/* =========================================================
   bada.quest — brutalist HUD, softened
   Palette tokens from DESIGN.md
   ========================================================= */

@layer reset, tokens, elements, objects, components, utilities;

@layer reset {
    *, *::before, *::after { box-sizing: border-box; }
    html, body { margin: 0; padding: 0; }
    body {
        min-height: 100vh;
        -webkit-font-smoothing: antialiased;
        text-rendering: optimizeLegibility;
    }
    img, svg { display: block; max-width: 100%; }
    button {
        font: inherit; color: inherit;
        background: none; border: none; cursor: pointer;
    }
    a { color: inherit; text-decoration: none; }
    ul, ol { list-style: none; padding: 0; margin: 0; }
    input, textarea {
        font: inherit; color: inherit;
        background: transparent; border: none;
    }
    input:focus, textarea:focus, button:focus { outline: none; }
}

@layer tokens {
    :root {
        --paper:       #F6EFE2;
        --paper-deep:  #EBE0C9;
        --ink:         #1E2A33;
        --ink-soft:    #4B5A63;
        --tide:        #A9C6C2;
        --buoy:        #E8A87C;
        --sun:         #F2D6A2;
        --kelp:        #6E8B7A;
        --siren:       #C96F5A;

        --hud-top-h:    48px;
        --hud-bot-h:    44px;
        --rail-w:       80px;

        --t-fast:   120ms;
        --t-mid:    240ms;
        --t-slow:   400ms;
        --ease:     cubic-bezier(0.2, 0.6, 0.2, 1);

        --grid-gap: 24px;

        --font-sans: "Inter", "IBM Plex Sans", system-ui, sans-serif;
        --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
    }
}

@layer elements {
    body {
        background: var(--paper);
        color: var(--ink);
        font-family: var(--font-sans);
        font-size: 16px;
        line-height: 1.5;
        background-image:
            linear-gradient(to right, rgba(30,42,51,0.04) 1px, transparent 1px),
            linear-gradient(to bottom, rgba(30,42,51,0.04) 1px, transparent 1px);
        background-size: 48px 48px;
    }
    h1, h2, h3 { margin: 0; font-weight: 600; letter-spacing: -0.01em; }
    p { margin: 0; }
}

@layer utilities {
    .mono {
        font-family: var(--font-mono);
        text-transform: uppercase;
        letter-spacing: 0.08em;
        font-size: 11px;
        line-height: 1.5;
        color: var(--ink-soft);
    }
    .ko { font-family: "Inter", "IBM Plex Sans", "Apple SD Gothic Neo", "Noto Sans KR", sans-serif; }
    .bracket { color: var(--ink-soft); margin: 0 2px; }
}

/* =========================================================
   HUD frames (top, bottom, rails)
   ========================================================= */
@layer components {
    .hud {
        position: fixed;
        left: 0; right: 0;
        z-index: 50;
        background: var(--paper);
        border-color: var(--ink);
        display: flex;
        align-items: center;
        padding: 0 16px;
        gap: 16px;
    }
    .hud-top {
        top: 0;
        height: var(--hud-top-h);
        border-bottom: 1px solid var(--ink);
        justify-content: space-between;
    }
    .hud-bottom {
        bottom: 0;
        height: var(--hud-bot-h);
        border-top: 1px solid var(--ink);
        justify-content: space-between;
        gap: 24px;
    }

