:root {
    --bg: #fff;             /* Light mode: pure white background */
    --top-bg: #fff;         /* Light mode: pure white top section */
    --container-bg: #fff;   /* Light mode: pure white container */
    --brand-blue: #00AEEF;
    --brand-green: #8DC63F;
    --brand-dark: #444444;
    --brand-light: #f4f4f4;
    --brand-gray: #e0e0e0;
    --brand-white: #fff;
    --brand-shadow: rgba(0,0,0,0.08);
    --brand-border: #d1d1d1;
    --fg: #444444;
    --button: var(--brand-blue);
    --button-hover: #007fa3;
    --refresh: var(--brand-green);
    --refresh-hover: #6fa32d;
    --input-bg: #f7f7f7;
    --input-bg-dark: #555555;
    --copied: var(--brand-green);
}

html[data-theme="dark"] {
    --bg: #444444;           /* Dark mode: dark background */
    --top-bg: #444444;       /* Dark mode: match background */
    --container-bg: #666666; /* Dark mode: lighter gray for container */
    --fg: #f4f4f4;
    --input-bg: #555555;     /* Dark mode: lighter for password items */
}

html, body {
    height: 100%;
    min-height: 100%;
    margin: 0;
    padding: 0;
}

body {
    background: var(--bg);
    color: var(--fg);
    font-family: 'Segoe UI', Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    width: 100%;
    max-width: 600px;
    margin: 40px auto;
    background: var(--container-bg);
    border-radius: 14px;
    box-shadow: 0 2px 16px var(--brand-shadow);
    border: 1px solid var(--brand-border);
    padding: 30px;
    position: relative;
    box-sizing: border-box;
    text-align: center;
}

.logo-wrap {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 18px;
}

.logo {
    max-width: 320px;
    width: 100%;
    height: auto;
    display: block;
}

h1 {
    text-align: center;
    font-size: 1.7em;
    margin: 0 0 18px 0;
    font-weight: 600;
    letter-spacing: 0.01em;
    color: var(--fg);
}

.ip-section {
    background: var(--input-bg);
    border-radius: 6px;
    padding: 20px;
    margin: 20px 0;
    box-shadow: 0 1px 2px var(--brand-shadow);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.ip-address {
    font-size: 2em;
    font-weight: 600;
    color: var(--fg);
    margin: 10px 0;
    padding: 15px;
    background: var(--container-bg);
    border-radius: 6px;
    box-shadow: 0 1px 2px var(--brand-shadow);
    width: 70%;
    text-align: center;
    word-break: break-all;
}

.copy-btn {
    background: var(--button);
    color: #fff;
    border: none;
    border-radius: 4px;
    padding: 8px 20px;
    cursor: pointer;
    font-size: 1em;
    font-weight: 500;
    transition: background 0.2s, color 0.2s;
    margin-top: 10px;
}

.copy-btn.copied {
    background: var(--copied);
    color: #fff;
}

.copy-btn:hover:not(.copied) {
    background: var(--button-hover);
}

.theme-switch {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 18px;
    gap: 10px;
}

.theme-label {
    font-size: 1em;
    font-weight: 500;
}

.theme-toggle {
    width: 44px;
    height: 24px;
    background: var(--input-bg);
    border-radius: 12px;
    position: relative;
    cursor: pointer;
    border: 1px solid var(--brand-border);
    transition: background 0.3s;
    display: flex;
    align-items: center;
}

.theme-toggle .slider {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: var(--button);
    border-radius: 50%;
    transition: left 0.3s, background 0.3s;
}

.theme-toggle.dark .slider {
    left: 22px;
    background: var(--refresh);
}

.theme-toggle.auto .slider {
    left: 12px;
    background: var(--brand-blue);
}

.theme-toggle.light .slider {
    left: 2px;
    background: var(--button);
}

@media (max-width: 600px) {
    .container { 
        max-width: 98vw; 
        padding: 8px 2vw; 
    }
    .logo { 
        max-width: 90vw; 
    }
}