* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-primary: #1a1a2e;
    --color-secondary: #16213e;
    --color-accent: #0f3460;
    --color-highlight: #e94560;
    --color-text: #2d2d2d;
    --color-text-light: #5a5a5a;
    --color-bg: #fafafa;
    --color-white: #ffffff;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.8;
    color: var(--color-text);
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-white) 100%);
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 24px;
}

header {
    text-align: center;
    margin-bottom: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.logo {
    max-width: 280px;
    width: 100%;
    height: auto;
    margin-bottom: 20px;
    filter: grayscale(20%);
    transition: filter 0.3s ease;
}

.logo:hover {
    filter: grayscale(0%);
}

.tagline {
    font-size: 1.5rem;
    color: var(--color-text-light);
    letter-spacing: 0.3em;
    font-weight: 400;
}

main {
    font-size: 1.125rem;
}

section {
    margin-bottom: 32px;
}

section p {
    margin-bottom: 24px;
    text-align: justify;
    hyphens: auto;
}

section p:last-child {
    margin-bottom: 0;
}

.intro p {
    font-size: 1.25rem;
    color: var(--color-primary);
}

.history p strong {
    color: var(--color-accent);
}

.legacy {
    margin-top: 48px;
    padding: 32px;
    background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-accent) 100%);
    border-radius: 8px;
    color: var(--color-white);
}

.legacy p {
    text-align: center;
    font-style: italic;
    font-size: 1.1rem;
}

.legacy a {
    color: var(--color-white);
    text-decoration: underline;
    text-underline-offset: 3px;
    transition: opacity 0.2s ease;
}

.legacy a:hover {
    opacity: 0.8;
}

.founder {
    margin-top: 60px;
    text-align: right;
    padding-right: 40px;
}

.founder .signature {
    font-size: 1.5rem;
    font-style: italic;
    color: var(--color-primary);
    margin-bottom: 4px;
}

.founder .title {
    font-size: 0.95rem;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.15em;
}

.founder .note {
    font-size: 0.875rem;
    color: var(--color-text-light);
    font-style: italic;
    margin-top: 16px;
}

.acknowledgment {
    margin-top: 48px;
}

.acknowledgment h2 {
    font-size: 1rem;
    color: var(--color-text-light);
    font-weight: 500;
    margin-bottom: 12px;
}

.acknowledgment p {
    font-size: 0.9rem;
    color: #6a6a6a;
}

footer {
    margin-top: 80px;
    padding-top: 40px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    text-align: center;
}

footer p {
    font-size: 0.875rem;
    color: var(--color-text-light);
    letter-spacing: 0.05em;
}

@media (max-width: 600px) {
    .container {
        padding: 40px 20px;
    }

    header {
        margin-bottom: 40px;
        padding-bottom: 30px;
    }

    .logo {
        max-width: 200px;
    }

    .tagline {
        font-size: 1.2rem;
        letter-spacing: 0.2em;
    }

    main {
        font-size: 1rem;
    }

    .intro p {
        font-size: 1.1rem;
    }

    section p {
        text-align: left;
    }

    .legacy {
        padding: 24px;
    }

    .founder {
        padding-right: 0;
        text-align: center;
    }

    .founder .signature {
        font-size: 1.3rem;
    }

    footer {
        margin-top: 60px;
    }
}

/* Theme Toggle Button */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 50%;
    background: var(--color-secondary);
    color: var(--color-white);
    cursor: pointer;
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease, transform 0.2s ease;
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.theme-toggle:hover {
    transform: scale(1.1);
}

.theme-toggle .icon-moon {
    display: none;
}

.theme-toggle .icon-sun {
    display: block;
}

/* Dark Theme */
[data-theme="dark"] {
    --color-text: #e0e0e0;
    --color-text-light: #a0a0a0;
    --color-bg: #121212;
    --color-white: #1a1a1a;
}

[data-theme="dark"] body {
    background: linear-gradient(180deg, #121212 0%, #1e1e1e 100%);
}

[data-theme="dark"] .logo {
    filter: brightness(0.9) grayscale(20%);
}

[data-theme="dark"] .logo:hover {
    filter: brightness(1) grayscale(0%);
}

[data-theme="dark"] header,
[data-theme="dark"] footer {
    border-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .intro p {
    color: #b8c5d6;
}

[data-theme="dark"] .history p strong {
    color: #6fa3ef;
}

[data-theme="dark"] .legacy {
    background: linear-gradient(135deg, #1e3a5f 0%, #2d5a87 100%);
    color: #f0f0f0;
}

[data-theme="dark"] .legacy a {
    color: #f0f0f0;
}

[data-theme="dark"] .founder .signature {
    color: #e0e0e0;
}

[data-theme="dark"] .acknowledgment p {
    color: #808080;
}

[data-theme="dark"] .theme-toggle {
    background: var(--color-accent);
}

[data-theme="dark"] .theme-toggle .icon-moon {
    display: block;
}

[data-theme="dark"] .theme-toggle .icon-sun {
    display: none;
}

/* Light Theme (explicit) */
[data-theme="light"] .theme-toggle .icon-moon {
    display: none;
}

[data-theme="light"] .theme-toggle .icon-sun {
    display: block;
}