    .wordmark {
        font-family: var(--font-mono);
        font-weight: 700;
        text-transform: lowercase;
        letter-spacing: 0;
        font-size: 14px;
        color: var(--ink);
    }
    .wordmark::before {
        content: "▣";
        color: var(--buoy);
        margin-right: 6px;
        font-size: 12px;
    }
    .hud-divider {
        width: 1px;
        height: 16px;
        background: var(--ink);
        opacity: 0.4;
    }
    .hud-tag,
    .coords,
    .clock,
    .signal-label,
    .hud-top-right .mono {
        color: var(--ink);
        font-size: 11px;
    }
    .hud-top-left, .hud-top-mid, .hud-top-right {
        display: flex; align-items: center; gap: 12px;
    }
    .hud-top-mid { flex: 1; justify-content: center; }
    .signal-bars {
        display: inline-flex;
        align-items: flex-end;
        gap: 2px;
        height: 12px;
    }
    .signal-bars i {
        width: 3px;
        background: var(--ink);
        display: block;
    }
    .signal-bars i:nth-child(1) { height: 4px; }
    .signal-bars i:nth-child(2) { height: 7px; }
    .signal-bars i:nth-child(3) { height: 10px; }
    .signal-bars i:nth-child(4) { height: 12px; opacity: 0.4; }
    .status-dot {
        width: 8px; height: 8px;
        border-radius: 50%;
        background: var(--kelp);
        box-shadow: 0 0 0 1px var(--ink);
        animation: blink 2.4s steps(2, end) infinite;
    }
    @keyframes blink {
        0%, 60% { opacity: 1; }
        61%, 100% { opacity: 0.35; }
    }

    /* Bottom HUD: tide gauge */
    .hud-bottom-mid {
        flex: 1;
        position: relative;
        height: 100%;
        display: flex;
        align-items: center;
    }
    .tide-gauge {
        appearance: none;
        -webkit-appearance: none;
        width: 100%;
        height: 6px;
        border: 1px solid var(--ink);
        background: var(--paper-deep);
        overflow: hidden;
    }
    .tide-gauge::-webkit-progress-bar {
        background: var(--paper-deep);
    }
    .tide-gauge::-webkit-progress-value {
        background: var(--tide);
        transition: none;
    }
    .tide-gauge::-moz-progress-bar {
        background: var(--tide);
    }
    .tide-ticks {
        position: absolute;
        left: 0; right: 0;
        bottom: 1px;
        height: 6px;
        display: flex;
        justify-content: space-between;
        pointer-events: none;
    }
    .tide-ticks span {
        width: 1px;
        background: var(--ink);
        opacity: 0.3;
        height: 4px;
        align-self: flex-end;
    }
    .tide-ticks span.major { height: 8px; opacity: 0.7; }

    .hud-bottom-left,
    .hud-bottom-right {
        display: flex; align-items: center; gap: 6px;
        font-size: 11px;
        color: var(--ink);
        white-space: nowrap;
    }

    /* Rails */
    .rail {
        position: fixed;
        top: var(--hud-top-h);
        bottom: var(--hud-bot-h);
        width: var(--rail-w);
        z-index: 40;
        background: var(--paper);
        display: flex;
        flex-direction: column;
        padding: 16px 8px;
        gap: 12px;
    }
    .rail-left {
        left: 0;
        border-right: 1px solid var(--ink);
    }
    .rail-right {
        right: 0;
        border-left: 1px solid var(--ink);
    }
    .rail-label {
        text-align: center;
        color: var(--ink);
        font-size: 11px;
        padding-bottom: 6px;
        border-bottom: 1px solid var(--ink);
        opacity: 0.9;
    }
    .rail-foot {
        margin-top: auto;
        text-align: center;
        font-size: 10px;
        opacity: 0.6;
    }
    .section-index {
        display: flex;
        flex-direction: column;
        gap: 4px;
    }
    .rail-item {
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 2px;
        padding: 8px 4px;
        border: 1px solid transparent;
        color: var(--ink-soft);
        font-size: 10px;
        transition: border-color var(--t-fast) var(--ease),
                    color var(--t-fast) var(--ease),
                    background-color var(--t-fast) var(--ease);
    }
    .rail-item .rail-num {
        font-weight: 700;
        color: var(--ink);
        font-size: 13px;
    }
    .rail-item:hover {
        border-color: var(--ink);
        color: var(--ink);
    }
    .rail-item.active {
        background: var(--ink);
        color: var(--paper);
        border-color: var(--ink);
    }
    .rail-item.active .rail-num {
        color: var(--sun);
    }

