:root {
    /* Brand color channels (RGB) */
    --primary-blue-raw: 63, 140, 255;
    --secondary-blue-raw: 125, 184, 255;

    /* Base colors */
    --primary-color: rgb(var(--primary-blue-raw));
    --secondary-color: rgb(var(--secondary-blue-raw));

    /* Surfaces & backgrounds */
    --primary-background: #07111d;
    --secondary-background: #0b1730;
    --card-surface: #101c2f;
    --card-surface-soft: #14253d;

    /* Gradients */
    --brand-gradient: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    --card-gradient: linear-gradient(180deg, var(--card-surface) 0%, var(--card-surface-soft) 100%);
    --card-gradient-hover: linear-gradient(180deg, #14243b 0%, #1a304e 100%);

    /* Borders & glows */
    --theme-border: rgba(var(--primary-blue-raw), 0.18);
    --theme-border-hover: rgba(var(--primary-blue-raw), 0.45);
    --theme-glow: rgba(var(--primary-blue-raw), 0.22);
    --theme-glow-strong: rgba(var(--primary-blue-raw), 0.4);
}

/* Hero */
.hero {
    min-height: calc(85vh - 72px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 3rem 0 5rem;
    text-align: center;
}

.hero__content {
    max-width: 860px;
}

.hero__badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1rem;
    background: rgba(var(--primary-blue-raw), 0.1);
    border: 1px solid var(--theme-border);
    border-radius: 999px;
    color: var(--secondary-color);
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.05rem;
    margin-bottom: 1.5rem;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--primary-color);
    border-radius: 50%;
    box-shadow: 0 0 8px var(--primary-color);
}

.hero h1 {
    font-size: clamp(2.6rem, 5.5vw, 4.8rem);
    line-height: 1.3;
    letter-spacing: -0.04em;
    margin-bottom: 1.25rem;
    background: var(--brand-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    white-space: nowrap;
}

.hero__description {
    max-width: 660px;
    margin: 0 auto 2.5rem;
    color: var(--secondary-color);
    font-size: clamp(1.05rem, 2vw, 1.25rem);
    line-height: 1.7;
    opacity: 0.9;
}

.hero__actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Sections */
.community,
.philosophy,
.about,
.open-source {
    padding: 5rem 0;
    border-top: 1px solid var(--theme-border);
}

.section__header {
    max-width: 760px;
    margin: 0 auto 3rem;
    text-align: center;
}

.section__header h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    line-height: 1.15;
    letter-spacing: -0.03em;
}

/* Philosophy Grid */
.philosophy__grid {
    max-width: 1100px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.philosophy__card {
    padding: 2.2rem 1.8rem;
    background: var(--card-gradient);
    border: 1px solid var(--theme-border);
    border-radius: 18px;
    transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.philosophy__card:hover {
    background: var(--card-gradient-hover);
    transform: translateY(-4px);
    border-color: var(--theme-border-hover);
    box-shadow: 0 16px 36px var(--theme-glow);
}

.philosophy__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
}

.philosophy__kanji {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1;
}

.philosophy__stage {
    font-size: 0.75rem;
    color: var(--secondary-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08rem;
    background: rgba(var(--primary-blue-raw), 0.1);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
}

.philosophy__card h3 {
    margin-bottom: 0.8rem;
    font-size: 1.35rem;
    letter-spacing: -0.02em;
}

.philosophy__card p {
    color: var(--text, #ffffff);
    font-size: 0.96rem;
    line-height: 1.65;
    opacity: 0.88;
}

/* Content Cards (Community, About & Open Source) */
.content-card {
    max-width: 820px;
    margin: 0 auto;
    padding: 2.5rem 2rem;
    background: var(--card-gradient);
    border: 1px solid var(--theme-border);
    border-radius: 18px;
    box-shadow: 0 18px 48px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.content-card:hover {
    border-color: var(--theme-border-hover);
    box-shadow: 0 20px 50px var(--theme-glow);
}

.content-card--center {
    text-align: center;
}

.content-card p {
    color: var(--text, #ffffff);
    font-size: 1.05rem;
    line-height: 1.8;
    margin-bottom: 1.25rem;
    opacity: 0.9;
}

.content-card p:last-child {
    margin-bottom: 0;
}