:root {
    --star-teal: #4f9aae;
    --deep-ink: #173640;
    --night-line: #2f5660;
    --cloud: #f7fbfc;
    --mist: #e2f0f3;
    --signal: #f0b44d;
    --white: #ffffff;
    --shadow: 0 24px 70px rgba(23, 54, 64, 0.14);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--deep-ink);
    background:
        linear-gradient(120deg, rgba(79, 154, 174, 0.08), transparent 34rem),
        linear-gradient(180deg, rgba(255, 255, 255, 0.82), rgba(226, 240, 243, 0.38)),
        var(--cloud);
    font-family: "Microsoft JhengHei", "Noto Sans TC", "PingFang TC", Arial, sans-serif;
    line-height: 1.7;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    display: block;
    max-width: 100%;
}

.protected-logo {
    user-select: none;
    -webkit-user-drag: none;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    width: 100%;
    margin: 0;
    padding: 10px max(16px, calc((100vw - 1120px) / 2));
    background: rgba(247, 251, 252, 0.9);
    backdrop-filter: blur(14px);
}

.brand img {
    width: 116px;
    height: auto;
}

.nav-toggle {
    display: none;
    width: 44px;
    height: 44px;
    border: 0;
    padding: 0;
    background: transparent;
    color: var(--star-teal);
    cursor: pointer;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
}

.nav-toggle span {
    display: block;
    width: 18px;
    height: 2px;
    border-radius: 999px;
    background: currentColor;
    transform-origin: center;
    transition: opacity 180ms ease, transform 180ms ease;
}

.site-header.nav-open .nav-toggle span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.site-header.nav-open .nav-toggle span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.site-header.nav-open .nav-toggle span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 1.4rem;
    color: rgba(23, 54, 64, 0.76);
    font-size: 0.95rem;
    font-weight: 700;
}

.site-nav a {
    border-radius: 6px;
}

.site-nav a[aria-current="page"] {
    color: var(--star-teal);
}

.nav-dropdown {
    position: relative;
    display: flex;
    align-items: center;
}

.nav-dropdown::after {
    content: "";
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    height: 0.8rem;
}

.nav-dropdown-menu {
    position: absolute;
    top: calc(100% + 0.7rem);
    left: 50%;
    z-index: 20;
    display: grid;
    min-width: 148px;
    border: 1px solid rgba(79, 154, 174, 0.24);
    border-radius: 8px;
    padding: 8px;
    background: rgba(255, 255, 255, 0.96);
    box-shadow: 0 18px 48px rgba(23, 54, 64, 0.12);
    opacity: 0;
    pointer-events: none;
    transform: translate(-50%, -4px);
    transition: opacity 160ms ease, transform 160ms ease;
}

.nav-dropdown-menu a {
    color: rgba(23, 54, 64, 0.76);
    padding: 8px 10px;
    white-space: nowrap;
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu {
    opacity: 1;
    pointer-events: auto;
    transform: translate(-50%, 0);
}

.site-nav a:focus-visible,
.nav-toggle:focus-visible,
.brand:focus-visible {
    outline: 3px solid rgba(240, 180, 77, 0.72);
    outline-offset: 4px;
}

.tools-section {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
}

.tools-page-header {
    border-bottom: 1px solid rgba(79, 154, 174, 0.24);
    padding: clamp(2.6rem, 6vw, 4.5rem) 0 clamp(1.6rem, 4vw, 2.4rem);
}

h1 {
    width: min(1120px, calc(100% - 32px));
    margin-right: auto;
    margin-left: auto;
    margin-top: 0;
    margin-bottom: 0;
    font-size: clamp(2.5rem, 5.2vw, 4.7rem);
    font-weight: 900;
    letter-spacing: 0;
    line-height: 1.08;
    text-align: center;
}

.tools-section {
    padding: clamp(2rem, 5vw, 3.5rem) 0 clamp(4rem, 9vw, 7rem);
}

.tool-grid {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 1rem;
}

.tool-card {
    display: grid;
    grid-template-rows: 1fr auto;
    align-items: stretch;
    aspect-ratio: 1 / 1;
    min-width: 0;
    border: 1px solid rgba(79, 154, 174, 0.22);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.76);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.tool-icon {
    display: grid;
    place-items: center;
    min-width: 0;
    color: var(--star-teal);
    font-size: clamp(2.8rem, 5vw, 4.4rem);
}

.tool-icon::before {
    content: "";
    width: 1em;
    height: 1em;
    background: currentColor;
    -webkit-mask: var(--tool-icon) center / contain no-repeat;
    mask: var(--tool-icon) center / contain no-repeat;
}

.tool-name {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 64px;
    border-top: 1px solid rgba(79, 154, 174, 0.22);
    padding: 14px;
    color: var(--deep-ink);
    font-size: 1.05rem;
    font-weight: 900;
    line-height: 1.25;
    text-align: center;
}

.site-footer {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    width: 100%;
    margin: 0;
    border-top: 1px solid rgba(79, 154, 174, 0.24);
    padding: 26px max(16px, calc((100vw - 1120px) / 2)) 34px;
    background: rgba(247, 251, 252, 0.58);
    color: rgba(23, 54, 64, 0.66);
    font-size: 0.95rem;
}

@media (hover: hover) {
    .site-nav a:hover {
        color: var(--star-teal);
    }

    .tool-card:hover {
        border-color: rgba(240, 180, 77, 0.78);
        box-shadow: 0 20px 54px rgba(23, 54, 64, 0.14);
        transform: translateY(-2px);
    }

}

@media (max-width: 900px) {
    .site-header {
        flex-wrap: wrap;
    }

    .nav-toggle {
        display: inline-flex;
    }

    .site-nav {
        display: none;
        order: 3;
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        border-top: 1px solid rgba(79, 154, 174, 0.2);
        padding-top: 0.75rem;
        gap: 0;
        overflow: visible;
    }

    .site-header.nav-open .site-nav {
        display: flex;
    }

    .site-nav > a,
    .nav-dropdown > a {
        padding: 0.7rem 0;
    }

    .nav-dropdown {
        display: block;
    }

    .nav-dropdown-menu {
        position: static;
        display: grid;
        min-width: 0;
        border: 0;
        border-left: 1px solid rgba(79, 154, 174, 0.24);
        border-radius: 0;
        margin: 0 0 0.35rem 0.4rem;
        padding: 0 0 0 0.75rem;
        background: transparent;
        box-shadow: none;
        opacity: 1;
        pointer-events: auto;
        transform: none;
        transition: none;
    }

    h1 {
        max-width: 100%;
    }

    .tool-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

@media (max-width: 620px) {
    .brand img {
        width: 136px;
    }

    .site-nav {
        font-size: 0.88rem;
    }

    .site-footer {
        flex-direction: column;
    }

    .tool-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}