    .legend-body { display: flex; flex-direction: column; gap: 10px; padding: 6px 4px; }
    .legend-row { display: flex; align-items: center; gap: 8px; font-size: 10px; }
    .legend-row .mono { color: var(--ink); }
    .sw {
        width: 14px; height: 14px;
        border: 1px solid var(--ink);
        display: inline-block;
    }
    .sw-tide  { background: var(--tide); }
    .sw-buoy  { background: var(--buoy); }
    .sw-sun   { background: var(--sun); }
    .sw-kelp  { background: var(--kelp); }
    .sw-siren { background: var(--siren); }
    .legend-meta {
        margin-top: 6px;
        padding-top: 6px;
        border-top: 1px dashed var(--ink-soft);
        font-size: 10px;
        color: var(--ink);
    }
}

/* =========================================================
   Main content + sections
   ========================================================= */
@layer objects {
    .main-content {
        margin-left: var(--rail-w);
        margin-right: var(--rail-w);
        margin-top: var(--hud-top-h);
        margin-bottom: var(--hud-bot-h);
        padding: 32px 28px 64px;
        position: relative;
    }

    .sec {
        position: relative;
        padding: 56px 0 72px;
        border-bottom: 1px solid var(--ink);
        opacity: 0;
        transform: translateY(8px);
        transition: opacity var(--t-slow) var(--ease),
                    transform var(--t-slow) var(--ease);
    }
    .sec.in-view { opacity: 1; transform: none; }
    .sec:last-of-type { border-bottom: none; }

    .sec-tag {
        position: absolute;
        top: 16px; left: 0;
        font-size: 11px;
        color: var(--ink);
        letter-spacing: 0.08em;
    }

    .sec-head { max-width: 720px; margin: 0 0 32px; }
    .kicker { color: var(--ink); font-size: 11px; margin-bottom: 12px; }
    .sec-h2 {
        font-size: 41px;
        line-height: 1.1;
        margin-bottom: 16px;
        letter-spacing: -0.015em;
    }
    .sec-lede {
        font-size: 19px;
        line-height: 1.45;
        color: var(--ink-soft);
        max-width: 560px;
    }
}

/* =========================================================
   Section 00 — Surface (hero)
   ========================================================= */
@layer components {
    .sec-surface { padding-top: 64px; }
    .sec-grid {
        display: grid;
        grid-template-columns: 1.05fr 1.2fr;
        gap: 40px;
        align-items: stretch;
    }
    .hero-text { display: flex; flex-direction: column; gap: 22px; }
    .hero-h1 {
        display: flex;
        flex-direction: column;
        gap: 6px;
        font-size: 49px;
        line-height: 1.04;
        letter-spacing: -0.02em;
    }
    .hero-h1 .ko {
        font-size: 49px;
        font-weight: 600;
        color: var(--ink);
    }
    .hero-h1 .hero-en {
        font-size: 28px;
        font-weight: 500;
        color: var(--ink-soft);
        letter-spacing: -0.005em;
    }
    .hero-lede {
        font-size: 17px;
        line-height: 1.55;
        color: var(--ink-soft);
        max-width: 520px;
        border-left: 2px solid var(--ink);
        padding-left: 14px;
    }
    .hero-cta-row { display: flex; gap: 12px; flex-wrap: wrap; }
    .meta-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        border: 1px solid var(--ink);
        margin-top: 6px;
    }
    .meta-grid > div {
        padding: 10px 12px;
        border-right: 1px solid var(--ink);
        display: flex;
        flex-direction: column;
        gap: 2px;
    }
    .meta-grid > div:last-child { border-right: none; }
    .meta-grid dt { color: var(--ink-soft); font-size: 10px; letter-spacing: 0.08em; }
    .meta-grid dd { margin: 0; color: var(--ink); font-size: 13px; font-weight: 600; font-family: var(--font-mono); }

