/* ==========================================================================
   1. THEME COLOR VARIABLES (LIGHT & DARK) - POSTCARD SPECIFIC
   ========================================================================== */

:root {
    --western-font: 'Caveat', cursive;
    --eastern-font: 'Nanum Myeongjo', serif;
}

/* ==========================================================================
   2. MAIN CONTAINER & SECTION STYLES
   ========================================================================== */

#postcard-section {
    background-image: url('../img/Alfheim-dark.png');
    background-color: var(--primary-bg);
    background-size: cover;
    background-position: center;
    color: var(--text-color);
    transition: background-color var(--transition-duration), color var(--transition-duration);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    box-sizing: border-box;
    overflow-x: hidden;
    padding: 80px 0;
}

body[data-theme="light"] #postcard-section {
    background-image: url('../img/Alfheim-bright.png');
    background-color: var(--primary-bg);
}

.connect-postcard-layout-wrapper {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    box-sizing: border-box;
    padding: 0 120px;
}

.connect-postcard-content {
    width: 100%;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    position: relative;
    justify-content: center;
}

/* ==========================================================================
   3. POSTCARD FLIP & ANIMATION STYLES
   ========================================================================== */
.postcard-container {
    position: relative;
    width: 100%;
    max-width: 450px;
    height: 650px;
    perspective: 1500px;
    background-color: transparent;
    transition: transform 1.5s ease-in-out, opacity 1s ease-in-out, max-width var(--transition-duration);
}

.postcard-flipper {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.8s cubic-bezier(0.68, -0.55, 0.27, 1.55);
    transform-style: preserve-3d;
}

.postcard-container.is-flipped .postcard-flipper {
    transform: rotateY(180deg);
}

.postcard-face {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 10px;
    box-shadow: 0 8px 32px var(--glass-shadow2);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    background-color: var(--primary-bg-opacity2);
    backdrop-filter: var(--glass-blur2);
    -webkit-backdrop-filter: var(--glass-blur2);
    border: 1px solid var(--glass-border2);
}

.postcard-front {
    transform: rotateY(180deg);
}

.postcard-back {
    transform: rotateY(0deg);
    padding: 20px;
    box-sizing: border-box;
}

/* ==========================================================================
   4. POSTCARD HEADER & CONTENT STYLES
   ========================================================================== */

.section-header {
    width: 100%;
    text-align: center;
    word-break: break-word;
    margin-bottom: 30px;
}

#postcard-greeting {
    font-size: 2.5em;
}

#postcard-sub-greeting {
    font-size: 1.2em;
    color: var(--subheading-color);
    margin-top: 20px;
    line-height: 1.7;
}

.connect-floating-menu {
    position: absolute;
    top: -20px;
    right: -20px;
    z-index: 10;
    background-color: var(--primary-bg-opacity2);
    backdrop-filter: var(--glass-blur2);
    -webkit-backdrop-filter: var(--glass-blur2);
    padding: 8px 12px;
    border-radius: 20px;
    box-shadow: 0 8px 32px var(--glass-shadow2);
    border: 1px solid var(--glass-border2);
    display: flex;
    align-items: flex-start;
    gap: 10px;
    transition: all var(--transition-duration);
}

.connect-writing-style-controls,
.connect-language-controls-inline {
    display: flex;
    gap: 8px;
    align-items: center;
}

.connect-floating-menu button {
    padding: 6px 10px;
    border: 1px solid var(--glass-border2);
    border-radius: 15px;
    cursor: pointer;
    background-color: var(--secondary-bg);
    color: var(--subheading-color);
    font-size: 0.8em;
    font-family: 'Poppins', sans-serif;
    transition: all var(--transition-duration);
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.connect-floating-menu button:hover {
    border-color: var(--primary-accent);
}

.connect-floating-menu button.active {
    background: var(--point-gradient2);
    color: var(--text-color);
    border-color: transparent;
    font-weight: bold;
}

.postcard-image-container {
    flex-grow: 1;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

.postcard-cover-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.western-text {
    font-family: var(--western-font), sans-serif;
}

