/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* Base */
html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
    background-image: var(--color-bg-gradient);
    min-height: 100vh;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a,
a:link,
a:visited {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-hover);
}

h1, h2, h3 {
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2.25rem, 5vw, 3.5rem);
    font-weight: 900;
}

h2 {
    font-size: clamp(1.5rem, 3vw, 2.25rem);
}

/* Layout */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.content-narrow {
    max-width: var(--max-width-narrow);
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Navigation */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--color-nav-bg);
    backdrop-filter: var(--blur-nav);
    -webkit-backdrop-filter: var(--blur-nav);
    border-bottom: 1px solid var(--color-border);
    height: var(--nav-height);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.nav-logo,
.nav-logo:link,
.nav-logo:visited {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 700;
    font-size: 1rem;
    color: var(--color-text);
    text-decoration: none;
}

.nav-logo:hover {
    color: var(--color-text);
}

.nav-icon {
    border-radius: 7px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--space-xl);
    align-items: center;
}

.nav-links a {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text);
}

/* Page header */
.page-header {
    padding: calc(var(--nav-height) + var(--space-4xl)) 0 var(--space-3xl);
    text-align: center;
}

.page-subtitle {
    color: var(--color-text-secondary);
    font-size: 1rem;
    margin-top: var(--space-sm);
}

/* Forms: no form styling exists elsewhere in this repo, so it starts here. */
.signup-form {
    margin-top: var(--space-xl);
    width: 100%;
    max-width: 480px;
}

.signup-row {
    display: flex;
    gap: var(--space-sm);
}

.signup-form input[type="email"] {
    flex: 1;
    min-width: 0;
    font-family: inherit;
    font-size: 1rem;
    color: var(--color-text);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    padding: 0.875rem var(--space-md);
    transition: border-color var(--transition-fast), background var(--transition-fast);
}

.signup-form input[type="email"]::placeholder {
    color: var(--color-text-tertiary);
}

.signup-form input[type="email"]:hover {
    background: var(--color-surface-hover);
}

.signup-form input[type="email"]:focus {
    outline: none;
    border-color: var(--color-accent);
    background: var(--color-surface-hover);
}

.signup-form button {
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    white-space: nowrap;
    color: var(--color-accent-contrast);
    background: var(--color-accent);
    border: none;
    border-radius: var(--border-radius-sm);
    padding: 0.875rem var(--space-lg);
    cursor: pointer;
    transition: background var(--transition-fast), opacity var(--transition-fast);
}

.signup-form button:hover:not(:disabled) {
    background: var(--color-accent-hover);
}

.signup-form button:disabled {
    opacity: 0.55;
    cursor: default;
}

.form-message {
    min-height: 1.5rem;
    margin-top: var(--space-sm);
    font-size: 0.9375rem;
}

.form-message.success {
    color: var(--color-success);
}

.form-message.error {
    color: var(--color-error);
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: var(--space-2xl) 0;
    text-align: center;
}

.site-footer p {
    color: var(--color-text-tertiary);
    font-size: 0.8125rem;
}

/* Mobile */
@media (max-width: 768px) {
    .nav-links {
        gap: var(--space-lg);
    }

    .signup-row {
        flex-direction: column;
    }
}