    /* Buttons */
    .btn {
        display: inline-flex;
        align-items: center;
        gap: 10px;
        padding: 12px 18px;
        border: 1px solid var(--ink);
        font-size: 12px;
        letter-spacing: 0.1em;
        font-weight: 600;
        position: relative;
        cursor: pointer;
        transition: background var(--t-fast) var(--ease),
                    color var(--t-fast) var(--ease),
                    transform var(--t-fast) var(--ease);
    }
    .btn .btn-arrow {
        transition: transform var(--t-fast) var(--ease);
    }
    .btn:hover .btn-arrow { transform: translateX(3px); }
    .btn-primary {
        background: var(--buoy);
        color: var(--ink);
    }
    .btn-primary:hover {
        background: var(--ink);
        color: var(--paper);
    }
    .btn-ghost {
        background: var(--paper);
        color: var(--ink);
    }
    .btn-ghost:hover {
        background: var(--ink);
        color: var(--paper);
    }

    /* Pulse halo on primary CTA */
    .pulse-target { position: relative; }
    .pulse-halo {
        position: absolute;
        inset: -16px;
        border-radius: 50%;
        background: radial-gradient(circle, var(--sun) 0%, rgba(242,214,162,0) 70%);
        pointer-events: none;
        opacity: 0;
        z-index: -1;
    }
    .pulse-active {
        animation: pulseHalo 2s var(--ease) 1;
    }
    @keyframes pulseHalo {
        0%   { opacity: 0;   transform: scale(0.6); }
        20%  { opacity: 0.55;}
        100% { opacity: 0;   transform: scale(1.6); }
    }

    /* Hero figure */
    .hero-figure { margin: 0; display: flex; flex-direction: column; gap: 8px; }
    .fig-cap {
        font-size: 11px;
        color: var(--ink);
    }
    .harbor-frame {
        position: relative;
        border: 1px solid var(--ink);
        background: var(--paper);
        padding: 28px 18px 18px;
        overflow: hidden;
    }
    .harbor-svg { width: 100%; height: auto; }

    /* Corner brackets */
    .corner {
        position: absolute;
        width: 14px; height: 14px;
        border: 1.5px solid var(--ink);
        transition: width var(--t-fast) var(--ease),
                    height var(--t-fast) var(--ease),
                    transform var(--t-fast) var(--ease);
    }
    .corner.tl { top: -1px; left: -1px; border-right: none; border-bottom: none; }
    .corner.tr { top: -1px; right: -1px; border-left: none; border-bottom: none; }
    .corner.bl { bottom: -1px; left: -1px; border-right: none; border-top: none; }
    .corner.br { bottom: -1px; right: -1px; border-left: none; border-top: none; }
}

/* =========================================================
   Figure panels (generic)
   ========================================================= */
@layer components {
    .figure-panel {
        margin: 32px 0 0;
        display: flex;
        flex-direction: column;
        gap: 8px;
    }
    .figure-frame {
        position: relative;
        border: 1px solid var(--ink-soft);
        background: var(--paper);
        padding: 36px 18px 18px;
        transition: border-color var(--t-fast) var(--ease);
    }
    .figure-frame:hover { border-color: var(--ink); }
    .figure-frame:hover .corner { transform: translate(0, 0); }
    .figure-frame .corner {
        border-color: var(--ink-soft);
    }
    .figure-frame:hover .corner { border-color: var(--ink); }

    .figure-meta {
        position: absolute;
        top: 10px; left: 16px; right: 16px;
        display: flex;
        align-items: center;
        gap: 10px;
        font-size: 10px;
        color: var(--ink);
    }
    .meta-sep { color: var(--ink-soft); opacity: 0.5; }
    .meta-btn {
        font-family: var(--font-mono);
        font-size: 10px;
        letter-spacing: 0.08em;
        text-transform: uppercase;
        padding: 2px 8px;
        border: 1px solid var(--ink);
        background: var(--paper);
        color: var(--ink);
        margin-left: auto;
        cursor: pointer;
        transition: background var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
    }
    .meta-btn:hover { background: var(--ink); color: var(--paper); }