.pen-cursor {
    cursor: url('../img/pen.png') 0 32, auto;
}

.brush-cursor {
    cursor: url('../img/brush.png') 0 32, auto;
}

/* 다크 모드에서만 별도 이미지 사용 */
body[data-theme="dark"] .pen-cursor {
    cursor: url('../img/pen2.png') 0 32, auto;
}
body[data-theme="dark"] .brush-cursor {
    cursor: url('../img/brush2.png') 0 32, auto;
}

.form-container {
    padding-top: 20px;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.form-container h3 {
    text-align: center;
    margin-bottom: 20px;
    color: var(--text-color);
    font-weight: bold;
}

.form-group {
    margin-bottom: 12px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    color: var(--subheading-color);
    font-size: 0.95em;
}

.form-container input[type="text"],
.form-container input[type="email"],
.form-container textarea {
    width: 100%;
    padding: 10px 12px;
    border: none;
    border-bottom: 1.5px solid var(--glass-border2);
    border-radius: 0;
    box-sizing: border-box;
    background-color: transparent;
    color: var(--text-color);
    transition: border-bottom-color var(--transition-duration) ease;
    font-family: var(--western-font);
    font-size: 1.3em;
    line-height: 1.6;
}

.form-container input:focus,
.form-container textarea:focus {
    outline: none;
    border-bottom-color: var(--primary-accent);
}

.form-container input.invalid,
.form-container textarea.invalid {
    border-bottom-color: var(--error-color);
    animation: shake 0.4s ease-in-out;
}

.error-message {
    display: block;
    margin-top: 4px;
    margin-left: 0;
    color: #e63a3a;
    font-size: 0.95rem;
    font-weight: 400;
    letter-spacing: 0.01em;
    opacity: 0;
    transition: opacity 0.18s;
    pointer-events: none;
    visibility: hidden;
    position: absolute;
    left: 0;
    bottom: -22px;
    background: rgba(255,255,255,0.85);
    padding: 3px 10px;
    border-radius: 8px;
    box-shadow: 0 2px 8px 0 rgba(230,58,58,0.08);
    z-index: 2;
}
body[data-theme="dark"] .error-message {
    background: rgba(40, 0, 0, 0.90);
    color: #ff6b6b;
}
.error-message.visible {
    opacity: 1;
    visibility: visible;
}

.form-container textarea {
    resize: none;
    flex-grow: 1;
}

.send-button {
    display: block;
    width: 100%;
    padding: 12px 15px;
    background: var(--point-gradient2);
    color: var(--text-color);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1.1em;
    font-weight: bold;
    transition: all 0.2s ease;
    margin-top: auto;
}

.send-button:hover {
    filter: brightness(1.15);
    transform: translateY(-2px);
}

.hidden {
    display: none !important;
}

/* ==========================================================================
   5. RESPONSIVE MEDIA QUERIES
   ========================================================================== */

@media (min-width: 768px) {
    .connect-postcard-layout-wrapper {
        padding: 0 100px;
    }
}

@media (min-width: 900px) {
    .connect-postcard-layout-wrapper {
        display: flex;
        align-items: flex-start;
        justify-content: center;
        
        /* gap 동적 값 설정:
          - 최소 gap: 2.5rem (40px)
          - 선호하는 gap: 뷰포트 너비의 5% (5vw)
          - 최대 gap: 5rem (80px)
        */
        gap: clamp(2.5rem, 5vw, 5rem);
        
        /* 좌우 padding 동적 값 설정:
          - 최소 padding: 2.5rem (40px)
          - 선호하는 padding: 뷰포트 너비의 7.5% (7.5vw)
          - 최대 padding: 7.5rem (120px)
        */
        padding: 0 clamp(2.5rem, 7.5vw, 5rem);
    }

    .section-header {
        flex: 1;
        max-width: 350px;
        text-align: left;
        margin-bottom: 0;
        margin-top: 20px;
    }

    .connect-postcard-content {
        flex: 2;
        max-width: 900px;
        justify-content: flex-start;
    }
    
    .postcard-container {
        max-width: none;
        width: 100%;
    }
}

@media (max-width: 480px) {
    .connect-postcard-layout-wrapper {
        padding: 0 40px;
    }
    
    .postcard-container {
        height: 600px;
    }
    
    .connect-floating-menu {
        top: 10px;
        right: 10px;
    }

    #postcard-greeting {
        font-size: 1.8em;
    }
}