(--space-sm) var(--space-md);
    background-color: var(--color-red);
    color: var(--color-white);
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.error-title {
    font-weight: 700;
    font-size: 0.85rem;
    letter-spacing: 0.05em;
}
input:focus {
    outline: none;
}
a:focus-visible, button:focus-visible {
    outline: 2px solid var(--color-red);
    outline-offset: 4px;
}
@media (prefers-reduced-motion: reduce) {
    * {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        scroll-behavior: auto !important;
    }
}