    .figure-caption {
        display: flex;
        gap: 12px;
        font-size: 13px;
        color: var(--ink-soft);
        line-height: 1.4;
    }
    .cap-no {
        color: var(--ink);
        font-size: 10px;
        padding-top: 2px;
        flex: 0 0 auto;
        min-width: 36px;
    }
    .cap-text { max-width: 64ch; }
}

/* =========================================================
   Section 01 — Tide
   ========================================================= */
@layer components {
    .tide-svg {
        width: 100%;
        height: auto;
        display: block;
    }
    #tideDots circle {
        cursor: crosshair;
        transition: r var(--t-fast) var(--ease), fill var(--t-fast) var(--ease);
    }
    #tideDots circle:hover { fill: var(--buoy); }
    .tide-readout {
        margin-top: 10px;
        display: flex;
        gap: 12px;
        align-items: center;
        border-top: 1px dashed var(--ink-soft);
        padding-top: 8px;
        font-size: 11px;
    }
    .readout-key { color: var(--ink-soft); }
    .readout-val { color: var(--ink); font-weight: 700; }

    .tutorial-grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 18px;
        margin-top: 32px;
    }
    .panel {
        position: relative;
        border: 1px solid var(--ink);
        background: var(--paper);
        padding: 22px 20px 20px;
        display: flex;
        flex-direction: column;
        gap: 10px;
        transition: background var(--t-fast) var(--ease),
                    color var(--t-fast) var(--ease);
    }
    .panel-tag {
        font-size: 10px;
        color: var(--ink);
        margin-bottom: 4px;
    }
    .panel-h3 {
        font-size: 19px;
        line-height: 1.25;
    }
    .panel-p {
        font-size: 14px;
        line-height: 1.55;
        color: var(--ink-soft);
    }
    .panel-tut:nth-child(1) { background: var(--paper); }
    .panel-tut:nth-child(2) { background: var(--paper-deep); }
    .panel-tut:nth-child(3) { background: var(--paper); }
    .panel-tut:hover { background: var(--ink); color: var(--paper); }
    .panel-tut:hover .panel-tag,
    .panel-tut:hover .panel-p { color: var(--paper-deep); }
}

/* =========================================================
   Section 02 — Current
   ========================================================= */
@layer components {
    .current-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 18px;
        margin-bottom: 8px;
    }
    .panel-curr {
        gap: 14px;
        padding: 24px 22px;
    }
    .panel-curr-deep { background: var(--paper-deep); }
    .panel-icon {
        width: 64px; height: 64px;
        border: 1px solid var(--ink);
        padding: 6px;
        background: var(--paper);
    }
    .panel-icon svg { width: 100%; height: 100%; }
    .spec-list {
        display: flex;
        flex-direction: column;
        gap: 4px;
        margin-top: 6px;
        border-top: 1px solid var(--ink);
        padding-top: 8px;
    }
    .spec-list li {
        display: flex;
        justify-content: space-between;
        font-size: 11px;
        color: var(--ink);
    }
    .spec-list li span:last-child { color: var(--ink-soft); }
    .panel-curr:hover {
        border-color: var(--ink);
    }
    .vector-svg { width: 100%; height: auto; }
}

