/* ==========================================================================
   WhichAIPlan - Shared Layout, Header Navbar, Container & Intro Banners
   ========================================================================== */

/* Top Navbar (Seamless Seamless Canvas with Zero Bottom Border Line) */
header#siteNavbar {
    background: var(--bg-primary);
    border-bottom: none;
    padding: 10px 24px 4px 24px;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
}

.navbar-container {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    gap: 16px;
}

.navbar-brand {
    justify-self: start;
    font-size: 19px;
    font-weight: 800;
    color: #ffffff;
    letter-spacing: -0.5px;
    display: flex;
    align-items: center;
    gap: 2px;
    cursor: default;
    white-space: nowrap;
    user-select: none;
}
.navbar-brand span { color: var(--accent-cyan); }

/* Plan Toggle in Navbar (Strict Center + Relative Anchor) */
.tier-toggle-wrapper {
    justify-self: center;
    position: relative;
    display: inline-flex;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 30px;
    padding: 4px;
    gap: 4px;
}

.tier-btn {
    background: transparent;
    border: 1px solid transparent;
    color: #e2e8f0;
    font-family: var(--font-sans);
    font-size: 20px;
    font-weight: 700;
    padding: 6px 15px;
    border-radius: 24px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 5px;
    white-space: nowrap;
}
.tier-btn:not(.active):hover {
    color: #ffffff;
    border-color: var(--accent-cyan);
    background: rgba(0, 240, 255, 0.08);
    box-shadow: 0 0 12px rgba(0, 240, 255, 0.25);
}
.tier-btn.active {
    background: #ffffff;
    color: #000000;
    border-color: #ffffff;
    box-shadow: 0 2px 10px rgba(255, 255, 255, 0.35);
}

/* Seamless Hanging Mode Switcher Tab (Floats naturally below toggle bar) */
.mode-switch-btn {
    position: absolute;
    top: calc(100% - 1px);
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-top: 1px solid var(--bg-card);
    color: #f1f5f9;
    font-family: var(--font-sans);
    font-size: 14.5px;
    font-weight: 700;
    padding: 5px 20px;
    border-radius: 0 0 16px 16px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 7px;
    white-space: nowrap;
    user-select: none;
    z-index: 10;
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.45);
}
.mode-switch-btn:hover {
    border-color: var(--accent-cyan);
    border-top-color: var(--bg-hover);
    background: var(--bg-hover);
    color: #ffffff;
    box-shadow: 0 6px 18px rgba(0, 240, 255, 0.25);
}

/* Navigation Tabs (Right Side) */
.nav-tabs {
    justify-self: end;
    display: flex;
    align-items: center;
    gap: 8px;
    white-space: nowrap;
}

.tab-btn {
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    color: #e2e8f0;
    font-family: var(--font-sans);
    font-size: 16px;
    font-weight: 600;
    padding: 8px 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
    transition: all 0.2s ease;
    border-radius: 6px;
}
.tab-btn:hover { color: #ffffff; background-color: rgba(255, 255, 255, 0.06); }
.tab-btn.active { color: var(--accent-cyan); border-bottom-color: var(--accent-cyan); background-color: rgba(0, 240, 255, 0.06); }
.tab-btn.tab-disabled { display: none; }

@media (max-width: 880px) {
    header#siteNavbar { padding: 10px 16px; }
    .navbar-container {
        display: flex;
        flex-wrap: wrap;
        justify-content: space-between;
        align-items: center;
        row-gap: 12px;
    }
    .navbar-brand { order: 1; }
    .nav-tabs { order: 2; }
    .tier-toggle-wrapper { order: 3; width: 100%; max-width: 440px; margin: 0 auto; justify-content: center; }
}

@media (max-width: 600px) {
    .tier-toggle-wrapper {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        padding: 3px;
        gap: 3px;
        border-radius: 20px;
        margin-bottom: 24px;
        max-width: 100%;
    }
    .tier-btn {
        font-size: 13px;
        padding: 6px 2px;
        justify-content: center;
        text-align: center;
        border-radius: 16px;
        min-width: 0;
    }
    .mode-switch-btn {
        font-size: 12px;
        padding: 3px 14px;
        border-radius: 0 0 12px 12px;
    }
    .tab-btn {
        font-size: 13px;
        padding: 6px 8px;
        gap: 4px;
    }
}