/* Shared styles: reset, theme variables, nav, dark-mode toggle, footer */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #7b9ab8;
    --secondary-color: #5d7a99;
    --accent-color: #9ab5ce;
    --text-dark: #2d3748;
    --text-light: #4a5568;
    --bg-light: #f0f4f8;
    --bg-white: #ffffff;
    --border-color: #cbd5e0;
}

[data-theme="dark"] {
    --primary-color: #6b8fb0;      /* Navy blue */
    --secondary-color: #7a9fc0;    /* Medium navy */
    --accent-color: #b8a8d8;       /* Purple pastel */
    --text-dark: #e2e8f0;          /* Light text */
    --text-light: #cbd5e0;         /* Muted text */
    --bg-light: #1a202c;           /* Dark background */
    --bg-white: #2d3748;           /* Card background */
    --border-color: #4a5568;       /* Border */
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

/* Navigation */
nav {
    background-color: var(--bg-white);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

nav .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

nav .logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

nav .back-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

nav .back-link:hover {
    color: var(--primary-color);
}

/* Dark mode toggle */
.dark-mode-toggle {
    background: none;
    border: none;
    color: var(--text-dark);
    cursor: pointer;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    transition: background-color 0.3s, transform 0.2s;
}

.dark-mode-toggle:hover {
    background-color: var(--bg-light);
    transform: scale(1.1);
}

.dark-mode-toggle svg {
    width: 20px;
    height: 20px;
}

/* Post/talk/award date label */
.post-date {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

/* Footer */
footer {
    background-color: #2d3748;
    color: white;
    text-align: center;
    padding: 2rem;
}

[data-theme="dark"] footer {
    background-color: #1a202c;
}

footer a {
    color: #9b8bb8;
    text-decoration: none;
}

[data-theme="dark"] footer a {
    color: #c9b8e8;
}

footer a:hover {
    text-decoration: underline;
}