/* =========================================================
   Section 03 — Sonar
   ========================================================= */
@layer components {
    .sonar-wrap {
        display: grid;
        grid-template-columns: 1.1fr 1fr;
        gap: 24px;
        align-items: start;
    }
    .sonar-frame {
        background: var(--paper-deep);
        padding: 36px 18px 18px;
    }
    .sonar-svg {
        width: 100%;
        height: auto;
        max-width: 460px;
        margin: 0 auto;
    }
    .sonar-readouts {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 14px;
    }
    .readout-card {
        border: 1px solid var(--ink);
        padding: 16px 16px 14px;
        background: var(--paper);
        display: flex;
        flex-direction: column;
        gap: 10px;
    }
    .readout-label {
        font-size: 10px;
        color: var(--ink);
    }
    .readout-num {
        font-size: 32px;
        font-weight: 700;
        line-height: 1;
        color: var(--ink);
        font-family: var(--font-mono);
        letter-spacing: -0.01em;
        display: flex;
        align-items: baseline;
        gap: 6px;
    }
    .readout-unit {
        font-size: 11px;
        color: var(--ink-soft);
        font-weight: 400;
        letter-spacing: 0.08em;
        text-transform: uppercase;
    }
    .readout-bar {
        height: 6px;
        background: var(--paper-deep);
        border: 1px solid var(--ink);
        position: relative;
        overflow: hidden;
    }
    .readout-bar > span {
        display: block;
        height: 100%;
        background: var(--tide);
        transition: width var(--t-mid) var(--ease);
    }

    /* Sonar animations */
    #sonarSweep {
        transform-origin: 180px 180px;
        animation: sweep 6s linear infinite;
    }
    @keyframes sweep {
        from { transform: rotate(0deg); }
        to   { transform: rotate(360deg); }
    }
    #sonarPing {
        transform-origin: 180px 180px;
        animation: ping 6s var(--ease) infinite;
    }
    @keyframes ping {
        0%   { r: 4;   opacity: 0.9; stroke-width: 1.6; }
        80%  { r: 160; opacity: 0;   stroke-width: 0.6; }
        100% { r: 160; opacity: 0;   stroke-width: 0.6; }
    }
    .sonar-paused #sonarSweep,
    .sonar-paused #sonarPing { animation-play-state: paused; }
    #sonarContacts circle {
        transition: r var(--t-fast) var(--ease), fill var(--t-fast) var(--ease);
    }
    #sonarContacts circle:hover { r: 5; fill: var(--siren); }
}

/* =========================================================
   Section 04 — Logbook
   ========================================================= */
@layer components {
    .logbook-wrap {
        display: grid;
        grid-template-columns: 1.4fr 1fr;
        gap: 20px;
        align-items: start;
    }
    .logbook-form { margin: 0; }
    .logbook-frame {
        position: relative;
        border: 1px solid var(--ink);
        background: var(--paper-deep);
        padding: 36px 22px 22px;
    }
    .logbook-head {
        position: absolute;
        top: 10px; left: 16px; right: 16px;
        display: flex;
        align-items: center;
        gap: 10px;
        font-size: 10px;
        color: var(--ink);
    }
    .form-row {
        display: grid;
        grid-template-columns: 90px 1fr;
        align-items: center;
        gap: 12px;
        padding: 10px 0;
        border-bottom: 1px dashed var(--ink-soft);
        position: relative;
    }
    .form-row:last-of-type { border-bottom: none; }
    .form-row .lbl {
        color: var(--ink);
        font-size: 11px;
    }
    .form-row input,
    .form-row textarea {
        width: 100%;
        font-family: var(--font-mono);
        font-size: 14px;
        color: var(--ink);
        padding: 6px 0;
        border-bottom: 1px solid transparent;
        transition: border-color var(--t-fast) var(--ease);
        resize: vertical;
    }
    .form-row input::placeholder,
    .form-row textarea::placeholder {
        color: var(--ink-soft);
        opacity: 0.55;
    }
    .form-row input:hover,
    .form-row textarea:hover { border-bottom-color: var(--ink-soft); }
    .form-row input:focus,
    .form-row textarea:focus { border-bottom-color: var(--ink); }
    .cursor {
        position: absolute;
        right: 4px;
        top: 50%;
        transform: translateY(-50%);
        width: 8px;
        height: 16px;
        background: var(--ink);
        animation: blinkCursor 1s steps(2, end) infinite;
    }
    @keyframes blinkCursor {
        0%, 50% { opacity: 1; }
        51%, 100% { opacity: 0; }
    }
    .form-actions {
        display: flex;
        align-items: center;
        gap: 14px;
        margin-top: 14px;
    }
    .form-status {
        font-size: 10px;
        color: var(--kelp);
        padding: 4px 8px;
        border: 1px solid var(--kelp);
    }
    .form-status.error { color: var(--siren); border-color: var(--siren); }
    .form-status.sent  { color: var(--ink); border-color: var(--ink); background: var(--sun); }

