/* CSS Variables */
:root {
    /* Colors */
    --color-primary: #3d3846;
    --color-secondary: #002c52;
    --color-dark: #000d19;
    --color-gray: #e5e5e5;
    --color-light: #f6f5f4;
    --color-background: #f4f4f4;
    --color-text: #333;
    --color-white: #fff;
    --color-hover: #e6e6e6;
    --color-footer: #333;
    
    /* Alert colors */
    --color-alert-bg: #fff3cd;
    --color-alert-border: #ffe69c;
    --color-alert-text: #664d03;
    
    /* Instagram colors */
    --color-instagram-1: rgb(255, 225, 125);
    --color-instagram-2: rgb(255, 205, 105);
    --color-instagram-3: rgb(250, 145, 55);
    --color-instagram-4: rgb(235, 65, 65);
    --color-instagram-5: rgb(35, 75, 215);
    --color-instagram-6: rgb(195, 60, 190);
    
    /* Spacing */
    --spacing-xs: 0.3rem;
    --spacing-sm: 0.625rem;
    --spacing-md: 0.75rem;
    --spacing-base: 1rem;
    --spacing-lg: 1.25rem;
    --spacing-xl: 1.5rem;
    --spacing-xxl: 2.5rem;
    --spacing-xxxl: 3.5rem;
    
    /* Typography */
    --font-family-base: 'Inter', sans-serif;
    --font-size-base: 1rem;
    --font-size-h1: 2rem;
    --font-weight-bold: 600;
    
    /* Layout */
    --container-max-width: 1200px;
    --border-radius-sm: 0.3rem;
    --border-radius-md: 1rem;
    --border-radius-lg: 2rem;
    --header-height-normal: 5rem;
    --header-height-scrolled: 3.2rem;
    
    /* Transitions */
    --transition-speed: 0.3s;
}

/* Base styles */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 4rem;
    box-sizing: border-box;
}

*, *:before, *:after {
    box-sizing: inherit;
}

body {
    font-family: var(--font-family-base);
    margin: 0;
    padding: 0;
    background-color: var(--color-background);
    color: var(--color-text);
    font-size: var(--font-size-base);
}

.d-flex {
    display: flex;
}

/* Typography */
h1 {
    font-size: var(--font-size-h1);
}

p {
    margin-bottom: var(--spacing-base);
}

/* Layout */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
}

/* Header */
header {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: var(--color-light);
    color: var(--color-primary);
    padding: var(--spacing-lg) 0;
    text-align: center;
    transition: padding var(--transition-speed) ease;
    z-index: 1000;
}

header .header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--spacing-base);
}

header .logo {
    max-height: var(--header-height-normal);
    transition: max-height var(--transition-speed) ease;
}

header nav a {
    margin: 0 var(--spacing-sm);
    color: var(--color-primary);
    text-decoration: none;
}

header nav a:hover {
    text-decoration: underline;
}

body.scrolled header {
    padding: var(--spacing-sm) 0;
}

body.scrolled header .logo {
    max-height: var(--header-height-scrolled);
}

/* Main content */
main {
    padding-top: 9.5rem;
    text-align: center;
}

section {
    margin: 0;
    padding: var(--spacing-xxl) var(--spacing-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
    text-align: center;
}

#intro {
    padding: var(--spacing-xxxl) var(--spacing-lg);
}

/* Sections with background colors */
.intro-section {
    color: var(--color-white);
    padding: var(--spacing-xxl) var(--spacing-lg);
    background-color: var(--color-secondary);
}

.intro-section .buttons {
    margin-top: var(--spacing-lg);
}

.dark-section {
    background-color: var(--color-dark);
    color: var(--color-light);
}

.gray-section {
    background-color: var(--color-gray);
}

/* Grid system */
.row {
    margin: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-md);
    text-align: center;
}

.columns {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
}

.column {
    flex-direction: column;
    flex: 1;
    padding: var(--spacing-lg);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--border-radius-sm);
    text-decoration: none;
    font-weight: var(--font-weight-bold);
    margin: var(--spacing-xs);
    font-size: var(--font-size-base);
}

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

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

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

.btn-dark:hover {
    background-color: var(--color-hover);
}

.btn-outline-dark {
    background-color: transparent;
    border: 0.125rem solid var(--color-primary);
    color: var(--color-primary);
}

.btn-outline-dark:hover {
    background-color: var(--color-hover);
}

.btn-outline-light {
    background-color: transparent;
    border: 0.125rem solid var(--color-white);
    color: var(--color-white);
}

.btn-outline-light:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.btn-small {
    padding: 0.35rem var(--spacing-base);
}

.btn-instagram {
    background: radial-gradient(
        circle farthest-corner at 0% 150%,
        var(--color-instagram-1) 0%,
        var(--color-instagram-2) 12%,
        var(--color-instagram-3) 25%,
        var(--color-instagram-4) 41%,
        transparent 95%
    ),
    linear-gradient(-15deg, var(--color-instagram-5) -10%, var(--color-instagram-6) 65%);
    background-size: 120% 120%;
    display: inline-flex;
    gap: 0.6rem;
    vertical-align: middle;
}

.centered-button {
    margin-top: var(--spacing-lg);
}

/* Footer */
footer {
    background-color: var(--color-footer);
    color: var(--color-white);
    text-align: center;
    padding: var(--spacing-sm) 0;
}

/* Components */
.alert {
    background-color: var(--color-alert-bg);
    border-color: var(--color-alert-border);
    color: var(--color-alert-text);
    padding: var(--spacing-base);
    border-width: 1px;
    border-style: solid;
    border-radius: var(--border-radius-md);
}

#map {
    pointer-events: none;
}

/* Utilities */
.text-left {
    text-align: left;
}

.rounded {
    border-radius: var(--border-radius-lg);
}

.w-100 {
    width: 100%;
}

/* Images */
img {
    max-width: 100%;
    height: auto;
}

/* Media Queries */
@media (max-width: 768px) {
    :root {
        --font-size-h1: 1.75rem;
    }
    
    .columns {
        flex-direction: column;
    }

    nav {
        display: none;
    }

    header {
        position: absolute;
    }

    /* investigators overrides */
    #services .column {
        display: flex;
        flex-direction: row;
        padding: 0;
        gap: 2rem;
    }
    #services img {
        max-width: 10%;
    }
    #services .columns {
        gap: 0;
    }
}