/* Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
    transition: all 0.3s ease;
}

body {
    background: var(--bg);
    color: var(--text);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Theme variables */
:root {
    --bg: #f9f9f9;
    --text: #111;
    --card-bg: #fff;
    --card-border: #e0e0e0;
    --card-shadow: rgba(0,0,0,0.03);
    --footer: #888;
}

body.dark {
    --bg: #111;
    --text: #f0f0f0;
    --card-bg: #1a1c1f;
    --card-border: #222;
    --card-shadow: rgba(0,0,0,0.5);
    --footer: #aaa;
}

/* Top Bar */
.top-bar {
    display: flex;
    height: 80px;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;   /* remove top/bottom padding */
    background: var(--card-bg);
    border-bottom: 1px solid var(--card-border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-links {
    font-size: 22px;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 1.5rem;
  }

  .nav-links a {
    position: relative;       /* required for ::after positioning */
    text-decoration: none;    /* remove default underline */
    color: var(--text);
    font-weight: 400;
    transition: color 0.2s ease;
}

/* Animated underline */
.nav-links a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -3px;             /* distance below text */
    width: 0;                  /* start hidden */
    height: 2px;               /* underline thickness */
    background: currentColor;  /* same as text color */
    transition: width 0.25s ease;
}

/* Hover effect */
.nav-links a:hover::after {
    width: 100%;
}

/* Active page underline stays visible */
.nav-links a.active::after {
    width: 100%;
}


.top-bar .logo img {
    max-height: 40px; /* adjust as needed */
    width: auto;
    display: block;   /* removes tiny spacing issues */
}

.top-bar .logo {
    font-weight: 600;
    font-size: 1.2rem;
}

#theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text);
    display: flex;
    align-items: center;
    padding: 0.25rem;
}

#theme-toggle svg {
    width: 24px;
    height: 24px;
    transition: transform 0.3s ease, stroke 0.3s ease;
}

/* Header */
header {
    text-align: center;
    padding: 6rem 1rem 3rem 1rem;
}

header h1 {
    font-size: 3rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

header p {
    font-size: 1.1rem;
    color: #666;
}

/* Links Section */
.links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 2rem 4rem;
    justify-items: center;
}

.link-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 1rem;
    padding: 2rem;
    width: 100%;
    max-width: 280px;
    text-align: center;
    transition: all 0.25s ease;
    cursor: pointer;
    box-shadow: 0 4px 10px var(--card-shadow);
}

.link-card h2 {
    margin-bottom: 1rem;
    color: var(--text);
    font-weight: 500;
}

.link-card p {
    color: #666;
    font-size: 0.95rem;
}

.link-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 10px 20px var(--card-shadow);
    border-color: var(--card-border);
}

/* Vertical links page */
.links-vertical {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;       /* space between boxes */
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

.link-box {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 1rem;
    padding: 1.5rem 2rem;
    cursor: pointer;
    box-shadow: 0 4px 8px var(--card-shadow);
    transition: all 0.25s ease;
}

.link-box:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px var(--card-shadow);
}

.link-box h2 {
    margin: 0 0 0.5rem 0;
    color: var(--text);
}

.link-box p {
    margin: 0;
    color: #666;
    font-size: 0.95rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 1rem;
    margin-top: auto;
    color: var(--footer);
    font-size: 0.85rem;
}