    .logbook-side {
        display: flex;
        flex-direction: column;
        gap: 16px;
    }
    .panel-side { padding: 18px 18px 16px; }
    .contact-list {
        display: flex;
        flex-direction: column;
        gap: 6px;
    }
    .contact-list li {
        display: flex;
        justify-content: space-between;
        font-size: 11px;
        color: var(--ink);
    }
    .contact-list li span:last-child { color: var(--ink-soft); }
    .panel-quote .quote-p {
        font-size: 14px;
        line-height: 1.55;
        color: var(--ink);
    }
    .panel-quote .ko {
        display: block;
        font-size: 18px;
        margin-bottom: 6px;
        font-weight: 600;
    }

    .page-footer {
        margin-top: 56px;
        padding-top: 16px;
        border-top: 1px solid var(--ink);
    }
    .foot-row {
        display: flex;
        gap: 12px;
        flex-wrap: wrap;
        font-size: 10px;
        color: var(--ink-soft);
    }
    .foot-row a {
        color: var(--ink);
        border-bottom: 1px solid transparent;
        transition: border-color var(--t-fast) var(--ease);
    }
    .foot-row a:hover { border-bottom-color: var(--ink); }
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 1100px) {
    :root { --rail-w: 64px; }
    .sec-h2 { font-size: 34px; }
    .hero-h1 { font-size: 41px; }
    .hero-h1 .ko { font-size: 41px; }
    .hero-h1 .hero-en { font-size: 23px; }
    .sec-grid { grid-template-columns: 1fr; gap: 28px; }
    .sonar-wrap { grid-template-columns: 1fr; }
    .logbook-wrap { grid-template-columns: 1fr; }
}

@media (max-width: 900px) {
    :root {
        --rail-w: 0px;
        --hud-top-h: 56px;
    }
    .rail-left,
    .rail-right { display: none; }
    .main-content {
        margin-left: 0;
        margin-right: 0;
        padding: 24px 18px 56px;
    }
    .hud-top { flex-wrap: wrap; height: auto; padding: 8px 12px; gap: 8px; }
    .hud-top-mid { order: 3; flex-basis: 100%; justify-content: flex-start; gap: 8px; }
    .hud-top-right { gap: 8px; }
    .tutorial-grid { grid-template-columns: 1fr; }
    .current-grid { grid-template-columns: 1fr; }
    .sonar-readouts { grid-template-columns: 1fr 1fr; }
    .meta-grid { grid-template-columns: repeat(2, 1fr); }
    .meta-grid > div:nth-child(2) { border-right: none; }
    .meta-grid > div:nth-child(1),
    .meta-grid > div:nth-child(2) { border-bottom: 1px solid var(--ink); }
}

@media (max-width: 540px) {
    .hero-h1, .hero-h1 .ko { font-size: 32px; }
    .hero-h1 .hero-en { font-size: 19px; }
    .sec-h2 { font-size: 28px; }
    .sonar-readouts { grid-template-columns: 1fr; }
    .form-row { grid-template-columns: 1fr; gap: 4px; }
    .hud-bottom-left, .hud-bottom-right { font-size: 10px; }
    .hud-bottom { gap: 12px; padding: 0 12px; }
}